DOCSLIB.ORG

Structure and Chronology of the Oval Peak Batholith and Adjacent Rocks: Implications for the Ross Lake Fault Zone, North Cascades, Washington

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Structure and Chronology of the Oval Peak Batholith and Adjacent Rocks: Implications for the Ross Lake Fault Zone, North Cascades, Washington Structure and chronology of the Oval Peak batholith and adjacent rocks: Implications for the Ross Lake fault zone, North Cascades, Washington ROBERT B. MILLER Department of Geology, San Jose State University, San Jose, California 95192 SAMUEL A. BO WRING Department of Earth and Planetary Sciences, Washington University, St Louis, Missouri 63130 ABSTRACT The Foggy Dew and Twisp River fault this region (for example, Davis and others, zones separate the batholith and its wall 1978). These faults experienced protracted The >200-km-long Ross Lake fault zone rocks on the northeast from weakly meta- movement histories with both strike- and dip- (RLFZ) forms the northeastern border of the morphosed strata of the Methow basin. The slip motion (Misch, 1966,1977; Tabor and oth- crystalline core of the North Cascades. This Foggy Dew fault zone contains mylonitic ers, 1984; Monger, 1986; Ray, 1986). The Ross Late Cretaceous(?) and Paleogene structure is gneiss derived from the Oval Peak batholith, Lake fault zone (RLFZ) is one of these major an ~lS-km-wide system of faults and fault Skagit Gneiss, and tonalitic rock that displays structures. It forms the northeastern border of zones, several of which deform the Paleocene U-Pb zircon systematics suggestive of an Eo- the predominantly Mesozoic crystalline core of (-65 Ma, U-Pb zircon) Oval Peak batholith. cene age. Sillimanite schist and amphibolite the North Cascades, generally separating the The southern segment of the Gabriel Peak are also present. Mylonites record dextral plutonic-metamorphic core from slightly meta- tectonic belt of the RLFZ is defined by strike slip with a component of normal slip, morphosed Jurassic-Cretaceous strata of the strongly deformed rocks of the foliated down to the northeast. Movement in the fault Methow basin (Fig. 1). southwestern margin of the Oval Peak batho- zone continued subsequent to deformation in As originally defined by Misch (1966,1977), lith, structurally underlying pre-Late Cre- the Gabriel Peak tectonic belt and ended by the RLFZ consists of a series of major faults and taceous Twisp Valley Schist, and structurally 48 Ma. Mylonites in the Twisp River fault associated fault zones (Fig. 2). Most are steep highest part of the subjacent Skagit Gneiss, zone also reveal dextral strike slip, but appar- north-northwest- to northwest-striking struc- which here consists of Late Cretaceous ently with less normal slip. tures and include the Ross Lake fault proper (87 Ma) and Paleocene (60 Ma) orthogneiss. The RLFZ experienced a diachronous his- (Misch, 1966), Hozameen-North Creek fault Kinematic indicators in moderately steeply tory from at least 65 to 45 Ma. This history (Misch, 1966; McGroder, 1987), Twisp River northeast-dipping mylonitic orthogneiss re- was dominated by dextral strike slip, but fault (Barksdale, 1975), Foggy Dew fault cord reverse slip. The strong solid-state flat- there were significant components of normal (Barksdale, 1975), and Gabriel Peak tectonic tening fabric in the foliated margin of the slip and reverse slip on some structures. Dur- belt (Misch, 1977; Miller, 1987). Oval Peak batholith formed during or shortly ing the latter part of this interval (-57-45 The RLFZ extends for more than 200 km after emplacement and overprinted a mag- Ma), the RLFZ probably recorded a trans- from near the Columbia River in Washington, matic fabric observed in the core of the batho- tensional tectonic regime transitional between where it is covered by Miocene basalts (Misch, lith. Foliation and associated stretching linea- extension to the east in Omineca metamor- 1966; Raviola, 1988), to southern British Co- tion within the Gabriel Peak tectonic belt are phic core complexes and dextral strike slip to lumbia, where it is truncated by the Fraser- oblique to the regional structural grain but the west related to oblique convergence along Straight Creek fault (Fig. 1) (Monger, 1985). concordant with the contacts of the batholith. the continental margin. Early Cenozoic plu- Several major faults are candidates for the offset These patterns in part record emplacement of tonism, metamorphism, and ductile deforma- Ross Lake fault proper west of the Fraser- the batholith as an expanding diapir into the tion have strongly overprinted any of the Straight Creek fault. Kleinspehn (1985) corre- tectonic belt. Reverse slip in the tectonic belt major Cretaceous deformation postulated in lated the Ross Lake fault with the dextral Yala- occurred before, during(?), and shortly after previous tectonic models for the RLFZ. kom fault, Monger (1986) matched the Ross emplacement but ended by -55-58 Ma. Lake fault with the Kwoiek and Bralorne (Rus- The core of the Oval Peak batholith in- INTRODUCTION more, 1986) faults, and Coleman (1989) corre- truded a large tongue of Twisp Valley Schist lated the Ross Lake and Mission Ridge faults on the north. Porphyroblast microstructures Strike-slip faults played an important role in (Fig. 1). and Ar-Ar and K-Ar geochronology indicate the late Mesozoic(?)