DOCSLIB.ORG

NUREG/CR-1621, "Characterization of Faults in Appalachian Foldbelt."

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
NUREG/CR-1621, m NUREG/CR-1621 A Characterization of Faults in the Appalachian Foldbelt Prepared by A. L. Odom, R. D. Hatcher, Jr. Florida State University Prepared for U.S. Nuclear Regulatory Commission £CLos uRE I NOTICE This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, or any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for any third party's use, or the results of such use, of any information, apparatus product or process disclosed in this report, or represents that its use by such third party would not infringe privately owned rights. Available from GPO Sales Program Division of Technical Information and Document Control U. S. Nuclear Regulatory Commission Washington, D. C. 20555 and National Technical Information Service Springfield, Virginia 22161 NUREG/CR-1621 A Characterization of Faults in the Appalachian Foldbelt Manuscript Completed: July 1980 Date Published: September 1980 Prepared by A. L. Odom, R. D. Hatcher, Jr. Contributing Authors: D. E. Dunn - University of New Orleans T. J. Engelder - Lamont-Doherty Geologic Observatory P. A. Geiser - University of Connecticut S. A. Kish - University of North Carolina S. Schamel - Lafayette College D. U. Wise - University of Massachusetts Florida State University Tallahassee, FL 32306 Prepared for Division of Siting, Health and Safeguards Standards Office of Standards Development U.S. Nuclear Regulatory Commission Washington, D.C. 20555 NRC FIN No. B1053-8 ABSTRACT The characterization is a synthesis of available data on geologic faults in the Appalachian foldbelt regarding their description, generic implications, rate of movement, and potential as geologic-seismic hazards. It is intended to assist applicants and reviewers in evaluating faults at sites for nuclear facilities. Appalachian faults were found to fall into 13 groups which can be defined on either their temporal, generic, or descriptive properties. They are as follows: Group 1, faults with demonstrable Cenozoic movement; Group 2, Wildflysch type thrust sheets; Group 3, bedding plane thrusts - decollements; Group.4, pre- to synmetamorphic thrusts in medium to high grade terranes; Group 5, post-metamorphic thrusts in medium to high grade terranes; Group 6, thrusts rooted in low crystalline basement; Group 7, high angle reverse faults; Group 8, strike slip faults; Group 9, normal (block) faults; Group 10, compound faults; Group 11, structural lineaments; Group 12, faults associated with local centers; and Group 13, faults related to geomorphic phenomena. Unhealed faults (Groups 1, 6, 8, 9, and 12) must be considered candidates for reactivation. Heated brittle or ductile faults (Groups 4, 5, and 10) are not places of mechanical discontinuity and are unlikely candidates for reactivation. The remaining groups (2, 3, 7, 11, and 1:3) should be individually assessed as to their potential for reactivation. iii CONTENTS Page I. Introduction .................................................. I A. Purpose ....................... ......... ................... I B. Rationale ................................................. 2 II. Summary of Characteristics and Distribution of FaulTs in The Appalachian Foldbelt .......................................... 5 III. Fault Reactivation ............................................ 37 A. Fault classes most subject to reactivation ................ .37 B. Fault classes least subject to reactivation ............... 37 C. Successful techniques for dating last motion .............. 38 D. Relation of seismicity to surface breaks .................. 39 IV. Definition of Key Terms ....................................... 40 A. Fault ...................................................... 40 I. Ductile fault ......................................... 40 2. Brittle fault ......................................... 40 a. Unhealed .......................................... 40 b. Filled ............................................ 40 c. Healed ............................................ 40 B. Slip Versus Separation .................................... 42 C. Fault Zone Materials ...................................... 42 I. Products of cataclasis ................................ 42 2. Products of mylonitization .......................... 42 V. Faults With Demonstrable Cenozoic Movement (Group I) .......... 43 VI. Wlldflysche Type Sheets (Group 2) ............................. 