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Transcript of on the CHAMBE BASIN AREA OF EXCLUSIVE PROSPECTING LICENCE EPL 0325… · 2015. 12. 22. · November...
Geological report
on the
CHAMBE BASIN AREA
OF
EXCLUSIVE PROSPECTING LICENCE
EPL 0325/11
MULANJE MASSIF
SOUTHERN MALAWI
EAST AFRICA
to
Gold Canyon Resources Inc
Suite 810,
609 Granville St,
Vancouver, BC,
Canada, V7Y 1G5
by
P.C. Le Couteur, Ph.D (UBC), P.Eng (BC)
President, Micron Geological Ltd.
Effective date: November 25, 2011 Vancouver, BC
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TABLE OF CONTENTS
Item page
1 Summary 5
2 Introduction 6
3 Reliance on Other Experts 11
4 Property Description and Location 15
5 Accessibility, Climate, Local Resources,
Infrastructure, and Physiography
19
6 History 21
7 Geological Setting and Mineralization 23
8 Deposit types 34
9 Exploration 39
10 Drilling 40
11 Sample Preparation, Analyses and Security 40
12 Data Verification 41
13 Mineral Processing and Metallurgical Testing 67
14 Mineral Resource Estimates 67
15 Mineral Reserve Estimates 67
16 Mining Methods 67
17 Recovery Methods 67
18 Project Infrastructure 67
19 Market Studies and Contracts 68
20 Environmental Studies , Permitting and Social or
Community Impact
68
21 Capital and Operating Costs 68
22 Economic Analysis
23 Adjacent Properties 68
24 Other Relevant Data and Information 69
25 Interpretation and Conclusions 69
26 Recommendations 69
27 References 72
Date and Signature Page 74
3
List of Figures
page
Fig 1 Relationships of companies involved in the Malawi Project 6
Fig 2 Location of Malawi 8
Fig 3 Map of Malawi 9
Fig 4 Map of southern Malawi to show location of the Mulanje Massif 10
Fig 5 View of Mulanje Massif 10
Fig 6 View of Chambe Basin 12
Fig 7 View of Chambe Basin 12
Fig 8 Geology of Mulanje Massif showing EPL 0325/11 13
Fig 9 Geology of Chambe Basin 14
Fig 10 Contour map of soil depth in Chambe Basin 26
Fig 11 Chondrite normalized REE distributions of REE deposits 37
Fig 12 Location of samples taken by Ishikawa, MINDECO, Le Couteur 38
Fig 13 Chondrite-normalized REE distribution of leached ore 55
Fig 14 Example of roadside cut sample (CHA-4) 56
Fig 15 Photo of plus 0.25 mm fraction of screened soil sample E686956 57
Fig 16 Photomicrograph of soil E 686956, crossed polars 58
Fig 17 Photomicrograph of soil E 686956, plain light 58
Fig 18 XRD scan of sample E686964 60
Fig 19 Alkali v silica classification plot for Chambe Basin syenite 61
Fig 20 Polished surface of syenite sample E686961 62
Fig 21 Sample E686961 stained for potassium (K’spar) 62
Fig 22 Photomicrograph of syenite E686961 , crossed polars 64
Fig 23 Photomicrograph of syenite E686961 , plain light 64
Fig 24 Drill plan proposed by MINDECO for phase 1 exploration 70
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List of tables
page
Table 1 Property boundaries 15
Table 2 Soil samples collected by J. Ishikawa 27
Table 3 Soil samples collected by MINDECO 28
Table 4 REE analyses of Ishikawa samples 29
Table 5 Total and leached REE in MINDECO samples 30
Table 6 Recovery of leachable REE from MINDECO samples 31
Table 7 Leachable REE in Ishikawa samples by MINDECO 31
Table 8 Samples collected by P. Le Couteur 44
Table 9 Reanalysis of 3 Ishikawa samples 45
Table 10 Total REE in Le Couteur samples 48
Table 11 Leachable REE in Le Couteur samples (method ME-MS04) 49
Table 12 Ratio of soil REE to syenite REE 50
Table 13 Leachable REE in Le Couteur samples (method ME-MS23) 50
Table 14 Comparative analyses by Ishikawa, MINDECO, Le Couteur 51
Table 15 Screen size of 2 soils 57
Table 16 Composition of Chambe Basin syenite 61
Table 17 Energy dispersive analyses of minerals in syenite E686961 63
Table 18 Exploration expenditures estimated by MINDECO for phase 1 70
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1 SUMMARY
Property Description Chambe Basin is part of Malawi Exclusive Prospecting Licence 0325/11, a rectangular block about 40 km E-W and 27 km N-S with an area of 1,050 sq km, within which the licencee has exclusive rights to prospect for rare earths (“REE”) and bauxite. Location The Property is located in southernmost Malawi (south central East Africa) and covers the Mulanje Massif. The centre of the Property is at approximately 15˚ 57”S, 35˚ 37”E. Ownership EPL 0325/11 is held in the name of Spring Stone Limited, a private Malawi company that is a 100% subsidiary of Spring Stone Exploration Inc., a private company registered in British Columbia and a 100% subsidiary of Canadian public company Gold Canyon Resources Inc. The project is a joint venture between Gold Canyon Resources Inc, and Japan Oil, Gas and Metals National Corporation (“JOGMEC”), which provides 67% of funding for Spring Stone Exploration Inc. and consequently has a 67% equity option holding in licence-holder Spring Stone Ltd. Geology A gneissic basement complex of Precambrian to Lower Paleozoic age forms the oldest rocks in the area. This is intruded by a series of partly overlapping, subcircular, mostly syenitic plutons that are part of the Chilwa Alkaline Province, of Upper Jurassic to Lower Cretaceous age. Chambe Basin is an area of low relief covered by thick, bouldery, residual kaolinitic soils in the middle of one of these syenite intrusions that is surrounded by a circular outer rim of bare syenite. Mineralization A small number of reconnaissance samples of soils collected in 2010 and early 2011 from Chambe Basin and analysed for leachable rare earths (“REE”) suggest there is potential for a bulk REE deposit in these soils. Exploration concept Chambe Basin is being explored for a REE deposit of the “ion adsorption” type. Such deposits are quite important REE producers in China but few have been found elsewhere. Typically the REE content is low, but a significant part is easily extractable by ion exchange using dilute solutions of common chemicals such as ammonium sulphate. Other characteristics include very low U and Th, a large proportion of high value “mid” and “heavy” REE, and they may be mined by relatively inexpensive shallow surface excavations or in situ. Status of exploration The Property licence was acquired on 18 March of 2011, mostly on the basis of reconnaissance samples by Geological Survey Dept headed by J. Ishikawa in 2010. An exploration program of systematic short-hole drilling, with some pitting, initial environmental sampling, and analysis of soils for leachable REE is currently being carried out by Mitsui Mineral Development Engineering Co. Ltd (“MINDECO”) under contract to Spring Stone Exploration Inc., the vehicle for the joint venture between Gold Canyon Resources Inc and JOGMEC. Conclusions and recommendations Only a small number of reconnaissance samples of soils from the Chambe Basin have so far been analyzed, but from review of these and verifying analyses the author agrees with the interpretation by J. Ishikawa, JOGMEC and MINDECO that there is potential for a REE deposit of the ion adsorption type. A US~$1.1 M program proposed by MINDECO, and accepted by the Malawi Government, is currently under way. While the author has had no opportunity to recommend changes to this approved program he endorses it as a well-designed and thorough first phase plan of exploration of the Chambe Basin for ion-adsorption REE potential.
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2 INTRODUCTION
(a) Company for which the technical report is prepared.
This report concerning exploration for rare earth elements (“REE”) in the Chambe Basin area
of Malawi, East Africa, was made at the request of A. Levinson, President and Director of Gold
Canyon Resources Inc (“Gold Canyon”). Gold Canyon is a public Canadian-based mineral
exploration company that trades on the Toronto Stock Exchange (TSX Venture Exchange,
symbol GCU), is incorporated under the laws of British Columbia, and has a business address at
Suite 810, 609 Granville St, Vancouver, BC, Canada, V7Y 1G5. Some details on Gold Canyon
and its exploration activities are available on the company’s website www.goldcanyon.ca .
Figure 1. Relationships between companies involved in the Malawi REE project
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Relationships between companies involved in the Malawi project are shown in Figure 1.
Chambe Basin lies within Exclusive Prospecting Licence EPL 0325/11 (the “Property”) in the
Mulanje Mountain area of southern Malawi, also referred to as the Mulanje Massif. This licence
was initially granted in March of 2011 to the Japan Oil, Gas and Metals National Corporation
(“JOGMEC”). JOGMEC is a semi-governmental corporation of the Japanese Government, with
office address 2-10-1, Toranomon Minato-ku, Tokyo, 105-0001, Japan. Subject to a then-existing
agreement between Gold Canyon and JOGMEC, at the request of JOGMEC and with the assent
of Gold Canyon, the Malawi Government agreed to transfer Licence EPL 0325/11 to Spring
Stone Limited, a limited private company incorporated in Blantyre, Malawi under the Government
of Malawi Companies Act on 15th June 2011 with registration number 11406. The office address
of Spring Stone Limited is c/o Sacranie, Gow and Company Legal Practitioners, Realty House,
Churchill Road, PO .Box 5133, Limbe, Malawi. Spring Stone Limited, an indirect wholly-owned
subsidiary of Gold Canyon, was formed to acquire and maintain the Property and other properties
in Malawi and to facilitate mineral exploration and development in Malawi.
Spring Stone Limited is a wholly-owned subsidiary of Spring Stone Exploration
Limited, an indirect wholly-owned subsidiary of Gold Canyon (with the same office address)
formed for the purpose of managing the Malawi project and is the operator of a joint venture
between Gold Canyon and JOGMEC to explore for REE in Malawi. Details of this joint venture are
contained in a Project Venture Agreement (“PVA”) between JOGMEC, Gold Canyon, Spring
Stone Limited and Spring Stone Exploration Inc. dated September 13, 2011, but effective on
November 14, the date of transfer by the Malawi Government of EPL 0325/11 from JOGMEC to
Spring Stone Limited. Under the PVA JOGMEC has the option to acquire a 67% interest in the
Malawi Project and Gold Canyon 33%. Some details of the PVA are contained in a news release
on September 8 of 2011 by Gold Canyon, which is available on their website. This PVA
supersedes a 2009 joint venture agreement between JOGMEC and Gold Canyon to explore for
rare earth resources, initially in the USA and more recently in Malawi, through private USA
company Gold Canyon Kratz Springs LLC.
Exploration on EPL 0325/ 11 will be carried out by Mitsui Mineral Development
Engineering Co. Ltd (“MINDECO” ) a wholly-owned subsidiary of Mitsui Mining and Smelting
Co of Japan under a Technical Service Agreement with Spring Stone Exploration Inc. (Figure 1).
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The author of this report, P.C. Le Couteur, is President of Micron Geological Ltd, a
geological service company with office address at 4900 Skyline Drive, North Vancouver, British
Columbia, Canada, V7R 3J3, is independent of Gold Canyon and is a "qualified person" as
defined by Canadian Securities Administrators (“CSA”) National Instrument (“NI”) 43-101. This
report has been prepared in compliance with the requirements of NI 43-101 of the CSA, as set out
in Form 43-101F1, with effective date June 30, 2011.
Figure 2 Location of Malawi in east Africa, showing towns of Lilongwe (the capital) and Blantyre
(the main commercial centre). Source Magellan Geographixs.
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Figure 3. More detailed map of Malawi. The town of Mulanje in the SE is close to the Property. .
Source: Magellan Geographix
10
Figure 4 Southern Malawi showing general location of Mulanje Massif. Towns of Blantyre, Zomba
and Mulanje shown. Source :Google
Figure 5. The Mulanje Massif, including Chambe Basin.
Source :Landsat image, NASA Earth Observatory Sept 12, 2004.
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(b) Purpose of report
According to J. Larkins, corporate legal counsel to Gold Canyon Resources Inc, “This report
has been commissioned for the purposes of evaluating the geological, geophysical, geochemical,
metallurgical, and other similar information concerning the Mulanje property for the purposes of
defining or delineating the potential mineral prospects of this property for the Issuer or any
successor thereto.”
(c) Sources of information
Published information sources are acknowledged in the report and listed in the reference
section. Unpublished company reports, analyses, correspondence and other documents that are
also acknowledged in the references were made available from Gold Canyon records by A.
Levinson, President and Director of Gold Canyon and by S. Miyatake, Director, Exploration
Technology Division, Metals Exploration Dept. of JOGMEC.
(d) Details of personal inspection
The author has neither worked in, nor previously visited the Mulanje Mountain area of
Malawi. For the purpose of this report the author visited the Chambe Basin part of EPL 0325/11
on the 22nd and 23rd of August of 2011. Chambe Basin was accessed on foot via the Likhubula
Skyline Path in company with R. Kojima, General Manager of Spring Stone Ltd in Zomba , and M.
Nyirongo, Geologist with the Geological Survey of Malawi in Zomba, but currently employed by
Spring Stone Ltd on this project, and 9 porters from Nakoya Village.
Some samples were collected on 22nd August, the night was spent at Frances Cottage in
Chambe Basin, and further sampling was done on the 23rd August. Road-side samples were
taken by the author and M. Nyirongo, and from pits by porters under direction of the author and M.
Nyirongo.
3 RELIANCE ON OTHER EXPERTS
Not applicable
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Figure 6 View from the south lip of Chambe Basin north across the basin toward the east face of
Chambe Peak (8,390 feet).
Figure 7. View of Chambe Basin west toward Chambe Peak. Soils in this area are reported by Garson and Walshaw (1969) to be about 25 feet (7.6 m) thick. Large grey boulders are syenite , probably residual joint-bounded blocks (“core stones”). Bare rock of the far basin rim is syenite of the outer ring dike.
