--OUR MEETING PLACE--

BOULDER BUSTER Volume #56 Issue #4, 2021

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HELL’S CANYON GEM CLUB Serving the Valley for

P.O . BOX 365 69 YEARS

LEWISTON, IDAHO 83501

PURPOSE OF HELLS CANYON GEM CLUB, INC. The purpose of this nonprofit, social club is to promote the rock hound hobby by providing opportunities for the collection, working and displaying

of gems and minerals, as well as educational programs in the field of geology.

MEETINGS: 2nd Friday of each month Business Meeting: 6:45 pm VISITORS ARE ALWAYS WELCOME

Dues: Adult (per person) $15.00; Junior (under 18) Free with a responsible adult membership.

2021 BOARD OF DIRECTORS

President Randy Squires 208-413-1806 2nd Year Trustee Ted Havens 509-780-2871

Vice President Jerry Northrup 208-743-6944 1st Year Trustee Jerry Lindstrom 208-582-2056

Secretary Lola Collinsworth 509-254-7482 1st Year Trustee Tom Blimka --

Treasurer Mary Lou Northrup 208-743-6944 Federation Director Jerry Northrup 208-743-6944 Past President Bruce Borgelt 208-935-0806 Federation Delegate Mary Lou Northrup 208-743-6944 2nd Year Trustee Barbara Jo Burditt 208-446-4184 WSMC Representative

HELLS CANYON WEBSITE: http://www.hellscanyongemclub.com WEBMASTER: Rick Westerholm: [email protected]

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--OUR MEETING PLACE--

To get to the meeting location for the Hells Canyon Club, go south on 15th Street in Clarkston . 15th turns into Scenic Way and goes up the hill . Scenic Way turns into Appleside Rd . Continue south on Appleside Rd to where it turns and becomes Reservoir Rd . The Grange Hall is located at 2220 Reservoir Rd, at the junction of Reservoir Rd, 6th Avenue and 22nd Street . Additional parking is available in the Church parking lot across 6th Avenue.

http://www.hellscanyongemclub.com/

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mailto:[email protected]


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April meeting on the 9th-- @ the Grangehall !!!!! For membership cards call Lola 509-254-7482

American Lands Access Association, Inc. www.amlands.org Volume 13 Issue 1 January - March 2021

President’s Message Doug True [email protected] Welcome to a new year from ALAA. We are going to attempt a new direction this year, with “let’s work together”. Let’s have all clubs reach out to the BLM, Forest service, state parks, by all clubs, ALAA members or not, let’s start working with all agencies. Helping with management, or where ever they need help, let’s see what a difference we can make, many of the closures are because of staff shortages, they might be open to us helping. Let’s cut the rhetoric on the closing of Collecting areas and let’s jump in and see what kind of difference we can make. Wilderness is going to be wilderness, we have to accept that, you can still surface collect from existing roads, lets put our effort into working on areas we can make a difference. Looking forward to seeing everyone in Big Piney, Wyoming, ALAA will have a Program, a live auction, to help fund ALAA, Field Trips, Junior programs and more. Hope you all are doing well.

Memorandums of Understanding (MOU’s) What Are They?

There are many ways working together as AFMS Societies with Public Lands management can help achieve our mission of conserving public lands, for the use and enjoyment of present and future generations of Recreational Rockhounding.

Working on creating a MOU for the Hauser Geode Beds in Riverside County, CA., is one of many good examples.

A Memorandum of Understanding (MOU) is not a contract. It is a short-written statement outlining a mutually beneficial agreement. It describes the project the parties involved in intend to work on together, and what each party’s expected contribution will be.

Why did the California Federation of Mineralogical Societies with the help of ALAA decide to work on creating a MOU with the BLM? The Hauser Beds were in jeopardy of being swallowed up in a wilderness bill. Fortunately, for rockhounds the bill didn’t pass. Then there were discussions in the U.S. Senate to designate three National Monuments in the California deserts by presidential proclamation.

