OFR 2003-16, Geologic Map of the Copalis Beach 1
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WASHINGTON DIVISION OF GEOLOGY AND EARTH RESOURCES OPEN FILE REPORT 2003-16 R. 13 W. 124°15¢ R. 12 W. R. 11 W. 124°00¢ 47°30¢ DESCRIPTION OF MAP UNITS Qapwo „Emr 2 Qapwo2 Quaternary Sediments Qapw1 Qapw2 NONGLACIAL DEPOSITS „mr „m Qapwo1 Qapw1 st Evb „m „m Qb Beach deposits (Holocene)—Sand and (or) gravel, with minor shell r r 101 Qb Qapo „Ebx Qa „m fragments, deposited along shorelines; includes back-beach dune st „m „mr r fields and minor estuarine deposits; clasts are typically well rounded. ‰„n Qapo Qa Alluvium (Holocene)—Sorted combinations of silt, sand, and gravel „Ebx „mst „m T. 23 N. Qa r Qapo deposited in streambeds and alluvial fans; clasts are generally ‰„n „Ebx Evb „mst Qapw2 rounded and composed mostly of lithofeldspathic and feldspatholithic „Ebx Qa sandstone from the core of the Olympic Mountains, with minor Qa Evb amounts of volcanic rock from the periphery of the Olympic „Ebx Qap Qapo Peninsula; may include alpine drift, peat, lacustrine, or landslide Evb Evb Qapo „mr deposits; generally lacks discernable weathering; surface is Qapo „Ebx Qapo „mst undissected by streams relative to pre-Holocene terrace surfaces. Qc Continental sediments (Pleistocene)—Laminated, blocky, blue-gray Evb Qc d „mr d silt with interbedded peat; situated stratigraphically between units ‰„n Qapwo1 and Qapwo2 along the Humptulips River; designated the Evb Damon silt by Moore (1965). Qapw2 Qapt „Ebx ALPINE GLACIAL DEPOSITS Evb „mr „mr Qao Alpine outwash, late Wisconsinan (Pleistocene)—Stratified sand Evb Qao ‰„n and gravel derived from sandstone, slate, and minor basaltic rocks of ‰„n Qa the Olympic Mountains; contains some silt and clay; clasts are ‰„n Qa generally more rounded than and lack the facets and striations „mr ‰„n „m ‰„n r associated with till clasts; generally not deeply weathered; composes ‰„n „mst lower stream terraces; terrace surfaces are very poorly dissected by ‰„n streams; consists of younger outwash of the Chow Chow drift of Evb Evb T. 22 N. Qa Moore (1965). Qapo „Ebx Qap Alpine drift, pre-late Wisconsinan (Pleistocene)—Till and outwash Qap ‰„n Evb Qa sand and gravel; clasts consist of sandstone, slate, and basalt of the „Ebx Evb Qa Olympic Mountains core; gray with local orange weathering; may be „Ebx covered with cream-colored weathered loess; comprises ground Qapo Qao moraine of the older part of the Chow Chow drift of Moore (1965), ‰„n „mr Qapw2 Qapo Qapo which lies west of Lake Quinault. ‰„n Qapt Alpine till, pre-late Wisconsinan (Pleistocene)—Compact, Qap Qapt Qapw nonstratified, poorly sorted mixture of clay, silt, sand, and gravel with ‰„n „Ebx Qapo 1 boulders disseminated throughout; clasts consist of sandstone and Qa basalt of Olympic Mountains core and peripheral provenance, respectively, and are commonly striated, faceted, and less rounded Qa Qapo Qapo than outwash clasts, especially in the sand-size fraction; gray where fresh, mottled yellowish brown to red-brown near the ground surface; Qapwo Qapw2 may be covered with cream-colored weathered loess; occurs as 2 „m ‰„n r erosional remnants of the terminal moraine of the older part of Qapo Qapw2 Moore’s (1965) Chow Chow drift; till is surrounded by outwash „mst trains (unit Qapo). „mr Qapo Alpine outwash, pre-late Wisconsinan (Pleistocene)—Stratified Qapo Em Qapwt2 sand, gravel, and cobbles of mostly sandstone and minor basalt from Qapo the Olympic Mountains core and peripheral rocks; includes some T. 21 N. Evb Qapo peat, silt, clay, and weathered loess; clasts are generally more rounded Qapwt 2 than clasts in till and lack facets and striations; poorly to moderately Evb sorted; gray to subtle yellow with wispy orange weathering; forms Qapt gravel trains that rise at the terminal moraine of the older part of the Qapwt2 Chow Chow drift (Moore, 1965) and merge laterally along the coast Qapw2 with and are indistinguishable from the Lyman Rapids outwash of „Emr Qapwo2 Thackray (1996); both the Chow Chow and Lyman Rapids outwash were deposited along a paleo-shoreline that truncates the till plain of Qapw 1 the Humptulips drift of Moore (1965). Qapw Qapw2 Alpine drift, younger pre-Wisconsinan (Pleistocene)— 2 Qapw2 Undifferentiated till and outwash; outwash consists of sand and gravel with laterally discontinuous beds of lacustrine silt and clay; till Qapo is locally capped by loess; clasts are composed primarily of litho- Qapw2 feldspathic and feldspatholithic sandstone and basalt; weathered to depths exceeding 12 ft (4 m); red-orange weathering rinds on clasts; Qapwo2 ancient surfaces are moderately dissected by streams; includes part of the Whale Creek drift (Thackray, 1996) in the Queets River basin and Qb Qapwo1 the Humptulips drift (Moore, 1965) in the Quinault River basin. Qapwo 1 Qapwt2 Alpine till, younger pre-Wisconsinan (Pleistocene)—Compact Qapwt2 mixture of silt, sand, and gravel; may contain some faceted and Qapwo2 Qapo striated boulders; deeply weathered to a brownish red color; may also contain minor outwash sand and gravel