Figure 8 General geology of the Mulanje Massif, from “Mlanje Sheet” 1:100,000 scale, by Garson and Walshaw (1969).
Rectangular outline shows the extent of Prospecting Licence 0325/11 and of the Chambe Basin area.
Figure 9. Detail of geology of Chambe area . From Mlanje Sheet 1:100,000 scale, Garson and
Walshaw (1969). For detail of outlined “Chambe Basin area” see Figure 10.
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4 PROPERTY DESCRIPTION AND LOCATION
(a) Area of property
Exclusive Prospecting Licence EPL 0325/11 (Figure 8) has a rectangular shape about
40 km E-W and 27 km N-S, minus a small triangular area at the SE corner. According to
the licence document the area of the Property is 1, 050 sq km.
(b) Location of property
The general location of the Property in southernmost Malawi is shown on Figure 3
and in more detail in Figure 4 and 5. The Property is covered by the “Blantyre” 1:250,000
scale topographic map and the 1:100,000 scale “Mlanje” geological map sheet. Chambe
Basin is covered by the 1:50,000 scale “Mulanje” topographic sheet 1535D3. The
approximate latitude and longitude at the centre of the Property is 15˚ 57’S, 35˚ 37’ E. The
Property boundaries are defined in the licence document by the UTM coordinates (Zone
36L, Clarke (1880) modified spheroid) listed in Table 1.
Table 1 Property boundaries
Corner Easting Northing
m m
A (NW) 760000 8247000
B (NE) 800000 8247000
C (SE) 800000 8226000
D (SE) 790000 8220000
E (SW) 760000 8220000
(c) Type of mineral tenure, identifying number
The Property is an “Exclusive Prospecting Licence” EPL (no 0325/11) issued
on 18th March of 2011 by the Government of the Republic of Malawi acting through the
Minister of Natural Resources, Mining, Energy and Environment.
Licence EPL 0325/11 was issued for exclusive rights to carry out prospecting for
REE and bauxite.
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(d) Ownership, surface rights, legal access, obligations, expiration date.
The Chambe Basin lies within the Mulanje Mountain Forest Reserve and the mineral
and surface rights are owned by the Government of the Republic of Malawi. Licence EPL
0325/11 permits exclusive rights to carry on prospecting operations for rare earth elements
and bauxite. Legal access is by public roads and paths administered by the Likhubula
Forestry Office of the Department of Forestry .
Obligations assumed by licence-holder Spring Stone Ltd include the carrying out of
the exploration program for rare earths and bauxite as proposed in the licence application
(Anonymous (2011), Anonymous (2011a), Kojima (2011), Kojima (2011a). The originally
proposed expenditure of US $2.5 million was later reduced to US$1.0 million. The
exploration program was designed and will be carried out by Mitsui Mineral Development
Engineering Co (“MINDECO”) under contract to Spring Stone Exploration Inc. Phase I of
this program is to be carried out in fiscal year 2011 and consists of systematic shallow
drilling and pitting in Chambe Basin, with analysis and testing of soils for recovery of rare
earths. Environmental observations will also be made.
Conditions specified in the licence include requirements to commence operations
within 3 months of granting of the licence, to supply quarterly progress reports and annual
reports, to annually report the proposed program and budget for the next year’s work, to
employ and train Malawian citizens, to use goods and services from Malawi whenever
possible, to conserve the environment, and to reclaim and restore areas damaged by
exploration activities. Any shortfall from the proposed expenditures is considered a debt to
the Republic of Malawi.
The Licence was granted on the 18th day of March of 2011 for a period of 3 years, with
an option to renew the Licence in accordance with Section 50 of the Malawi Mines and
Minerals Act 1981.
(e) Royalties, back-in rights, payments, agreements, encumbrances
The joint venture between JOGMEC and Gold Canyon concerning a program for
exploration of minerals in Malawi, defined as the “Malawi Project”, is detailed in a Project
Joint Venture Agreement (”PVA”) made on September 13 of 2011 between JOGMEC, Gold
Canyon, Spring Stone Limited and Spring Stone Exploration Inc and effective on November
14 of 2011, the date of reassignment of Exclusive Prospecting Licence 0325/11 from
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JOGMEC to Spring Stone Limited by the Government of Malawi. Some details of this
agreement are contained in a news release made on September 8 of 2011 by Gold Canyon
and available on the Gold Canyon website.
Among other provisions and conditions of the PVA the Malawi Project is defined to
include EPL 0325/11 and any other properties that may be acquired in Malawi. JOGMEC
holds the option to acquire 67% equity interest in the Malawi Project, which may be
converted to a proportionate shareholding in any Joint Venture formed from the Malawi
Project. Gold Canyon holds the option to acquire 33% by contributing to the PVA. The PVA
also addresses matters such as conversion to net smelter royalty interests of 1.5% if diluted
to <5%, and further reduction to 0.5% on payment of US$0.5 M on each property. It also
addresses conditions of transfer of rights, obligations and interests and disposal or
encumbrance of equity interest by JOGMEC or Gold Canyon. The structure of the
Operating Committee, and assignment and obligations of Spring Stone Exploration Inc. as
Operator are also included.
(f) Environmental liabilities
The forests of the Mulanje Massif have been logged since the early 1900’s, initially for
the indigenous Mulanje Cypress. The Mexican pine was then introduced as shelter for
replantings of the cypress, but soon became dominant and was eventually logged
throughout the Chambe Basin, the logs being transported on a network of dirt roads to the
southern basin rim and then by a cable-way SW down to the lower Likhubula River valley.
The pine is also now nearly exhausted, the dwindling stands supporting small manual pit-
sawing operations, the sawn lumber being carried down toward Nakoya Village on the
heads and shoulders of porters. Several streams drain the basin south into the Likhubula
River and a network of dirt roads and footpaths remain from logging activities. As a result of
nearly complete deforestation the Chambe Basin today has a bare, denuded appearance
(Figure 6, 7) with a gently rolling, rounded topography and thick bouldery soils, thinly
covered by low bushes and grass.
Even though the Chambe Basin is far from a pristine environment the current
exploration phase being carried out by MINDECO on behalf of the JOGMEC-Gold Canyon
Joint Venture has been designed to have minimal impact. For example, drilling is being
done by small drills that will be moved by porters, one is a human-powered drill (Banka
18
drill) and the other a small portable diesel-powered drill (YBM-05). Drilling will be mostly
dry, chemicals will not be used, drill-sites should have minimal disturbance and holes will
be backfilled. Topsoil from pits and trenches will be stripped and replaced when backfilled.
Accommodation will be in existing huts with piped water supplies. The Joint Venture has
retained a biologist familiar with the area to ensure environmental issues of the current
exploration are monitored. In the author’s opinion the environmental impact of the current
exploration will be insignificant.
However, the Chambe Basin lies within the Mulanje Mountain Reserve, which was
established in 1927, and environmental issues for any eventual mining operation are
important. Although mining can apparently proceed within this reserve, development must
be done in a way that conserves the environment, especially water catchment areas such
as the Chambe Basin. There is also now an interest in eradicating introduced plants such
as the Mexican pine, Himalayan raspberry and the Australian eucalyptus and in replanting
the native cypress. Clearly, it is too early to consider the impact of any eventual mine but
the Joint Venture has proposed that it might be possible to combine restoration of a mined
area with reforestation of the basin with cypress.
The Mulanje Mountain Conservation Trust was founded in 2000 with funding by the
World Bank for research and conservation of biological diversity and promotion of
sustainable use of natural resources in the Mulanje Mountain Forest Reserve. It has
advocated removal of introduced flora and restoration of endemic species, particularly the
Mulanje cypress, and has lead opposition to proposed mining of bauxite from the Mulanje
Massif, principally on the Lichenya Plateau. While solution extraction of REE from soils in
Chambe Basin has little in common with the stripping and removal of large tonnages of
bauxite, environmental issues of REE resource extraction if it affected streams or created
dust, etc. will need to be considered.
(g) Work permits
No work permit is required for the current work on the Joint Venture, but approval
was required by the Ministry of Environmental Affairs before this work began.
If the project proceeds to a second phase (in 2012) an Environmental Impact Study
(“EIS”) will need to be initiated. Should the project eventually prove feasible the EIS will
need to be completed and a “Mining Licence” from the Ministry of Natural Resources would
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be required, and also a “Licence to Operate in a Forest Reserve” from the Ministry of
Forests.
(h) Other significant factors and risks affecting access, title, and ability to perform
work.
In the author’s opinion there are no significant factors and risks affecting access and
ability to perform exploration for REE in the Chambe Basin. Although the Property covers a
forest reserve, exploration and mining within the reserve is apparently possible. However, if
a mine proves feasible it is clear that environmental impacts will be closely scrutinized and
the benefits to the local community and to Malawi will be weighed against environmental
risks of development.
5 ACCESSIBILITY, CLIMATE, LOCAL RESOURCES, INFRASTRUCTURE AND PHYSIOGRAPHY (a) Topography, elevation and vegetation
The Mulanje Massif rises steeply above the densely-populated surrounding Chilwa-
Phalombe Plain at 650-750 m to Mt Sapitwa at 3,002 m, the highest peak in south-central
East Africa. The massif is covered by the Mulanje Mountain Forest Reserve and contains a
diverse and partly endemic vegetation, particularly the once more common Mulanje
Cypress, (Widdringtonia whytei) which became scarce by the 1950’s due to logging. The
Mulanje Cypress is one of 4 African Widdringtonia species of the Family Cupressaceae and
is often erroneously referred to as a “cedar”, which belong to the Family Pinacea and are
unrelated to cypresses. A smaller cypress (Widdringtonia Nodiflora) and gladioli, ground
orchids, proteas, aloe, crysanthemum, ferns, mosses, wild peach, yellow wood and other
plants are also present. Lists of some of the 6 endemic trees, the 66 mammals, 300 birds,
31 snakes, 25 lizards, 33 frogs, 233 butterflies and 7 fish known from the Mulanje Forest
Reserve can be found in Deppe and Bishop (2010). Introduced plants include the Mexican
Pine (Pinus patula), eucalyptus and the Himalayan raspberry.
The floor of the Chambe Basin has a rolling, subdued topography (Figure 6, 7, 9)
ranging from about 1,690 m at the southern lip to about 1,875 m and is surrounded by a
circular rim, partly of bare rock ( Figure 6, 7), which rises to a maximum height of 2,557 m
at Chambe Peak. Chambe Basin apparently was once covered by a forest of the Mulanje
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Cypress, but few of these trees remain there today and the basin was later planted in
Mexican pine and most of this has also now been logged. The basin today has only a thin
cover of small bushes and grasses (Figure 6, 7).
(b) Means of access
Chambe Basin can be reached from Blantyre by vehicle on a good sealed road ESE
about 1 hour to Chitikale Village and then east a few km to the road end at the Likhubula
Forestry Station by a gravel road, which passes through Nakoya Village. Several footpaths
lead to Chambe Basin from the lower southern slopes, the main one being the Skyline
Path, which begins at the Likhubula Forestry Station at about 835 m and climbs to the
south rim of the basin at about 1,690 m and takes 2 to 3 hours. From this point the footpath
continues across the approximately 3.5 km wide basin and connects with a network of dirt
roads that lead to several forestry / tourist huts.
The present access to the property by footpaths is clearly insufficient for any
significant mining activity and would need to be improved. In the past a cable-way, which
runs for about 2.1 km from a short road above the Likhubula Forestry Station to the Upper
Skyline Station on the south rim of the basin, was used to bring logs down from the basin.
The load bearing cables (about 1.5 inch) are still in place and, if the project continues, the
cable-way might be re-activated or replaced and used to transport materials and perhaps
people to and from Chambe Basin. It is understood the Joint Venture will evaluate this
option and any other access possibilities if the first phase of the project is encouraging.
(c) Proximity to population centres, nature of transport
The nearest population centre to the Chambe Basin is Nakoya Village in the
lower Likhubula Valley, where many mountain porters live, about 8 km SW of the basin.
Chitikale, the commercial centre of the Mulanje district, lies a few km west of the Likhubula
Forestry Station and the small town of Mulanje is about 9 km to the south on a paved road.
Blantyre, the largest town (population ~730,000) and main commercial centre in Malawi,
lies about 60 km in a direct line to the WNW.
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(d) Climate, length of operating season
The climate of Malawi is hot and wet from November to April, cool and dry from
May to August and hot and dry from September to October. Annual rainfall is very different
on the Mulanje Massif (>100 inches) than on the surrounding plains (~40 inches). Rain may
fall at higher elevations at any time of the year, although it is more frequent and intense
during the wet season. Intermittent rain and mist centred on the massif is common.
Temperatures on the Phalombe Plain range from about 15˚ to 35˚C but on the massif
temperatures are generally lower, especially at night, and in June and August may drop
below zero and snow may fall occasionally at higher elevations.
Conditions may be more difficult in the wet season, but exploration and mining
operations could continue throughout the year.
(e) Sufficiency of surface rights, availability of mining operation
infrastructure, areas for tailings, waste, leach pad areas and plants
Surface rights are owned by the Government of Malawi. There is very little mining
infrastructure in Malawi, mostly quarrying operations, and mining equipment would
probably need to be brought from South Africa or from outside Africa. The only significant
mine in Malawi is the Keyelekera uranium mine, which opened in 2009. The World Bank
(Land and others (2009)) identified unreliable power and transport as significant
impediments to developing mining operations in Malawi.
At the present preliminary stage of exploration no study of areas for tailings, waste or
plants has been made or is warranted.
6 HISTORY
(a) Prior ownership and ownership changes
Previous interest in the mineral resources of the Mulanje Mountain area has
centred on their extensive bauxite deposits, developed by weathering mainly on the Linje
and Lichenya plateaux at elevations of 1,800 -2,000 metres (Garson and Walshaw (1969)).