-early Cenozoic evolution Although there are numerous conflicting in- that amphibolite-facies dynamothermal met- of the Cordillera of British Columbia and Wash- terpretations of the chronology, magnitude of amorphism of the schist occurred during ington by disrupting and juxtaposing different movement, and overall displacement history of intrusion. parts of a mosaic of small accreted terranes in the RLFZ, most workers (Misch, 1966; Hau- Additional material for this article (an appendix) is available free of charge by requesting Supplementary Data 9019 from the GSA Documents Secretary. Geological Society of America Bulletin, v. 102, p. 1361-1377, 12 figs., 3 tables, October 1990. 1361 Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/102/10/1361/3380696/i0016-7606-102-10-1361.pdf by guest on 26 September 2021 1362 MILLER AND BOWRING 122 120 1 18 51° Figure 1. Simplified geo- logic map showing major early Cenozoic high-angle faults of the North Cascades (N.C.) and southern Cana- dian Coast Mountains and „ their spatial relations to ma- so jor Eocene extensional faults (tick marks on upper plate) along the margins of the Omineca metamorphic core complexes. Several units dis- cussed in the text are also shown on the map. CB, Chil- liwack batholith (Oligocene- 49° Miocene); CM, Cooper Moun- tain batholith (mid-Eocene); K, Kettle dome; MRF, Mis- sion Ridge fault; NWCS, Northwest Cascades thrust system (Cretaceous); OK, Okanogan Complex; RLF, Ross Lake fault; RLFZ, Ross Lake fault zone; V, Valhalla 48° Complex. Modified from Johnson (1985), Parrish and others (1988), Potter (1986), Price and others (1985), and Roddick and others (1979). Coast Plutonic Complex Undifferentiated • (mainly Cretaceous - Eocene) Methow-Tyaughton basin Crystalline Core of the North Cascades (Jurassic - Cretaceous) (Cretaceous - Eocene) Bridge River-Hozameen terrane Omineca Metamorphic Complexes (Permian - Jurassic) (mainly Jurassic - Eocene) gerud, 1985; Miller and others, 1985) consid- marks a suture across which the North Cascades Trexler and Bourgeois (1985) contended that ered the fault zone to have undergone major were accreted, whereas Ray (1986) postulated the fault zone was active during mid-Cretaceous dextral movement. Davis and others (1978) that the crystalline core was thrust eastward deposition in the Methow basin and that the suggested a minimum of 160 km of Late Juras- along a structure that subsequently was steep- basin formed by Cretaceous "oblique-transla- sic or Early Cretaceous dextral movement on a ened and then experienced large dextral move- tional compression." "proto-Ross Lake fault" in order to restore the ments. Kriens and Wernicke (1986) argued that Numerous plutons that range between 90 and North Cascades crystalline core to a position at there is little displacement on the fault zone. 48 Ma occur within the RLFZ (Fig. 2). Some the south end of the Okanogan crystalline belt. The timing of movement on the RLFZ is also plutons have intruded parts of the fault zone but In contrast, Barksdale (1975) emphasized dip problematic. Misch (1966) proposed that dis- were deformed by continued movement. One slip and sinistral slip in the southernmost RLFZ. placement occurred prior to 90 Ma, whereas such pluton, the Oval Peak batholith (Adams, Hamilton (1978) suggested that the RLFZ Haugerud (1985) argued for middle Eocene slip. 1961; Libby, 1964), intruded the southern seg- Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/102/10/1361/3380696/i0016-7606-102-10-1361.pdf by guest on 26 September 2021 OVAL PEAK BATHOLITH, NORTH CASCADES, WASHINGTON 1363 ment of the fault zone. This batholith and its The TVS is predominantly siliceous biotite tilting of originally more-gentle isograds (Hau- wall rocks occupy a critical position, as they schist and impure quartzite (metachert). Am- gerud and others, 1988; Kriens, 1988). have been affected by three major strands of the phibolite, greenschist, calc-silicate rock and RLFZ, the Foggy Dew fault, Twisp River fault, marble (Adams, 1961), and local ultramafite Skagit Gneiss and Gabriel Peak tectonic belt. This report de- form small (<50 m wide) lenses. scribes the emplacement and deformation histo- The TVS displays two generally coaxial The Skagit Gneiss (Misch, 1966,1968) forms