Electrical conductivity and Paleo‐Proterozoic foredeeps

Sedimentary facies associated with Paleo-Proterozoic foredeeps are apparently highly conductive. The conductive lithology appears to be a euxinic carbonaceous shale deposited on preforedeep continental margin facies. The shale is overlaid by axial turbidites and often incorporated into the succeeding fold and thrust belt. Carbonaceous shales can be made highly conducting if graphitized by exposure to temperatures exceeding 400°C. Although foredeep facies develop diachronously, the most conductive unit is usually found in the core of the fold and thrust belt, suggesting that deformation may be essential for the complete graphitization of the carbon. The foredeep hypothesis offers an attractive explanation for several highly conductive features detected in the upper and middle crust in Laurentia, and possibly throughout the world. The euxinic facies represent highly specific, tectonic marker horizons that are readily delineated by using electromagnetic methods.

[1]  J. Rouzaud,et al.  Mechanisms of graphite formation from kerogen: experimental evidence , 1995 .

[2]  R. Kurtz,et al.  Buried Proterozoic foredeep under the Western Canada Sedimentary Basin , 1995 .

[3]  C. Beaumont,et al.  Preliminary Results from a Planform Kinematic Model of Orogen Evolution, Surface Processes and the Development of Clastic Foreland Basin Stratigraphy , 1995 .

[4]  B. Milkereit,et al.  Timing constraints on deformation history of the Sudbury Impact Structure , 1994 .

[5]  V. Dubrovsky,et al.  Deep electromagnetic sounding in Turkmenia , 1994 .

[6]  K. Collerson,et al.  Crustal history of the Rae and Hearne provinces, southwestern Canadian Shield, Saskatchewan: constraints from geochronologic and isotopic data , 1994 .

[7]  D. K. McDaniel,et al.  Petrographic, Geochemical, and Isotopic Constraints on the Provenance of the Early Proterozoic Chelmsford Formation, Sudbury Basin, Ontario , 1994 .

[8]  A. Green,et al.  Paleo-Proterozoic thick-skinned tectonics: Lithoprobe seismic reflection results from the eastern Trans-Hudson Orogen , 1994 .

[9]  K. Condie,et al.  Laurentia-Siberia connection revisited , 1994 .

[10]  C. Doglioni,et al.  Some remarks on the origin of foredeeps , 1993 .

[11]  S. Hjelt,et al.  Electromagnetic studies in the Fennoscandian Shield—electrical conductivity of Precambrian crust , 1993 .

[12]  Alan G. Jones,et al.  North American Central Plains conductivity anomaly within the Trans-Hudson orogen in northern Saskatchewan, Canada , 1993 .

[13]  F. Chamalaun,et al.  The Large-Scale Electrical Conductivity Structure of Australia , 1993 .

[14]  T. Skulski,et al.  Early Proterozoic (1.88–1.87 Ga) tholeiitic magmatism in the New Québec orogen , 1993 .

[15]  Alan G. Jones,et al.  Trans-Hudson orogen and Williston basin in Montana and North Dakota: New COCORP deep-profiling results , 1993 .

[16]  A. Jones.  Electromagnetic images of modern and ancient subduction zones , 1993 .

[17]  Z. Hajnal,et al.  Deep seismic profile across a Proterozoic collision zone: surprises at depth , 1993, Nature.

[18]  D. Boerner,et al.  Inductive Source EM Sounding of the Sudbury Structure , 1994 .

[19]  R. S. Houston.  Proterozoic mineral deposits near plate margins of the archean wyoming province, USA , 1992 .

[20]  K. Card.  Circa 1.75 Ga Ages For Plutonic Rocks From the southern Province and Adjacent Grenville Province: What Is the Expression of the Penokean Orogeny?: Discussion , 1992 .

[21]  G. Einsele.  Sedimentary Basins: Evolution, Facies, and Sediment Budget , 1992 .

[22]  G. L. Farmer,et al.  Identification of 2.0 to 2.4 Ga Nd model age crustal material in the Cheyenne belt, southeastern Wyoming: Implications for Proterozoic accretionary tectonics at the southern margin of the Wyoming craton , 1991 .

