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The Great Rift Valleys of Pangea in Eastern North America

The Great Rift Valleys of Pangea in Eastern North America: Volume 1

Copyright Date: 2003
Pages: 240
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  • Book Info
    The Great Rift Valleys of Pangea in Eastern North America
    Book Description:

    Rift basins of Triassic-Jurassic age that are associated with the breakup of the Pangean supercontinent contain an extraordinary record of the physical and biological conditions during this important period of Earth history. Rather than studying the rift basins as local features, ongoing work reveals that the Triassic-Jurassic rifts should be considered in a broader context that spans the entire proto-Atlantic realm. The rift province, collectively called the central Atlantic margin system, spans more than 45 degrees of paleolatitude and records over 35 million years of Earth history. The central Atlantic margin basins are of broad appeal to researchers interested in topics as diverse as extensional tectonics, the global magnetostratigraphic timescale, the evolution of early mammals, the appearance and diversification of dinosaurs, rift to drift crustal dynamics, astronomical forcing of climate, and models for the formation and occurrence of economic minerals and fossil fuel deposits. This extensive two-volume work offers in-depth coverage of the North American components of the Central Atlantic Magmatic Province rifts by experts in the field.

    In volume 1, leading researchers give thoroughly reviews and highlight recent advances in our understanding of the structural geology, tectonics, and volcanism of the Central Atlantic Magmatic Province.

    The companion volume, The Great Rift Valleys of Pangea in Eastern North America: Volume 2, Sedimentology, Stratigraphy, and Paleontology, 0-231-12676-X, covers such topics as sedimentary rocks, stratigraphic architecture, early dinosaur and reptile footprints, and vertebrate fossils of the Central Atlantic Magmatic Province. It is edited by Peter M. LeTourneau and Paul E. Olsen and is also available from Columbia University Press.

    eISBN: 978-0-231-53437-6
    Subjects: Paleontology, Geology, General Science, Geography

Table of Contents

  1. Front Matter
    (pp. i-iv)
  2. Table of Contents
    (pp. v-vi)
    (pp. vii-xii)
    Peter M. LeTourneau and Paul E. Olsen
  4. 1 Introduction
    (pp. 1-4)
    Peter M. LeTourneau and Paul E. Olsen

    Rift basins of the Triassic–Jurassic age associated with the breakup of the Pangean supercontinent contain an extraordinary record of the physical and biological conditions at a critical period of Earth history. Rather than considering the rift basins as local features of limited interest, ongoing work reveals that these Triassic–Jurassic rifts should be studied in a broader context that spans the entire proto-Atlantic realm, including eastern North America, Greenland, the British Isles, and North Africa, as well as South America and central West Africa (figure 1.1). The rift province, collectively called the central Atlantic margin (CAM) system (Olsen 1977),...

  5. PART I Tectonics and Structure of Supercontinent Breakup

    • 2 Introduction
      (pp. 7-10)
      Martha Oliver Withjack and Roy W. Schlische

      The chapters in part I provide new and valuable information about the tectonic and structural evolution of eastern North America during the breakup of the Pangean supercontinent. Specifically, these chapters reveal a remarkably consistent story about the synrift and postrift stages of development of this passive continental margin. This consistency is especially noteworthy because the authors employ different approaches applied at different scales along virtually the entire length of the Mesozoic rift system.

      In chapter 3, Dennis V. Kent and Giovanni Muttoni use paleomagnetic data to discuss the likely platetectonic configurations of Pangea from Permian to Middle Jurassic time. In...

    • 3 Mobility of Pangea: Implications for Late Paleozoic and Early Mesozoic Paleoclimate
      (pp. 11-20)
      Dennis V. Kent and Giovanni Muttoni

      Several recent analyses of paleomagnetic data support the concept of Pangea, the late Paleozoic and early Mesozoic assemblage of most of the world’s continents, that was mobile in terms of large-scale internal deformation and with respect to paleolatitude. The main feature of internal deformation involved the transformation from a Pangea B–type configuration in the late Paleozoic, with northwestern South America adjacent to eastern North America, to a more traditional Pangea A–type configuration in the early Mesozoic, with northwestern Africa adjacent to eastern North America. Pangea B thus seems to coincide in time with extensive low-latitude coal deposition and...