ries of the Oval Peak batholith and its wall generations of tight to isoclinal folds (F[, F2) much of the northern crystalline core of the rocks, and the implications of these histories for and axial-planar foliation (Si, S2). Transposition North Cascades. We have subdivided the Skagit the development of the RLFZ. We show that makes it difficult to distinguish Fi from F2, and Gneiss in the map area into three northeast- both strike- and dip-slip displacement have been the predominant foliation (S1.2) is considered to dipping orthogneiss units, in descending order, important and present geochronological data be composite. Mineral lineation (L1.2) is parallel the Battle Mountain gneiss, Tuckaway Lake that bracket the timing of the latest major to FI_2 axes. Abundant open to tight folds (F3) gneiss, and Lake Juanita leucogneiss (Figs.
Load more

Recommended publications
  • Review Article Magma Loading in the Southern Coast Plutonic Complex, British Columbia and Washington
    GeoScienceWorld Lithosphere Volume 2020, Article ID 8856566, 17 pages https://doi.org/10.2113/2020/8856566 Review Article Magma Loading in the Southern Coast Plutonic Complex, British Columbia and Washington E. H. Brown Department of Geology, Western Washington University, USA Correspondence should be addressed to E. H. Brown; [email protected] Received 2 May 2020; Accepted 22 September 2020; Published 10 November 2020 Academic Editor: Tamer S. Abu-Alam Copyright © 2020 E. H. Brown. Exclusive Licensee GeoScienceWorld. Distributed under a Creative Commons Attribution License (CC BY 4.0). The southen end of the 1800 km long Coast Plutonic Complex (CPC), exposed in the Harrison Lake area of British Columbia and in the North Cascades of Washington, bears a record of great crustal thickening -20 to 40 km in localized zones during Late Cretaceous times. During this period, the CPC was positioned at the continental margin during collision/subduction of the Farallon plate. Arc magmatism and regional orogenic contraction were both active as potential crustal thickening processes. Magmatism is favored in this report as the dominant factor based on the delineation of four spatially and temporally separate loading events, the close association of the loaded areas with emplacement of large plutons, and a paucity of evidence of deep regional tectonic contraction. The timing and spatial location of crustal loading events are documented by the following: zircon ages in plutons; an early event of low pressure in pluton aureoles evidenced by andalusite, now pseudomorphed by high- pressure minerals; high pressures in country rock in pluton aureoles measured by mineral compositions in the assemblages garnet-biotite-muscovite-plagioclase and garnet-aluminum silicate-plagioclase; high pressures recorded in plutons by Al-in- hornblende barometry; and uplift ages of plutons derived from K-Ar and Ar-Ar ages of micas and hornblende in plutons.
    [Show full text]
  • Stratigraphy, Age, and Provenance of the Eocene Chumstick Basin
    Stratigraphy, age, and provenance of the Eocene Chumstick basin, Washington Cascades; implications for paleogeography, regional tectonics, and development of strike-slip basins Erin E. Donaghy1,†, Paul J. Umhoefer2, Michael P. Eddy1, Robert B. Miller3, and Taylor LaCasse4 1 Department of Earth, Planetary, and Atmospheric Sciences, Purdue University, West Lafayette, Indiana 47907, USA 2 School of Earth Sciences and Sustainability, Northern Arizona University, Flagstaff, Arizona 86011, USA 3 Department of Geology, San Jose State University, San Jose, California 95192, USA 4 Department of Geology, Carleton College, Northfield, Minnesota 55057 USA ABSTRACT tions can be constrained at high temporal Here we present a large provenance data set resolution (0.5–1.5 m.y. scale) for an ancient coupled with new lithofacies mapping from Strike-slip faults form in a wide variety strike-slip basin and permits a detailed re- the Chumstick basin within the framework of a of tectonic settings and are a first-order construction of sediment routing pathways recently developed precise depositional chronol- control on the geometry and sediment accu- and depositional environments. As a result, ogy (Eddy et al., 2016b). This basin formed in mulation patterns in adjacent sedimentary we can assess how varying sediment supply a strike-slip setting in central Washington and basins. Although the structural and depo- and accommodation space affects the depo- provides a unique opportunity to track changes sitional architecture of strike-slip basins is sitional architecture during strike-slip basin in sediment routing systems that are related well documented, few studies of strike-slip evolution. to rapidly changing paleogeography in basin- basins have integrated depositional age, bounding basement blocks.
