GEOLOGIC MAP OF WASHINGTON - NORTHWEST QUADRANT by JOE D. DRAGOVICH, ROBERT L. LOGAN, HENRY W. SCHASSE, TIMOTHY J. WALSH, WILLIAM S. LINGLEY, JR., DAVID K . NORMAN, WENDY J. GERSTEL, THOMAS J. LAPEN, J. ERIC SCHUSTER, AND KAREN D. MEYERS WASHINGTON DIVISION Of GEOLOGY AND EARTH RESOURCES GEOLOGIC MAP GM-50 2002 •• WASHINGTON STATE DEPARTMENTOF 4 r Natural Resources Doug Sutherland· Commissioner of Pubhc Lands Division ol Geology and Earth Resources Ron Telssera, Slate Geologist WASHINGTON DIVISION OF GEOLOGY AND EARTH RESOURCES Ron Teissere, State Geologist David K. Norman, Assistant State Geologist GEOLOGIC MAP OF WASHINGTON­ NORTHWEST QUADRANT by Joe D. Dragovich, Robert L. Logan, Henry W. Schasse, Timothy J. Walsh, William S. Lingley, Jr., David K. Norman, Wendy J. Gerstel, Thomas J. Lapen, J. Eric Schuster, and Karen D. Meyers This publication is dedicated to Rowland W. Tabor, U.S. Geological Survey, retired, in recognition and appreciation of his fundamental contributions to geologic mapping and geologic understanding in the Cascade Range and Olympic Mountains. WASHINGTON DIVISION OF GEOLOGY AND EARTH RESOURCES GEOLOGIC MAP GM-50 2002 Envelope photo: View to the northeast from Hurricane Ridge in the Olympic Mountains across the eastern Strait of Juan de Fuca to the northern Cascade Range. The Dungeness River lowland, capped by late Pleistocene glacial sedi­ ments, is in the center foreground. Holocene Dungeness Spit is in the lower left foreground. Fidalgo Island and Mount Erie, composed of Jurassic intrusive and Jurassic to Cretaceous sedimentary rocks of the Fidalgo Complex, are visible as the first high point of land directly across the strait from Dungeness Spit. The lowland to the right of Mount Erie is Whidbey Island, consisting predominantly of late Pleistocene glacial and nonglacial sediments. The highest visible peak, Mount Baker (10,778 ft), consists primarily of late Quaternary andesitic lava flows. The lower peaks in the fore­ ground of Mount Baker compose Twin Sisters Mountain, which consists of the Permian to Triassic Twin Sisters Dunite. Mount Shuksan (9,127 ft) is visible to the right and behind Mount Baker. The Mount Shuksan massif is composed of Ju­ rassic Shuksan Greenschist of the Easton Metamorphic Suite. Peaks to the left of Mount Baker along the skyline consist of Permian to Devonian metasedimentary and metavolcanic rocks of the Chilliwack Group. Photograph by Karl W. Wegmann. Project cartographers: Chuck Caruthers, Anne Heinitz, Eric Schuster, Keith Ikerd, and Carl Harris Project editors: Karen Meyers and Jari Roloff Project librarians: Connie Manson and Lee Walkling Project support: Jan Allen, Tara Salzer, Diane Frederickson, and Mary Ann Shawver Special thanks to Don Hiller of the Washington Department of Natural Resources, Resource Mapping Division, for cartographic consultation. Prepared in cooperation with the U.S. Geological Survey. Disclaimer: This product is provided 'as is' without warranty of any kind, either expressed or implied, including, but not limited to, the implied warranties of merchantability and fitness for a particular use. The Washington Department of Natural Resources will not be liable to the user of this product for any activity involving the product with respect to the following: (a) lost profits, lost savings, or any other consequential damages; (b) the fitness of the product for a par­ ticular purpose; or (c) use of the product or results obtained from use of the product. This product is considered to be exempt from the Geologist Licensing Act [RCW 18.220.190 (4)] because it is geological research conducted by the State of Washington, Department of Natural Resources, Division of Geology and Earth Resources. This report is for sale by: Publications Washington Department of Natural Resources Division of Geology and Earth Resources PO Box 47007 Olympia, WA 98504-7007 E-mail: geology(ifwadnr.gov Printed in the United States of America. Printed on recycled stock. ii CONTENTS Page Introduction. 1 Map compilation 1 Acknowledgments . 1 Map design and standards . 3 Base map. 3 Geologic map. 3 Geologic provinces and terranes . 4 Faults and folds . 4 Descriptions of map units 5 Unconsolidated sediments and sedimentary and volcanic rocks 5 Intrusive rocks 5 Metamorphic rocks 6 List of named units . 6 Sources of map data 7 Ages of map units. 7 Unconsolidated sediments . 7 Sedimentary rocks and deposits 9 Mixed volcanic and sedimentary rocks 13 Volcanic rocks and deposits 13 Intrusive rocks . 16 Mixed metamorphic and igneous rocks 22 Ultramafic rocks . 22 Metamorphic rocks. 22 Edge matches with other quadrants. 