Geologic Map of the Yacolt Quadrangle, Clark County, Washington

Metadata:

• Identification_Information
• Data_Quality_Information
• Spatial_Data_Organization_Information
• Spatial_Reference_Information
• Entity_and_Attribute_Information
• Distribution_Information
• Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator: Russell C. Evarts

Originator: Philip Dinterman (database)

Publication_Date: 2006

Title: Geologic Map of the Yacolt Quadrangle, Clark County, Washington

Geospatial_Data_Presentation_Form: vector digital data

Series_Information:

Series_Name: Scientific Investigations Map

Issue_Identification: SIM-2901

Online_Linkage: <https://pubs.usgs.gov/sim/2006/2901>

Description:

Abstract:

This digital map database, compiled from previously published and unpublished data, and new mapping by the authors, represents the general distribution of bedrock and surficial deposits of the Yacolt 7.5-minute quadrangle. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The scale of the source maps limits the spatial resolution (scale) of the database to 1:24,000 or smaller.

Purpose:

This database and accompanying plot files depict the distribution of geologic materials and structures at a regional (1:24,000) scale. The report is intended to provide geologic information for the regional study of materials properties, earthquake shaking, landslide potential, mineral hazards, seismic velocity, and earthquake faults. In addition, the report contains new information and interpretations about the regional geologic history and framework. However, the regional scale of this report does not provide sufficient detail for site development purposes.

Supplemental_Information:

DIGITAL COMPILATION-Several different feature classes were generated within a geodatabase during the construction of the Yacolt quadrangle geologic map. The topographic base map remains as a digital raster graphic (DRG) and is overlain on the geology feature class in ArcMap at a 60% transparency level. Some custom menus were used to project, transform, edit, tag, and build points in the map. A digital layout or map collar was made with Adobe Illustrator. The map was exported from the layout view in ArcMap as an Adobe Illustrator file and added to a single Adobe Illustrator file that also contained the description of map units, correlation of map units, cross sections, and an index map. Differences between the maps as they appear in the final map sheet and as they appear in the either the .mxd or .pmf files represent changes made in the Adobe Illustrator file to the symbology only and do not reflect any changes in the actual source data. The map is in UTM projection, zone 10, meters, and 1:24,000 scale. The explanatory pamphlet was saved to PDF from Microsoft Word.

BASE MAP-The base map for the digital compilation is a Digital Raster Graphic (DRG) of the U.S. Geological Survey, 1:24,000-scale topographic map of the Yacolt 7.5' quadrangle (1990), which has a 20-foot contour interval. The image inside the map neatline is georeferenced to the Universal Transverse Mercator projection, zone 10. The horizontal positional accuracy and datum of the DRG matches the accuracy and datum of the source map. The base map layer is a digital image, but no information other than location is attached to the lines. The base map is provided for reference only.

SPATIAL RESOLUTION-Uses of this digital geologic map should not violate the spatial resolution of the data. Although the digital form of the data removes the constraint imposed by the scale of a paper map, the detail and accuracy inherent in map scale are also present in the digital data. The fact that this database was edited at a scale of 1:24,000 means that higher resolution information is not present in the dataset. Plotting at scales larger than 1:24,000 will not yield greater real detail, although it may reveal fine-scale irregularities below the intended resolution of the database. Similarly, where this database is used in combination with other data of higher resolution, the resolution of the combined output will be limited by the lower resolution of these data.

Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 2006

Currentness_Reference: publication date

Status:

Progress: Complete

Maintenance_and_Update_Frequency: As needed

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -122.501118

East_Bounding_Coordinate: -122.373600

North_Bounding_Coordinate: 45.875617

South_Bounding_Coordinate: 45.749383

Keywords:

Theme:

Theme_Keyword: Geology

Theme_Keyword: Ar/Ar Geochronology

Theme_Keyword: volcanic arc

Theme_Keyword: glacial geology

Place:

Place_Keyword: Pacific Northwest

Place_Keyword: Washington

Place_Keyword: Clark County

Place_Keyword: Cascade Range

Place_Keyword: Portland Basin

Stratum:

Stratum_Keyword: Troutdale Formation

Stratum_Keyword: Tertiary Volcanic Stratigraphy

Stratum_Keyword: intrusive rocks

Stratum_Keyword: Hayden Creek Drift

Stratum_Keyword: Amboy Drift

Access_Constraints: None

Use_Constraints:

Uses of this digital geologic map should not violate the spatial resolution of the data. Although the digital form of the data removes the constraint imposed by the scale of a paper map, the detail and accuracy inherent in map scale are also present in the digital data. The fact that this database was edited for a scale of 1:24,000 means that higher resolution information is not present in the dataset. Plotting at scales larger than 1:24,000 will not yield greater real detail, although it may reveal fine-scale irregularities below the intended resolution of the database. Similarly, where this database is used in combination with other data of higher resolution, the resolution of the combined output will be limited by the lower resolution of these data.

Native_Data_Set_Environment:

Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.1.0.722

Data_Quality_Information:

Lineage:

Process_Step:

Process_Description: Metadata imported.

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Vector

Point_and_Vector_Object_Information:

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: String

Point_and_Vector_Object_Count: 416

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Map_Projection:

Map_Projection_Name: Transverse Mercator

Transverse_Mercator:

Scale_Factor_at_Central_Meridian: 0.999600

Longitude_of_Central_Meridian: -123.000000

Latitude_of_Projection_Origin: 0.000000

False_Easting: 500000.000000

False_Northing: 0.000000

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: coordinate pair

Coordinate_Representation:

Abscissa_Resolution: 0.000065

Ordinate_Resolution: 0.000065

Planar_Distance_Units: meters

Geodetic_Model:

Horizontal_Datum_Name: D_Clarke_1866

Ellipsoid_Name: Clarke 1866

Semi-major_Axis: 6378206.400000

Denominator_of_Flattening_Ratio: 294.978698

Vertical_Coordinate_System_Definition:

Altitude_System_Definition:

Altitude_Resolution: 0.000010

Altitude_Encoding_Method:

Explicit elevation coordinate included with horizontal coordinates

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: YacoltContacts

Entity_Type_Definition: Geologic Contacts

Entity_Type_Definition_Source: Author

Attribute:

Attribute_Label: OBJECTID

Attribute_Definition: Internal feature number.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain:

Sequential unique whole numbers that are automatically generated.

Attribute:

Attribute_Label: Shape

Attribute_Definition: Feature geometry.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Coordinates defining the features.