    [Show full text]
  • Midcretaceous Thrusting in the Southern Coast Belt, British
    TECTONICS, VOL. 15, NO. 2, PAGES, 545-565, JUNE 1996 Mid-Cretaceous thrusting in the southern Coast Belt, British Columbia and Washington, after strike-slip fault reconstruction Paul J. Umhoefer Departmentof Geology,Northern Arizona University, Flagstaff Robert B. Miller Departmentof Geology, San JoseState University, San Jose,California Abstract. A major thrust systemof mid-Cretaceousage Introduction is presentalong much of the Coast Belt of northwestern. The Coast Belt in the northwestern Cordillera of North North America. Thrusting was concurrent,and spatially America containsthe roots of the largest Mesozoic mag- coincided,with emplacementof a great volume of arc intrusives and minor local strike-slip faulting. In the maticarc in North America, which is cut by a mid-Creta- southernCoast Belt (52ø to 47øN), thrusting was followed ceous,synmagmatic thrust system over muchof its length by major dextral-slipfaulting, which resultedin significant (Figure 1) [Rubin et al., 1990]. This thrust systemis translationalshuffling of the thrust system. In this paper, especiallywell definedin SE Alaska [Brew et al., 1989; Rubin et al., 1990; Gehrels et al., 1992; Haeussler, 1992; we restorethe displacementson major dextral-slipfaults of the southernCoast Belt and then analyze the mid-Creta- McClelland et al., 1992; Rubin and Saleeby,1992] and the southern Coast Belt of SW British Columbia and NW ceousthrust system. Two reconstructionswere madethat usedextral faulting on the Yalakom fault (115 km), Castle Washington(Figure 1)[Crickmay, 1930; Misch, 1966; Davis et al., 1978; Brown, 1987; Rusrnore aad Pass and Ross Lake faults (10 km), and Fraser fault (100 Woodsworth, 199 la, 1994; Miller and Paterson, 1992; km). The reconstructionsdiffer in the amount of dextral offset on the Straight Creek fault (160 and 100 km) and Journeayand Friedman, 1993; Schiarizza et al.
    [Show full text]
  • Preliminary Geologic Map of the Mount Baker 30- by 60-Minute Quadrangle, Washington
    U.S. DEPARTMENT OF THE INTERIOR U.S. GEOLOGICAL SURVEY Preliminary Geologic Map of the Mount Baker 30- by 60-Minute Quadrangle, Washington by R.W. Tabor1 , R.A. Haugerud2, D.B. Booth3, and E.H. Brown4 Prepared in cooperation with the Washington State Department of Natural Resources, Division of Geology and Earth Resources, Olympia, Washington, 98504 OPEN FILE REPORT 94-403 This report is preliminary and has not been reviewed for conformity with U.S.Geological Survey editorial standards or with the North American Stratigraphic Code. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. iu.S.G.S., Menlo Park, California 94025 2U.S.G.S., University of Washington, AJ-20, Seattle, Washington 98195 3SWMD, King County Department of Public Works, Seattle, Washington, 98104 ^Department of Geology, Western Washington University, Bellingham, Washington 98225 INTRODUCTION The Mount Baker 30- by 60-minute quadrangle encompasses rocks and structures that represent the essence of North Cascade geology. The quadrangle is mostly rugged and remote and includes much of the North Cascade National Park and several dedicated Wilderness areas managed by the U.S. Forest Service. Geologic exploration has been slow and difficult. In 1858 George Gibbs (1874) ascended the Skagit River part way to begin the geographic and geologic exploration of the North Cascades. In 1901, Reginald Daly (1912) surveyed the 49th parallel along the Canadian side of the border, and George Smith and Frank Calkins (1904) surveyed the United States' side. Daly's exhaustive report was the first attempt to synthesize what has become an extremely complicated geologic story.