According to Garson and Walshaw (1969) and Anonymous (1994) the bauxite deposits
were discovered in 1924 and have been explored by various companies, including the
22
Anglo American Corporation (1934, 1943), the British Aluminium Co. (1951-1958) and, on
behalf of the Malawi Government, Lonrho (1969-1973)..
According to Chimwala (2009) in 2001 BHP Billiton considered developing the
Mulanje bauxite for their Mozal Smelter in Mozambique, and in 2005 South African
company Gondo Resources was granted an exclusive prospective licence over about 29 sq
km covering Mulanje bauxite. This licence expired in 2008, and although the company
requested an extension until Sept 3 of 2010 to produce a feasibility study and an
environmental impact assessment, this was rejected in January of 2010. There has been
considerable opposition to this project, especially because of the possible effects of dust
on the important tea-growing area near Mulanje, on water sources flowing from the Mulanje
Massif, and on further loss of the Mulanje Cypress by surface stripping, mainly on the
Lichenya Plateau. .
(b) Nature, extent and general results of previous exploration.
No exploration is known to the author from the Chambe Basin prior to the analyses
by Ishikawa and MINDECO described in Item 7b. These two reconnaissance sampling
programs consist of a small number (25 samples in total) of mainly roadside samples and
analyses indicate some samples contain easily-leachable REE.
According to Garson and Walshaw (1969) there is negligible bauxite in the Chambe
Basin, but as noted above significant bauxite resources have been found on other areas of
the Mulanje Massif within EPL0325/11. A study of feasibility of development of the Mulanje
bauxite on these other areas was made by Met-Chem (Anonymous (1994)) on behalf of the
Mineral Investment Development Corporation (MIDCOR), acting for the Government of
Malawi and funded by the African Development Bank. They recommended development of
bauxite (for aluminum) at a mining rate of 589,000 TpA, that an aerial tramway be
constructed to transport the bauxite to the plains below, and construction of a 200,000 TpA
alumina plant. They also recommended that an aluminum smelter should not be built in
Malawi, but instead that a commitment be sought from the aluminum smelter at Richards
Bay in South Africa to purchase Mulanje alumina. They estimated capital costs at US$820
M, which did not include a US$50 M investment in power, railways, and port facilities.
23
(c) Significant historical mineral resources or reserves
Using the Lonrho data Met-Chem (Anonymous (1994)) reported a resource of 25.6
MT of bauxite, using a cutoff grade of 30% Al2O3, with an average grade of 43.3% Al2O3.
However, it must be clearly stated that this historical resource is not 43-101
compliant, it is not relied upon in this report, and it is not of exploration interest to
Gold Canyon. More specifically, the bauxite resources, whatever their size or economic
potential, are not germane to the potential REE resources of the Chambe Basin that are the
present interest of Gold Canyon on the Mulanje Massif.
(d) Production
The author knows of no mineral production from the Property.
7 GEOLOGICAL SETTING AND MINERALIZATION
(a) Regional, local and Property geology
This part of southern Malawi (Figure 8) is underlain by a basement complex (Garson
and Walshaw, 1969) consisting of folded and metamorphosed rocks of Precambrian to
Lower Paleozoic age, mostly paragneiss, but also including granulites, calcareous gneiss,
marble, several types of amphibolite and varieties of mostly migmatitic and anatectic
granite.
Intruding the basement complex are rocks of the Chilwa Alkaline Province of Upper
Jurassic to Lower Cretaceous age. The major alkaline rocks are a series of overlapping
sub-circular intrusions of mainly syenite, some quartz syenite and granite that form the
Mulanje Massif, an inselberg (Figure 5) that rises high above the surrounding plains.
The Chambe ring structure (Figure 5, 9) is one of several syenite complexes of the
Mulanje Massif and is about 8.5 Km across. The outer ring dike syenite(s) form a
prominent bare rock rim (Figure 6, 7) that encloses a basin about 3.5 km across within
which a central syenite plug has recessively weathered to soils that are up to about 15 m
thick and contain scattered syenite boulders (Figure 6, 7) , probably residual joint-bounded
blocks (“core stones”). Leachable rare earths in these soils are the main target of the
24
current exploration begun in August of 2011 under the direction of H. Harada of MINDECO
on behalf of Gold Canyon.
(b) Mineralized zones, rock types, controls, length, width, depth and continuity of
mineralization. Description of type, character, and distribution of mineralization.
The REE mineralization in the Chambe Basin is so far known only from a very small
number (total 25) of soil and rock samples collected on several days of reconnaissance
sampling, mostly from road cuts along old forestry tracks. The controls on mineralization
and the vertical and horizontal extent of the mineralization are therefore unknown at
present, and the principal objectives of the current exploration program of systematic
drilling and detailed sampling being carried out by MINDECO are to document the REE-
mineralized material and investigate the distribution of the REE in the soil profile, the size
and grade of any resource, and the recoverability of the REE.
An indication of the size of the soil mantle over the central syenite plug in Chambe
Basin is given by the work of Garson and Walshaw (1969, Plate X), who mapped the basin
and described the soils from 69 pits ranging in depth from 5 feet to 50 feet (1.5 to 15.2 m).
A contoured map of thickness of the soils from the pit data reported by Garson and
Walshaw (1969) is shown as Figure 10. Garson and Walshaw described the deposits as
mainly kaolinitic, with bauxite only in small patches, and the following summary of the soil
profiles is derived from their account (with inferred standard soil horizons A to C added).
Weathered rock (C soil horizon?) immediately above the bedrock syenite plug may
preserve the texture of the parent syenite, may also contain fragments of feldspar,
amphibole and biotite and is mainly white, with pink, yellow and black mottling. The mottling
increases upward and red, pink and purple colours predominate, and in the upper parts (B
soil horizon?) the soil is red-brown and only quartz from the weathered syenite survives. A
yellowish-brown subsoil is locally present and the uppermost soil (A soil horizon?) contains
humus and is dark grey to black and rooty.
The possibility that the Mulanje Mountain area might contain REE deposits of the
ion-adsorption type was proposed by Ishikawa (2010), a geologist from the Japan
International Cooperation Agency currently working with the Geological Survey of Malawi in
Zomba. Ishikawa collected 8 samples (Table 2) from Chambe Basin in September of 2010.
25
The following year, on May 22-23 of 2011, a group of 7 geologists from MINDECO,
JOGMEC and the Geological Survey of Malawi collected 16 samples at 9 sites (Table 3)
including 13 soil samples from 6 sites and 3 rocks.
It should be noted that only a small number of samples have been analyzed so far,
that these are scattered over a large area, and that most are shallow (generally less than 3
m) relative to the deep soils (Figure 10) reported by Garson and Walshaw (1969).
Analyses (Table 4) of 3 “kaolinitic” samples (Table 2) collected by Ishikawa indicated
these soils contain from 475 to 739 ppm total REE of which 31% to 74 % is easily-
leachable (41% to 86% if Ce is excluded). Subsequent “weathered rock” samples taken by
MINDECO, JOGMEC and Geological Survey of Malawi were found to contain (Table 5 and
6) between 198 and 642 ppm total REE, and recoveries by leaching were in the range 0.1
to 30% (38% if Ce is excluded), with 8 of 13 samples having 5% or less of their total REE
leachable. This high variability of recovery of REE and the lower % of recovery than the
Ishikawa samples was considered by JOGMEC as possibly due to natural variability or
perhaps to differences in leaching chemistry or methods between the earlier analyses
(Nittetsu Lab) and the later analyses (Mitsui Lab). However, as an inter-laboratory check
two original Ishikawa samples were leached by the Mitsui Lab and these show fair
agreement in % of leached REE (see Table 7, 66% vs 74% for CHA-4 and 56 % vs 70% for
CHA-6). This result suggests the methods produce comparable results and therefore imply
a fair degree of natural variability. These analyses show that Ce is 13 to 32% of the total
REE in the soils, but only 1 to 16% of the leachable REE, suggesting that Ce occurs in a
different form than other REE, an observation that is consistent with studies of ion
adsorption deposits elsewhere.
Samples were collected by the author from Chambe Basin on 22-23 of August of
2011 from 11 sites (Table 8) for verification purposes and are discussed in Item 12. Many
of these samples were taken as checks at sites originally sampled by Ishikawa, and the
author is also grateful to J. Ishikawa for providing 3 of his original samples for re-analysis
(see Table 9 under Item 12). Re-analysis of these samples has essentially confirmed his
initial reports that the Chambe Basin may contain a REE deposit of the “ion-adsorption clay
type “.
26
Figure 10 Contour map of depth of soils (in feet) above bedrock in Chambe Basin. Depth
data are from Garson and Walshaw (1969, Plate X). Shallower areas shown in blue. The
black enclosing line is the approximate boundary drawn by Garson and Walshaw (1969)
between weathered and bare rock.
Table 2 Samples collected by J. Ishikawa in Sept of 2010
Sample latitude longitude error
m Sample
Organic depth(cm)
Sampling depth(cm)
Colour rock
fragments (mm)
radiometric (μSv/hr)
CHA 1 15°54'40.7"S
35°32'25.5"E4 Kaolinite 10 85 white-pale brown 1 0.15
CHA 2 15°54'55.2"S
35°32'25.8"E5 Kaolinite 5 50 white-pale brown 2 0.15
CHA 3 15°55'08.8"S
35°32'21.1"E4 Laterite 30 100 brown 1 0.15
CHA 4 15°55'11.6"S
35°32'16.1"E4 Kaolinite 20 160 pale brown 1 0.15
CHA 5 15°55'13.3"S
35°32'15.9"E6 Kaolinite 15 100 white-pale brown 1 0.15
CHA 6 15°55'22.4"S
35°32'03.8"E6 Kaolinite 10 300 white-pale brown 1 0.15
CHA 7 15°55'27.5"S
35°31'42.7"E4 Kaolinite 5 50 white-pale brown 2 0.15
CHA 8 15°55'32.0"S
35°31'46.7"E3 Kaolinite 20 100 pale brown 2 0.15
28Table 3 Samples collected by MINDECO / JOGMEC / Geol Survey of Malawi in May of 2011
WGS84 WGS84 Sample ID Type Zone Easting Northing Description Depth (cm) Site type 11052201A WR 36L 770837 8237604 Reddish brown weathered syenite 80 Road cut 11052201B WR 36L 770837 8237604 Pale pink weathered syenite 200 Road cut 11052201C WR 36L 770837 8237604 Pale pinkish white weathered syenite 80 Road cut 11052301A WR 36L 772317 8239705 Grey surface soil 10 Road cut 11052301B WR 36L 772317 8239705 Reddish brown weathered syenite soil 40 Road cut 11052302A WR 36L 772073 8239945 Grey white weathered syenite, rock texture remains 800 Road cut 11052302B WR 36L 772073 8239945 Grey white weathered syenite, rock texture remains 1200 Road cut 11052303A WR 36L 771825 8240116 Pale brown weathered syenite with feldspar 20 Road cut 11052303B WR 36L 771825 8240116 Pale brownish white weathered syenite 200 Road cut 11052303C WR 36L 771825 8240116 Pale brownish white weathered syenite 350 Road cut 11052304A WR 36L 771861 8238542 Brownish grey surface muddy soil 20 Surface 11052304B WR 36L 771865 8238567 Reddish brown weathered syenite soil 50 Road cut 11052305 Rock 36L 771862 8239064 Grey white medium grain biotite syenite, not fresh 0 Boulder
11052306 Rock 36L 771745 8238371 Brown fine grain weathered dyke, weathered to soft brick
0 Road
surface 11052307 WR 36L 770972 8237830 Dark reddish brown weathered syenite soil 0 Road cut 11052308 Rock 36L 770582 8237383 Yellowish white fine grain syenite dyke, not fresh 0 Trail surface WR: weathered rock (saprolite)
29Table 4 REE analyses of 3 leached samples collected by J. Ishikawa in September of 2010.
Total REE
Sample La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Y TREETREE-
Ce no ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm
CHA-4 125 126 31 127 23 9 22 3 18 4 11 1 9 1 111 620 495CHA-6 104 88 24 93 17 6 17 3 14 3 8 1 6 1 92 475 387CHA-8 127 203 34 140 27 11 27 4 22 4 11 1 8 1 120 739 536
REE in leach liquor
Sample La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Y TREETREE-
Ce no ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm
CHA-4 100 31 26 107 19 7 21 3 16 3 10 1 7 1 104 456 425CHA-6 57 8 17 74 14 5 17 3 14 3 8 1 5 1 105 332 324CHA-8 20 11 7 35 9 5 12 2 12 3 8 1 6 1 100 232 221
Percentage of total REE leached from solid
Sample La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Y TREETREE-
Ce no % % % % % % % % % % % % % % % % %
CHA-4 80 25 84 85 84 77 95 94 87 81 92 69 80 77 94 74 86CHA-6 55 9 72 80 83 85 102 120 99 108 103 101 83 110 114 70 84CHA-8 16 5 21 25 33 46 45 51 55 72 70 74 75 84 83 31 41
30Table 5 Analyses of REE in solid samples and leach solutions by MINDECO on samples listed in Table 3 .
Assays by Tokyo University by ICP/MS. Leaching by Mitsui Mining R&D Centre, Japan.