59 VII. Bedding Plane Thrusts -- Decollements (Group 3) ............... 81 V VIII. Pre-to Synmetamorphic Faults in Medium to High Grade Terrane (Group 4) ........................................................... III IX. Postmetamorphic Thrusts In Medium to High Grade Terranes (Group 5) .................................. ... ...... 125 X. Thrusts Rooted in Low Grade To Unmetamorphosed Crystalline Basement (Group 6) .................................... ......... 139 XI. High Angle Reverse Faults (Group 7) ............ 153 XII. Strike -slip Faults (Group 8) ....................... 162 XIII. Normal (Block) Faults (Group 9) ..................................... 190 XIV. Compound Faults With Long, Repeated Movement History (Group 10) .......................................................... 208 XV. Structural Lineaments (Group II) .................................... 233 XVI. Faults Associated With Local Centers (Group 12) ...................... 242 XVII. Geomorphic Faults (Group 13) ........................................ 252 XVIII. Glossary ............................................................ 261 XIX. Suggestions ......................................................... 270 XX. Appendices A. Critical need for in situ stress measurements ................... 275 B. Problems of DistinguishIng Between Seismic and Aseismic Faults i. 279 C. Cataclasis versus mylonitization ................................ 282 D. Linemanship ..................................................... 289 vi List of Illustrations Figure Page I-I Geotectonic map of the Appalachian Foldbelt ................ 6 11-2 Map Showing Distribution of Group I Faults ................. 7 11-3 I I 11 it i 2 It 8 11-4 i t if i W 3 I .99................. 11-5 If I I " It 4 ................. 10 11-6 I iI15 I. 5 ". II 12 11-7 W it WI ". 6 I. 11-8 I I i W W 8 ................. 13 . 14 11- 9 Wt WI I. 9 . ... ... 15 11-10 WI... W 10.WI10 12 ............. 16 WISW W" W" WI 13 WI" 17 1112 17 1 1 o .......... IV-I Relation Between Brittle and Ductile Faults ................ 41 V-I Recent Thrusting and Folding of a Syncline ................ 45 V-2 Map of Stafford and Brandywine Fault Systems .............. 48 V-3 Stratigrafic Variations across Stafford Fault Systems ...... 50 V-4 Geologic Cross Section in Area of Stafford ................ 51 Vl-I Schematic Representation of Three Types of Submarine Slides. 60 VI-2 Eastern North America During the Ordovician ................ 62 VI-3 Tectonic Units of the Taconic Allochthon ................... 63 VI-4 Cross Section of Central Taconic Range ..................... 63 VI-5 Map of Pennsylvania Great Valley and Allochthonous Rocks in Martinsburg Fm ....................................... 65 VI-6 Allochthons of Martinsburg Fm, Pennsylvania ................ 66 VI-7 Geologic Cross Section Along West Bank of Susquehanna River. 67 VI-8 Pre-Taconic and Taconian Evolution of North American in Western New England ....................... 71 VI-9 Model for the Evolution of the Appalachian Orogen ....... 72 VI-lO Diagram of Alternative Gravitational Emplacement Models .... 74 VI-II Schematic Section Showing Emplacement of Thrust Sheets ... 74 VII-I Ramping of Bedding Plane Fault ............................ 82 VII-2 Bedding Plane Fault Climbing Section by Decollement ..... 83 VII-3 Relationship Between Folding and Faulting .................. 84 VII-4 Apparent Violations of Dahlstroms Rules of Thrusting ...... 86 VI1-5 Thrust Fault Anatomy ...................................... 86 VII-6 Thrust Fault Terminology .................................. 87 VII-7 Complications of Thrust Faulting Geometry-Leading Edge ..... 8 VII-8 It it "I Wi "I -Trailing 8892 VI1-9 Bow Thrust ................................................ 92 V II-I 0 Rectangular Thrust ............... ........ ................ 92 Vi I-Il Secondary Transverse Tear Faults ........................... 93 VI1-12 Termination of Bedding Plane Thrust Into Folds ............. 93 VII-13 Terminations of Bedding Plane Thrust ..................... 94 VI 1-14 Relationship Between Detachment Surface and Silurian Salt Horizon ............................................ 100 VIl-15 Independence Between Paleo-isotherms and Detachment Surface ................................................. 103 VIII-I Folded, Imbricate Group 4 Thrusts of the Martic Region ..... 113 VIII-2 Major Structural Features of Eastern Connecticut ........... 114 Vii IX-I Typical Group 5 Thrust ....................................... 126 IX-2 Geologic Section of the Blue Ridge Province (N.C. - Tenn.) 129 IX-3 Cross Section of the Southern Appalachians ... 130 IX-4 Geologic Map of the Northeast End of the Alto AIlochthon ..... 131 X-1 Cross Section along the Valley and Ridge - Blue Ridge Boundary .................................................. 140 X-2 Section Acrossthe Reading Prong, Delaware Valley ............ 141 X-3 Map and Section of Little Stone Mountain (Tenn.) ............. 142 X-4 Map and Section of South Sandis field Quadrangle (Mass.) ..... 144 X-5 Geologic