The geode collecting site was within one of the designated areas. The concerns to rockhounds were one too many of losing the special collecting site known for generations by rockhounds not only within the CFMS, but for rockhounds across the U.S.

Because of a good growing relationship between the federation and ALAA, with the BLM field officers, a MOU was written and signed by all parties during a California Desert Advisory Council (DAC) meeting in February 2016.

John Martin-CFMS President & Public Lands Advisory Chairman at that time along with Shirley Leeson-Director and Ambassador of ALAA, both signed the MOU on behalf of Rockhounds with the Bureau of Land Management (BLM). There are conditions the CFMS and ALAA have to meet annually to keep the MOU in force, but the compliance is extremely easy for a Rockhound.

The benefits in creating ongoing good working relationships with public lands management does have beneficial effects long term, for current and future generations of Recreational Rockhounding.

We must all do our part to comply with the Hauser Geode Bed MOU when visiting the collecting site. Adhering to the MOU is easy to do! It’s also important for you to document each field trip there, and to

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send that information to ALAA, so we can show the BLM rockhounds continue to use the site to collect. Use any one of the ALAA Field Trip information forms on the ALAA website.

H.R. 803 “Protecting America’s Wilderness and Public Lands Act” This bill has passed the House and will pass the Senate

The bill will create over 3 million acres of public land into Wilderness there by denying access to millions of American Citizens. Unless you hike in and Hike out!

Following is more information on each of the eight individual bills approved Feb 26, 2021 as part of the broader package: ---Read the Bill: HR 803 Learn More http://www.amlands.org/6652/index.html

• The Colorado Wilderness Act – protects 660,000 acres in Colorado. The Colorado Wilderness Act will protect more than 660,000 acres in 36 areas across Colorado. Unlike many of Colorado’s high-elevation landscapes that Congress has protected under previous land-protection bills, the Colorado Wilderness Act seeks to protect more of the state’s mid and low-elevation areas that often serve as critical habitats for a variety of plants and wildlife – and often serve as ideal locations for a wide-range of outdoor recreation activities. While more than two-thirds of the areas included in the bill are already being treated as wilderness areas – including Handies Peak, Dolores River Canyon and Little Bookcliffs – this legislation would provide them the permanent protection they deserve.

• The CORE Act – protects 400,000 acres in Colorado. The legislation would protect 400,000 acres to support the state’s multi-billion-dollar recreation economy. (H.R. 577)

• The Grand Canyon Protection Act – protects 1 million acres in Arizona. The legislation would permanently withdraw more than 1 million acres of federal land north and south of Grand Canyon National Park from eligibility for any future mining claims and leaves valid existing claims intact. Local stakeholders agree that uranium deposits in this part of Northern Arizona should not be mined for fear of contaminating the Grand Canyon or the seeps and springs in the region. (H.R. 1052)

• The Northwest California Wilderness, Recreation, and Working Forests Act – protects 306,500 acres in Northwest California. The legislation would expand nine existing wilderness areas in Northwest California and establish eight new ones. It would also add 480 river miles to the National Wild and Scenic River System. (H.R. 878)

• The Central Coast Heritage Protection Act – protects 287,500 acres in Central California. The legislation would create two new potential wilderness areas and two new scenic areas in the Los Padres National Forest and Carrizo Plain National Monument. It would also create a 400-mile hiking trail to connect the wilderness areas in the southern and northern portions of the Los Padres National Forest. (H.R. 973).

• The San Gabriel Mountains Foothills and Rivers Protection Act – protects 139,700 acres in Southern California. The legislation would expand the San Gabriel Mountains National Monument, establish a new National Recreation Area, and designate approximately 30,659 acres as wilderness. It would also add approximately 45.5 river miles to the National Wilde and Scenic Rivers System. (H.R. 693).

