Generalized Surficial Geologic Units - Washington...By K.A. Sinclair and D.B. Bilhimer 2007...
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By K.A. Sinclair and D.B. Bilhimer 2007 GENERALIZED SURFICIAL GEOLOGIC UNITS AND APPROXIMATE LOCAL EXTENT OF VASHON PUGET LOBE ICE 300 T.16N T.17N R.1W R.1E Tbu Qgos Qgt Qgog Tbu Qgd Qapu Qgm Qgt Qgog Qga Qa B u d d I n le t Qls μ Pu g e t S o u n d Approximate Local Extent of Vashon Puget Lobe Ice (after Walsh et al, 1987; and Walsh and Logan, 2005) 100 300 600 100 100 300 300 100 300 100 300 100 WASHINGTON Figure Location and Project Study Area Sinclair, K.A., and Bilhimer, D.B., 2007, Assessment of surface water / groundwater interactions and associated nutrient fluxes in the Deschutes River and Percival Creek watersheds, Thurston County. PLATE 1 WASHINGTON STATE DEPARTMENT OF ECOLOGY PUBLICATION NO. 07-03-002 Generalized surficial geology and local extent of Vashon ice De s chute s Riv e r Capitol Lake Offut Lake McIntosh Lake Lawrence Lake Pe r c i v a l C k 100 Generalized Surficial Geologic Units EXPLANATION 0 6 3 Miles 0 10 5 Kilometers Source data: Logan, 1987a; Logan, 1987b; Schasse, 1987; and Walsh,1987: 1:100,000 scale geologic maps of the Shelton, Chehalis river, Centralia, and Tacoma Quadrangles respectively. Walsh and Logan, 2005; 1:24,000 scale geologic map of the E. Olympia Quadrangle. Approximate thickness of unconsolidated deposits (after Jones, 1998) (Qa) Alluvium (Qls) Landslide deposits (Qgos) Vashon outwash, sand (Qgog) Vashon outwash, gravel (Qgd) Vashon drift, undifferentiated (Qgt) Vashon till (Qga) Vashon advance outwash (Qgp) Pre-Frasier drift, undifferentiated (Qapu) Pre-Frasier alpine drift, undifferentiated (Tbu) Tertiary bedrock, undifferentiated Quaternary Pleistocene Vashon drift, undifferentiated Unstratified, poorly-sorted, and often hummocky appearing deposits of clay, silt, sand, gravel, and soil, with occasional larger cohesive blocks that slumped or were otherwise disturbed through mass wasting processes. Deposits generally too localized to be a significant water source. Alluvium Gray- to-tan colored deposits of loose sand, gravel, and cobbles. This unit is a productive, generally unconfined aquifer where saturated. Localized deposits of outwash sand and gravel, lacustrine deposits, ice-contact stratified drift, and peat that are not separately mapped at this scale. Vashon recessional outwash, sand and silt Holocene Landslide deposits Period Epoch Unit symbol Geologic Unit Light-tan-to-gray or yellow-brown deposits of discontinuous till, sand, and gravel. Generally not exposed at land surface. Groundwater in this unit is confined and is used extensively for industrial and domestic supply. Sandstones, siltstones, andesites, basaltic-andesites, basalts, and other consolidated rocks and sediments that form the basal confining unit for the study area, and underlie the surrounding foothills to the south and west. This unit is generally consolidated and provides little water to wells, although secondary fractures may yield usable quantities of sometimes poor-quality water. Pre-Vashon continental drift, undifferentiated Pre-Frasier alpine drift, undifferentiated Typically yellow-gray to yellow-brown deposits of cemented sand and gravel with interspersed sand and clay lenses. Where exposed, the upper surface of this unit is often deeply weathered. Vashon recessional outwash, gravel and sand Generally well-sorted deposits of loose, tan-to-brown colored sand and silt with minor gravel interbeds. Can be a productive, generally unconfined aquifer where saturated. Lithologic and hydrologic characteristics of geologic units within the Deschutes Watershed Bedrock, undifferentiated Lithology and hydrologic characteristics Generally loose, poorly-sorted deposits of sand, well-rounded gravel, and silt deposited within stream channels and upon area flood plains by modern rivers. The coarser sand and gravel fractions of this unit can be a productive localized aquifer where saturated. Gray-to-light-brown colored deposits of compact sand, well-rounded gravel, and silt that were laid down during the Vashon glacial advance. Groundwater in this unit is generally confined and is used extensively for domestic supply in the area north of Offut Lake. Gray-to-light-tan colored deposits of generally compacted and non-sorted clay, silt, sand, gravel, and boulders that were laid down directly by glacial ice. Serves as a regional confining unit but can yield usable amounts of water to wells from thin interspersed sand and gravel lenses. Tertiary Eocene - Miocene Vashon till Vashon advance outwash Qa Qls Qgog Qga Qgos Qgt Qgd Tbu Qgp Qapu
Transcript of Generalized Surficial Geologic Units - Washington...By K.A. Sinclair and D.B. Bilhimer 2007...