Load more

Recommended publications
  • Chapter 1 -- the Place of Faults in Petroleum Traps
    Sorkhabi, R.,and Y. Tsuji, 2005, The place of faults in petroleum traps, in R. Sorkhabi and Y. Tsuji, eds., Faults, fluid flow, and petroleum traps: AAPG Memoir 85, 1 p. 1 – 31. The Place of Faults in Petroleum Traps Rasoul Sorkhabi1 Technology Research Center, Japan National Oil Corporation, Chiba, Japan Yoshihiro Tsuji2 Technology Research Center, Japan National Oil Corporation, Chiba, Japan ‘‘The incompleteness of available data in most geological studies traps some geologists.’’ Orlo E. Childs in Place of tectonic concepts in geological thinking (AAPG Memoir 2, 1963, p. 1) ‘‘Although the precise role of faults has never been systematically defined, much has been written that touches on the subject. One thing is certain: we need not try to avoid them.’’ Frederick G. Clapp in The role of geologic structure in the accu mulation of petroleum (Structure of typical American oil fields II, 1929, p. 686) ABSTRACT ver since Frederick Clapp included fault structures as significant petroleum traps in his landmark paper in 1910, the myriad function of faults in petroleum E migration and accumulation in sedimentary basins has drawn increasing atten- tion. Fault analyses in petroleum traps have grown along two distinct and successive lines of thought: (1) fault closures and (2) fault-rock seals. Through most of the last century, geometric closure of fault traps and reservoir seal juxtaposition by faults were the focus of research and industrial application. These research and applications were made as structural geology developed quantitative methods for geometric and kine- matic analyses of sedimentary basins, and plate tectonics offered a unified tool to correlate faults and basins on the basis of the nature of plate boundaries to produce stress.
    [Show full text]
  • Exhibit 9 Northern Pass Project General Area Map of South Section
    Exhibit 9 Northern Pass Project General Area Map of South Section \\ESPSRV\Data\Data2\Projects\NUS\53899_DC_Tline\GIS\DataFiles\ArcDocs\Presidential Permit\Exhibit_9_South_Section_22x34_062713.mxd Map Index .! LEGEND Project Area State Boundary *# Existing Substation Appalachian Trail North *# Proposed Converter Station o Airport .! Proposed Route Public Lands and Conservation Easements Primary Protecting Agency Existing Transmission ROW Central George Duncan State Forest Federal Huston - Morgan State Forest Scenic Roads/Byways (!11 Ellacoya State Park New Hampton State Meredith .! City/Village Municipal/County CARROLLSouth Town Boundary Opechee Bay State Forest Other Public/Quasi-Public Governors State Park COUNTY County Boundary Private NEWWolfeboro HAMPSHIRE Sleeper - Agric. Pres. Rest. Knights Pond Black Brook WMA Laconia 3 ¤£ Saltmarsh Pond Boat Launch Facility Sanbornton Gilford Beaver Brook CE .! Hill Laconia Beaver Brook WMA *# Saltmarsh Pond State Forest Laconia S/S Belknap Mountain State Forest Mount Major State Forest (!11 Franklin Falls Reservoir Hidden Valley CE Alton Welch - Agric. Pres. Rest. Webster Lake WMA (!127 Brennick Lochmere Archaeological Site Merrymeeting Lake Dam Lochmere Dam Site Belmont Alton Bay State Forest Powdermill Fish Hatchery Franklin Tilton BELKNAP Webster S/S 107 New Durham (! COUNTY Merrymeeting Marsh Dam - Alton *# Coldrain Pond Remote Access Facility Sanborn State Forest .! Alton Franklin STRAFFORD .! Tilton .! .! COUNTY Belmont .! Northfield (!140 Merrymeeting Marsh WMA Page State Forest Gilmanton Northfield Meadow Pond State Forest Daniel Webster Birthplace Historic Site Rocky Pond Restoration Area North Island Proposed Converter Station Ingalls Island *# Salisbury Mitigation Tract State Forest Nursery Shaker State Forest Ayers State Forest Meeh, M.G. & T. Easement B Meeh & McCullough Prescott (!132 ¤£4 (!106 Shaker Village Barnstead Farmington Easement G Canterbury Soucook River WMA Bergeron WMA Blue Job WMA Osborne WMA Smith Tract (Lot 2) Merrimack River State Forest Grady Tract Hildreth - Agric.