    • 4 Progress in Understanding the Structural Geology, Basin Evolution, and Tectonic History of the Eastern North American Rift System
      (pp. 21-64)
      Roy W. Schlische

      Five key developments have contributed significantly to our understanding of the structural geology, basin evolution, and tectonic history of the eastern North American rift system:

      1. Acquisition of new data. Over the past two decades, regional and local geologic mapping, drilling and coring, and seismic-reflection profiling have increased vastly our structural and tectonic database. It is now clear that these basins are predominantly half-graben, with generally synthetic intrabasinal faults and fault-perpendicular folds that in many cases are related to fault segmentation.

      2. Role of preexisting structures. The rift system is located within the Appalachian orogen, and thus the border-fault systems of the...

    • 5 Tectonics of the Lantern Hill Fault, Southeastern Connecticut: Embryonic Rifting of Pangea Along the Central Atlantic Margin
      (pp. 65-79)
      Robert J. Altamura

      The Lantern Hill fault is a 16 km long, N–S-trending, hypersilicified, breccia zone that transgresses meta-igneous and metasedimentary units of the Proterozoic Z Avalonian terrane in southeastern Connecticut. The fault zone is massively silicified along its length, especially at its northern end, where it intersects the Honey Hill fault—the terrane boundary between Avalonian and Gander terranes.

      An analysis of stress and sense-of-slip indicators as recorded by faults and quartz-filled fractures in the Lantern Hill fault zone indicates that it formed in a region of crustal extension with $ \sigma_{1} $ subvertical and $ \sigma_{3} $ subhorizontal along an azimuth of 105˚. Analysis...

    • 6 Estimates of Eroded Strata Using Borehole Vitrinite Reflectance Data, Triassic Taylorsville Rift Basin, Virginia: Implications for Duration of Synrift Sedimentation and Evidence of Structural Inversion
      (pp. 80-103)
      MaryAnn Love Malinconico

      Linear regression of the base 10 logarithm (log10) of percent mean random vitrinite reflectance versus depth for boreholes in the early Mesozoic Taylorsville basin, Virginia, was used to estimate the amount of synrift strata eroded and, with estimates of sedimentation rate, the duration of synrift sedimentation. The basin is one of several Triassic–Jurassic continental rift basins containing Newark Supergroup lacustrine and fluvial sediments that formed during the breakup of Pangea. The amount of missing section varies across the basin from approximately 0.9 to 2.6 km, the maximum occurring over a basement antiform, which is attributed to postrift inversion. The...

    • 7 Stress Regimes in the Newark Basin Rift: Evidence from Core and Downhole Data
      (pp. 104-117)
      David Goldberg, Tony Lupo, Michael Caputi, Colleen Barton and Leonardo Seeber

      Analysis of composite geophysical and borehole televiewer logs in the Newark basin drill holes indicate basinwide changes in its physiochemical properties and stress regimes from the Late Triassic to the present day. During its evolution as an enclosed lake basin, approximately 2% organic content was deposited in gray-black shales, which we have estimated from the resistivity log. The basin was extensively deformed throughout its history, and we consequently observed significant fracturing in acoustic images recorded by the borehole televiewer. Both open and filled fractures having greater than 0.5 cm aperture are identified in two well-defined populations, one dipping steeply and...

    • 8 A Lagerstätte of Rift-Related Tectonic Structures from the Solite Quarry, Dan River–Danville Rift Basin
      (pp. 118-134)
      Rolf V. Ackermann, Roy W. Schlische, Lina C. Patiño and Lois A. Johnson

      The Solite Quarry within the Dan River–Danville basin contains an extensive suite of riftrelated structures. The cyclical upper member of the Cow Branch Formation has been deformed both in continuous fashion and via three brittle failure modes, exhibiting fracture partitioning such that failure mode is lithologically dependent. All structures are tectonic; extension estimates are roughly comparable for all failure modes; and there is an absence of bedding-parallel detachment horizons with normal separation. All extensional structures formed in response to Triassic rifting. These observations imply that different beds failed coevally or semicoevally in extension. All contractional structures are consistent with...