    [Show full text]
  • Structure and Emplacement of the Eocene Golden Horn Batholith, North Cascades, Washington
    San Jose State University SJSU ScholarWorks Master's Theses Master's Theses and Graduate Research Spring 2018 Structure and Emplacement of the Eocene Golden Horn Batholith, North Cascades, Washington Christopher Scudder San Jose State University Follow this and additional works at: https://scholarworks.sjsu.edu/etd_theses Recommended Citation Scudder, Christopher, "Structure and Emplacement of the Eocene Golden Horn Batholith, North Cascades, Washington" (2018). Master's Theses. 4919. DOI: https://doi.org/10.31979/etd.p6p4-am45 https://scholarworks.sjsu.edu/etd_theses/4919 This Thesis is brought to you for free and open access by the Master's Theses and Graduate Research at SJSU ScholarWorks. It has been accepted for inclusion in Master's Theses by an authorized administrator of SJSU ScholarWorks. For more information, please contact [email protected]. STRUCTURE AND EMPLACEMENT OF THE EOCENE GOLDEN HORN BATHOLITH, NORTH CASCADES, WASHINGTON A Thesis Presented to The Faculty of the Department of Geology San José State University In Partial Fulfillment of the Requirement for the Degree Master of Science by Christopher A. Scudder May 2018 © 2018 Christopher A. Scudder ALL RIGHTS RESERVED The Designated Thesis Committee Approves the Thesis Titled STRUCTURE AND EMPLACEMENT OF THE EOCENE GOLDEN HORN BATHOLITH, NORTH CASCADES, WASHINGTON by Christopher A. Scudder APPROVED FOR THE DEPARTMENT OF GEOLOGY SAN JOSÉ STATE UNIVERSITY May 2018 Dr. Robert Miller Department of Geology Dr. Ellen Metzger Department of Geology Dr. Jonathan Miller Department of Geology ABSTRACT STRUCTURE AND EMPLACEMENT OF THE EOCENE GOLDEN HORN BATHOLITH, NORTH CASCADES, WASHINGTON By Christopher A. Scudder The 48 Ma Golden Horn batholith is a ~310 km2, shallow intrusion constructed of sub-horizontal sheets in the crystalline core of the North Cascades of Washington.
    [Show full text]
  • Geologic Map of Washington - Northwest Quadrant
    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.
    [Show full text]
  • Decision Notice and Finding of No Significant Impact
    Final Decision Notice and Finding of No Significant Impact Mission Restoration Project and Forest Plan Amendment #59 U.S.D.A. Forest Service Okanogan-Wenatchee National Forest Methow Valley Ranger District Okanogan County, Washington Introduction and Background Information Based on the analysis presented in the Mission Restoration Project Final Environmental Assessment, I have decided to select a modified version of Alternative 2. The Proposed Action as modified is hereby incorporated by reference. Project Location The 50,200 acre Mission Restoration Project is principally located in the Libby Creek and Buttermilk Creek drainages including Smith Canyon, Elderberry Canyon, Ben Canyon, Chicamun Canyon, Mission Creek, Black Pine Creek, Yoyo Creek, Nickel Canyon, and Hornet Draw. The project area also includes a small portion of the Twisp River Watershed that was added at the request of adjacent private land owners to reduce wildfire hazards on National Forest System (NFS) lands adjacent to the private lands. The project area is located west of Highway 153, between Carlton and Twisp, Washington. The project area includes portions ofTownship 32 North, Ranges 19, 20, 21, and 22 East; and Township 33 North, Range 20 East, W.M. Landmark locations include Lookout Mountain, Mission Peak, Buttermilk Butte, and Black Pine Lake. The primary access routes into the project area include State Highway 153; Okanogan County Roads 1049, 1051, 1090, 1091, and 9114; and NFS roads 4300000, 4340000, 4342100, 4342200, and 4342300. Background The intent of this project is to implement the Forest Restoration Strategy (2012) by treating areas in need of vegetation and aquatic restoration actions (based on landscape and stand-level restoration ecology principles).