    [Show full text]
  • Geology of the Blue Heron Nature Preserve, Atlanta, Georgia
    Geology of the Blue Heron Nature Preserve, Atlanta, Georgia By naturalist L. Scott Ranger There are two stories to tell about the geology of the Blue Heron Nature Preserve: the very small scale of rocks on the ground at the preserve; and, the very large scale of both time and space of the preserve and its place on the surface of planet earth. On the ground at the preserve… The entire property—and much of this part of North Atlanta—is located on a geologic formation mapped as the button schist (POb). Unlike most geologic formation names, this really isn’t a name, but simply a description of the kind of rock that is found here. It has been called this since the early twentieth century but became more formalized in 1966 with the publishing of Michael W. Higgin’s The Geology of the Brevard Lineament Near Atlanta, Georgia as Bulletin 77 of the now defunct Georgia Geological Survey. This map locates the Blue Heron Nature Preserve in its North Atlanta setting. National Park Service (NPS) Geologic Resources Inventory (GRI) program. 2012. Unpublished Digital Geologic Map of the Northern portion of Chattahoochee River National Recreation Area, Georgia (NPS, GRD, GRI, CHAT, CHTN digital map) adapted from U.S. Geological Survey Open-File Report Series digital map by Dicken et. al. (2005). National Park Service (NPS) Geologic Resources Inventory (GRI) program. Geospatial Dataset-2188723. https://irma.nps.gov/App/Reference/Profile/2188723 National Park Service (NPS) Geologic Resources Inventory (GRI) program. 2012. Unpublished Digital Geologic Map of the Southern portion of Chattahoochee River National Recreation Area, Georgia (NPS, GRD, GRI, CHAT, CHTS digital map) adapted from a U.S.
    [Show full text]
  • Fault Rocks and Fault Mechanisms
    Fault rocks and fault mechanisms R. H. SIBSON SUMMARY Physical factors likely to affect the genesis of the with the production of mylonite series rocks various fault rocks--frictional properties, tem- possessing strong tectonite fabrics. In some cases, perature, effective stress normal to the fault and fault rocks developed by transient seismic fault- differential stress--are examined in relation to ing can be distinguished from those generated the energy budget of fault zones, the main by slow aseismic shear. Random-fabric fault velocity modes of faulting and the type of fault- rocks may form as a result of seismic faulting ing, whether thrust, wrench, or normal. In a within the ductile shear zones from time to conceptual model of a major fault zone cutting time, but tend to be obliterated by continued crystalline quartzo-feldspathic crust, a zone of shearing. Resistance to shear within the fault elastico-frictional (EF) behaviour generating zone reaches a peak value (greatest for thrusts random-fabric fault rocks (gouge--breccia-- and least for normal faults) around the EF/OP cataclasite series--pseudotachylyte) overlies a transition level, which for normal geothermal region where quasi-plastic (QP) processes of gradients and an adequate supply of water, rock deformation operate in ductile shear zones occurs at depths of lO-15 km. SINCE LAPWORTH'$ (I885) description of the type mylonite from the Moine Thrust in NW Scotland, there have been many petrographic descriptions and classifications of the texturally distinctive rocks found associated with fault zones (e.g. Waters & Campbell 1935, Hsu 1955, Christie 196o , 1963, Reed 1964, Spry I969, Higgins 1971 ).