ByK.A. Sinclair and D.B. Bilhimer
2007
GENERALIZED SURFICIAL GEOLOGIC UNITS AND APPROXIMATE LOCAL EXTENT OF VASHON PUGET LOBE ICE
300
T.16NT.17N
R.1W
R.1E
Tbu
QgosQgt
Qgog
Tbu
Qgd
Qapu
Qgm
Qgt
Qgog Qga
Qa
Budd
Inlet
Qls
µ
Puget Sou nd
Approximate Local Extent of Vashon Puget Lobe Ice
(after Walsh et al, 1987; and Walsh and Logan, 2005)
100
300 600100
100
300
300
100
300100
300
100
WASHINGTON
Figure Location andProject Study Area
Sinclair, K.A., and Bilhimer, D.B., 2007, Assessment of surface water / groundwater interactions and associated nutrient fluxes in the Deschutes River and Percival Creek watersheds, Thurston County.
PLATE 1WASHINGTON STATE DEPARTMENT OF ECOLOGY PUBLICATION NO. 07-03-002
Generalized surficial geology and local extent of Vashon ice
Deschutes River
CapitolLake
OffutLake
McIntoshLake
LawrenceLake
Perci
val C
k
100
Generalized Surficial Geologic UnitsEXPLANATION
0 63 Miles
0 105 Kilometers
Source data: Logan, 1987a; Logan, 1987b; Schasse, 1987; and Walsh,1987:1:100,000 scale geologic maps of the Shelton, Chehalis river, Centralia, and Tacoma Quadranglesrespectively. Walsh and Logan, 2005; 1:24,000 scale geologic map of the E. Olympia Quadrangle.
Approximate thickness of unconsolidated deposits(after Jones, 1998)
(Qa) Alluvium(Qls) Landslide deposits(Qgos) Vashon outwash, sand(Qgog) Vashon outwash, gravel(Qgd) Vashon drift, undifferentiated(Qgt) Vashon till(Qga) Vashon advance outwash(Qgp) Pre-Frasier drift, undifferentiated(Qapu) Pre-Frasier alpine drift, undifferentiated(Tbu) Tertiary bedrock, undifferentiated
Quate
rnary
Pleist
ocen
e
Vashon drift, undifferentiated
Unstratified, poorly-sorted, and often hummocky appearing deposits of clay, silt, sand, gravel, and soil, with occasional larger cohesive blocks that slumped or were otherwise disturbed through mass wasting processes. Deposits generally too localized to be a significant water source.
Alluvium
Gray- to-tan colored deposits of loose sand, gravel, and cobbles. This unit is a productive, generally unconfined aquifer where saturated.
Localized deposits of outwash sand and gravel, lacustrine deposits, ice-contact stratified drift, and peat that are not separately mapped at this scale.
Vashon recessional outwash, sand and silt
Holoc
ene
Landslide deposits
Period Epoch Unit symbolGeologic Unit
Light-tan-to-gray or yellow-brown deposits of discontinuous till, sand, and gravel. Generally not exposed at land surface. Groundwater in this unit is confined and is used extensively for industrial and domestic supply.
Sandstones, siltstones, andesites, basaltic-andesites, basalts, and other consolidated rocks and sediments that form the basal confining unit for the study area, and underlie the surrounding foothills to the south and west. This unit is generally consolidated and provides little water to wells, although secondary fractures may yield usable quantities of sometimes poor-quality water.
Pre-Vashon continental drift, undifferentiated Qgp
Pre-Frasier alpine drift, undifferentiated Qapu
Typically yellow-gray to yellow-brown deposits of cemented sand and gravel with interspersed sand and clay lenses. Where exposed, the upper surface of this unit is often deeply weathered.
Vashon recessional outwash, gravel and
sand
Generally well-sorted deposits of loose, tan-to-brown colored sand and silt with minor gravel interbeds. Can be a productive, generally unconfined aquifer where saturated.
Lithologic and hydrologic characteristics of geologic units within the Deschutes Watershed
Bedrock, undifferentiated Tbu
Lithology and hydrologic characteristics
Qls
QaGenerally loose, poorly-sorted deposits of sand, well-rounded gravel, and silt deposited within stream channels and upon area flood plains by modern rivers. The coarser sand and gravel fractions of this unit can be a productive localized aquifer where saturated.
Gray-to-light-brown colored deposits of compact sand, well-rounded gravel, and silt that were laid down during the Vashon glacial advance. Groundwater in this unit is generally confined and is used extensively for domestic supply in the area north of Offut Lake.
Gray-to-light-tan colored deposits of generally compacted and non-sorted clay, silt, sand, gravel, and boulders that were laid down directly by glacial ice. Serves as a regional confining unit but can yield usable amounts of water to wells from thin interspersed sand and gravel lenses.
Tertia
ry
Eoce
ne - M
iocen
e
Qgos
Qgog
Qgd
Vashon till Qgt
Vashon advance outwash Qga
Qa
Qls
Qgog
Qga
Qgos
Qgt
Qgd
Tbu
Qgp
Qapu