• The Rim of the Valley Corridor Preservation Act – protects 191,000 acres in Southern California. The legislation would expand the existing Santa Monica Mountains National Recreation Area by adding 191,000 acres of the Rim of the Valley Corridor. (H.R. 1075).

• The Wild Olympics Wilderness and Wild and Scenic Rivers Act – protects 131,900 acres in Washington State. The legislation would designate 126,544 acres on the Olympic Peninsula as wilderness and another 5,346 as potential wilderness. It would be the first new wilderness designation in Olympic National Forest in nearly 30 years and would add more than 460 river miles to the National Wild and Scenic Rivers Systems. (H.R. 999).


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Fieldtrip Information for May and June 2021

During the 2nd Qtr of 2021, there will be 2 multi-Federation Field trips, both to the same area:

May 19-23- Blue Forest, camp on site, dig for petrified wood. One of the five days we will try our hands at The Fish Quarry. (Fee) Camp fires at night come and have fun

June 16 Trip to collect Pet Wood north of Farson, Wyoming, this trip will be lead by the local Marbleton club.

June 21 a One Day trip to Blue Forest and on June 22 a One day trip to fish quarry (fee)

These trips will leave from parking lot In front main entrance of AFMS show

General info: 7000 ft elevation collecting area, No snakes, some cacti, mostly sagebrush and sand, always have plenty of water, food. Tools needed are shovels, pick, hand tools, a steel rod probe if you have one. Keep your fuel tank full and be safe.

For more information on these field trips contact: Doug True 406-670-0506

For more information about the AlAA----- amlands

Life is like a Camera

Just focus on what’s important

Develop from the negatives

And if things don’t turn out

--just take another shot

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“Life is like riding a bicycle. To keep your balance you must keep moving”…Albert Einstein

========================================== A Guide To The Geological Formations Around You analise.dubner Updated January 15, 2021 (continued from last month) Everywhere we go we are surrounded by the story of the Earth. We rarely think about the candy-stripped rocks or the weird outcrop in the woods that looks like a face or if the ground we walk on every day used to be the floor of an ancient sea. There are clues are all around us that hint of volcanos long gone, faults that push and pull the rocks, waterways that grind out shapes and valleys and upheavals that happened long before humans came down from the trees. Every single hill, valley, rock and lake you see has a blueprint for how it got that way. There is so much to the Earth's history written in rocks, this guide barely scrapes the surface. It only provides a basic primer... an overview to naming and understanding all the different rock formations we live in and around every day. Alluvium Alluvium is loose soil or sediment which has been eroded, reshaped by water in some form, and redeposited in a non-marine setting. Alluvium is typically made up of a variety of materials, including fine particles of silt and clay and larger particles of sand and gravel. When this loose material is deposited or cemented, it is called an alluvial deposit or alluvial fan.

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It is usually deposited in the lower part of the course of a river, forming floodplains and deltas, but may be deposited at any point where the river overflows its banks or where the velocity of a river is checked—for example, where it runs into a lake. Desert Pavement Desert pavement is a desert surface covered with closely packed, interlocking angular or rounded rock fragments of pebble and cobble size. They typically top alluvial fans. The most common formation theory suggests that the gradual removal of sand, dust and other fine-grained material by the wind and intermittent rain leaves the larger fragments behind which are shaken into place through the forces of rain, running water, wind, gravity, creep, thermal expansion and contraction, wetting and drying, frost heaving, animal traffic, and the Earth's constant microseismic vibrations. The removal of small particles by wind does not continue indefinitely, because once the pavement forms, it acts as a barrier to resist further erosion. Oxbow Lake An oxbow lake is a U-shaped body of water that forms when a wide meander from the main stem of a river is cut off, creating a free-standing body of water. This landform is so named for its distinctive curved shape, resembling the bow pin of an oxbow. This is one of the results of a type of river avulsion. Bioturbation This formation is the reworking of soils and sediments by animals or plants. Common bioturbators include annelids ("ringed worms"); bivalves like mussels, clams, gastropods, and holothurians; or any other infaunal or epifaunal organisms.