    [Show full text]
  • Lithology and Internal Structure of the San Andreas Fault at Depth Based
    1 1 Lithology and Internal Structure of the San Andreas Fault at depth based on 2 characterization of Phase 3 whole-rock core in the San Andreas Fault Observatory at 3 Depth (SAFOD) Borehole 4 By Kelly K. Bradbury1, James P. Evans1, Judith S. Chester2, Frederick M. Chester2, and David L. Kirschner3 5 1Geology Department, Utah State University, Logan, UT 84321-4505 6 2Center for Tectonophysics and Department of Geology and Geophysics, Texas A&M University, College Station, 7 Texas 77843 8 3Department of Earth and Atmospheric Sciences, St. Louis University, St. Louis, Missouri 63108 9 10 Abstract 11 We characterize the lithology and structure of the spot core obtained in 2007 during 12 Phase 3 drilling of the San Andreas Fault Observatory at Depth (SAFOD) in order to determine 13 the composition, structure, and deformation processes of the fault zone at 3 km depth where 14 creep and microseismicity occur. A total of approximately 41 m of spot core was taken from 15 three separate sections of the borehole; the core samples consist of fractured arkosic sandstones 16 and shale west of the SAF zone (Pacific Plate) and sheared fine-grained sedimentary rocks, 17 ultrafine black fault-related rocks, and phyllosilicate-rich fault gouge within the fault zone 18 (North American Plate). The fault zone at SAFOD consists of a broad zone of variably damaged 19 rock containing localized zones of highly concentrated shear that often juxtapose distinct 20 protoliths. Two zones of serpentinite-bearing clay gouge, each meters-thick, occur at the two 21 locations of aseismic creep identified in the borehole on the basis of casing deformation.
    [Show full text]
  • Bare Bedrock Erosion Rates in the Central Appalachians, Virginia
    W&M ScholarWorks Undergraduate Honors Theses Theses, Dissertations, & Master Projects 5-2009 Bare Bedrock Erosion Rates in the Central Appalachians, Virginia Jennifer Whitten College of William and Mary Follow this and additional works at: https://scholarworks.wm.edu/honorstheses Part of the Geology Commons Recommended Citation Whitten, Jennifer, "Bare Bedrock Erosion Rates in the Central Appalachians, Virginia" (2009). Undergraduate Honors Theses. Paper 326. https://scholarworks.wm.edu/honorstheses/326 This Honors Thesis is brought to you for free and open access by the Theses, Dissertations, & Master Projects at W&M ScholarWorks. It has been accepted for inclusion in Undergraduate Honors Theses by an authorized administrator of W&M ScholarWorks. For more information, please contact [email protected]. BARE BEDROCK EROSION RATES IN THE CENTRAL APPALACHIANS, VIRGINIA A thesis submitted in partial fulfillment of the requirement for the degree of Bachelors of Science in Geology from The College of William and Mary by Jennifer Whitten Accepted for ___________________________________ (Honors, High Honors, Highest Honors) ________________________________________ Gregory Hancock, Director ________________________________________ Christopher Bailey ________________________________________ James Kaste ________________________________________ Scott Southworth Williamsburg, VA April 30, 2009 Table of Contents Abstract......................................................................................................................................................3
    [Show full text]
  • Skempton's Poroelastic Relaxation
    Datashare 129 Skempton’s poroelastic relaxation: The mechanism that accounts for the distribution of pore pressure and exhumation-related fractures in black shale of the Appalachian Basin Terry Engelder and Rose-Anna Behr AAPG Bulletin, v. 105, no. 4 (April 2021), pp. 669–694 Copyright ©2021. The American Association of Petroleum Geologists. All rights reserved. EXPLANATIONS FOR TABLE 2: In an expansion of work by Sheldon (1912) on COMPARATIVE TERMINOLOGIES FROM the Appalachian Plateau, east-northeast fractures were SELECTED JOINT STUDIES IN THE mapped across a region large enough to sample rocks APPALACHIAN BASIN through a 20° swing of the Appalachian oroclinal bend (Parker, 1942). Parker (1942) relabeled the strike fi The rst depictions of Appalachian Basin fractures joints in Sheldon (1912) as set III (accompanying paper were in wood block prints by Sarah Hall as they appear Table 2 and in this Datashare). This was necessary ’ in her husband s paper from the geological survey of because the azimuth of these set III joints (i.e., the east- the fourth district of New York (Hall, 1843). A print northeast set) did not follow around the oroclinal of Taughannock Falls cascading over the Geneseo bend as defined by fold axes. Parker (1942, p. 406) black shale a few kilometers north of Ithaca, New York, writes, “Their different character and constant strike shows two major joint sets that are not quite orthogonal. over the whole region point definitely to an indepen- The artist even captured a hint of lithological control dent origin, perhaps simultaneous or perhaps much of the black shale on joint development.