Attribute:

Attribute_Label: LTYPE

Attribute_Definition: Geologic Contact description

Attribute_Definition_Source: Author

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: contact, approx. located

Enumerated_Domain_Value_Definition:

Approximately located boundary between geologic units; positional accuracy generally within 5 mm at 1:24,000 (120 m on the ground)

Enumerated_Domain:

Enumerated_Domain_Value: contact, certain

Enumerated_Domain_Value_Definition:

Boundary between geologic units, positional accuracy generally within 2 mm at 1:24,000 (48 m on the ground)

Enumerated_Domain:

Enumerated_Domain_Value: contact, concealed

Enumerated_Domain_Value_Definition:

Boundary between geologic units that is concealed by a younger unit; positional accuracy uncertain but probably generally within 5 mm at 1:24,000 (120 m on the ground)

Enumerated_Domain:

Enumerated_Domain_Value: contact, inferred

Enumerated_Domain_Value_Definition:

Boundary of uncertain location between geologic units; positional accuracy uncertain contact exists but location inferred from indirect evidence

Enumerated_Domain:

Enumerated_Domain_Value: fault, approx. located

Enumerated_Domain_Value_Definition:

Trace of approximately located fault positional accuracy generally within 5 mm at 1:24,000 (120 m on the ground)

Enumerated_Domain:

Enumerated_Domain_Value: fault, certain

Enumerated_Domain_Value_Definition:

Trace of fault, positional accuracy generally within 2 mm at 1:24,000 (48 m on the ground)

Enumerated_Domain:

Enumerated_Domain_Value: fault, concealed

Enumerated_Domain_Value_Definition:

Trace of fault concealed by younger unit positional accuracy uncertain but probably generally within 5 mm at 1:24,000 (120 m on the ground)

Enumerated_Domain:

Enumerated_Domain_Value: map boundary

Enumerated_Domain_Value_Definition: map boundary of this 1:24000 study

Enumerated_Domain:

Enumerated_Domain_Value: normal fault, approx. located_mN

Enumerated_Domain_Value_Definition:

Trace of approximately located normal fault positional accuracy generally within 5 mm at 1:24,000 (120 m on the ground), marker symbol showing downdip direction towards north

Enumerated_Domain:

Enumerated_Domain_Value: normal fault, approx. located_mS

Enumerated_Domain_Value_Definition:

Trace of approximately located normal fault positional accuracy generally within 5 mm at 1:24,000 (120 m on the ground), marker symbol showing downdip direction towards south

Enumerated_Domain:

Enumerated_Domain_Value: normal fault, concealed

Enumerated_Domain_Value_Definition:

Trace of normal fault concealed by younger unit positional accuracy uncertain but probably generally within 5 mm at 1:24,000 (120 m on the ground)

Enumerated_Domain:

Enumerated_Domain_Value: normal fault, concealed_mN

Enumerated_Domain_Value_Definition:

Trace of normal fault concealed by younger unit positional accuracy uncertain but probably generally within 5 mm at 1:24,000 (120 m on the ground), marker symbol showing downdip direction towards north

Enumerated_Domain:

Enumerated_Domain_Value: normal fault, concealed_mS

Enumerated_Domain_Value_Definition:

Trace of normal fault concealed by younger unit positional accuracy uncertain but probably generally within 5 mm at 1:24,000 (120 m on the ground), marker symbol showing downdip direction towards south

Enumerated_Domain:

Enumerated_Domain_Value: s.s. fault, r.l., approx. located_m

Enumerated_Domain_Value_Definition:

Trace of approximately located right lateral strike-slip fault positional accuracy generally within 5 mm at 1:24,000 (120 m on the ground)

Enumerated_Domain:

Enumerated_Domain_Value: s.s. fault, r.l., concealed_m

Enumerated_Domain_Value_Definition:

Trace of right lateral strike-slip fault concealed by younger unit positional accuracy uncertain but probably generally within 5 mm at 1:24,000 (120 m on the ground) with marker

Enumerated_Domain:

Enumerated_Domain_Value: water boundary, certain

Enumerated_Domain_Value_Definition:

Outline of a body of open water; positional accuracy within 1:24,000 National Map Accuracy Standards

Attribute:

Attribute_Label: Shape_Length

Attribute_Definition: Length of feature in internal units.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Positive real numbers that are automatically generated.

Detailed_Description:

Entity_Type:

Entity_Type_Label: YacoltGeologyPolys

Entity_Type_Definition: Geologic Unit Descriptions

Entity_Type_Definition_Source: Author

Attribute:

Attribute_Label: OID

Attribute_Definition: Internal feature number.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain:

Sequential unique whole numbers that are automatically generated.

Attribute:

Attribute_Label: Shape

Attribute_Definition: Feature geometry.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Coordinates defining the features.

Attribute:

Attribute_Label: Shape_Length

Attribute_Definition: Length of feature in internal units.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Positive real numbers that are automatically generated.

Attribute:

Attribute_Label: Shape_Area

Attribute_Definition: Area of feature in internal units squared.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Positive real numbers that are automatically generated.

Attribute:

Attribute_Label: PTYPE

Attribute_Definition: Geologic Unit Abbreviation

Attribute_Definition_Source: Author

Attribute:

Attribute_Label: STYLE

Attribute_Definition: Reference Number for Color of Polygon Links to Style

Attribute_Definition_Source: Author

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: af

Enumerated_Domain_Value_Definition:

Artificial fill (Holocene) Unconsolidated soil, sand, gravel, and crushed rock used to construct road and railroad beds and small dams

Enumerated_Domain:

Enumerated_Domain_Value: Qa

Enumerated_Domain_Value_Definition:

Alluvium (Holocene and Pleistocene) Unconsolidated silt, sand, and gravel along active streams; poorly sorted to well sorted, crudely stratified to well laminated, locally cross-stratified. Includes small alluvial fan east of Crawford that may be coeval with drift of Mason Creek (Qmt)

Enumerated_Domain:

Enumerated_Domain_Value: Qt

Enumerated_Domain_Value_Definition:

Talus deposits (Holocene and Pleistocene) Unsorted accumulations of angular bedrock blocks below steep slopes in East Fork Lewis River valley. Chiefly rockfall and rock-avalanche deposits but in places includes much colluvium

Enumerated_Domain:

Enumerated_Domain_Value: Qls

Enumerated_Domain_Value_Definition:

Landslide deposits (Holocene and Pleistocene) Diamictons of angular bedrock and (or) surficial material transported down slope en masse. Chiefly deep-seated, semi-coherent slumps and internally disrupted rockslide, earthflow, and debris-flow deposits. Many mapped slides head at arcuate scars and exhibit subhorizontal tops, bulbous toes, and hummocky, poorly drained surfaces. Most slides, including large ones on Bells Mountain, generated by failure of deeply weathered, clay-rich, volcanic breccia (Tvb) beds; those north and west of Yacolt Mountain are mostly shallow-seated slides derived from till (Qat)

Enumerated_Domain:

Enumerated_Domain_Value: Qfs

Enumerated_Domain_Value_Definition:

Cataclysmic-flood deposits, sand and silt facies (Pleistocene) Unconsolidated silt and fine sand mantling paleosurfaces below about 300 ft (90 m) near southwest corner of quadrangle. Rarely exposed; distribution inferred largely from well logs, which indicate thickness of unit in map area ranges from 0 to about 15 m. Contains abundant quartz, potassium feldspar, and muscovite grains, indicating deposition by Columbia River rather than by local streams. Interpreted as slackwater deposits of colossal glacier-outburst floods initiated by repeated failure of ice dam at Glacial Lake Missoula in Idaho and Montana during the late Pleistocene (Bretz, 1925, 1959; Baker and Bunker, 1985; Waitt, 1985, 1994, 1996; Atwater, 1986; OConnor and Baker, 1992; Benito and OConnor, 2003). Hydraulically dammed floodwaters temporarily ponded in Portland Basin and deposited suspended sediment load (Trimble, 1963). Radiocarbon and tephrochronologic data from outside the map area indicate depositional ages between about 17,000 and 13,000 14C years B.P. (Waitt, 1985, 1994; Atwater, 1986; Clague and others, 2003)

Enumerated_Domain:

Enumerated_Domain_Value:

Terrace Deposits (Qtd1, Qtd2, Qtd3) Individual Units Descriptions Follow

Enumerated_Domain_Value_Definition:

Terrace deposits (Pleistocene) Fluvial gravel and sand forming sets of terraces along East Fork Lewis River; clasts consist of Tertiary volcanic and granitic rocks eroded from Cascade Range. Divided into three units based on differences in tread elevations and weathering characteristics

Enumerated_Domain:

Enumerated_Domain_Value: Qtd1

Enumerated_Domain_Value_Definition:

Terrace deposits 1 Deposits forming terraces with tread elevations about 1015 m above East Fork Lewis River; exposed along both banks of river downstream from Moulton Falls. Large surface of unit west of Lucia Falls preserves surface morphology of old river channels. About 1012 m thick, composed chiefly of weakly indurated, crudely stratified, and poorly sorted cobble and boulder gravel with subrounded blocks as large as 2 m across; locally includes beds of coarse-grained sand or grit. In several places, lowest exposed bed in unit is a diamicton, inferred to be a landslide-induced debris-flow deposit, which contains rounded and angular volcanic clasts to 25 cm across in a matrix of compact brown silt. Deposits characterized by weakly developed soils and clasts with little or no weathering rinds. Corresponds in part to terrace deposits (Qt) and older alluvium (Qoa) mapped by Howard (2002) in adjacent Battle Ground quadrangle

Enumerated_Domain:

Enumerated_Domain_Value: Qtd2

Enumerated_Domain_Value_Definition:

Terrace deposits 2 Deposits forming terrace along the south side of East Fork Lewis River upstream from Lucia Falls with tread elevations between 25 and 30 m above East Fork Lewis River. Approximately 1520 m thick; consist of poorly sorted bouldery cobble gravel with well rounded to subrounded clasts as large as 1 m across in a matrix of coarse oxidized sand. Weathering rinds on volcanic clasts 1 to 2 mm thick. Probably downstream equivalents of Amboy-age outwash (Qao) beneath Yacolt

Enumerated_Domain:

Enumerated_Domain_Value: Qtd3

Enumerated_Domain_Value_Definition:

Terrace deposits 3 Deposits forming terraces with tread elevations between 40 and 50 m above East Fork Lewis River; underlies broad area south of river at Heisson and several smaller areas upstream. Up to 30 m thick. Predominantly bouldery cobble and pebble gravel with sand matrix; well sorted to poorly sorted and clast-supported; contains well rounded to subrounded clasts as large as 2 m across. Terraces commonly capped by several meters of sand and silt with thick soil profile; weathering rinds on aphanitic andesitic clasts typically 2 to 5 mm thick. Near Heisson, upper 1 m of unit contains tephra bed mineralogically similar to tephra set C of Mount St. Helens, so must be older than 35 ka (Mullineaux, 1996) and possibly as old as 300 ka (Evarts and others, 2003). Terrace surfaces grade upstream to elevation higher than that of Amboy Drift outwash deposits (Qao) north of Moulton Falls; contiguous at west edge of quadrangle with deposits mapped as alluvial fan member of Troutdale Formation (QTta) and glacial drift (Qd) by Howard (2002)

Enumerated_Domain:

Enumerated_Domain_Value:

Glacial Deposits-Amboy Drift (Qao, Qat) Individual Descriptions Follow

Enumerated_Domain_Value_Definition:

Amboy Drift (Pleistocene) Moderately weathered till and glaciofluvial deposits (Mundorff, 1984) characterized by weathering profiles about 2 m thick and by development of weathering rinds 1 to 2 mm thick on aphanitic andesitic clasts from upper part of weathered zone; unoxidized till light brownish- to bluish-gray. Clasts composed of diverse volcanic rocks similar to Tertiary rocks of the western Cascade Range. Based on weathering characteristics, Amboy Drift is correlative with Hayden Creek Drift, which Crandell and Miller (1974) interpreted to be the product of the penultimate glaciation in the Washington Cascade Range. Age poorly known; estimates range from about 50 ka to greater than 300 ka (Crandell and Miller, 1974; Crandell, 1987; Colman and Pierce, 1981; Dethier, 1988, Grigg and Whitlock, 2002, Evarts and others, 2003; Evarts, 2004b, 2005). As mapped, may include deposits of more than one glacial advance

Enumerated_Domain:

Enumerated_Domain_Value: Qao

Enumerated_Domain_Value_Definition:

Outwash Poorly consolidated pebbly to cobbly gravel and sand that forms south-sloping valley fill of basin in which Yacolt is situated. As thick as 42 m beneath Yacolt, according to well logs. Deposits moderately weathered, crudely stratified, moderately to well sorted; commonly weakly cemented by limonite or clay. Composed mostly of well-rounded clasts of diverse volcanic rocks, some with grooved or striated surfaces, similar to those in associated till (Qat). Interpreted as glaciofluvial deposits of the Amboy Drift (Mundorff, 1984) deposited during retreat of Lewis River glacier in late Pleistocene time

Enumerated_Domain:

Enumerated_Domain_Value: Qat

Enumerated_Domain_Value_Definition:

Till Unconsolidated to compact, massive diamicton mantling much of terrain north of East Fork Lewis River to elevations as high as 1400 ft (425 m). As much as 15 m thick; in several places observed to rest on glacially smoothed and striated bedrock surface. Consists of angular to rounded clasts up to boulder size, some grooved or striated, dispersed in matrix of sand, silt, and clay; locally includes postglacial colluvium; east of Yacolt includes alluvium deposited in glacier-margin stream. Some till north and west of Yacolt Mountain is atypically clay-rich (Mundorff, 1984), and deposits mapped as Amboy Drift in that area may locally include a more deeply weathered older drift

Enumerated_Domain:

Enumerated_Domain_Value: Qmt

Enumerated_Domain_Value_Definition:

Drift of Mason Creek (Pleistocene) Deeply weathered, dark-brown, moderately compact cobbly till on east side of Yacolt Mountain between 1400 to 1670 ft (425-510 m) elevation and stratified drift(?) on hills north and east of Battle Ground Lake. Distinguished from Amboy Drift (Qat and Qao) by more pervasive weathering and thicker weathering rinds (3 mm to 12 mm thick) on aphanitic andesitic clasts; resembles drift of Mason Creek of Evarts (2004b) in Ariel quadrangle and deeply weathered till described by Crandell (1987) in Battle Ground quadrangle (Howard, 2002). Hills near Battle Ground Lake, each about 640 ft (195 m) high, may be eroded end-moraine remnants; roadside ditch about 0.7 km northeast of Crawford exposes poorly sorted, limonite-cemented gravel composed of subrounded volcanic cobbles to 25 cm across. Crandell (1987) interpreted deeply weathered till in adjacent Battle Ground quadrangle to be correlative with or older than the Wingate Hill Drift of the Mount Rainier region (Crandell and Miller, 1974), estimated by Colman and Pierce (1981) and Dethier (1988) to have occurred between 300 and 600 ka; underlies basalt of Battle Ground (Qbbg)

Enumerated_Domain:

Enumerated_Domain_Value: Qbgl

Enumerated_Domain_Value_Definition:

Basalt of Battle Ground Lake (Pleistocene) Basaltic pyroclastic deposits forming maar occupied by Battle Ground Lake. Deeply weathered and poorly exposed deposits consist of red-orange basaltic ash and scoriaceous lapilli; include abundant angular cobbles of nonvesicular olivine-phyric basalt apparently ripped from older lava flow (Qbbg), now exposed in crater wall, during phreatomagmatic eruption that formed maar; sparse exotic clasts including quartzite pebbles and blocks of Tertiary volcanic rocks also present. Age unknown but must be younger than about 100 ka (age of disrupted lava flow) and older than 20 ka (oldest radiocarbon age obtained from lake sediments by Barnosky, 1985)

Enumerated_Domain:

Enumerated_Domain_Value: Qbbg

Enumerated_Domain_Value_Definition:

Basalt of Battle Ground (Pleistocene) Two or more flows of light to medium gray, diktytaxitic, olivine-phyric basalt with highly vesicular flow tops; equivalent to basalt of Battle Ground of Howard (2002). Underlies gently sloping surfaces around base of Battle Ground Lake maar; also locally exposed in crater walls as thick as 40 m. Probably erupted from cinder cone(s) in adjacent Battle Ground quadrangle (Howard, 2002). Contains phenocrysts of olivine (1112 percent; as large as 3 mm across; enclosing abundant chromian spinel inclusions) and sparse microphenocrysts of greenish augite in an intergranular to trachytic groundmass. Whole-rock 40Ar/39Ar age of basalt flow exposed in west crater wall of Battle Ground Lake maar is 99±57 ka (table 2); age of chemically similar basalt in Battle Ground quadrangle is 108±21 ka (R.J. Fleck, written commun., 2002)

Enumerated_Domain:

Enumerated_Domain_Value: Qalf

Enumerated_Domain_Value_Definition:

Andesite of Lucia Falls Road (Pleistocene?) Light- to medium-gray, typically microvesicular, aphyric andesite. Small remnant of eroded flow crops out at elevation of about 550 to 900 ft (165 to 275 m) on north wall of East Fork Lewis River valley between Lucia Falls and Moulton Falls. Trachytic, flow-banded; composed of plagioclase, augite, hypersthene, and Fe-Ti oxide. Young age inferred from lack of vesicle fillings

Enumerated_Domain:

Enumerated_Domain_Value: Ttf

Enumerated_Domain_Value_Definition:

Troutdale Formation (Pliocene and (or) Miocene) Semi-consolidated, massive to crudely stratified, pebbly and cobbly conglomerate with sparse lenses of friable sandstone; moderately to well sorted and clast supported, with sandstone matrix. Underlies broad, southwest-sloping surfaces between about 500 and 650 ft (150 to 200 m) elevation in southwestern part of quadrangle, part of the Troutdale bench of Mundorff (1964). Clasts well rounded; clast population dominated by cobbles of basalt from the Columbia River Basalt Group but typically includes light-colored granitic and quartzofeldspathic metamorphic rocks and distinctive, white to light-gray, iron-oxide stained quartzite; clasts of volcanic rocks eroded from Cascade Range are scarce. Sandstone interbeds and matrix of conglomerate range from basaltic grit to micaceous arkose compositionally similar to sandy beds of underlying Sandy River Mudstone (Tsr). These rock types indicate dominant source areas east of the Cascade Range and deposition by the ancestral Columbia River. Sedimentary structures observed west of map area are consistent with deposition during floods in a gravel-dominated braided river system. In most places, upper several meters weathered to reddish-brown clayey soil, and presence of scattered quartzite pebbles in soil is only indicator of conglomeratic parent material. Water-well logs indicate unit is generally less than 30 m thick in quadrangle. Basal contact with Sandy River Mudstone is low-relief disconformity. Equivalent to upper member of Troutdale Formation of Mundorff (1964) and to quartzite-clast member of Troutdale Formation of Howard (2002). Pliocene and (or) Late Miocene age inferred from stratigraphic relations outside of this quadrangle (Tolan and Beeson, 1984)

Enumerated_Domain:

Enumerated_Domain_Value: Tsr

Enumerated_Domain_Value_Definition:

Sandy River Mudstone (Miocene) Semiconsolidated, well-bedded sandstone, siltstone, claystone, and minor quartzite-bearing pebble conglomerate, pumice-lapilli tuff, and lignite. Poorly exposed beneath Troutdale Formation (Ttf) in creek valleys east of Gravel Point. Water-well logs indicate unit is at least 140 m thick southeast of Crawford. Sandy and silty beds are bluish gray in fresh exposures, weather to light brown; commonly limonite-cemented. Sandstones range from lithic to arkosic, contain subangular grains of quartz, feldspar, various rock fragments, muscovite and minor biotite, tourmaline, magnetite, hornblende. Thin claystone beds varicolored, commonly carbonaceous, tuffaceous in part. Better outcrops west of quadrangle reveal sedimentary structures that indicate a fluvial depositional environment (Howard, 2002; Evarts, 2004c). Equivalent to lower member of Troutdale Formation of Mundorff (1964) and to fine-grained member of Troutdale Formation of Howard (2002). Age poorly constrained. Plant fossils from near top of unit at localities outside of quadrangle assigned Pliocene or Late Miocene ages (Trimble, 1963; Mundorff, 1964; Tolan and Beeson, 1984)

Enumerated_Domain:

Enumerated_Domain_Value: Tqdy

Enumerated_Domain_Value_Definition:

Quartz diorite of Yacolt Mountain (Miocene) Light- to medium-gray, fine- to medium-grained, pyroxene quartz diorite underlying Yacolt Mountain. Seriate to hypidiomorphic granular; composed of plagioclase, (65 percent; as long as 4 mm), augite (6 percent; 1 to 3 mm across; locally replaced by brown hornblende), hypersthene (11 percent; 1 to 2 mm across), olivine (<1 percent; about 1 mm across; totally altered to smectite; surrounded by fine-grained granular orthopyroxene + magnetite), Fe-Ti oxide (2 percent; <0.5 mm across), complexly intergrown quartz and potassium feldspar (about 12 percent), and minor fine-grained hornblende, biotite, apatite, and interstitial clay. Miarolitic cavities filled with quartz and stilbite. Local slight to moderate deuteric alteration to stilbite, calcite, and clay minerals. As mapped, includes dark porphyritic rock containing abundant interstitial devitrified glass and clay that crops out in creek valley southeast of Yacolt Mountain; this rock is chemically similar to the diorite on Yacolt Mountain (table 1, nos. 81 and 82; fig. 2) and is interpreted as a chilled border phase of the intrusion; plagioclase from this rock gave an 40Ar/39Ar age of 21.5±0.1 Ma (table 2)

Enumerated_Domain:

Enumerated_Domain_Value: Tbem

Enumerated_Domain_Value_Definition:

Basaltic andesite of Elkhorn Mountain (Oligocene) Tholeiitic basaltic andesite and basalt flows and flow breccia that constitute most of bedrock in south part of map area. Flows are dark-gray to brown, porphyritic to seriate to aphyric, locally columnar-jointed, commonly weathered into spheroidal blocks 1-3 m across. About 300 m thick in southeast part of map area; top not exposed; basal contact unconformable. Interbedded with thick breccias and other volcaniclastic rocks on Bells Mountain and along East Fork Lewis River, but to the south sedimentary interbeds are too thin or too poorly exposed to map. Individual flows typically about 5-8 m thick, range up to 75 m thick. Typical porphyritic flows contain phenocrysts and glomerocrysts of weakly zoned plagioclase (055 percent; 1 to 6 mm, locally more than 10 mm long; variably replaced by zeolites and (or) clay) and olivine (generally <1 percent; locally as much as 5 percent; 0.5 to 3 mm across; commonly partly resorbed and surrounded by rinds of granular pyroxene and (or) magnetite; rarely contain minute chromian spinel inclusions; invariably replaced by some combination of smectite, hematite, carbonate, serpentine, quartz and kaolinite). Some flows also contain phenocrysts of augite (<3 percent; 0.5 to 1 mm, rarely as much as 5 mm across) and microphenocrysts of Fe-Ti oxide; a few contain phenocrysts of hypersthene, (<1 percent; 0.5 to 2 mm long) as well. Groundmass consists of plagioclase, augite, Fe-Ti oxide, and minor to abundant interstitial glass (generally devitrified or replaced by smectite, quartz, or calcite); groundmass textures chiefly intergranular to trachytic, less commonly subophitic, intersertal, or microphyric. Many flows in unit abundantly plagioclase-phyric, reflected in Al2O3 contents greater then 19 wt percent, and have probably accumulated excess feldspar. All flows in unit are tholeiitic, and many are exceptionally Fe-rich (FeO* as high as 12.8 wt percent) and poor in Sr (mostly <320 ppm but higher in plagioclase-accumulative lavas) compared to mafic rocks elsewhere in southern Washington Cascade range (Evarts, 2001, 2002, 2004a, b, 2005, R.C. Evarts, unpub. data). Whole-rock 40Ar/39Ar age of 27.1±0.1 Ma (table 2) obtained for sample from summit of Bells Mountain

Enumerated_Domain:

Enumerated_Domain_Value: Td

Enumerated_Domain_Value_Definition:

Dacite (Oligocene) Flow of medium- to dark-gray, porphyritic to glomerophyric, mafic dacite exposed on ridge south of Basket Creek. Contains phenocrysts of plagioclase (1213 percent; 1 to 2 mm long), augite (11.5 percent; 0.5 to 1 mm across), hypersthene (11.5 percent; 0.5 to 1 mm long), and Fe-Ti oxide (0.51.0 percent; <0.5 mm across) in a pilotaxitic groundmass. 40Ar/39Ar age of 26.4±0.1 Ma (table 2) obtained for plagioclase from sample collected on Spring Hill Road

Enumerated_Domain:

Enumerated_Domain_Value: Tvs

Enumerated_Domain_Value_Definition:

Volcaniclastic sedimentary rocks (Oligocene) Diverse assemblage of continental volcaniclastic rocks inferred to be mostly of epiclastic origin. Consists of thin- to thick-bedded, well to poorly sorted siltstone, sandstone, grit, conglomerate, and clast-supported breccia, all composed of volcanic debris. Locally includes thin lignite beds, diamictites of probable lahar origin and rare pumiceous pyroclastic rocks. Beds dark green and brown where fresh, weather light brown to olive green, greenish gray, tan, or white; locally developed paleosols typically maroon. Texturally and compositionally immature; most abundant clasts are volcanic rocks petrographically similar to interbedded lava flows and tuffs; other components include plagioclase, Fe-Ti oxide, and pyroxene crystals, pumice, vitric ash, and fine-grained plutonic rocks. Plant remains, including reed and leaf impressions, locally abundant. Interpreted as debris eroded from older and contemporaneous volcanoes and deposited in fluvial and lacustrine settings in low-lying medial to distal intervolcano environments. Moderate to pervasive alteration to assemblages of clay minerals, zeolites (chiefly heulandite-clinoptilolite), quartz, calcite; weathering generally much more intense than in associated lava flows. Volcaniclastic strata exceptionally well exposed in bed of East Fork Lewis River near the bridge north of Heisson; section includes diamicton with logs as large as 1 m in diameter and 4 to 8 m long

Enumerated_Domain:

Enumerated_Domain_Value: Tvb

Enumerated_Domain_Value_Definition:

Volcanic breccia (Oligocene) Thick bedded to massive tuff-breccia and lithic lapilli tuff interfingered with basaltic andesite flows (Tbem) on Bells Mountain; as thick as 200 m. Light brown to olive, poorly sorted to unsorted, polylithologic to (rarely) monolithologic, matrix-supported; interpreted as debris-flow deposits. Composed of mostly angular to subangular clasts of mafic rocks similar to interbedded flows; clasts commonly as large as 1 m across, some as large as 8 m or more. Generally more altered and (or) weathered than interbedded lava flows

Enumerated_Domain:

Enumerated_Domain_Value: Tba

Enumerated_Domain_Value_Definition:

Basaltic andesite (Oligocene) Flows and flow breccia of dark, vesicular, plagioclase-phyric, basaltic andesite interbedded with volcaniclastic rocks along East Fork Lewis River between Moulton Falls and Lucia Falls; stratigraphically below unconformity at base of basaltic andesite of Elkhorn Mountain (Tbem). Flow breccia abundant, typically zeolitic. Sample from massive interior of coarsely porphyritic flow gave whole-rock 40Ar/39Ar age of 31.9±1.2 Ma (table 2)