Sample no
Light REE Mid REE Heavy REE
La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Y TREE ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm
solid 77 133 24 94 17 5 13 2 9 2 5 1 4 1 38 424 11052201A
leach 13 4 4 15 2 1 2 0.2 1 0.2 1 0.1 0.4 0.1 8 52 solid 88 181 26 99 19 5 15 2 11 2 5 1 4 1 54 513
11052201B leach 21 5 7 29 5 2 5 1 3 1 2 0.2 1 0.2 19 99 solid 100 144 29 117 25 8 26 4 22 4 12 2 10 2 139 642
11052201C leach 33 5 10 43 8 3 11 1 9 2 5 1 3 0.5 59 192
11052301A solid 109 162 29 102 19 5 14 2 10 2 4 1 4 1 31 494
leach 1 2 0 1 0.1 0.0 0.1 0.0 0.1 0.0 0.0 0.0 0.0 0.0 0.3 5
11052301B solid 100 139 26 88 16 4 12 2 8 1 3 0 3 0 21 423
leach 0.1 0.2 0.0 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1
11052302A solid 38 64 10 38 7 4 6 1 5 1 2 0 2 0 20 199
leach 0.1 0.2 0.1 1 0 0.1 1 0.1 0.5 0.1 0.3 0.0 0.1 0.0 3 7
11052302B solid 33 72 10 37 7 4 6 1 5 1 2 0.3 2 0.3 19 198
leach 0.3 0.2 0.2 1 0.4 0.1 0.5 0.1 0.4 0.1 0.2 0.0 0 0.0 3 7
11052303A solid 54 150 15 53 10 3 7 1 5 1 3 0.5 3 0.5 24 330
leach 2 7 1 3 1 0.2 0.4 0.0 0.2 0.0 0.1 0.0 0 0.0 1 16
11052303B solid 54 139 17 70 12 5 8 1 5 1 2 0.3 2 0.4 19 337
leach 11 3 4 18 3 1 2 0.2 1 0.2 1 0.1 0.4 0.1 5 50
11052303C solid 44 96 15 62 14 6 16 3 16 3 8 1 5 1 86 375
leach 6 1 3 17 4 2 7 1 7 1 4 0.4 2 0.3 45 101
11052304A solid 107 217 31 113 22 5 17 2 14 3 8 1 7 1 55 603
leach 6 12 2 7 1 0 1 0.2 1 0.2 1 0.1 0.4 0.1 6 38
11052304B solid 85 287 24 81 15 3 10 2 9 2 5 1 5 1 35 564
leach 6 10 2 6 1 0 1 0.1 1 0.1 0.3 0.0 0.2 0.0 3 31
11052305 solid 80 186 19 62 12 2 11 2 13 3 9 1 8 1 71 479
11052306 solid 127 1447 76 353 129 8 176 43 347 82 264 39 241 31 2131 5495
11052307 solid 49 226 11 36 6 2 4 1 3 1 1 0 1 0 9 350
leach 0 0 0 0 0 0 0 0 0 0 0
11052308 solid 40 87 10 34 6 1 4 1 4 1 2 0 2 0 14 207
31Table 6 REE recovered from leach liquors of samples of Table 3 as a % of REE in the solid samples.
Calculated from data of Table 5 above for the “weathered rock” samples ( rock samples were not leached)
Sample La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Y TREE TREE-Ce
no rec %
rec %
rec %
rec %
rec %
rec %
rec %
rec %
rec %
rec %
rec %
rec %
rec %
rec %
rec % rec % rec %
11052201A 17 3 16 16 13 16 16 13 13 14 14 11 9 10 20 12 1611052201B 24 3 26 29 26 32 31 29 29 32 32 30 27 27 36 19 2811052201C 33 3 34 36 34 37 41 40 39 40 40 37 34 33 42 30 3811052301A 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 111052301B 0.1 0.2 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 0.2 0.3 0.2 0.1 0.111052302A 0.3 0.4 1 3 5 4 9 9 9 11 11 10 8 7 17 4 511052302B 1 0.3 3 4 5 3 8 8 8 9 9 8 6 5 14 3 511052303A 5 4 5 6 5 5 6 5 5 5 4 3 3 3 5 5 511052303B 20 2 23 26 22 22 25 21 20 22 23 20 19 18 27 15 2411052303C 14 1 22 27 31 31 43 44 45 47 47 44 41 39 53 27 3611052304A 6 5 6 6 6 7 9 8 8 8 7 6 6 5 11 6 711052304B 7 4 7 8 7 8 8 7 6 6 5 4 3 3 9 5 7
11052307 0.1 0.1 0.1 0.1 0.0 0.0 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.1 0.1 0.1
Table 7 Re-analysis of 4 Ishikawa samples (CHA-2, 4, 6, 7) by MINDECO (WR-2, 4, 6, 7).
Analyses by ICP/MS at Tokyo University, leach tests at Mitsui R & D Centre, Japan
7A REE concentrations in the solid sample
LRE ppm MRE ppm HRE ppm TREE TREE-
Ce Sample La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Y ppm ppm CHA-2 132 144 35 134 25 6 21 3 13 2 5 1 3 0 43 568 424 WR2 129 215 35 132 26 6 21 3 16 3 8 1 7 1 62 663 448
CHA-4 125 126 31 127 23 9 22 3 18 4 11 1 9 1 111 620 495 WR4 143 158 38 150 29 11 28 4 22 5 13 2 10 2 125 739 581
CHA-6 104 88 24 93 17 6 17 3 14 3 8 1 6 1 92 475 387 WR6 104 82 29 121 25 9 28 4 23 5 13 2 10 2 149 606 525
CHA-7 215 132 42 146 21 5 18 2 12 2 6 1 5 1 59 665 533 WR7 221 234 45 152 23 5 18 2 13 2 7 1 6 1 64 794 560
327B Individual REE in the solid sample as a % of total REE
Light REE % Mid REE % Heavy REE % TREE TREE-
Ce Sample La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Y % % CHA-2 23 25 6 24 4 1 4 1 2 0 1 0 1 0 8 100 75 WR2 19 32 5 20 4 1 3 0 2 0 1 0 1 0 9 100 68
CHA-4 20 20 5 20 4 1 4 1 3 1 2 0 1 0 18 100 80 WR4 19 21 5 20 4 1 4 1 3 1 2 0 1 0 17 100 79
CHA-6 22 19 5 20 4 1 3 1 3 1 2 0 1 0 19 100 81 WR6 17 13 5 20 4 1 5 1 4 1 2 0 2 0 25 100 87
CHA-7 32 20 6 22 3 1 3 0 2 0 1 0 1 0 9 100 80 WR7 28 29 6 19 3 1 2 0 2 0 1 0 1 0 8 100 71
7C Concentration of REE leached from solid into liquor
Light REE ppm Mid REE ppm Heavy REE ppm TREE TREE-
Ce Sample La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Y ppm ppm CHA-2 - - - - - - - - - - - - - - - - WR2 10 8 3 11 2 0 2 0 1 0 1 0 1 0 10 49 42
CHA-4 100 31 26 107 19 7 21 3 16 3 10 1 7 1 104 456 425 WR4 105 35 28 115 20 8 23 3 18 4 10 1 7 1 113 490 455
CHA-6 57 8 17 74 14 5 17 3 14 3 8 1 5 1 105 332 324 WR6 57 9 17 75 15 5 19 3 15 3 8 1 6 1 109 342 333
CHA-7 - - - - - - - - - - - - - - - - WR7 160 5 30 105 14 2 12 1 7 1 4 1 3 0 48 394 389
33
7D Individual REE composition of leached liquor as a % of total REE in liquor
Light REE % Mid REE % Heavy REE % TREE TREE-
Ce Sample La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Y % % CHA-2 - - - - - - - - - - - - - - - - WR2 21 16 5 23 3 1 4 0 3 1 2 0 1 0 21 100 84
CHA-4 22 7 6 23 4 2 5 1 4 1 2 0 2 0 23 100 93 WR4 22 7 6 23 4 2 5 1 4 1 2 0 2 0 23 100 93
CHA-6 17 2 5 22 4 2 5 1 4 1 2 0 2 0 32 100 98 WR6 17 3 5 22 4 2 6 1 4 1 2 0 2 0 32 100 97
CHA-7
WR7 41 1 8 27 3 0 3 0 2 0 1 0 1 0 12 100 99
7E Percentage extraction of the REE in the solid sample into the leach liquor
Light REE % Mid REE % Heavy REE % TREE TREE-
Ce Sample La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Y % % CHA-2 - - - - - - - - - - - - - - - - WR2 8 4 8 9 6 7 9 8 8 10 10 9 8 9 17 7 9
CHA-4 80 25 84 85 84 77 95 94 87 81 92 69 80 77 94 74 86 WR4 74 22 72 77 70 74 82 79 78 78 79 75 71 70 90 66 78
CHA-6 55 9 72 80 83 85 102 120 99 108 103 101 83 110 114 70 84 WR6 54 11 56 62 59 62 69 65 65 64 63 60 56 55 73 56 63
CHA-7 WR7 73 2 67 69 59 39 66 59 55 59 60 59 54 54 74 50 69
8 DEPOSIT TYPES
The type of REE deposit being explored for in the Chambe Basin is
commonly referred to as the “ion-adsorption clay type”, although various other
names have been used including “south China type”, “Jiangxi rare earth ores” ,
“weathered crust elution-deposited rare earth ores”, “MEX-REY ores”, and “ionic
REE ores” . The following summary is taken from a number of sources, including
Bao and Zhao (2008), Chi (1988), Chi and others (2005) , Chi and Tian (2008),
Ishihara and others (2008), Kanazawa and Kamitami (2005), Maksimovic and
Panto (1996), Morteani and Preinfalk (1996), Murakami and Ishihara (2008),
Orris and Grauch (2002), Sanematsu and others (2009), and Wu and others
(1996).
Ion adsorption type REE deposits are fairly common in China, where they
were first discovered in the 1970’s, and now number at least 214 deposits (Bao
and Zhao (2008)), but are almost unknown elsewhere in the world. About 90% of
the Chinese ionic deposits are in the southern provinces, principally Jiangxi,
Guang Dong, and Guang Xi, but also in Hunan and Fujian. These areas are
generally subtropical areas south of 28˚ N with warm, humid conditions and
annual rainfalls exceeding 1,500 mm. In these areas they generally develop in
the weathering zone where topography is gentle, denudation rates are low but
long-continued, and soils are consequently deep and well preserved. Most
appear to have formed by in situ weathering of granite, but some have developed
by weathering of other igneous rock types (eg pyroclastics), and rarely even from
other types of rock (eg phyllite). There is also evidence from clays washed into
karst depressions in eastern Europe (Maksimovic and Panto (1996)) that REE
concentrations can develop in clays not formed in situ.
Whatever the environment, REE enrichments of the ionic type appear to
be due to continuous ground water leaching that mainly decomposes accessory
REE minerals in soils, and to a lesser extent trace REE in rock- forming minerals,
from the upper soils . The REE are progressively leached in upper layers and
redeposited at greater depths. In China it appears the REE are mostly loosely
bound to clays, However, in soils developed on REE-bearing carbonatites in
Brazil (Morteani and Preinfalk (1996) the REE may be mainly held in phosphates,
35
(such as apatite or the barium aluminum phosphate gorceixite ), or in REE
fluorocarbonates of the bastnäsite group. Less is known of the leachability of
these minerals but it likely is less than the ionic clay type.
Weathered soil profiles in the REE deposits of south China are of lateritic
character and range from 5 to 30 m depth, are generally 8-10 m thick but may
locally reach as much as 60 m (Chi and Tian (2008) , Bao and Zhao (2008)).
Typically there is a surface layer of organic soils (A soil layer), a strongly
weathered clayey, grey, yellow to red coloured layer (B soil layer) which usually
has the highest REE enrichment, and a lower pale-coloured layer with remnant
silicate minerals in clay (C soil layer) that may also retain primary igneous
textures (“saprolite”).
About 60 to 90% of the total REE are adsorbed on clays such as kaolinite
and halloysite (Chi and Tian (2008)).The grade of raw ore is between 0.05 % and
0.35% total RE oxides but there is considerable variability (2 to 6 times) in grade
within a single deposit, commonly with better grades on ridges than gullies. The
deposits are relatively small, generally 3,000 to 12,000 tonnes but the annual
output from this type of deposit from China is about 10,000 tonnes REE oxide
according to Bao and Zhao (2008). According to Chi and Tian (2008) “proven
reserves of RE are approximately 1.48 million tons” in ion-adsorption deposits,
inferior only to the resource at Bayan Obo.
This type of deposit is important as providing a significant proportion of mid
and heavy REE in China. Figure 11 shows the REE distribution in two important
Chinese ion-adsorption deposits (Longnan and Xunwu) compared with three
carbonatite-related REE deposits Mountain Pass REE Mine, the Bayan Obo REE
Mine and the Mt Weld REE deposit. Individual ion-adsorption deposits vary in
their distribution of the REE but Figure 11 shows some characteristic features.
The carbonatite deposits have a high proportion of light REE, while the ionic
deposits have low light REE, higher mid and heavy REE. They also commonly
show a distinctive deficiency in Ce and sometimes in Eu. The Ce deficiency has
been explained (eg Bao and Zhao , 2008) by the tendency of Ce to oxidize from
Ce3+ to Ce4+ , the formation of cerianite or absorption of Ce on Fe and Al
oxyhydroxides .
36
The ion-adsorption REE deposits can only be processed chemically.
Extraction is by ion exchange using a variety of common chemicals such as the
sulphate, nitrate or chloride of ammonium, which provide the NH4+ cations to
replace REE ions, but Na+, K+ and other cations are also effective. The REE
may be extracted by batch-leaching, by heap-leaching or can be extracted by in
situ leaching (“ISR”). The leached REE are commonly recovered from the
leachate by precipitation with oxalic acid or ammonium bicarbonate.
The principal features of the ion-adsorption REE deposits are summarized
below
1 The REE deposits are soils developed in tropical areas with high rainfall by
long-continued weathering, generally on granite bedrock.
2 Much of the REE is derived from weathered accessory minerals, naturally
leached by ground waters in the upper soils (A layer) and redeposited at greater
depth where it is loosely bound to clays, generally in the B soil layer but also in
the C layer.
3 Although ion-adsorption deposits vary in their composition of individual REE,
they tend to have a distinctly different distribution than other sources such as
carbonatites, with less light REE, and higher proportions of the valuable mid-REE
and heavy REE. They also often have a Ce deficiency and a smaller Eu
deficiency.