    [Show full text]
  • Regatta Displays Students' Sailing Skills
    THURSDAY, JULY 30, 2015 GILFORD, N.H. - FREE Regatta displays students’ sailing skills BY ERIN PLUMMER “You’re teaching [email protected] them a lifelong skill,” A flurry of white sail- Sperazzo said. “These boats raced across Win- kids, age seven, eight, nipesaukee, all piloted nine, 10, will use this for by kids and teens from the rest of their life.” around New Hampshire, Students from the Maine, and beyond sailing school have gone during the annual Win- onto race in high school nipesaukee Annual Re- and college and one is gatta. teaching at the college Students from ele- level. mentary school through The association also high school ages put has a sailing program their boats in the water for adults. at the Winnipesaukee LWSA’s programs Yacht Club on Thursday will see around 230 kids morning and took off for over the summer and the annual race put on around 30 adults, mak- by the Lake Winnipesau- ing for around 260 people kee Sailing Association. taking part. Students in the regatta The race was a unique came from the Lake Win- experience for all par- nipesaukee Sailing As- ticipants, including the sociation as well as the ones from other clubs. Sunapee Yacht Club and Jess Young and Peter PHOTO BY ERIN PLUMMER the Agamenicus Yacht O’Brien are associate Students race across the water during the annual Winnipesaukee Regatta. Club out of York, Maine. race coaches for the Ag- Participants on a Winnipesaukee Yacht high regatta. to 16-years-old. Sperazzo said the stu- amenicus Yacht Club. small fleet of eleven 420 Club for an awards cere- The regatta is part of Students in the pro- dents put their skills to “We brought these boats and four on the mony and a barbeque.
    [Show full text]
  • Sedimentological Constraints on the Initial Uplift of the West Bogda Mountains in Mid-Permian
    www.nature.com/scientificreports OPEN Sedimentological constraints on the initial uplift of the West Bogda Mountains in Mid-Permian Received: 14 August 2017 Jian Wang1,2, Ying-chang Cao1,2, Xin-tong Wang1, Ke-yu Liu1,3, Zhu-kun Wang1 & Qi-song Xu1 Accepted: 9 January 2018 The Late Paleozoic is considered to be an important stage in the evolution of the Central Asian Orogenic Published: xx xx xxxx Belt (CAOB). The Bogda Mountains, a northeastern branch of the Tianshan Mountains, record the complete Paleozoic history of the Tianshan orogenic belt. The tectonic and sedimentary evolution of the west Bogda area and the timing of initial uplift of the West Bogda Mountains were investigated based on detailed sedimentological study of outcrops, including lithology, sedimentary structures, rock and isotopic compositions and paleocurrent directions. At the end of the Early Permian, the West Bogda Trough was closed and an island arc was formed. The sedimentary and subsidence center of the Middle Permian inherited that of the Early Permian. The west Bogda area became an inherited catchment area, and developed a widespread shallow, deep and then shallow lacustrine succession during the Mid- Permian. At the end of the Mid-Permian, strong intracontinental collision caused the initial uplift of the West Bogda Mountains. Sedimentological evidence further confrmed that the West Bogda Mountains was a rift basin in the Carboniferous-Early Permian, and subsequently entered the Late Paleozoic large- scale intracontinental orogeny in the region. The Central Asia Orogenic Belt (CAOB) is the largest accretionary orogen on Earth, which was formed by the amalgamation of multiple micro-continents, island arcs and accretionary wedges1–5.
    [Show full text]
  • Geologic Controls on the Morphology of the Chattooga River
    Geologic Controls on the Morphology of the Chattooga River Scott E. Brame Geological Sciences Clemson University Clemson, SC 29634 and Robert D. Hatcher, Jr. Earth and Planetary Sciences and Science Alliance Center of Excellence University of Tennessee Knoxville, TN 37996–1410 Abstract The East fork of the Wild and Scenic Chattooga River drains the south side of Whiteside Mountain in North Carolina and flows in a predominant southwesterly direction following the predominant joint direction, and to a much lesser extent the foliation, until it turns sharply to the southeast becoming part of the Savannah River system and flows to the Atlantic Ocean. Paralleling the northeast to southwest trend is the Brevard fault zone and two other river systems, the Chauga River in South Carolina and the Chattahoochee River in Georgia. The Chauga follows a pattern similar to that of the Chattooga, turning sharply to the southeast after flowing predominantly to the southwest from its headwaters. The locations that mark the abrupt turn of the flow of the Chattooga and Chauga Rivers from the southwest to the southeast are likely the result of stream piracy as proposed by Acker and Hatcher. The upper sections of the Chattooga and Chauga represent an extension of the Dahlonega Plateau with a topographic surface that has a maximum elevation of approximately 1600 feet. The 1600’ surface is a piedmont surface at the base of the Blue Ridge. Differential erosion along northeast- and northwest-trending joint sets has exerted a powerful control on the development of the landscape. The northwest-trending joint sets have encouraged headward erosion and breaching of the Dahlonega Plateau surface resulting in stream capture of both the Chattooga and Chauga watersheds by the Savannah River system.