    [Show full text]
  • Lithology, Structure, Geochronology, and Tectonic Implications of the Spider Glacier Unit and Holden Assemblage, North Cascades, Washington
    San Jose State University SJSU ScholarWorks Master's Theses Master's Theses and Graduate Research Spring 2020 Lithology, Structure, Geochronology, and Tectonic Implications of the Spider Glacier Unit and Holden Assemblage, North Cascades, Washington Colin Phillips San Jose State University Follow this and additional works at: https://scholarworks.sjsu.edu/etd_theses Recommended Citation Phillips, Colin, "Lithology, Structure, Geochronology, and Tectonic Implications of the Spider Glacier Unit and Holden Assemblage, North Cascades, Washington" (2020). Master's Theses. 5108. DOI: https://doi.org/10.31979/etd.wcje-w4t5 https://scholarworks.sjsu.edu/etd_theses/5108 This Thesis is brought to you for free and open access by the Master's Theses and Graduate Research at SJSU ScholarWorks. It has been accepted for inclusion in Master's Theses by an authorized administrator of SJSU ScholarWorks. For more information, please contact [email protected]. LITHOLOGY, STRUCTURE, GEOCHRONOLOGY AND TECTONIC IMPLICATIONS OF THE SPIDER GLACIER UNIT AND HOLDEN ASSEMBLAGE, NORTH CASCADES, WASHINGTON A Thesis Presented to The Faculty of the Department of Geology San José State University In Partial Fulfillment of the Requirements for the Degree Master of Science by Colin Phillips May 2020 © 2020 Colin Phillips ALL RIGHTS RESERVED ii The Designated Thesis Committee Approves the Thesis Titled LITHOLOGY, STRUCTURE, GEOCHRONOLOGY AND TECTONIC IMPLICATIONS OF THE SPIDER GLACIER UNIT AND HOLDEN ASSEMBLAGE, NORTH CASCADES, WASHINGTON by Colin Phillips APPROVED FOR
    [Show full text]
  • Department of the Interior Fish and Wildlife Service
    Thursday, February 28, 2008 Part II Department of the Interior Fish and Wildlife Service 50 CFR Part 17 Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Contiguous United States Distinct Population Segment of the Canada Lynx (Lynx canadensis); Proposed Rule VerDate Aug<31>2005 18:58 Feb 27, 2008 Jkt 214001 PO 00000 Frm 00001 Fmt 4717 Sfmt 4717 E:\FR\FM\28FEP2.SGM 28FEP2 sroberts on PROD1PC70 with PROPOSALS 10860 Federal Register / Vol. 73, No. 40 / Thursday, February 28, 2008 / Proposed Rules DEPARTMENT OF THE INTERIOR Wildlife Service; 4401 N. Fairfax Drive, refined to more closely circumscribe the Suite 222; Arlington, VA 22203. boreal forest landscapes occupied by Fish and Wildlife Service We will not accept e-mail or faxed lynx. Refined maps that accurately comments. We will post all comments depict the specific vegetation types on 50 CFR Part 17 on http://www.regulations.gov. This all land ownerships are not readily generally means that we will post any available. We are especially interested [FWS–R6–ES–2008–0026] personal information you provide us in this information for the Greater 92210–1117–0000-B4] (see the Public Comments section below Yellowstone Area unit. RIN 1018–AV78 for more information). (9) Whether our proposed revised FOR FURTHER INFORMATION CONTACT: critical habitat for the lynx should be Endangered and Threatened Wildlife Mark Wilson, Field Supervisor, altered in any way to account for and Plants; Revised Critical Habitat for Montana Ecological Services Office, 585 climate change. the Contiguous United States Distinct Shepard Way, Helena, MT, 59601; (10) Whether the proposed revised critical habitat designation for the lynx Population Segment of the Canada telephone 406–449–5225.