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Concretions Concretions are pseudofossils bound with mineral cement in curious shapes. When minerals in water are deposited about any type of nucleus (such as a leaf or shell or other particle) they form a rounded mass whose composition is usually different from the surrounding rock. They are often spherical in shape, although irregular shapes can occur. Laminations Lamination is a small scale sequence of fine layers of sediment in rock. Laminations are normally smaller and less pronounced than bedding layering, though weathering can enhance the differences between layers. A single sedimentary rock can have both laminae and beds, the bedding being defined as thicker than one centimeter and the laminae as being less. They are caused by changes in the supply of sediment that affect grain size, color and composition. Amygdules These are mineral-filled bubbles in petrified lava. They form when the gas bubbles or vesicles in extrusive igneous rocks are filled with another mineral like calcite, quartz or chlorite. Some amygdules are stretched, not round. These started out as spherical vesicles and were deformed while the lava was still fluid. Amygdules and vesicles are usually indicators of movement in ancient lavas. Fiamme Fiamme are lens-shaped, usually millimetres to centimetres in size, seen on surfaces of some volcaniclastic rocks. Some fiamme represent fragments of volcanic ejecta that have been flattened by compaction and/or shear.


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Vein A vein is a distinct sheetlike body of crystallized minerals within a rock. Veins form when mineral constituents carried by water within the rock mass are deposited. They are usually thought of as being the result of growth of crystals on the walls of fractures in rocks, with the crystal growth happening on the walls of the cavity, and the crystal protruding into open space. This certainly is the method for the formation of some veins. However, it is rare in geology for significant open space to remain open in large volumes of rock, especially a long distance below the surface. Thus, there are two main mechanisms considered likely for the formation of veins: open-space filling and crack-seal growth. Flute Casts Flute casts (also Scour marks) are gouges dug into soft, fine sediment which typically get filled by an overlying bed. Flute casts can be characterized into four types:Parabolic flute, Spindle-shaped, Comet-shaped & Asymmetrical. Liesegang Rings Liesegang rings are colored bands of cement found in sedimentary rocks that typically cut-across layers. They show bands of minerals that are arranged in a regular repeating pattern. Exactly how Liesegang rings form is not entirely known and is still being researched. Though they are considered common in sedimentary rocks, rings composed of iron oxide have also been found in permeable igneous and metamorphic rocks that have been chemically weathered. Boudinage The folding a nd stretching of different layers of strata creates these sausage-y forms. Boudinage can develop in two ways: planar fracturing into rectangular fragments or by tapering into elongate depressions and swells. They are typical features of sheared veins and shear zones where, due to stretching and shortening, rigid bodies break up. This causes the resulting boudin to be its characteristic sausage or barrel shape. They can also form rectangular structures. They range in size from about 20 m thick to about 1 cm.


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Desert Varnish This is the orange-yellow to black coating found on exposed, physically stable rock surfaces such as cliff faces and large boulders in arid environments. Desert varnish is usually around one micrometer thick and represents nanometre-scale layering. The varnish is primarily composed of particles of clay along with iron and manganese oxides. Mudcracks Mudcracks are sedimentary structures formed as muddy sediment dries and contracts. Crack formation also occurs in clayey soils as a result of a reduction in water content. They are generally polygonal in plan view and v-shaped in cross section. The "v" opens towards the top of the bed and the crack tapers downward. Pele's Hair Wind can stretch hot lava into blonde fibers called Pele's Hair. These volcanic glass threads or fibers are formed when small particles of molten material are thrown into the air and spun out by the wind into long hair-like strands. The diameter of the strands is less than 0.5 millimetres, and they can be as long as 2 meters. Ripples Ripple marks originally form in conditions with flowing water. There are two types of ripple marks: Symmetrical ripple marks - Often found on beaches, they are created by a two way current, for example the waves on a beach create ripple marks with pointed crests and rounded troughs, which aren't inclined more to a certain direction. Asymmetrical ripple marks - These are created by a one way current, for example in a river, or the wind in a desert. This creates ripple marks with still pointed crests and rounded troughs, but which are inclined more strongly in the direction of the current.