4 REE grades are low (0.05-0.35 % total RE oxide), but the soils can be mined
by relatively inexpensive shallow surface excavations or by in situ recovery.
5 In contrast to other types of REE deposits, which commonly require complex
and expensive processing, REE in ion-adsorption deposits can be extracted by
simple leaching of common chemicals. The amount recoverable is commonly 60
to 90% of the total REE in the soil.
37
6 U and Th, which are generally associated with REE deposits of other types,
are typically very low in the soils of ion-adsorption REE deposits and of this low
U and Th in the soil only a small percentage reports to the leach solution.
10
100
1000
10000
100000
La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Y
Mt Pass Bayan Obo Mt Weld Longnan Xunwu
Figure 11 Chondrite-normalized REE distributions of REE from REE deposits in
China , Australia and USA. Chondrite values from Anders and Grevesse (1989)
x 1.36 (volatile-free CI chondrite). Longnan and Xunwu are important ion-
adsorption REE mines in China. Mountain Pass is an important bastnäsite mine
in carbonatite in California. Bayan Obo REE Mine in China is the largest REE
deposit in the World, with debated origin but probably carbonatite-related ?. Mt
Weld is an undeveloped REE deposit derived by secondary enrichment from a
carbonatite in Australia. Note steep smooth curves for carbonatite-related
deposits, flatter REE distributions for ionic deposits and Ce and Eu deficiencies.
Figure 12. Location of samples taken by Ishikawa (Table 2), MINDECO/JOGMEC/Geol Survey of Malawi (Table 3) and by
Le Couteur (Table 8).
9 EXPLORATION
Reconnaissance samples taken include 9 samples taken in 2010 before
the Prospecting Licence was granted and another 16 after granting of the licence
in early 2011.
(a) Procedures and parameters
Samples taken so far (Table 2 and 3) are only of a reconnaissance nature,
were taken mainly from convenient roadside exposures and are 1 to 5 kg in size.
(b) Sampling methods and sample quality, representativeness, bias.
Samples shown in Tables 2 and 3 were scraped mainly from available road
cuts and appear typical of the soils exposed at shallow depths. There is
insufficient data to determine how representative these soils are of those
throughout the basin. As the leachable REE content is not directly observable in
the field it cannot be said whether they are biased toward higher or lower values.
(c) Location, number, type, nature, sample spacing, size of area covered.
Locations of the 21 soils and 3 rocks taken are listed in Table 2 and 3 and
shown in Figure 12. These are mainly from exposures along logging tracks,
spaced from 50 m to 500 m apart over about 2.5 km and mainly in the eastern
and southern part of the basin.
(d) Significant results and interpretation of exploration information
The most significant result of the analyses from the few samples so far
analyzed (Table 2 to 7) is that some of them contain easily-leachable REE (up to
74% recovery from TREE of 620 ppm in one sample). The interpretation of this
meagre information is that it suggests the possibility that Chambe Basin may
contain REE mineralization of the ion adsorption type. The purpose of the current
drill program is to provide sufficient data to evaluate this possibility.
Of interest is MINDECO dike sample 11052306 with 5,495 ppm TREE
(Table 5), including 2,131 ppm Y and high levels of other REE, an indication of
the presence of primary REE enrichment in the rocks of Chambe Basin.
40
10 DRILLING
Drilling soils in Chambe Basin using two hand-portable drills was carried out
by MINDECO from August to October of 2011 but no details are currently
available, and as no analyses have yet been made there is no new information
on the REE potential.
11 SAMPLE PREPARATION, ANALYSES AND SECURITY
(a) Sample preparation methods, quality control prior to analyses.
The author was not involved in taking the samples listed in Tables 2 and 3,
collected in Sept of 2010 and May of 2011, and has no information on these
aspects for these samples. However, it is thought samples were placed in plastic
bags and submitted in this form to the analyzing laboratories.
(b) Sample preparation and analysis procedures, laboratory.
Samples collected by J. Ishikawa listed in Table 2 were split, pulverized and
analyzed for 14 REE and other elements (Ba, Co, Cr, Cs, Ga, Hf, Mo, Nb, Rb,
Sn, Sr, Ta, Th, Tl, U, V, W, Zr) using method ME-MS81 at the North Vancouver
Laboratory of ALS-Chemex. This method involves fusing the sample to a glass
with Li tetraborate, dissolution in acids and analysis by ICP-MS and is intended
to break down refractory minerals and provide total contents of the elements
analyzed. The results are listed in Table 4. The ALS-Chemex North Vancouver
lab is accredited to ISO-9001 standard. At the laboratory of Nittetsu Mining R &
D Centre in Japan splits of the samples were dried at 105˚ C for 24 hours,
ground to 2 mm, and 50 g was leached in 500 mg of 2% ammonium sulphate for
6 hours. The leach liquor was separated by centrifuge and analyzed by ICP-MS,
with the results listed in Table 4.
Samples listed in Table 3 collected by MINDECO/JOGMEC and the
Geological Survey of Malawi were analyzed for REE by ICP-MS at Tokyo
University. Samples of 15 g were leached in 150 ml solution of ammonium
sulphate.
41
(c) Quality control procedures.
The author has no information on quality control procedures for samples
listed in Tables 4 to 7.
(d) Opinion on adequacy of sample preparation, security, analytical
procedures.
The author was not involved in the sampling program in Sept of 2010 or in
May of 2011 and has no opinion on sample preparation and security prior to
analyses. Analyses for REE were made by accepted and appropriate methods by
major laboratories and leaching for loosely-held REE was done by a variant of a
standard method (Chi (1988), Chi and Tian (2008)).
12 DATA VERIFICATION
(a) Data verification by qualified person.
A principal purpose of the property visit by the author was to re-collect soils
from some sites where samples taken by J. Ishikawa in September 2010 were
found to contain easily-leachable REE (Table 4 and 7). Work done for
verification purposes included re-analysis of three samples collected by J.
Ishikawa in 2010, analysis of samples re-collected at 4 of the Ishikawa sites and
at several other sites, two samples were checked for the identity of the clay
minerals, two samples were screened for size distribution, and two soil samples
and one syenite were thin-sectioned and examined by petrographic microscope.
Samples were exported on Export Permit EP 02911, issued by the
Commissioner for Mines and Minerals of Malawi on 23August of 2011.
All analyses were done by ALS Chemex at their North Vancouver laboratory
(2103 Dollarton Hwy, North Vancouver, BC, V7H 0A7) except for leach
procedure ME-MS04 which was done at their Perth laboratory (ALS Ammtec, 6
Macadam Place, Balcatta, Western Australia, 6021). Both laboratories have ISO
9001 accreditation, and also have ISO 17025 accreditation for their most
common procedures, but not for ME-MS81, MS-ICP06 or the selective leaches
One syenite rock analyzed for total REE was first crushed with procedure
CRU-31 (fine crush below 2 mm) and it and the soils were then pulverized by
42
procedure PUL-21 (pulverized to 85% -75 microns). Samples were analyzed for
total REE and other trace elements by procedure ME-MS81 and for major
elements by method MS-IP06. Samples of 0.2 g sample were fused with 0.9 g
lithium metaborate at 1,000˚ C, the glass was dissolved in 100 ml 4% HNO3/2%
HCl and analyzed by ICP-MS for method ME-MS81 and by ICP-AES for method
ME-ICP06. The REE results are reported in Table 10.
Soil samples were analyzed for leachable REE by ALS-Chemex as follows.
Soils were first air dried using procedure DRY-23 and leached by procedure ME-
MS23 (a selective leach of weakly bound ions by sodium cyanide with chelating
agents ammonium chloride, citric acid and EDTA, with the leachant buffered at
pH 8.5, analysis by ICP-MS) and by procedure ME-MS04 ( a weak leach with 1.0
g sample mixed with 25 ml of ammonium acetate solution in acetic acid, shaken
for 2 hours, the leachant separated by centrifuge and decantation, analysis by
ICP-MS and by ICP-AES). The leached residues from ME-MS04 were also
pulverized (PUL-21) and analyzed for REE by method ME-MS81 and ME-ICP06..
Results by method ME-MS04 for the samples listed in Table 8 are shown
in Table 10 (total REE) and in Table 11, (leachable REE).
1 Resampling and analysis of samples taken by J. Ishikawa On 21 August
of 2011 the author visited J. Ishikawa in his office at the Geological Survey of
Malawi in Zomba and was given sub-samples of 3 of his original samples for
check analyses both of total REE and leachable REE. These results are reported
in Table 9 along with the original analyses of these samples and analyses by
MINDECO of the same samples.
Samples CHA-4, CHA-6 and CHA-8 have now been analyzed for leachable
REE by 3 laboratories and these results are compared in Table 9 and Figure 12.
The result of re-analysis of the 3 original Ishikawa samples generally confirms
their high percentage of leachable REE, from 31 to 74% for all REE or 41 to 86%
for all REE except Ce. As previously noted, ionic REE deposits generally show a
lower percentage of leachable Ce than other REE.
It appears that method ME-MS04 gives results similar to the ammonium
sulphate leach used by Nittetsu and University of Tokyo. However, the ME-MS23
43
leach gives much lower values (see Table 13), is therefore considered unreliable
and unsuitable for testing REE deposits of the ionic type and is not discussed
further.
2 Resampling at previously sampled sites. Four of the roadside sites
sampled by Ishikawa (CHA-1, CHA-4, CHA-6, CHA-8) were relocated by hand-
held GPS and resampled at the same depths and from the same scrape as the
original samples. As it is conceivable that sampling only of roadside samples
might bias results, perhaps reducing leachable REE by rain washing or
increasing the leachable REE by evaporation of REE-bearing ground water at the
free surface, at 2 sites (CHA-1, CHA8) samples were taken from new pits dug
about 10 m away from the road cuts. These results are reported in Table 10 and
11 and compared with analyses of the original samples in Table 14.
Considering that these samples include subsamples of the original samples,
others re-collected at the same sites and nearby, and that analyses were done at
several labs using different methods the agreement is reasonably good. It is
concluded that the results at least demonstrate that some samples contain a
substantial percentage (31 to 74% in Table 14 c) of easily leachable REE.
However, the number of samples examined is very small and much more close-
spaced sampling and repeated reanalysis of a standard sample is needed to
separate analytical uncertainty from natural variability. Work on these aspects will
be part of the MINDECO program.
3 Blank and standard. A barren quartz sand sample was submitted as a
blank and a sample of REE standard SARF-1 was submitted as a standard.
These results are shown in Table 10. Analysis of this standard gave results
within 2 std deviations except for La. The blank gave a total of 25 ppm, slightly
high, with the larger values for the more abundant REE (Ce, La, Nd, Y).
Standards, blanks and duplicates analyzed by ALS Chemex as part of their
quality control gave acceptable results, although the standards used for the
leaches generally had much lower concentrations than the samples.