    [Show full text]
  • Paleomagnetism of Four Late Cretaceous Plutons North Cascades, Washington William J
    Western Washington University Western CEDAR WWU Graduate School Collection WWU Graduate and Undergraduate Scholarship 1984 Paleomagnetism of Four Late Cretaceous Plutons North Cascades, Washington William J. (William James) Harrison Western Washington University Follow this and additional works at: https://cedar.wwu.edu/wwuet Part of the Geology Commons Recommended Citation Harrison, William J. (William James), "Paleomagnetism of Four Late Cretaceous Plutons North Cascades, Washington" (1984). WWU Graduate School Collection. 830. https://cedar.wwu.edu/wwuet/830 This Masters Thesis is brought to you for free and open access by the WWU Graduate and Undergraduate Scholarship at Western CEDAR. It has been accepted for inclusion in WWU Graduate School Collection by an authorized administrator of Western CEDAR. For more information, please contact [email protected]. PALEOMAGNETISM OF FOUR LATE CRETACEOUS PLUTONS NORTH CASCADES, WASHINGTON A Thesis Presented to The Faculty of Western Washington University In Partial Fulfillment Of the Requirements for the Degree Master of Science by William J. Harrison PALEOMAGNETISM OF FOUR LATE CRETACEOUS PLUTONS NORTH CASCADES, WASHINGTON by wmiarn J. Harrison Accepted in Partial Completion Of the Requirements for the Degree Master of Science Dean of Graduate School ADVISORY COMMITTEE MASTER'S THESIS In presenting this thesis in partial fulfillment of the requirements for a master"s degree at Western Washington University, I grant to Western Washington University the non-exclusive royalty-free right to archive, reproduce, distribute, and display the thesis in any and all forms, including electronic format, via any digital library mechanisms maintained by WWU. I represent and warrant this is my original work and does not infringe or violate any rights of others.
    [Show full text]
  • Pdf/12/3/900/4092675/900.Pdf 900 by Guest on 24 September 2021 Research Paper
    Research Paper GEOSPHERE Linking deep and shallow crustal processes during regional transtension in an exhumed continental arc, North Cascades, GEOSPHERE; v. 12, no. 3 northwestern Cordillera (USA) doi:10.1130/GES01262.1 Robert B. Miller1, Stacia M. Gordon2, Samuel Bowring3, Brigid Doran1, Noah McLean3*, Zachary Michels1*, Erin Shea1*, and Donna L. Whitney4 11 figures; 3 tables; 1 supplemental file 1Department of Geology, San Jose State University, One Washington Square, San Jose, California 95192-0102, USA 2Department of Geological Sciences and Engineering, University of Nevada-Reno, 1664 N. Virginia Street, Reno, Nevada 89557, USA 3Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue MIT Building 54, Cambridge, Massachusetts 02139, USA CORRESPONDENCE: robert .b .miller@ sjsu .edu 4Department of Earth Sciences, University of Minnesota, 310 Pillsbury Drive SE, Minneapolis, Minnesota 55455, USA CITATION: Miller, R.B., Gordon, S.M., Bowring, S., Doran, B., McLean, N., Michels, Z., Shea, E., and Whitney, D.L., 2016, Linking deep and shallow ABSTRACT basin, sediments were deposited in part at ca. 51 Ma, folded shortly afterward, crustal processes during regional transtension in an and then covered by ca. 49 Ma Teanaway basalts and intruded by associated exhumed continental arc, North Cascades, north- The North Cascades orogen (northwestern USA) provides an exceptional mafic dikes. Directly after dike intrusion, the fault-bounded Chumstick basin western Cordillera (USA): Geosphere,
    [Show full text]
  • CHAPTER 3 Affected Environment and Environmental Consequences
    CHAPTER 3 Affected Environment and Environmental Consequences Changes Between Draft and Final Environment Impact Statement Updated the visitor use information. Added environmental analysis of Alternative 4 Added environmental analysis of forest plan amendment concerning camps within 200 feet of meadows, streams, lakes, and key interest areas. Expanded analysis in each section to address DEIS comments and concerns. Incorporated information from 2012 Needs Assessment. Added an Economic and Social Analysis. Made numerous, minor editorial and spelling corrections. Chapter 3 Affected Environment and Environmental Consequences Introduction This chapter summarizes the affected physical, biological, social, and economic environments of the project area and the effects of implementing each alternative. The scientific and analytic basis is presented for the comparison of alternatives listed in Chapter 2. The effects disclosed are based on the effectiveness of the design criteria and mitigation measures outlined in Chapter 2. The analysis of resources uses varying measures due to management direction, research, or field practice. Therefore, the effect of similar resources cannot always be directly compared, although analysis for each alternative can be compared for the same resource. The effects resulting from each action are described in terms of their context, intensity, speed, direction, magnitude and duration. Other activities occurring in the same area over time, under certain circumstances, may have incremental effects that produce cumulative effects. It is sometimes necessary to look beyond the defined project area to determine the cumulative effects on certain resources. The effects disclose the direct and indirect effects plus the past, present, and reasonably foreseeable actions that define cumulative effect in this chapter.
    [Show full text]