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Rip-Up Clasts Rip-Up Clasts are the signs of an ancient seafloor avalanche. They are usually pieces of shale or mudstone created when an erosive current containing suspended sediment flows over a shale bed, tears up pieces of it, and carries these "rip ups" some distance. Because clay can be quite cohesive, even when freshly deposited, large clasts of shale can be ripped up, transported and preserved when the current finally deposits its sediment. Slickenside A slickenside is a smoothly polished surface caused by frictional movement between rocks along the two sides of a fault. This surface is normally striated in the direction of movement. The plane may be coated by mineral fibres that grew during the fault movement, known as slickenfibres, which also show the direction of movement. Shatter Cones Shatter cones are rare geological features that are only known to form in the bedrock beneath meteorite impact craters or underground nuclear explosions.


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Phenocrysts Phenocrysts are crystals that stand out in igneous (volcanic) rocks. They are usually the first crystals to form from a cooling magma, and because they are first, they have sufficient room to grow to a large size. Normally the term phenocryst is not used unless the crystals are directly observable, which is sometimes stated as greater than .5 millimeter in diameter. They tend to be found in the lighter (higher silica) igneous rocks such as felsites and andesites. Moraine The basic definition for this formation is the formed accumulation of debris left by glacial activity. There are many types of moraines, but they are all formed by glacial activity. They may be composed of debris ranging in size from silt-sized glacial flour to large boulders that are typically sub-angular to rounded in shape. Moraines may be on the glacier’s surface or deposited as piles or sheets of debris where the glacier has melted. Moraines may also occur when glacier-or iceberg-transported rocks fall into a body of water as the ice melts. Moraine are further classified as:Lateral, Ground, Rogen, End (or Terminal), Recessional, medial, Supraglacial, Washboard, Veiki Cirque This is an amphitheatre-like valley head, formed at the top of a valley by glacial erosion. A cirque may also be a similarly shaped landform arising from fluvial erosion.


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Arête An arête is a thin, almost knife-like, ridge of rock which is typically formed when two glaciers erode parallel U-shaped valleys. The arête is a thin ridge of rock that is left separating the two valleys. Arêtes can also form when two glacial cirques erode headwards towards one another, although frequently this results in a saddle-shaped pass, called a col. The edge is then sharpened by freeze-thaw weathering, and the slope on either side of the arete steepened through mass wasting events and the erosion of exposed, unstable rock. Esker An esker is a long, winding ridge of stratified sand and gravel, examples of which occur in glaciated and formerly glaciated regions. They are frequently several miles long and, because of their peculiar uniform shape, look a little like railway embankments. Eskers form when the glacier is slow and sluggish. After the retaining ice walls melt away, stream deposits remain as long winding ridges. Eskers may exist as a single channel, or may be part of a branching system with tributary eskers. They are not often found as continuous ridges, but have gaps that separate the winding segments. They can sometimes reach hundreds of miles in length and are generally 20–30 meters high. Kame A kame is an irregularly shaped hill or mound composed of sand, gravel and till that accumulates in a depression on top of a retreating glacier. When the glacier melts, this debris is deposited on the land. Kames are often associated with kettles, and this is referred to as kame and kettle topography.