Table 8 Samples collected by P. Le Couteur on August 22 and 23, 2011
Assay UTM WGS84 WGS84 Sample comment Sampler Date Sample Depth Colour Weight
no E- zone Easting
m Northing
m type cm g 686951 36L 771708 8238275 CHA-4 original Ishikawa 7 Sept 10 soil 160 pale brown 169686952 36L 771338 8237947 CHA-6 original Ishikawa 7 Sept 10 soil 300 pale brown 308686953 36L 770825 8237658 CHA-8 original Ishikawa 7 Sept 10 soil 100 pale brown 523686954 36L Sarf-1 standard (pulp) standard 73686955 36L Quartz sand blank blank 300686956 36L 770825 8237658 CHA-8 resample Le Couteur 22-Aug-11 soil 100 pale grey 625686957 36L 771342 8237947 CHA-6 resample Le Couteur 22-Aug-11 soil 300 pale brown 642686958 36L 771712 8238278 CHA-4 resample Le Couteur 22-Aug-11 soil 150 brown 673686959 36L 772200 8239800 Pit near Frances Hut Le Couteur 23-Aug-11 soil 100 red brown 710686960 36L 772202 8239603 Pit near Frances Hut Le Couteur 23-Aug-11 soil 100 red brown 618686961 36L 772190 8239512 Unit 3 syenite Le Couteur 23-Aug-11 soil outcrop pale grey 544686962 36L 772006 8239223 10m from CHA-1 Le Couteur 23-Aug-11 soil 85 pale grey 700686963 36L 770831 8237667 10m from CHA-8 Le Couteur 23-Aug-11 soil 100 pale grey 867
686964 36L 772001 8239224 CHA-1 resample Le Couteur 23-Aug-11 soil 100 pale brown 750
TABLE 9 Analyses of REE in 3 Ishikawa soil samples and leached liquors by 3 labs
REE concentrations in the raw solid sample in ppm Light REE Mid REE Heavy REE
Sample by** La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Y TREE
ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm CHA-4 ISH 125 126 31 127 23 9 22 3 18 4 11 1 9 1 111 620
MIN 143 158 38 150 29 11 28 4 22 5 13 2 10 2 125 739 PCL 147 154 37 147 28 11 26 4 23 5 13 2 10 2 140 745
CHA-6 ISH 104 88 24 93 17 6 17 3 14 3 8 1 6 1 92 475 MIN 104 82 29 121 25 9 28 4 23 5 13 2 10 2 149 606 PCL 117 144 32 134 28 9 28 4 25 5 14 2 10 2 165 717
CHA-8 ISH 127 203 34 140 27 11 27 4 22 4 11 1 8 1 120 739 PCL 100 194 26 111 24 10 23 4 21 5 12 2 10 2 152 695
% of individual REE in the raw solid sample Light REE Mid REE Heavy REE
Sample by La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Y TREE
% % % % % % % % % % % % % % % % CHA-4 ISH 20 20 5 20 4 1 4 1 3 1 2 0 1 0 18 100
MIN 19 21 5 20 4 1 4 1 3 1 2 0 1 0 17 100 PCL 20 21 5 20 4 1 3 1 3 1 2 0 1 0 19 100
CHA-6 ISH 22 19 5 20 4 1 3 1 3 1 2 0 1 0 19 100 MIN 17 13 5 20 4 1 5 1 4 1 2 0 2 0 25 100 PCL 16 20 4 19 4 1 4 1 3 1 2 0 1 0 23 100
CHA-8 ISH 17 27 5 19 4 1 4 1 3 1 2 0 1 0 16 100 PCL 14 28 4 16 3 1 3 1 3 1 2 0 1 0 22 100
REE removed from the solid into the leach solution in ppm Light REE Mid REE Heavy REE
Sample by La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Y TREE
ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm CHA-4 ISH 100 31 26 107 19 7 21 3 16 3 10 1 7 1 104 456
MIN 105 35 28 115 20 8 23 3 18 4 10 1 7 1 113 490 PCL 96 33 26 113 21 9 23 3 18 3 10 1 7 1 99 463
CHA-6 ISH 57 8 17 74 14 5 17 3 14 3 8 1 5 1 105 332 MIN 57 9 17 75 15 5 19 3 15 3 8 1 6 1 109 342 PCL 57 10 17 79 16 6 20 3 17 3 9 1 6 1 106 348
CHA-8 ISH 20 11 7 35 9 5 12 2 12 3 8 1 6 1 100 232 PCL 26 14 8 39 9 5 15 2 13 3 8 1 6 1 107 257
Individual REE as % of the total REE in solution Light REE Mid REE Heavy REE
Sample by La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Y TREE
% % % % % % % % % % % % % % % %
CHA-4 ISH 22 7 6 23 4 2 5 1 4 1 2 0 2 0 23 100 MIN 22 7 6 23 4 2 5 1 4 1 2 0 2 0 23 100 PCL 21 7 6 24 4 2 5 1 4 1 2 0 2 0 21 100
CHA-6 ISH 17 2 5 22 4 2 5 1 4 1 2 0 2 0 32 100 MIN 17 3 5 22 4 2 6 1 4 1 2 0 2 0 32 100 PCL 16 3 5 23 4 2 6 1 5 1 2 0 2 0 30 100
CHA-8 ISH 9 5 3 15 4 2 5 1 5 1 3 0 3 0 43 100 PCL 10 5 3 15 4 2 6 1 5 1 3 0 2 0 42 100
REE leached as a % of original REE in the solid (% REE recovered) Light REE Mid REE Heavy REE TREE
Sample by La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Y TREE
-Ce % % % % % % % % % % % % % % % % %
CHA-4 ISH 80 25 84 85 84 77 95 94 87 81 92 69 80 77 94 74 86 MIN 74 22 72 77 70 74 82 79 78 78 79 75 71 70 90 66 78 PCL 66 22 71 77 74 79 89 73 80 72 78 70 69 66 71 62 73
CHA-6 ISH 55 9 72 80 83 85 102 120 99 108 103 101 83 110 114 70 84 MIN 54 11 56 62 59 62 69 65 65 64 63 60 56 55 73 56 63 PCL 49 7 54 59 56 65 71 59 67 57 63 58 56 55 64 49 59
CHA-8 ISH 16 5 21 25 33 46 45 51 55 72 70 74 75 84 83 31 41 PCL 26 7 30 35 39 52 63 53 59 56 68 63 64 63 70 37 48
**KEY
ISH=Ishikawa samples (Table 4. REE by ALS Chemex, leach by Nittetsu)
MIN=MINDECO samples (Table 7. REE by University of Tokyo, leach by Mitsui)
PCL=Le Couteur samples (Table 10. REE by ALS Chemex, leach by ALS Chemex)
CHA-4
0
50
100
150
200
La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Y
REE
pp
m
ISH
MIN
PCL
CHA-6
0
50
100
150
200
La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Y
pp
m
ISH
MIN
PCL
CHA-8
0
50
100
150
200
250
La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Y
pp
m
ISH
PCL
Figure 12. Comparison of analyses of 3 Ishikawa samples by 3 labs . Data
of Table 9.
TABLE 10. Analyses of total REE in samples collected by P. Le Couteur for verification purposes
(samples of Table 8). Analyses by ALS Chemex by ICP-MS. res=resampled, orig=original Ishikawa sample)
REE in solid soil samples (except syenite E686961 ) , method ME-MS81
Sample SAMPLE Ce Dy Er Eu Gd Ho La Lu Nd Pr Sm Tb Tm Y Yb TREETREE-
Ce no ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm CHA-4 orig E686951 154 23 13 11 26 5 147 2 147 37 28 4 2 140 10 745 592CHA-6 orig E686952 144 25 14 9 28 5 117 2 134 32 28 4 2 165 10 717 573CHA-8 orig E686953 194 21 12 10 23 5 100 2 111 26 24 4 2 152 10 695 502CHA-8 res E686956 140 22 12 9 22 5 83 2 93 22 21 4 2 153 9 598 458CHA-6 res E686957 177 24 13 8 25 5 104 2 118 28 25 4 2 164 11 710 533CHA-4 res E686958 136 17 10 8 18 3 111 1 107 27 21 3 1 104 8 574 439 Pit E686959 369 9 6 2 9 2 76 1 59 17 11 1 1 46 7 615 246 Pit E686960 195 9 4 4 12 2 104 1 88 25 16 2 1 37 4 502 307 Syenite E686961 96 6 3 3 8 1 49 0 50 13 10 1 0 29 2 272 176near CHA-1 E686962 146 16 9 6 19 3 101 1 105 27 19 3 1 94 8 556 410near CHA-8 E686963 126 13 8 8 15 3 61 1 72 17 15 2 1 88 6 435 310CHA-1res E686964 155 9 5 3 10 2 72 1 64 17 12 1 1 46 5 401 246
Standard
SAMPLE Ce Dy Er Eu Gd Ho La Lu Nd Pr Sm Tb Tm Y Yb Total REE
no ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm E686954 6830 26 3 53 99 3 2990 0 2490 780 248 9 0 49 1 13581SARF-1 6768 26 51 2665 2615 746 235 2SD 572 2.2 2.8 196 272 62 16 Blank E686955 9.8 0.5 0.3 0.1 0.5 0.1 4.7 0.1 3.9 1.1 0.7 0.1 0.0 2.6 0.3 24.7Blank 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
49Table 11 Results of leaching REE from samples of Table 8 by ALS Chemex ( method ME-MS04 )
REE in leach solution
Sample Sample Ce Dy Er Eu Gd Ho La Lu Nd Pr Sm Tb Tm Y Yb TREETREE-
Ce ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm CHA-4 orig E686951 33 18 10 9 23 3 96 1 113 26 21 3 1 99 7 463 429 CHA-6 orig E686952 10 16 9 6 20 3 57 1 79 17 16 3 1 106 6 347 337 CHA-8 orig E686953 14 13 8 5 15 3 26 1 39 8 9 2 1 107 6 257 243 CHA-8 res E686956 10 13 8 4 13 3 16 1 26 5 7 2 1 106 6 221 211 CHA-6 res E686957 12 17 9 6 20 3 51 1 73 16 15 3 1 110 6 342 330 CHA-4 res E686958 22 11 6 5 14 2 58 1 68 16 12 2 1 70 4 292 270 Pit E686959 12 1 0.35 0.22 1 0.12 6 0.04 7 2 1 0.13 0.05 3 0.30 33 22 Pit E686960 3 0.07 0.03 0.04 0.12 0.01 1 <0.005 0.77 0.19 0.14 0.02 <0.005 0.32 0.02 5 2 Syenite E686961 near CHA-1 E686962 5 11 6 4 13 2.00 39 1 60 13 11 2 0.72 69 4 240 235 near CHA-8 E686963 9 7 4 4 7 1 11 1 20 4 5 1 1 57 3 133 124 CHA-res E686964 6 3 2 1 4 0.55 12 0.17 19 4 4 0.53 0.18 19 1 77 71
Recovery of REE in leach solution as % of total REE in sample
Sample SAMPLE Ce Dy Er Eu Gd Ho La Lu Nd Pr Sm Tb Tm Y Yb TREETREE-
Ce Th U no % % % % % % % % % % % % % % % % % % % CHA-4 orig E686951 22 79 78 79 89 72 66 66 77 71 74 73 70 71 69 62 73 4 3CHA-6 orig E686952 7 63 63 65 71 57 49 55 59 54 56 59 58 64 56 48 59 2 2CHA-8 orig E686953 7 59 68 52 63 56 26 63 35 30 39 53 63 70 64 37 48 2 1CHA-8 res E686956 7 58 67 45 59 56 20 67 28 23 33 52 63 69 67 37 46 1 2CHA-6 res E686957 7 71 72 72 79 64 49 56 62 56 59 67 61 67 59 48 62 2 3CHA-4 res E686958 16 64 64 67 76 59 52 53 64 59 60 61 56 67 55 51 62 3 3 Pit E686959 3 9 6 10 12 6 7 4 12 11 12 10 5 6 4 5 9 2 4 Pit E686960 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 4 Syenite E686961 near CHA-1 E686962 3 68 67 73 72 64 38 55 57 48 58 68 61 74 57 43 57 2 3near CHA-8 E686963 7 50 56 48 45 49 18 53 28 22 32 46 57 65 54 31 40 2 2CHA-res E686964 4 37 34 44 41 33 16 23 30 25 33 39 28 41 25 19 29 2 4
50Table 12 REE in soils as a % of REE in parent syenite E686961 (data of Table 10)
Ratio of REE in soils to REE in syenite E686961 SAMPLE Ce Dy Er Eu Gd Ho La Lu Nd Pr Sm Tb Tm Y Yb TREE Th U
no % % % % % % % % % % % % % % % % % % E686951 2 4 5 4 3 4 3 4 3 3 3 4 4 5 4 3 5 5E686952 2 4 5 3 4 5 2 4 3 3 3 4 5 6 4 3 11 10E686953 2 3 4 4 3 4 2 4 2 2 2 3 4 5 4 3 2 2E686956 1 3 4 3 3 4 2 4 2 2 2 3 4 5 4 2 2 2E686957 2 4 5 3 3 4 2 4 2 2 3 4 5 6 5 3 18 12E686958 1 3 3 3 2 3 2 3 2 2 2 3 3 4 3 2 5 5E686959 4 1 2 1 1 2 2 2 1 1 1 1 2 2 3 2 24 16E686960 2 2 2 2 2 1 2 1 2 2 2 2 1 1 1 2 11 8E686961 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1E686962 2 3 3 2 2 3 2 3 2 2 2 2 3 3 3 2 5 4E686963 1 2 3 3 2 2 1 2 1 1 2 2 3 3 3 2 2 1E686964 2 1 2 1 1 1 1 2 1 1 1 1 2 2 2 1 6 5
Table 13 REE leached from samples of Table 8 by method ME-MS23
ME-MS23
ME-MS04
Sample Ce Dy Er Eu Gd Ho La Lu Nd Pr Sm Tb Tm Y Yb TREE TREE ppb ppb ppb ppb ppb ppb ppb ppb ppb ppb ppb ppb ppb ppb ppb ppm ppm E686951 885 2610 2090 476 1530 716 2180 204 4970 871 1085 336 254 19100 1405 39 463E686952 2610 4160 2330 1875 6120 895 17900 240 28700 5730 5230 842 274 29200 1560 108 347E686953 4860 5240 3500 2550 6670 1225 11400 444 20200 3640 4780 993 449 43600 2710 112 257E686956 2750 4530 3000 1740 4890 1070 5660 364 11300 1920 2980 813 383 38200 2300 82 221E686957 1905 3790 2100 1545 5420 807 12200 209 20700 3980 4160 776 236 25300 1335 84 342E686958 1.9 1.4 0.9 0.9 1.8 0.3 3.7 0.1 6.7 1.2 1.4 0.3 0.1 12.3 0.7 0.03 292E686959 2110 149 101.5 65.9 305 30.7 448 23.1 2020 330 439 34 15.9 718 133 7 33E686960 19.5 0.5 0.4 0.2 1 0.1 3.9 0.1 9.7 1.7 1.4 0.1 0.1 3 0.5 0.04 5E686962 736 3700 2050 1690 5330 789 9870 225 22700 3950 4490 756 240 20400 1415 78 240E686963 2920 3110 2070 1875 3420 739 3520 248 9790 1500 2440 553 266 25100 1565 59 133E686964 1615 1745 871 915 2450 345 1845 95.8 10350 1465 2350 356 100.5 8800 609 34 77
51Table 14 Soils analyzed by Ishikawa, MINDECO and the author for comparative purposes
14 a Total REE concentration in soils
Sample Ishikawa Comment Ce Dy Er Eu Gd Ho La Lu Nd Pr Sm Tb Tm Y Yb TREE TREE-Ce
no no ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm
CHA-4 Ishikawa analysis 126 18 11 9 22 4 125 1 127 31 23 3 1 111 9 620 495
WR4 CHA-4 MINDECO reanalysis 158 22 13 11 28 5 143 2 150 38 29 4 2 125 10 740 582
E686951 CHA-4 PCL reanalysis 154 23 13 11 26 5 147 2 147 37 28 4 2 140 10 745 592
E686958 CHA-4 resample PCL 136 17 10 8 18 3 111 1 107 27 21 3 1 104 8 574 439
CHA-6 Ishikawa analysis 88 14 8 6 17 3 104 1 93 24 17 3 1 92 6 475 387
WR6 CHA-6 MINDECO reanalysis 82 23 13 9 28 5 104 2 121 29 25 4 2 149 10 606 524
E686952 CHA-6 PCL reanalysis 144 25 14 9 28 5 117 2 134 32 28 4 2 165 10 717 573
E686957 CHA-6 resample PCL 177 24 13 8 25 5 104 2 118 28 25 4 2 164 11 710 533
CHA-8 Ishikawa analysis 203 22 11 11 27 4 127 1 140 34 27 4 1 120 8 739 536
E686953 CHA-8 PCL reanalysis 194 21 12 10 23 5 100 2 111 26 24 4 2 152 10 695 502 E686956 CHA-8 resample PCL 140 22 12 9 22 5 83 2 93 22 21 4 2 153 9 598 458
E686963 CHA-8 10 m from original 126 13 8 8 15 3 61 1 72 17 15 2 1 88 6 435 310
CHA-1 Ishikawa analysis 100 4 3 1 5 1 44 0 32 10 5 1 0 24 3 234 134
E686964 CHA-1 resample PCL 155 9 5 3 10 2 72 1 64 17 12 1 1 46 5 401 246
E686962 CHA-1 10 m from original 146 16 9 6 19 3 101 1 105 27 19 3 1 94 8 556 410
52
Table 14b REE concentrations leached from soil
Sample Ishikawa Comment Ce Dy Er Eu Gd Ho La Lu Nd Pr Sm Tb Tm Y Yb TREE TREE-Ce
no no ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm
CHA-4 Ishikawa analysis 31 16 10 7 21 3 100 1 107 26 19 3 1 104 7 456 425
WR4 CHA-4 MINDECO reanalysis 35 18 10 8 23 4 105 1 115 28 20 3 1 113 7 491 456
E686951 CHA-4 PCL reanalysis 33 18 10 9 23 3 96 1 113 26 21 3 1 99 7 463 430
E686958 CHA-4 resample PCL 22 11 6 5 14 2 58 1 68 16 12 2 1 70 4 292 270
CHA-6 Ishikawa analysis 8 14 8 5 17 3 57 1 74 17 14 3 1 105 5 332 324
WR6 CHA-6 MINDECO reanalysis 9 15 8 5 19 3 57 1 75 17 15 3 1 109 6 343 334
E686952 CHA-6 PCL reanalysis 10 16 9 6 20 3 57 1 79 17 16 3 1 106 6 347 337
E686957 CHA-6 resample PCL 12 17 9 6 20 3 51 1 73 16 15 3 1 110 6 342 330
CHA-8 Ishikawa analysis 11 12 8 5 12 3 20 1 35 7 9 2 1 100 6 232 221
E686953 CHA-8 PCL reanalysis 14 13 8 5 15 3 26 1 39 8 9 2 1 107 6 257 243
E686956 CHA-8 resample PCL 10 13 8 4 13 3 16 1 26 5 7 2 1 106 6 221 211
E686963 CHA-8 10 m from original 9 7 4 4 7 1 11 1 20 4 5 1 1 57 3 133 124
CHA-1 Ishikawa analysis
E686964 CHA-1 resample PCL 6 3 2 1 4 1 12 0 19 4 4 1 0 19 1 77 71
E686962 CHA-1 10 m from original 5 11 6 4 13 2 39 1 60 13 11 2 1 69 4 240 235
53
Table 14 c REE leached from soil as a % of total REE in soil
Values below 50% recovery highlighted
Note some values for CHA-6 are >100% possibly because two laboratories were involved (ALS and Nittetsu)
<50% of total REE recovered in the leach solution
Sample Ishikawa Comment Ce Dy Er Eu Gd Ho La Lu Nd Pr Sm Tb Tm Y Yb TREE TREE-Ce
no no % % % % % % % % % % % % % % % % %
CHA-4 Ishikawa analysis 25 87 92 77 95 81 80 77 85 84 84 94 69 94 80 74 86
WR4 CHA-4 MINDECO reanalysis 22 82 77 73 82 80 73 50 77 74 69 75 50 90 70 66 78
E686951 CHA-4 PCL reanalysis 22 79 78 79 89 72 66 66 77 71 74 73 70 71 69 62 73
E686958 CHA-4 resample PCL 16 64 64 67 76 59 52 53 64 59 60 61 56 67 55 51 62
Averages 21 78 78 74 85 73 68 61 75 72 72 76 61 81 69 63 75
CHA-6 Ishikawa analysis 9 99 103 85 102 108 55 110 80 72 83 120 101 114 83 70 84
WR6 CHA-6 MINDECO reanalysis 11 65 62 56 68 60 55 50 62 59 60 75 50 73 60 57 64
E686952 CHA-6 PCL reanalysis 7 63 63 65 71 57 49 55 59 54 56 59 58 64 56 48 59
E686957 CHA-6 resample PCL 7 71 72 72 79 64 49 56 62 56 59 67 61 67 59 48 62
Averages 8 74 75 69 80 72 52 68 66 60 65 80 67 80 65 56 67
CHA-8 Ishikawa analysis 5 55 70 46 45 72 16 84 25 21 33 51 74 83 75 31 41
E686953 CHA-8 PCL reanalysis 7 59 68 52 63 56 26 63 35 30 39 53 63 70 64 37 48
E686956 CHA-8 resample PCL 7 58 67 45 59 56 20 67 28 23 33 52 63 69 67 37 46
E686963 CHA-8 10 m from original 7 50 56 48 45 49 18 53 28 22 32 46 57 65 54 31 40
Averages 7 55 65 48 53 58 20 67 29 24 34 50 64 72 65 34 44
E686964 CHA-1 resample PCL 4 37 34 44 41 33 16 23 30 25 33 39 28 41 25 19 29
E686962 CHA-1 10 m from original 3 68 67 73 72 64 38 55 57 48 58 68 61 74 57 43 57
Averages 4 52 51 59 57 49 27 39 44 37 45 53 45 57 41 31 43
54
Table 14d Differences in values in Table 14c as a % difference from the averages
(differences higher than 20% highlighted ).
>20% difference from the average
Sample Ishikawa Comment Ce Dy Er Eu Gd Ho La Lu Nd Pr Sm Tb Tm Y Yb TREE TREE-
Ce
no no % % % % % % % % % % % % % % % % %
CHA-4 Ishikawa analysis 17 12 18 4 11 11 18 25 12 16 17 24 13 16 17 16 15
WR4 CHA-4 MINDECO reanalysis 5 5 -1 -1 -4 10 8
-19 2 3 -4 -1 -18 12 2 5 5
E686951 CHA-4 PCL reanalysis 2 1 1 7 4 -2 -3 7 2 -1 4 -4 14 -
12 1 -2 -3
E686958 CHA-4 resample PCL -
25 -
18 -
18 -9 -
11 -
19 -
23 -
13 -
15 -
18 -17 -
20 -9 -
16 -
19 -20 -17
CHA-6 Ishikawa analysis 9 33 38 22 28 49 6 62 22 19 29 50 50 43 29 25 25
WR6 CHA-6 MINDECO reanalysis 31
-12
-18
-20
-15
-17 6
-26 -6 -2 -7 -7 -26 -8 -7 1 -5
E686952 CHA-6 PCL reanalysis -
19 -
16 -
15 -6 -
11 -
21 -6 -
18 -
10 -
10 -13 -
26 -13 -
19 -
14 -13 -12
E686957 CHA-6 resample PCL -
21 -5 -4 3 -2 -
11 -6 -
17 -6 -7 -9 -
17 -10 -
15 -8 -14 -8
CHA-8 Ishikawa analysis -
18 -1 8 -3 -
15 24 -
20 26 -
13 -
14 -4 2 14 16 16 -8 -6
E686953 CHA-8 PCL reanalysis 6 6 4 10 18 -4 30 -6 22 27 14 5 -2 -2 -2 9 10
E686956 CHA-8 resample PCL 7 5 3 -6 11 -4 0 0 -4 -5 -3 2 -2 -4 3 9 5
E686963 CHA-8 10 m from original 6 -
11 -
14 0 -
14 -
16 -
10 -
21 -5 -9 -7 -9 -11 -
10 -
17 -10 -9
E686964 CHA-1 resample PCL 10 -
30 -
33 -
24 -
27 -
32 -
40 -
40 -
31 -
32 -28 -
28 -37 -
29 -
39 -38 -33
E686962 CHA-1 10 m from original -
10 30 33 24 27 32 40 40 31 32 28 28 37 29 39 38 33
55
Figure 13 Chondrite-normalized REE distribution of leached REE in samples E686956, E685957, and E686958.
.
10
100
1000
10000
100000
La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Y
Mt Pass Bayan Obo Mt Weld E686956
Longnan Xunwu E686957 E686958
Chondrite values of Anders and Grevesse (1989) x 1.36 (ie volatile-free CI chondrite).
4 Nature of soils
Two samples (E686956 and E866964) were screened to determine grain
sizes, were scanned by X-ray diffraction to determine clay type, and thin
sectioned to examine their mineralogy.
Figure 14 Example of a roadside-cut sample site. Sample E686958 repeats
Ishikawa sample CHA-4, both from the hollowed scrape at 1.5 m depth. This
sample contained 574 ppm TREE, of which 51% was leachable.
57
(a) Appearance The general appearance of a roadside bank initially sampled
by Ishikawa (CHA-4) and resampled by the author is shown in Figure 14. A thin
rooty grey A soil layer overlies a pale yellow-brown B soil horizon.
(b) Grain sizes. The size distributions of two screened samples are listed in
Table 15. Material coarser than 0.25 mm is shown for E686956 as Figure 15 ,
forms a large part (79% by weight) of this sample and consists of corroded-
looking grey-white feldspar with scattered flakes of golden-brown biotite.
Table 15 Grain size of two samples
Size E686 956 E686 964
mm gram % gram % +5 0.0 0 0.0 0
-5+1 20.5 14 10.2 6-1+0.5 30.4 20 26.0 14
-0.5+0.25 67.4 45 31.6 17-0.25+0.15 28.5 19 55.4 30
-0.15 4.4 3 60.8 33Total 151 100 184 100
Figure 15 Screened fraction of sample E686956 coarser than 0.25 mm. Field of
view 5 mm. Mainly composed of corroded (weathered) K’spar.
58
Figure 16. Photomicrograph of sample E686956 . Crossed polars. Field of
view=4.5 mm. Abundant fragments of K’spar and biotite in clay.
Figure 17. Same area as above figure. Plain light. Surprisingly fresh K’spar and
fresh and altered biotite in clay.
59
(c) Clay type
Two samples analyzed for clay type by X-ray diffraction (“XRD”) were
reported by J.A. McLeod (MASc, P.Eng) to contain kaolinite, along with residual
silicates from the syenite, as listed below.
Sample E686956 (re-sample of CHA-8) contains
1. Albite - significant. 2. Orthoclase - moderate. 3. Kaolinite - minor to moderate. 4. Phlogopite(?) - minor. Sample E685964 ( re-sample of CHA-1) contains: 1. Kaolinite - significant to abundant. 2. Orthoclase - minor. 3. Muscovite - minor. 4. Quartz - minor. One XRD scan is displayed as Figure 18.
5 Parent syenite A sample (E686961) of the central syenite plug (unit SY-
c of Garson and Walshaw,1969) was taken from an outcrop beside Frances
Hut (location Table 8) to determine the mineralogy and total REE content in this
rock, which appears to be the main source of the soils. Major and trace elements
are listed in Table 16, and REE are listed in Table 10. The major elements are
fairly typical of syenites, and the trace elements are unexceptional. The 3
samples in Table 16 are shown on an alkali vs silica classification plot as Figure
19.
Figure 18. Xray diffraction scan of sample E686964. Kaolinite and unaltered silicates from parent syenite
Table 16 Composition of Chambe Basin syenite plug.
W1026 and W1030 from Garson and Walshaw (1969, page 80)
E686961 W1026 W1030
unit Ag ppm <1 63.05 65.86
SiO2 % 64 Ba ppm 286 17.5 16.64
Al2O3 % 17.15 Co ppm <0.5 1.88 1.79
FeO total % 4.15 Cr ppm 10 1.76 1.2
CaO % 0.85 Cs ppm 0.14 0.82 0.73
MgO % 0.67 Cu ppm <5 6.47 5.4
Na2O % 6.62 Ga ppm 28 5.43 6.12
K2O % 6.3 Hf ppm 3
Cr2O3 % <0.01 Mo ppm <2 0.72 0.46 TiO2 % 0.94 Nb ppm 33 0.12 0.12 MnO % 0.18 Ni ppm <5 0.25 0.14 P2O5 % 0.26 Pb ppm <5 SrO % <0.01 Rb ppm 77 BaO % 0.03 Sn ppm 1 0.34 0.58 LOI % 0.8 Sr ppm 6 98.34 99.04 Total % 102 Ta ppm 2 Th ppm 1 Tl ppm <0.5 U ppm 0.3 V ppm 12 W ppm <1 Zn ppm 100 Zr ppm 93
Figure 19. Alkali v silica classification plot. Red dot=E686961, stars are W1026,
W1030 from Table 16 above. Syenite is the intrusive equivalent of trachyte.
62
Figure 20. Polished slab 40 mm long of Chambe Basin syenite E686961.
Slightly weathered (brown stain), mostly grey microperthite K’spar with thin rims
of cream albite, and interstitial black amphibole, biotite, and ilmenite.
Figure 21 . Same slab as above, stained for potassium (yellow). Mostly yellow-
stained K’spar, tracery of paler rimming albite.
63
The appearance of sample E686961 in hand specimen is shown in Figure
20 as a polished surface and stained for the abundant K’spar in Figure 21.
In thin section syenite E686961 (Figure 22, 23) consists mostly of
microperthite K’spar (~90%). Two sizes of K’spar are present; coarser anhedral
blocky equant grains reach 9 mm across, some with corroded K’spar cores
surrounded by clouds of minute (<0.05 mm) inclusions of biotite, amphibole and
ilmenite, and a finer-grained feldspar, tabular to rectangular in shape and
showing a weak common alignment. The feldspar has well-developed string
texture, slender spindle-shaped parallel lamellae, generally 0.01 to 0.04 mm
wide. Many K’spars are mantled by thin (0.1 mm) serrated albite rims (2%).