  6. PART II The Central Atlantic Large Igneous Province

    • 9 Introduction
      (pp. 137-140)
      Paul E. Olsen and J. Gregory McHone

      Large igneous provinces (LIPs) comprise enormous edifices of basaltic lava and associated igneous rocks emplaced over a relatively brief time interval (Coffin and Eldholm 1994). Two of the largest terrestrial LIPs, the Siberian Traps (~2.5 × 10⁶ km³) and Deccan Traps (~2.6 × 10⁶ km³), are continental flood basalts associated in time with a mass extinction—the Siberian Traps with the end-Permian extinction at 250 Ma and the Deccan Traps with the end-Cretaceous extinction at 65 Ma (McLean 1985; O’Keefe and Ahrens 1989; Caldeira and Rampino 1990; Courtillot et al. 1994) (figure 9.1). The early Mesozoic basaltic rocks of eastern...

    • 10 Flood Basalt Provinces of the Pangean Atlantic Rift: Regional Extent and Environmental Significance
      (pp. 141-154)
      J. Gregory McHone and John H. Puffer

      The original extent of Hettangian Pangean rift basalts is estimated from maps of feeder dikes and Mesozoic basins that contain remnants of the basalts. Dikes and basalts across the initial Pangean rift zone are correlated by radiometric dates near 200 Ma, stratigraphy of associated basin sediments, and chemical characteristics. Intermediate-Ti quartz-normative tholeiites in northeastern North America and Morocco were derived from large NE-trending dikes that define a northern subprovince over much of modern northeastern North America, northwestern Africa, and the Iberian Peninsula, with an area approximately 2.8 × 10⁶ km². Other quartz and olivine tholeiites comprise 2 × 10⁵ km²...

    • 11 Geochemistry and Origin of Pangean and Rodinian Continental Flood Basalts
      (pp. 155-171)
      John H. Puffer

      The rifting of the Pangean supercontinent during the Mesozoic was a rare geologic event. It was preceded, however, by the rifting of the Rodinian supercontinent during the late Proterozoic. In both cases, continental flood basalts (CFBs) were extruded along major portions of intracratonic rifts. With the quantity of geochemical analytical data presently available on a worldwide basis, it now is possible to compare Pangean and Rodinian basalts with each other and with the flood basalts that are not associated with the fragmentation of supercontinents. Such a comparison shows that there are major differences in the composition of most Pangean CFBs...

    • 12 A Geographic Trend for MgO-Standardized Major Oxides in Lower Mesozoic Olivine Tholeiites of the Southeastern United States
      (pp. 172-188)
      Paul C. Ragland, Vincent J. M. Salters and William C. Parker

      A dataset of 325 screened major-oxide analyses from lower Mesozoic, olivine-tholeiitic diabase dikes of the southeastern United States was compiled. These tholeiites are part of the recently recognized ~200 Ma Central Atlantic Magmatic Province (CAMP), a large igneous province found on four circum-Atlantic continents. The data were examined in the light of petrologic considerations, such as degree and depth of melting of a mantle source, as well as with regard to correlations between geographic location and geochemistry. Most of the samples are from the swarm of NW-trending dikes that extends from central Virginia to Alabama. The analyses were standardized to...

    • 13 Evidence for Predominant Lateral Magma Flow Along Major Feeder-Dike Segments of the Eastern North America Swarm Based on Magnetic Fabric
      (pp. 189-206)
      Jelle Zeilinga de Boer, Richard E. Ernst and Andrew G. Lindsey

      Studies of magma flow can be used to test source model hypotheses for giant radiating diabase dike swarms. Long “master” dikes in the eastern North American segment of the 200 Ma circum-Atlantic dike system were sampled, and flow directions were determined using the anisotropy of magnetic susceptibility (AMS) technique. Measurements were made on 215 cores collected at 25 sites distributed along the Higganum-Holden and Christmas Cove dikes of New England. These dikes can be traced for distances of approximately 250 km and 100 km, respectively.

      Chemical and paleomagnetic data suggest that emplacement of these dikes was contemporaneous and that they...

    (pp. 207-208)
  8. INDEX
    (pp. 209-214)