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Kettle Kettles are another result of glacial scouring. They are formed when blocks of ice calving from the front of a receding glacier become partially to wholly buried by glacial outwash. (Glacial outwash is when streams of meltwater flow away from the glacier and deposit sediment). When these ice blocks melt, kettle holes are left behind in the sediment beds. Kettle holes can also occur in ridge shaped deposits of loose rock fragments called till. Tarn A tarn (or corrie loch) is a mountain lake or pool, formed in a cirque excavated by a glacier. It is formed when either rain or river water fills the cirque. A moraine may form a natural dam below a tarn. Paternoster Lake A paternoster lake is one of a series of glacial lakes connected by a single stream or a braided stream system. Paternoster lakes occur in alpine valleys, climbing one after the other to the valley's head, called a corrie, which often contains a cirque lake. Paternoster lakes are created by end moraines, or rock dams, that are formed by the advance and subsequent upstream retreat and melting of the ice. Cinder Cone A cinder cone (or scoria cone) is a steep conical hill consisting of loose pyroclastic debris formed by explosive eruptions or lava fountains from a single, typically cylindrical, vent. As the gas-charged lava is blown violently into the air, it breaks into small fragments that solidify and fall as either cinders, clinkers, or scoria around the vent to form a cone that often is beautifully symmetrical; with slopes between 30-40°; and a nearly circular ground plan. Most cinder cones have a bowl-shaped crater at the summit.


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Diatreme A diatreme, sometimes known as a maar-diatreme volcano, is a volcanic pipe formed by a gaseous explosion. When magma rises up through a crack in the Earth's crust and makes contact with a shallow body of ground water, rapid expansion of heated water vapor and volcanic gases can cause a series of explosions. A relatively shallow crater is left (known as a maar) and a rock filled fracture (the actual diatreme) in the Earth's crust. Diatremes breach the Earth's surface and produce a steep inverted cone shape. Graben A graben is a depressed block of land bordered by parallel faults. This is usually the floor of a rift valley. Hanging Valley A hanging valley is a shallow valley carved by a small glacier in a valley already carved by a larger glacier. This creates a higher "hanging" elevation for the upper valley and often results in a waterfall. Shield Volcano A shield volcano is a type of volcano usually built almost entirely of fluid magma flows. They are named for their large size and low profile, resembling a shield lying on the ground. This is caused by the highly fluid lava they erupt, which spreads further than lava erupted from stratovolcanoes. This results in the steady accumulation of broad sheets of lava, building up the shield volcano's distinctive form.


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Stratovolcano A stratovolcano (also known as a composite volcano) is a conical volcano built up by many layers (strata) of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile and periodic explosive eruptions and effusive eruptions (like St. Helens), although some have collapsed craters called calderas. The lava flowing from stratovolcanoes typically cools and hardens before spreading far due to high viscosity. They are among the most common types of volcanoes, in contrast to the less common shield volcanoes. Maar A maar is a broad, low-relief volcanic crater that is created by an explosion caused by groundwater coming into contact with hot lava or magma. A maar characteristically fills with water to form a relatively shallow crater lake. Most maars have low rims composed of a mixture of loose fragments of volcanic rocks and rocks torn from the walls of the diatreme. Lava Dome A lava dome (or volcanic dome) is a roughly circular mound-shaped protrusion resulting from the slow extrusion of lava from a volcano. The characteristic dome shape is attributed to high viscosity that prevents the lava from flowing very far. Caldera A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption. They are sometimes confused with volcanic craters. A collapse is triggered by the emptying of the magma chamber beneath the volcano, usually as the result of a large volcanic eruption. If enough magma is ejected, the emptied chamber is unable to support the weight of the volcanic edifice above it. The collapse may occur as the result of a single cataclysmic eruption, or it may occur in stages as the result of a series of eruptions.