Angular anhedral bright green to olive-brown Na-Ca amphibole (4%) to 3 mm
across fills interstices between K’spar (Figure 20 to 23) and there is a little deep
green pyroxene. Red-brown to dark brown biotite (~2 %) forms anhedral
interstitial flakes to 1.2 mm across, commonly associated with amphibole.
Anhedral to subhedral, blocky ilmenite (~2 %) to 0.6 mm across shows slight
hematization. Apatite (<1 %) forms mostly blocky rounded grains to 1 mm
across, generally inclusions in K’spar. Quartz is a very minor interstitial
constituent.
Some typical analyses of minerals are listed in Table 17, made on the thin
section by an EDAX energy-dispersive X-ray unit attached to an AMRAY 1810T
scanning electron microscope.
Table 17 Energy dispersive analyses of minerals in syenite E686961
Mineral Na2O MgO Al2O3 SiO2 K2O CaO TiO2 MnO Fe2O3 Total
% % % % % % % % % %
microperthite 6 19 69 6 100
amphibole 4 11 5 50 2 8 2 1 18 99
biotite 1 11 9 42 7 2 3 1 23 99
albite 11 20 69 100
ilmenite 50 5 46 101
64
Figure 22 Photomicrograph of syenite E686961, Crossed polars, field of
view=4.5 mm.
Figure 23 Same area as above figure. Plain light. Inclusions of biotite, ilmenite.
(b) Limitations or failure to verify data
The soils analyzed for leachable REE are considered a reasonable test of the
small number of previously reported results from Chambe Basin soils.
(c) Opinion on adequacy of verification data
The amount and composition of easily-leachable REE are the principal matters
that required verification. However, obtaining a laboratory to provide the most
appropriate method for leaching proved difficult in the short time available. In the
opinion of the author better leaching methods should be found before further analyses
are done. The author initially attempted to persuade ALS Chemex to carry out exactly
the same procedure used by Nittetsu Mining R & D on the original Ishikawa samples,
a simple leach with a 2% ammonium sulphate aqueous solution described by Chi
(1988). Unfortunately, ALS declined to carry out this procedure, perhaps partly
because of pressure of work, partly due to the small number of samples involved, and
partly because they would first have to develop quality control procedures and
leachable-REE standard samples. Other commercial laboratories would likely have a
similar response and, while it may have been possible to persuade a university or
other laboratory to carry out these leaches these likely lack accreditation or even the
sort of quality assurance provided by commercial labs and required for 43-101 reports.
Because the ammonium sulphate leach noted above was not available two
different leach procedures (see Item 11 (b)) offered by ALS Chemex were chosen as
alternatives, both very weak leaches that selectively strip loosely bound ions. The
leach method ME-MS04 (ammonium acetate) gave results comparable to the
ammonium sulphate leaches at the Nittetsu and Mitsui laboratories, but method ME-
MS23 (ammonium chloride) appears to extract much lower percentages of REE
(Table 13).
Summary From the author’s brief August visit the following were verified.
1 Chambe basin is a large bowl in a subcircular syenite intrusion that contains thick
soils. The soils appear to be derived from the underlying syenite, which crops out in
many places and also occurs as residual boulders in the soils.
2 Soils consist of fragments of feldspar and ferromagnesian minerals from
breakdown of the syenite, mixed with kaolinite from weathering of the rock. Soil
66
profiles have well developed lower grey-white C layers, brown B layers, and thin
dark-grey organic A layers, although only shallow sections were seen. Analyses
suggest the soils generally have 2 to 3 times the REE values of the parent syenite.
3 Samples collected by J. Ishikawa were re-analyzed and the results of total REE
and leachable REE found to be generally consistent with the previous analyses.
4 Sample sites reported by J Ishikawa were re-located within a metre or two of the
positions he reported, four were resampled and analyzed, and 2 of them repeated also
from fresh pits dug nearby. Results from these samples are broadly consistent with
the previously reported total and leachable REE results at these locations. Eight
Ishikawa samples contained 234 to 739 ppm TREE, MINDECO (13 samples) 194-642
ppm TREE, this report (11 samples) 401-745 ppm TREE. Th and U contents of all
analyses are low, with Th from 1 to 29 ppm and U from <1 to 5 ppm.
5 Recoveries of leachable REE are quite variable, but can be substantial. Eight
Ishikawa samples gave recoveries of 31 to 74 %, MINDECO (11 samples) 0.1 to 30%,
and this report (11 samples) 1 to 62%. Recoveries of Th and U are generally <5%.
6 The distribution of REE shows similarities to the ion-adsorption clay deposits of
China (Figure 13), with a lower proportion of light REE and a higher proportion of
heavy REE, a different pattern than REE derived from carbonatites.
7 Features that suggest Chambe Basin contains REE mineralization of the ion-
adsorption type include the following. The REE occur in thick clayey soils developed
on igneous rocks in a tropical high-rainfall area. Values of total REE are fairly low
(~200 to 700 ppm) but a high proportion (to 74%) are easily leachable, suggesting
they are loosely attached to clays. The fairly flat distribution of the REE on a chondrite-
normalized plot, the anomalously low values of Ce, and low U and Th are all typical of
this type of deposit. It is concluded that the Chambe Basin soils fit the model of ionic
REE deposits known mostly from China, as first proposed by J. Ishikawa.
67
13 MINERAL PROCESSING AND METALLURGICAL TESTING
No mineral processing or metallurgical studies have been made. However, the
only feasible method of processing this type of deposit is by chemical leaching. In Item
8 it was noted that one of the attractions of the ion-adsorption REE type of deposit is
their metallurgical simplicity relative to the often-complex processing required for other
types of REE deposit. Analyses of REE leached from exploration samples, by dilute
solutions of ammonium salts for example, should be a good initial indication of their
extractability with such solutions on a commercial scale. However, these analyses are
no substitute for metallurgical tests.
14 MINERAL RESOURCE ESTIMATES
The scattered meagre data do not allow any estimate of a REE mineral
resource in the Chambe Basin.
15 MINERAL RESERVE ESTIMATES
The data are not yet available to estimate a REE mineral resource in the
Chambe Basin.
16 MINING METHODS
No consideration of mining methods has been made at the present time.
However, the potential material is surficial soil and is known to be shallow, extending
from surface down to about 15 m depth. Presumably, shallow surface mining and in
situ recovery will be considered if the project obtains encouraging results.
17 RECOVERY METHODS
At this preliminary stage of exploration no specific information on any recovery
method is appropriate, but would likely involve ion exchange of loosely-held REE by
dilute aqueous solutions.
18 PROJECT INFRASTUCTURE
No consideration has yet been given to project infrastructure. However, in Item
5 (c) the necessity of rehabilitating the existing cableway, or some other means of
68
transporting material and people to and from the basin should the project prove
encouraging was noted.
19 MARKET STUDIES AND CONTRACTS
Market studies or contracts for possible mineral products have not been made.
20 ENVIRONMENTAL STUDIES, PERMITTING AND SOCIAL OR COMMUNITY
IMPACT
No environmental studies have yet been made but Initial environmental studies
(see Item 27) are part of the current phase of exploration.
Permitting is not required for the current activities and possible future permit
requirements have already been commented on in Item 4 (g).
The present phase of exploration has a significant beneficial community impact.
It provides work and training (Anonymous (2011b) for at least 25 citizens of Malawi
including geologists, drillers, porters, samplers, and drivers, many from nearby villages
such as Nakoya. As required by the terms of the licence, labour and supplies are
obtained within Malawi to the extent possible.
21 CAPITAL AND OPERATING COSTS
No estimation of capital and operating costs has been made or is appropriate at
the present preliminary stage of exploration.
22 ECONOMIC ANALYSIS
At this early stage there is insufficient data to carry out an economic analysis
and none has been made.
23 ADJACENT PROPERTIES
Although a number of REE deposits are known in Malawi, some of which are
being evaluated economically, none are of the ion-adsorption REE type and therefore
cannot usefully be compared with the Chambe Basin.
69
24 OTHER RELEVANT DATA AND INFORMATION
To the author’s knowledge, there is no additional information or explanation
necessary to make this report understandable and not misleading.
25 INTERPRETATION AND CONCLUSIONS
Despite current interest in exploration for REE deposits, few deposits of the
ion-adsorption type are known outside China, where they are a significant source of
REE, especially of the mid and heavy REE, and they appear to have some
advantages over other types of REE deposit. Although only a small amount of
information is yet available, some soil samples of the Chambe Basin have high
percentages of leachable REE and suggest it may have potential for a REE deposit of
the ion adsorption type, as originally suggested by J. Ishikawa, JOGMEC and
MINDECO. The Chambe Basin deserves a thorough sampling to determine the size,
grade, recovery, and economic potential of leachable REE.
27 RECOMMENDATIONS
The program briefly described below to explore for a REE deposit of the ion
adsorption type was prepared by MINDECO and, as the work and the expenditures
have both been presented to and approved as commitments by the Government of
Malawi in the course of applying for the licence, the author has no opportunity to
recommend anything different. However, in the author’s opinion the MINDECO
program is well designed, systematic, and should provide the data to make an initial
evaluation of the leachable REE mineralization in the Chambe Basin. The author has
no hesitation in endorsing this program.
Field work on the exploration program, being conducted by MINDECO under
direction of H. Harada, began in August of 2011. Estimated expenditures are listed in
Table 18 and the principal activities of this program are as follows (Anonymous,
2011b).
Geology Drilling of about 160 shallow drill holes in soils on a 200 m grid (Figure 24)
using two portable drills. Holes will be logged lithologically and radiometrically, and
specific gravity of soils measured. Samples will be taken every metre or at lithological
70
boundaries. Pits and trenches will be excavated to examine the nature of the soil
profile. Surface geology will be mapped in Chambe Basin and a geological traverse
made on the bauxite of the nearby Lichenya Plateau to the east.
Analyses About 1,650 samples will be analyzed for 27 elements by ICP-MS and
leaching tests made on about 500 samples using dilute ammonium sulphate solution.
Selected samples will be examined petrographically and by X-Ray diffraction..
Environmental. Flow of streams will be monitored, their pH and electrical
conductivity measured and water samples taken. Growth of plants in leach residues
will be tested.
Table 18 Expenditures estimated by MINDECO for the first phase of
exploration in Chambe Basin.
Cost centre US $ Preliminary visits and presentations $ 98,393 Wages , including overheads $ 362,199 Personnel travel expenses $ 97,181 Equipment and supplies, transport to site $ 175,346 Laboratory analyses, tests $ 222,793 Spring Stone Ltd office costs $ 75,000 Local contractor costs $ 68,053 Accommodation, food, sample shipping, fuel $ 9,927
Total $ 1,108,892
If results in this initial exploration are encouraging then further phases of
exploration will be carried out, and will likely include closer-spaced drilling, pitting,
metallurgical tests, consideration of mining and REE recovery methods and costs,
improvement to access, evaluation of environmental issues, and market studies.
Accurate analyses of total REE appear to be readily obtained from several
laboratories, including ALS-Chemex. However, although the leachable REE analyses
by ALS Chemex method ME-MS04 appear to be compatible with analyses by Nittetsu
and Mitsui labs it is suggested the amount of soil analyzed is too small and should be
71
increased from 1 gram to at least 50 grams. If possible, a laboratory willing to carry out
the simpler ammonium sulphate leach should be found and appropriate testing of
leach performance done. No standard sample for leached REE is available and it is
recommended that a leach standard sample be made from soil on the Property,
perhaps from site CHA-4, which gave high recovery (74%) of leachable REE from a
sample with relatively high TREE (~620 ppm) and is easily accessed at the roadside.
Figure 24. The drill plan (200 m centres) by two man-portable drills proposed by
MINDECO in the first phase of exploration of the Chambe Basin in 2011
72
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'74
DATE AND SIGNATURE PAGE \
l, Peter G. Lecouteur, certify that:
(a) | am a geologist employed by Micron Geological Ltd as President. The businessaddress of Micron Geological Ltd is 4900 Skyline Drive, North Vancouver, BC, Canada,V7R 3J3, tel (604) 9804471, email [email protected].
(b) This certificate applies to the report titled "Geological Report on the ChambeBasin Area, Exclusive Prospecting Licence no EPL 0325111", dated November 25 of2011.
(c) I graduated in geology from the University of Auckland (New Zealand) with degrees ofB.Sc (1964) and M.Sc. (1967) in geology, and from the University of British Columbia witha Ph.D (1972) in geology.
I have been a Fellow (#F1378) of the Geological Association of Canada since 1969,and a Professional Engineer (#10,963) in good standing with the Association ofProfessional Engineers and Geoscientists of British Columbia since 1977.
I have been involved as a geologist since 1973 in mineral exploration for variouscommodities including base metals, precious metals, specialmetals, uranium, anddiamonds in North America, South America, Africa, Europe, Greenland, Asia andAustralasia. I have worked on rare earth properties in USA, BC, Greenland and theNorthwest Tenitories of Canada.
I have read the definition of "qualified person" set out in Nl 43-10'1 and certify that byreason of my education, current affiliation with a professional association and past relevantwork experience, I fulfill the requirements of a "qualified person" for the purposes of Nl 43-101 .
(d) I conducted a personal inspection of the property that is the subject of this report onthe 22nd and 23'd of August of 2011 for a duration of about 28 hours.
(e) | am responsible for all sections of this report.
(f) According to the test of independence in section 1.5 of Nl 43-101 , I am independentof Gold Canyon Resources Inc.
(g) | have had no prior involvement with the Property.
(h) | have read Nl 43-101, and this report has been prepared in compliance with Nl 43-101 and Form 43-101Fl (effective date June 30, 2011).
(i) As of the date of this certificate, to the best of my knowledge, information and belief,the technical report contains all scientific and technical information that is required to bedisclosed to make the technical report not misleading.
Effective date of report : November 25,2011
Signature date : November 25,2011
C. Le Couteur, PhD (UBC), P.Eng (BC)