or loess; mapped where Qa T. 20 N. Qapwo2 exposures are dominated by till of the Humptulips drift of Moore Qapo (1965). Qapwo 1 Qapwo2 Alpine outwash, younger pre-Wisconsinan (Pleistocene)—Sand Qapwo2 and gravel composed of lithofeldspathic and feldspatholithic sand- stone and basalt derived from the core of the Olympic Mountains; weathered to depths exceeding 12 ft (4 m) with characteristic red- Qapo orange weathering rinds; consists mostly of the “flat lying and slightly deformed sand and gravel” of Moore (1965). Qb Qapo Qapw1 Alpine drift, older pre-Wisconsinan (Pleistocene)— Qapwo Qapw1 2 Undifferentiated till and outwash; outwash consists of sand and gravel with lenses of lacustrine silt and clay; deep red-orange; clasts Qapwo2 thoroughly weathered to depths exceeding 60 ft (20 m); ancient surfaces are highly dissected by streams; includes part of the Wolf Qapwo2 Creek drift (Thackray, 1996) in the Queets River basin and pre- Humptulips drift equivalent to the Donkey Creek drift of Moore Qapwo2 (1965). Evc Qapwo1 Qapo Qapwo1 Alpine outwash, older pre-Wisconsinan (Pleistocene)—Sand and Qapwo1 Em1h pebble gravel with local beds of coarse gravel and silt; so deeply weathered that clasts can be cut by a knife; gravels are reddish brown Qb Qapwo1 Qapo and moderately cemented by iron oxide; extensive distribution of Qa deposits scattered along the southern and western flanks of the Qapwo T. 19 N. 2 Qapwo1 Olympic Mountains suggest a glacial origin; consists mostly of the “moderately and intensely deformed sand and gravel” of Moore Qapo (1965). Qapwo1 Qb Tertiary Sedimentary Rocks Disclaimer: This product is provided ‘as is’ without warranty of any Q PlMn Nearshore sedimentary rocks (Pliocene–Miocene)—Siltstone, kind, either expressed or implied, including, but not limited to, the cd ‰„n implied warranties of merchantability and fitness for a particular use. Qapwo2 sandstone, and conglomerate; fossiliferous; concretionary and The Washington Department of Natural Resources will not be liable to carbonaceous; contains flame and ball-and-pillow structures; consists the user of this product for any activity involving the product with Qapwo2 respect to the following: (a) lost profits, lost savings, or any other of the Quinault Formation. consequential damages; (b) the fitness of the product for a particular Mm Marine thin-bedded sedimentary rocks (Miocene)—Thin-bedded purpose; or (c) use of the product or results obtained from use of the „mrr product. This product is considered to be exempt from the Geologist (1–20 cm [1–8 in.]) and (or) laminated lithofeldspathic sandstone and Licensing Act [RCW 18.220.190 (4)] because it is geological research Qa siltstone with less abundant claystone, shale, and thick-bedded (>2 ft conducted by the State of Washington, Department of Natural [>60 cm]) sandstone; minor conglomerate and shale-clast breccia; Resources, Division of Geology and Earth Resources. Qcd Qapwo1 commonly weathers orange; rhythmically bedded and carbonaceous in part; consists of part of the Hoh rock assemblage (Rau, 1973). Qc Qapwo1 d Mm Marine thick-bedded sedimentary rocks (Miocene)—Thick units „mstst of laterally discontinuous, medium- to very coarse-grained, + micaceous, feldspatholithic to lithofeldspathic sandstone; minor siltstone-, shale-, and slate-clast breccia, granule conglomerate, and Qapwo2 pebble conglomerate; bedding generally thicker than 1 m (3 ft); Qc d common platy shale, slate, or siltstone clasts; thick sandstones are Qa T. 18 N. separated by thin-bedded (1–12 in. [1–30 cm]) sandstone, siltstone, Qapwo2 claystone, and shale; consists of part of the Hoh rock assemblage Qcd (Rau, 1973). Qapwo1 MEm Marine thin-bedded sedimentary rocks (Miocene–Eocene)— „Emrr Qb Laminated and (or) thin-bedded (1–20 cm [1–8 in.]), lithofeldspathic and feldspatholithic, micaceous sandstone, siltstone, and slate; thin- bedded units commonly rhythmically bedded; phacoidal structures common; occurs in the northeast corner of the map area. Qcd MEbx Breccia (Miocene–Eocene)—Lenses and angular blocks of „Ebx sandstone, siltstone, shale, conglomerate, and volcanogenic rocks in a 47°00¢ matrix of black shale with scaly cleavage or of intensely sheared R. 12 W. R. 11 W. 124°00¢ sandstone and siltstone; includes diapiric muds, fault breccias, and submarine landslide deposits; includes part of the Hoh rock assemblage (Rau, 1973). SCALE 1:100,000 Em Marine sedimentary rocks (Eocene)—Thick- to rhythmically Lambert conformal conic projection Em North American Datum of 1927 1 0 1 2 345 678 MILES bedded siltstone with thin laminae of fine-grained sandstone; Base map information from the Washington Department of interbedded with Eocene volcanic rocks (unit Evb) at Point Grenville Natural Resources Geographic Information System 1 012 43 56789 10 KILOMETERS (Rau, 1973, 1975). Digital cartography by Anne C. Heinitz, J. Eric Schuster, Em Marine sedimentary rocks (Eocene)—Medium- to coarse-grained and Charles G. Caruthers contour interval 120 feet; supplemental contours at 40 and 80 feet Em1h1h Editing and production by Karen D.