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Resurgent Dome Resurgent domes are formed by a swelling or rising of a caldera floor due to movement in the magma chamber beneath it. Unlike a lava dome, a resurgent dome is not formed by the extrusion of highly viscous lava onto the surface, but rather by the uplift and deformation of the surface itself by magma movement underground. In the monitoring of volcanic hazards, resurgent domes are often intensively monitored (like the one pictured to the right, in Yellowstone National Park -- which sits atop of a massive 'hot spot' under the crust), as an ongoing increase in elevation accompanied by seismic activity is certain evidence for magma rising beneath the surface. Fumarole A fumarole is an opening in the crust, often in the neighborhood of volcanoes, which emits steam and gases such as carbon dioxide, sulfur dioxide, hydrogen chloride, and hydrogen sulfide. The steam is created when superheated water turns to steam as its pressure drops when it emerges from the ground. They may occur along tiny cracks or long fissures, in chaotic clusters or fields, and on the surfaces of lava flows and thick deposits of pyroclastic flows. Fumaroles may persist for decades or centuries if they are above a persistent heat source, or disappear within weeks to months if they occur atop a fresh volcanic deposit that quickly cools. Flood Basalt Flood basalts are a type of prehistoric volcano. Some parts of the world are covered by thousands of square kilometers of thick basalt lava flows - individual flows may be more than 50 meters thick, and individual flows extend for hundreds of kilometers. One proposed explanation for flood basalts is that they were/might be caused by the combination of continental rifting and its associated decompression melting, in conjunction with a mantle plume also undergoing decompression melting, producing vast quantities of a tholeiitic basaltic magma. These have a very low viscosity, which is why they 'flood' rather than form taller volcanoes. Another explanation is that they result from the release, over a short time period, of melt that has accumulated in the mantle over a long time period. Solutional Cave Solutional caves are the most common types of cave. Usually they form in limestone (a very soluble rock), but can also form in other rocks, including chalk, dolomite, marble, salt, and gypsum. The rock dissolves under the action of rainwater and groundwater charged with carbonic acid and naturally occurring organic acids that seeps through bedding-planes, faults and joints. Lechuguilla Cave in New Mexico and Carlsbad Cavern are now believed to be examples of another type of solutional cave. They were formed by hydrogen sulfide gas rising from below, where reservoirs of oil give off


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sulfurous fumes. This gas mixes with ground water and forms sulfuric acid which dissolves the limestone from below, rather than from above. Primary Cave These are caves that formed at the same time as the surrounding rock deposits. Lava tubes (formed through volcanic activity) are the most common primary caves. As lava flows downhill, its surface cools and solidifies. Hot liquid lava continues to flow under that crust, and if most of it flows out, a hollow tube remains. Other caves formed through volcanic activity include rift caves, lava mold caves, open vertical volcanic conduits, and inflationary caves. Littoral Cave Also known as Sea caves, these types of cave are found along coasts and are formed by wave action in zones of weakness in sea cliffs. Often these weaknesses are faults, but they may also be dykes or bedding-plane contacts. Corrasional Cave Corrasional (or erosional) caves are those that form entirely via erosion by flowing streams carrying rocks and other sediments. These can form in any type of rock, including hard rocks such as granite, but in most cases there must be some zone of weakness to guide the water, such as a fault or joint. A subtype of the erosional cave is the wind or aeolian cave, carved by wind-born sediments. Fracture Cave Fracture caves are formed when layers of more soluble minerals, such as gypsum, dissolve out from between layers of less soluble rock. These rocks fracture and collapse in blocks of stone.


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Glacier Cave Glacier caves are formed by melting ice and flowing water within and under glaciers. The cavities are influenced by the very slow flow of the ice, which tends to collapse the caves again. Glacier caves are sometimes misidentified as "ice caves", though this latter term is properly reserved for bedrock caves that contain year-round ice formations. Talus Cave Talus caves are formed by the openings among large boulders that have fallen down into a random heap, often at the bases of cliffs. These unstable deposits are called "talus" or "scree", and may be subject to frequent rockfalls and landslides. Acasta Gneiss Outcrop There is much more... so much more. But I would like to close this portion of the list with a picture of the oldest known crustal fragment on the planet: the Acasta Gneiss in the Slave craton, located in Alberta, Canada. It is believed to be 3.58 to 4.031 billion years old from the Hadean Era... the first geological eon of Earth. You could potentially touch the very same rock that existed during the formation of the planet. This rock has seen it all.

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