Enumerated_Domain:

Enumerated_Domain_Value: Ta

Enumerated_Domain_Value_Definition:

Andesite (Oligocene) Andesite flows exposed in isolated outcrops near north edge of map area. Porphyritic flow in eastern outcrop contains phenocrysts of plagioclase (about 15 percent; 1 to 2 mm long) and microphenocrysts of augite, hypersthene, olivine, and Fe-Ti oxide (< 2 percent each) in a pilotaxitic groundmass; sparsely phyric flow to west contains plagioclase phenocrysts (12 percent; 0.51 mm long) and augite and Fe-Ti oxide microphenocrysts (<1 percent each) in a felty groundmass. Variably altered to quartz, clay minerals and Fe-oxides. Age probably about 32 Ma

Enumerated_Domain:

Enumerated_Domain_Value: Tvso

Enumerated_Domain_Value_Definition:

Older volcaniclastic rocks (Oligocene) Volcaniclastic strata exposed in East Fork Lewis River between Lucia Falls and Moulton Falls, below unconformity at base of basaltic andesite of Elkhorn Mountain (Tbem). Similar to volcaniclastic strata elsewhere but locally capped by well developed red paleosol; interbedded with 31.9±1.2-Ma basaltic andesite flow (Tba)

Enumerated_Domain:

Enumerated_Domain_Value: water

Enumerated_Domain_Value_Definition: water body

Attribute:

Attribute_Label: Subscript

Attribute_Definition: Subscript for Geologc Unit Label

Attribute_Definition_Source: Author

Detailed_Description:

Entity_Type:

Entity_Type_Label: Anno_2_6

Detailed_Description:

Entity_Type:

Entity_Type_Label: YacoltGeologyPolysAnno

Attribute:

Attribute_Label: OBJECTID

Attribute_Definition: Internal feature number.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain:

Sequential unique whole numbers that are automatically generated.

Attribute:

Attribute_Label: SHAPE

Attribute_Definition: Feature geometry.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Coordinates defining the features.

Attribute:

Attribute_Label: FeatureID

Attribute:

Attribute_Label: ZOrder

Attribute:

Attribute_Label: AnnotationClassID

Attribute:

Attribute_Label: Element

Attribute:

Attribute_Label: SHAPE_Length

Attribute_Definition: Length of feature in internal units.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Positive real numbers that are automatically generated.

Attribute:

Attribute_Label: SHAPE_Area

Attribute_Definition: Area of feature in internal units squared.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Positive real numbers that are automatically generated.

Detailed_Description:

Entity_Type:

Entity_Type_Label: Anno_2_6

Detailed_Description:

Entity_Type:

Entity_Type_Label: YacoltCrossSectionLines

Entity_Type_Definition: Location of Cross Section Lines

Entity_Type_Definition_Source: Author

Attribute:

Attribute_Label: OBJECTID

Attribute_Definition: Internal feature number.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain:

Sequential unique whole numbers that are automatically generated.

Attribute:

Attribute_Label: SHAPE

Attribute_Definition: Feature geometry.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Coordinates defining the features.

Attribute:

Attribute_Label: SHAPE_Length

Attribute_Definition: Length of feature in internal units.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Positive real numbers that are automatically generated.

Attribute:

Attribute_Label: LTYPE

Attribute_Definition: Cross Section Lines

Attribute_Definition_Source: Author

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: cross section

Enumerated_Domain_Value_Definition: Location of author's cross section

Attribute:

Attribute_Label: SectionLine

Attribute_Definition: Cross Section Label

Attribute_Definition_Source: Author

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: A

Enumerated_Domain_Value_Definition: Cross Section Line A-A'

Enumerated_Domain:

Enumerated_Domain_Value: B

Enumerated_Domain_Value_Definition: Cross Section Line B-B'

Detailed_Description:

Entity_Type:

Entity_Type_Label: YacoltStrucPoints

Entity_Type_Definition: Geologic Bedding Measurements

Entity_Type_Definition_Source: Author

Attribute:

Attribute_Label: OBJECTID

Attribute_Definition: Internal feature number.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain:

Sequential unique whole numbers that are automatically generated.

Attribute:

Attribute_Label: SHAPE

Attribute_Definition: Feature geometry.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Coordinates defining the features.

Attribute:

Attribute_Label: PTTYPE

Attribute_Definition: Geologic Bedding Description

Attribute_Definition_Source: Author

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: bedding

Enumerated_Domain_Value_Definition: Strike and dip of beds

Enumerated_Domain:

Enumerated_Domain_Value: horizontal bedding

Enumerated_Domain_Value_Definition: Strike of horizontal beds

Enumerated_Domain:

Enumerated_Domain_Value: platy parting

Enumerated_Domain_Value_Definition: Strike and dip of platy parting in lava flows

Attribute:

Attribute_Label: STRIKE

Attribute_Definition: Strike of beds

Attribute:

Attribute_Label: DIP

Attribute_Definition: Dip of beds

Detailed_Description:

Entity_Type:

Entity_Type_Label: Anno_3_4

Detailed_Description:

Entity_Type:

Entity_Type_Label: YacoltStrucPointsAnno

Attribute:

Attribute_Label: OBJECTID

Attribute_Definition: Internal feature number.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain:

Sequential unique whole numbers that are automatically generated.

Attribute:

Attribute_Label: SHAPE

Attribute_Definition: Feature geometry.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Coordinates defining the features.

Attribute:

Attribute_Label: FeatureID

Attribute:

Attribute_Label: ZOrder

Attribute:

Attribute_Label: AnnotationClassID

Attribute:

Attribute_Label: Element

Attribute:

Attribute_Label: SHAPE_Length

Attribute_Definition: Length of feature in internal units.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Positive real numbers that are automatically generated.

Attribute:

Attribute_Label: SHAPE_Area

Attribute_Definition: Area of feature in internal units squared.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Positive real numbers that are automatically generated.

Detailed_Description:

Entity_Type:

Entity_Type_Label: Anno_3_4

Detailed_Description:

Entity_Type:

Entity_Type_Label: YacoltGeochron

Entity_Type_Definition: Geochronologic Sample Locations

Entity_Type_Definition_Source: Author

Attribute:

Attribute_Label: OBJECTID

Attribute_Definition: Internal feature number.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain:

Sequential unique whole numbers that are automatically generated.

Attribute:

Attribute_Label: SHAPE

Attribute_Definition: Feature geometry.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Coordinates defining the features.

Attribute:

Attribute_Label: PTTYPE

Attribute_Definition: Geochronology Point

Attribute:

Attribute_Label: AGE

Attribute_Definition: Ar/Ar Date

Attribute_Definition_Source: Author

Detailed_Description:

Entity_Type:

Entity_Type_Label: Anno_46_48

Detailed_Description:

Entity_Type:

Entity_Type_Label: YacoltGeochronAnno

Attribute:

Attribute_Label: OBJECTID

Attribute_Definition: Internal feature number.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain:

Sequential unique whole numbers that are automatically generated.