    [Show full text]
  • Evolution of Extensional Basins and Basin and Range Topography West of Death Valley, California K.V
    TECTONICS, VOL. 8, NO. 3, PAGES453-467, JUNE 1989 EVOLUTION OF EXTENSIONAL BASINS AND BASIN AND RANGE TOPOGRAPHY WEST OF DEATH VALLEY, CALIFORNIA K.V. Hodges,L.W. McKenna,J. Stock •, J. Knapp, L. Page,K. Sternlof, D. Silverberg,G. Wrist2, and J. D. Walker 3 Department of Earth, Atmospheric,and Planetary Sciences,Massachusetts Institute of Technology, Cambridge Abstract. Neogeneextension in the Death Valley system remained active during development of region, SE California, has produced a variety of PanamintValley and, thus, during developmentof sedimentarybasins. Diachronousmovements on an modernBasin and Rangetopography as well. These array of strike-slip and normal fault systemshave results indicate that large-scale extension in the resultedin the uplift andpreservation of olderbasins Death Valley region,accommodated by movementon in modernranges. One of the bestexposed of these low- to moderate-angle normal fault systemsand is the Nova basin on the western flank of the high-angle strike-slipfault systems,is a continuing Panamint Mountains. The Nova basin includes over process. Basin and Range topography in the 2000 m of sedimentaryand volcanicrocks deposited PanamintValley- Death Valley areawas generatedat during denudation of the Panamint Mountains least in part by displacements on low-angle metamorphiccore complex in late Miocene(?)- early detachmentsrather than high-angle normal faults. Pliocenetime. The principalgrowth structure for the basinwas the Emigrant detachment,which initiated andmoved at a low angle. Modern PanamintValley, INTRODUCTION west of the range, developedas a consequenceof Late Pliocene- Recent,kinematically linked move- The fact that topographyin the Basin and Range ment on the right-slip, high-angleHunter Mountain Province of the western United States is controlled fault zone and the low-angle Panamint Valley by normal faulting has been recognizedfor over a detachment.
    [Show full text]
  • Mar 1995 Newsletter
    The Tennessee Eastman March 1995 HIKING & PADDLING NEWS Contents Next Two Months at a Glance Hiking Paddling For The Record NEXT TWO MONTHS May 6 Grandfather Mountain M R. Lott May 6-7 Bluestone II-III T. Dougherty May 13 A.T. - 421-McQueens Gap E-M C. Moorehouse May 13 A.T. Days in Damascus, VA FUN J. DeLoach May 13 Lower Nolichucky II B. Dayvolt May 18,20,21 Canoe School B. Dayvolt May 20 Laurel Fork Trail to Laurel Fork Falls E-M T. McClain May 27-June 3 A.T. - Central Pennsylvania D S. Banks June 3 National Trails Day June 4 Leader's Choice I-II T. Horton June 10 A.T. - Indian Grave Gap to Nolichucky E-M C. Moorehouse Grayson Highland State Park (Mt June 17 M S. Wilson Rogers) June 24 Lower Watauga I-II M. Morrow HIKING HUMP MOUNTAIN (Scheduled: Sat, 1 April 95) Leader: Collins Chew Hike canceled because of conflict with Southern Regional Management Committee Meeting. Sorry. MOUNTAIN BIKING ON THE CREEPER TRAIL- ABINGDON TO DAMASCUS AND BACK (Scheduled: Sat, 8 April 95) Leader: Liz West Rating: 30 miles of ~7% grade Participants must have a mountain bike or a properly outfitted cross-training bike and wear a helmet. Plan to carry plenty of water and a lunch. If we travel the itinerary at a good pace and stop for a brief picnic, we ought to be back in Kingsport by ~3pm. Contact trip leader if you are interested in attending. Meet in front of Eastman Employee Center at 8am.
    [Show full text]