29 Southwest quadrant 29 Northeast quadrant 29 References cited 30 ILLUSTRATIONS Figure 1. Flow chart for age assignment of geologic units 4 Figure 2. Map of major physiographic provinces of Washington 5 Figure 3. Map showing approximate southwestern limit of latest Pleistocene ice 6 Figure 4. Geologic map showing major lithotectonic domains . Sheet 3 Figure 5. Map showing major batholiths and plutons Of the North Cascades region. Sheet 3 Figure 6. A, Pressure and temperature metamorphic facies diagram; Sheet 3 B, Metamorphic facies map . Sheet 3 Figure 7. Index to sources of map data, scales 1:9,000 to 1 :23,000. 65 Figure 8. Index to sources of map data, scale 1:24,000 A, quadrangles 65 B, non-quadrangles 66 C, coastal. 66 Figure 9. Index to sources of map data, scales 1 :25,000 to 1 :60,000 67 Figure 10. Index to sources of map data, scales 1:62.500 to 1:63,360 67 Figure 11. Index to sources of map data, scales 1:69,700 to 1:95,000 68 Figure 12. Index to sources of map data, scale 1: 100,000 . 68 Figure 13. Index to sources of map data, scales 1: 104,870 to 1 :200,000. 69 Figure 14. Index to sources of map data, scales 1:230,000 to 1 :530,000 A 69 B 70 TABLES Table 1. 1 100,000-scale quadrangle, compiler, and chief source report for geologic maps in the northwest quadrant of Washington 1 Table 2. List of named units . 47 iii PLATES Sheet 1. Geologic map and key to geologic units Sheet 2. Descriptions of map units Sheet 3. Ages of map units, lithotectonic domain map, major batholiths and plutons map, pressure and temperature metamorphic facies diagram, and metamorphic facies map iv GEOLOGIC MAP OF WASHINGTON-NORTHWEST QUADRANT by Joe D. Dragovich, Robert L. Logan, Henry W. Schasse, Timothy J. Walsh, William S. Lingley, Jr., 2 David K. Norman, Wendy J. Gerstel1, Thomas J. Lapen , J. Eric Schuster, and Karen D. Meyers 1 currently at Washington State Department of Natural Resources, Land Management Division 2 currently at Department of Geology, University of Wisconsin, Madison, Wisconsin INTRODUCTION AG-01524, 1434-HQ-97-AG-01809, 98HQAG2062, 99HQAG0136, OOHQAG0107, and 01HQAG0105. Map­ The Geologic Map of Washington-Northwest Quad­ ping on the Olympic Peninsula was funded with grants rant is the last in a series of four 1:250,000-scale geologic from the Minerals Management Service, Continental Mar­ maps that together make up the third complete geologic gins Program (subagreement nos. 14-12-0001-30387, map of Washington at a scale of 1 :500,000 or larger pub­ 14-35-0001-30497, and 14-35-0001-30643), and the lished by the Washington Division of Geology and Earth Olympic Natural Resources Center (University of Wash­ Resources (OGER) and its predecessors. (The first two, ington contract nos. 234153 and ONR FY96-165). Culver and Stose, 1936, accompanied by Culver, 1936, The Geologic Map of Washington-Northwest Quad­ and Huntting and others, 1961, are out-of-print.) The first rant is a result of the efforts of scores of geologists over three quadrants of the third geologic map of Washington many decades. The contributions of many of these geolo­ are available as: Geologic Map of Washington-South­ gists are acknowledged by citation (see References Cited, west Quadrant, OGER Geologic Map GM-34 (Walsh and p. 30) and Sources of Map Data (p. 65). We gratefully ac­ others, 1987); Geologic Map of Washington-Northeast knowledge all of those geologists who have made vital Quadrant, OGER Geologic Map GM-39 (Stoffel and oth­ contributions toward deciphering the complex geology of ers, 1991 ); and Geologic Map of Washington-Southeast northwestern Washington. Quadrant, OGER Geologic Map GM-45 (Schuster and Rowland W. Tabor (USGS, retired) to whom this pub­ others, 1997). lication is dedicated, is the principal author of mapping Separate topographic base maps (OGER Topographic Maps TM-1, TM-2, and TM-3) are available for the first three Table 1. 1:100,000-scale quadrangle, compiler(s), and chief source report for geo­ quadrants (southwest, northeast, and logic maps in the northwest quadrant of Washington. For the Chelan, Mount Baker, southeast), but because the northwest Robinson Mountain, Sauk River, Skykomish River, Snoqualmie Pass, and Wenat­ quadrant was prepared digitally, a separate chee 1: 100,000-scale quadrangles, the compilers listed below modified the refer­ enced map by converting the map-unit symbology to the system used by DGER and topographic map was not printed. simplifying the geology for presentation at 1 :250,000 scale. R. W. Tabor (USGS, re­ tired) supplied digital geology for the Mount Baker, Sauk River, Skykomish River, MAP COMPILATION and Snoqualmie Pass 1: 100,000 quadrangles. Where the report is given as 'digital' there has been no conventional geologic map released; instead, the 1:100,000-scale The 1 :250,000-scale Geologic Map of geology for these quadrangles is available as digital (Arc/Info) coverages (Washing­ Washington-Northwest Quadrant was ton DGER, 2001) at the address listed inside the front cover of this pamphlet compiled chiefly from 1: 100,000-scale geologic maps that were prepared by staff Quadrangle Compiler(s) (1:250,000) Report (1:100,000) of the U.S.