Attribute:

Attribute_Label: SHAPE

Attribute_Definition: Feature geometry.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Coordinates defining the features.

Attribute:

Attribute_Label: FeatureID

Attribute:

Attribute_Label: ZOrder

Attribute:

Attribute_Label: AnnotationClassID

Attribute:

Attribute_Label: Element

Attribute:

Attribute_Label: SymbolID

Attribute:

Attribute_Label: Status

Attribute:

Attribute_Label: TextString

Attribute:

Attribute_Label: FontName

Attribute:

Attribute_Label: FontSize

Attribute:

Attribute_Label: Bold

Attribute:

Attribute_Label: Italic

Attribute:

Attribute_Label: Underline

Attribute:

Attribute_Label: VerticalAlignment

Attribute:

Attribute_Label: HorizontalAlignment

Attribute:

Attribute_Label: XOffset

Attribute:

Attribute_Label: YOffset

Attribute:

Attribute_Label: Angle

Attribute:

Attribute_Label: FontLeading

Attribute:

Attribute_Label: WordSpacing

Attribute:

Attribute_Label: CharacterWidth

Attribute:

Attribute_Label: CharacterSpacing

Attribute:

Attribute_Label: FlipAngle

Attribute:

Attribute_Label: Override

Attribute:

Attribute_Label: SHAPE_Length

Attribute_Definition: Length of feature in internal units.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Positive real numbers that are automatically generated.

Attribute:

Attribute_Label: SHAPE_Area

Attribute_Definition: Area of feature in internal units squared.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Positive real numbers that are automatically generated.

Detailed_Description:

Entity_Type:

Entity_Type_Label: Anno_46_48

Detailed_Description:

Entity_Type:

Entity_Type_Label: YacoltMapChemPts

Entity_Type_Definition: Chemical Data for points on map

Entity_Type_Definition_Source: Author

Attribute:

Attribute_Label: OBJECTID

Attribute_Definition: Internal feature number.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain:

Sequential unique whole numbers that are automatically generated.

Attribute:

Attribute_Label: Shape

Attribute_Definition: Feature geometry.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Coordinates defining the features.

Attribute:

Attribute_Label: MAP_NO

Attribute_Definition: Number designation on map

Attribute:

Attribute_Label: SAMPNO

Attribute_Definition: Sample number used in field collection

Attribute_Definition_Source: Author

Attribute:

Attribute_Label: PLOT

Attribute_Definition: Designation if point will be plotted

Attribute:

Attribute_Label: MAP_UNIT

Attribute_Definition: Geologic unit sample is located within

Attribute:

Attribute_Label: ROCK_TYPE

Attribute_Definition: Physical type of rock from which sample was taken

Attribute:

Attribute_Label: SIO2

Attribute_Definition: Silicon concentration expressed as weight percent oxide

Attribute:

Attribute_Label: TIO2

Attribute_Definition: Titanium concentration expressed as weight percent oxide

Attribute:

Attribute_Label: AL2O3

Attribute_Definition: Aluminum concentration expressed as weight percent oxide

Attribute:

Attribute_Label: FEO

Attribute_Definition: Ferrous iron concentration expressed as weight percent oxide

Attribute:

Attribute_Label: MNO

Attribute_Definition: Manganese concentration expressed as weight percent oxide

Attribute:

Attribute_Label: MGO

Attribute_Definition: Magnesium concentration expressed as weight percent oxide

Attribute:

Attribute_Label: CAO

Attribute_Definition: Calcium concentration expressed as weight percent oxide

Attribute:

Attribute_Label: NA2O

Attribute_Definition: Sodium concentration expressed as weight percent oxide

Attribute:

Attribute_Label: K2O

Attribute_Definition: Potassium concentration expressed as weight percent oxide

Attribute:

Attribute_Label: P2O5

Attribute_Definition: Phosphorous concentration expressed as weight percent oxide

Attribute:

Attribute_Label: TOTAL

Attribute_Definition: Total of weight percent oxides

Attribute:

Attribute_Label: SIO2_N

Attribute_Definition:

Silicon expressed as weight percent oxide from analysis recalculated volatile-free

Attribute:

Attribute_Label: TIO2_N

Attribute_Definition:

Titanium expressed as weight percent oxide from analysis recalculated volatile-free

Attribute:

Attribute_Label: AL2O3_N

Attribute_Definition:

Aluminum expressed as weight percent oxide from analysis recalculated volatile-free

Attribute:

Attribute_Label: FEO__N

Attribute_Definition:

Ferrous Iron expressed as weight percent oxide from analysis recalculated volatile-free

Attribute:

Attribute_Label: MNO_N

Attribute_Definition:

Manganese expressed as weight percent oxide from analysis recalculated volatile-free

Attribute:

Attribute_Label: MGO_N

Attribute_Definition:

Magnesium expressed as weight percent oxide from analysis recalculated volatile-free

Attribute:

Attribute_Label: CAO_N

Attribute_Definition:

Calcium expressed as weight percent oxide from analysis recalculated volatile-free

Attribute:

Attribute_Label: NA2O_N

Attribute_Definition:

Sodium expressed as weight percent oxide from analysis recalculated volatile-free

Attribute:

Attribute_Label: K2O_N

Attribute_Definition:

Potassium expressed as weight percent oxide from analysis recalculated volatile-free

Attribute:

Attribute_Label: P2O5_N

Attribute_Definition:

Phosphorous expressed as weight percent oxide from analysis recalculated volatile-free

Attribute:

Attribute_Label: MG_

Attribute_Definition: Atomic ratio 100Mg/(Mg+Fe2+) with Fe2+ set to 0.85x Fetotal

Attribute:

Attribute_Label: PLAGIOCLASE

Attribute_Definition: Modal percent plagioclase phenocrysts

Attribute:

Attribute_Label: CLINOPYROX

Attribute_Definition: Modal percent clinopyroxene phenocrysts

Attribute:

Attribute_Label: ORTHOPYROX

Attribute_Definition: Modal percent orthopyroxene phenocrysts

Attribute:

Attribute_Label: OLIVINE

Attribute_Definition: Modal percent olivine phenocrysts

Attribute:

Attribute_Label: FE_TI_OXIDE

Attribute_Definition: Modal percent iron-oxide phenocrysts

Attribute:

Attribute_Label: HORNBLENDE

Attribute_Definition: Modal percent hornblende phenocrysts

Attribute:

Attribute_Label: BIOTITE

Attribute_Definition: Modal percent biotite phenocrysts

Attribute:

Attribute_Label: QUARTZ

Attribute_Definition: Modal percent quartz phenocrysts

Attribute:

Attribute_Label: K_FELDSPAR

Attribute_Definition: Modal percent K-feldspar phenocrysts

Attribute:

Attribute_Label: OTHER

Attribute_Definition: Modal percent other phenocrysts

Attribute:

Attribute_Label: GROUNDMASS

Attribute_Definition: Modal percent of groundmass

Attribute:

Attribute_Label: NO__POINTS

Attribute_Definition: Number of points counted for modes

Attribute:

Attribute_Label: TEXTURE

Attribute_Definition: Rock and groundmass texture

Attribute:

Attribute_Label: BA

Attribute_Definition: Barium concentration in parts per million

Attribute:

Attribute_Label: RB

Attribute_Definition: Rubidium concentration in parts per million

Attribute:

Attribute_Label: SR

Attribute_Definition: Strontium concentration in parts per million

Attribute:

Attribute_Label: Y

Attribute_Definition: Yttrium concentration in parts per million

Attribute:

Attribute_Label: ZR

Attribute_Definition: Zirconium concentration in parts per million

Attribute:

Attribute_Label: NB

Attribute_Definition: Niobium concentration in parts per million

Attribute:

Attribute_Label: NI

Attribute_Definition: Nickel concentration in parts per million

Attribute:

Attribute_Label: CU

Attribute_Definition: Copper concentration in parts per million

Attribute:

Attribute_Label: ZN

Attribute_Definition: Zinc concentration in parts per million

Attribute:

Attribute_Label: CR

Attribute_Definition: Chromium concentration in parts per million

Attribute:

Attribute_Label: NOTES

Attribute_Definition: Specific notes about samples

Attribute:

Attribute_Label: LONGITUDE

Attribute_Definition: Measurement of longitude

Attribute:

Attribute_Label: LATITUDE

Attribute_Definition: Measurement of latitude

Detailed_Description:

Entity_Type:

Entity_Type_Label: Anno_60_61

Detailed_Description:

Entity_Type:

Entity_Type_Label: YacoltMapChemPtsAnno

Attribute:

Attribute_Label: OBJECTID

Attribute_Definition: Internal feature number.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain:

Sequential unique whole numbers that are automatically generated.

Attribute:

Attribute_Label: SHAPE

Attribute_Definition: Feature geometry.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Coordinates defining the features.

Attribute:

Attribute_Label: FeatureID

Attribute:

Attribute_Label: ZOrder

Attribute:

Attribute_Label: AnnotationClassID

Attribute:

Attribute_Label: Element

Attribute:

Attribute_Label: SymbolID

Attribute:

Attribute_Label: Status

Attribute:

Attribute_Label: TextString

Attribute:

Attribute_Label: FontName

Attribute:

Attribute_Label: FontSize

Attribute:

Attribute_Label: Bold

Attribute:

Attribute_Label: Italic

Attribute:

Attribute_Label: Underline

Attribute:

Attribute_Label: VerticalAlignment

Attribute:

Attribute_Label: HorizontalAlignment

Attribute:

Attribute_Label: XOffset

Attribute:

Attribute_Label: YOffset

Attribute:

Attribute_Label: Angle

Attribute:

Attribute_Label: FontLeading

Attribute:

Attribute_Label: WordSpacing

Attribute:

Attribute_Label: CharacterWidth

Attribute:

Attribute_Label: CharacterSpacing

Attribute:

Attribute_Label: FlipAngle

Attribute:

Attribute_Label: Override

Attribute:

Attribute_Label: SHAPE_Length

Attribute_Definition: Length of feature in internal units.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Positive real numbers that are automatically generated.

Attribute:

Attribute_Label: SHAPE_Area

Attribute_Definition: Area of feature in internal units squared.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Positive real numbers that are automatically generated.

Detailed_Description:

Entity_Type:

Entity_Type_Label: Anno_60_61

Detailed_Description:

Entity_Type:

Entity_Type_Label: YacoltGeologicUnit

Entity_Type_Definition: Map Unit Descriptions

Entity_Type_Definition_Source: Author

Attribute:

Attribute_Label: OBJECTID

Attribute_Definition: Internal feature number.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain:

Sequential unique whole numbers that are automatically generated.

Attribute:

Attribute_Label: Unit

Attribute_Definition: Unit Abbreviation on Map

Attribute:

Attribute_Label: Age

Attribute_Definition: Geologic Age

Attribute:

Attribute_Label: Unit_Name

Attribute_Definition: Name of formation or unit

Attribute:

Attribute_Label: Unit_Type1

Attribute_Definition: First Order Unit Heading

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: Surficial Deposits

Enumerated_Domain:

Enumerated_Domain_Value: Basin-Fill Deposits

Enumerated_Domain:

Enumerated_Domain_Value: Bedrock

Attribute:

Attribute_Label: Unit_Type2

Attribute_Definition: Second Order Unit Heading

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: Alluvial and mass wastage deposits

Enumerated_Domain:

Enumerated_Domain_Value: Glacial deposits

Enumerated_Domain:

Enumerated_Domain_Value: Volcanic rocks

Enumerated_Domain:

Enumerated_Domain_Value: Intrusive rocks

Enumerated_Domain:

Enumerated_Domain_Value: Volcanic and sedimentary rocks

Attribute:

Attribute_Label: Unit_Type3

Attribute_Definition: Third Order Unit Heading

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: Terrace Deposits

Enumerated_Domain:

Enumerated_Domain_Value: Amboy Drift

Attribute:

Attribute_Label: Unit_Description

Attribute_Definition: Map Unit Description

Distribution_Information:

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: USGS Information Services

Contact_Address:

Address_Type: mailing address

Address: Box 25286, Denver Federal Center

City: Denver

State_or_Province: CO

Postal_Code: 80225-0046

Country: USA

Contact_Voice_Telephone: (303) 202-4200

Contact_Voice_Telephone: 1-888-ASK-USGS

Contact_Facsimile_Telephone: (303) 202-4695

Contact_Electronic_Mail_Address: infoservices@usgs.gov

Resource_Description:

Downloadable Data USGS Scientific Investigations Map SIM-2901

Distribution_Liability:

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this publication has been subjected to rigorous review and is substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, it is released on condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use.

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Option:

Online_Option:

Computer_Contact_Information:

Network_Address:

Network_Resource_Name: <http://geopubs.wr.usgs.gov/sim/2006/2901/>

Fees: free

Metadata_Reference_Information:

Metadata_Date: 20060405

Metadata_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:

U.S. Geological Survey Pacific Northwest Urban Corridor Mapping Project

Contact_Person: Karen Wheeler

Contact_Address:

Address_Type: mailing and physical address

Address: 345 Middlefield Rd

Address: MS 973

City: Menlo Park

State_or_Province: CA

Postal_Code: 94025

Country: USA

Contact_Voice_Telephone: (650) 329-4935

Contact_Facsimile_Telephone: (650) 329-4936

Contact_Electronic_Mail_Address: kwheeler@usgs.gov

Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998

Metadata_Time_Convention: local time

Metadata_Extensions:

Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>

Profile_Name: ESRI Metadata Profile