[23]  J. Pasteris,et al.  Raman spectra of graphite as indicators of degree of metamorphism , 1991 .

[24]  G. Palacky,et al.  10. Airborne Electromagnetic Methods , 1991 .

[25]  Is addition of induction vectors meaningful , 1991 .

[26]  A. Brearley.  Carbon-rich aggregates in type 3 ordinary chondrites: Characterization, origins, and thermal history , 1990 .

[27]  R. Bustin,et al.  The role of strain energy in creep graphitization of anthracite , 1990, Nature.

[28]  J. Chiarenzelli,et al.  Proterozoic collisional tectonism in the Trans-Hudson orogen, Saskatchewan , 1990 .

[29]  A gap in the North American Central Plains conductivity anomaly , 1990 .

[30]  J. Craven,et al.  The North American Central Plains conductivity anomaly and its correlation with gravity, magnetic, seismic, and heat flow data in Saskatchewan, Canada , 1990 .

[31]  Alan G. Jones,et al.  Electromagnetic sounding and crustal electrical conductivity in the region of the Wopmay Orogen, Northwest Territories, Canada , 1989 .

[32]  R. McNutt,et al.  Nd model age mapping of the southeast margin of the Archean foreland in the Grenville province of Ontario , 1989 .

[33]  Ge-Fan Wang.  Carbonaceous material in the Ryoke metamorphic rocks, Kinki district, Japan , 1989 .

[34]  P. J. Patchett,et al.  Nd isotopes and the origin of 1.9-1.7 Ga Penokean continental crust of the Lake Superior region , 1989 .

[35]  W. Stanley.  Comparison of geoelectrical/tectonic models for suture zones in the western U.S.A. and eastern Europe: are black shales a possible source of high conductivities? , 1989 .

[36]  A. Bally,et al.  Precambrian geology and tectonic history of North America , 1989 .

[37]  K. Karlstrom,et al.  Early Proterozoic Assembly of Tectonostratigraphic Terranes in Southwestern North America , 1988, The Journal of Geology.

[38]  Alan G. Jones.  A magnetotelluric investigation under the Williston Basin of southeastern Saskatchewan: Discussion , 1988 .

[39]  P. Hoffman,et al.  United Plates of America, The Birth of a Craton: Early Proterozoic Assembly and Growth of Laurentia , 1988 .

[40]  J. Maidens,et al.  A magnetotelluric investigation under the Williston Basin of southeastern Saskatchewan , 1988 .

[41]  F. Ettensohn.  Rates of Relative Plate Motion During the Acadian Orogeny Based on the Spatial Distribution of Black Shales , 1987, The Journal of Geology.

[42]  Z. Hajnal,et al.  An evolutionary model of the western churchill province and western margin of the superior province in Canada and the North-Central United States , 1986 .

[43]  E. R. King,et al.  Precambrian basement geology of North and South Dakota , 1986 .

[44]  Alan G. Jones,et al.  North American Central Plains conductivity anomaly goes east , 1986 .

[45]  Michael S. Zhdanov,et al.  Electromagnetic studies on the Kola peninsula and in Northern Finland by means of a powerful controlled source , 1986 .

[46]  P. Sims,et al.  Early Proterozoic Central Plains orogen: A major buried structure in the north-central United States , 1986 .

[47]  R. Kurtz,et al.  A magnetotelluric sounding across Vancouver Island detects the subducting Juan de Fuca plate , 1986, Nature.

[48]  R. Kurtz,et al.  A geomagnetic induction anomaly from IMS data near Hudson Bay, and its relation to crustal electrical conductivity in central North America , 1985 .

[49]  T. Reimer.  Graphite in Precambrian rocks of Southern Africa: implications on the carbon content of metamorphic rocks , 1984 .

[50]  R. S. Houston,et al.  The Cheyenne Belt: analysis of a Proterozoic suture in southern Wyoming , 1984 .

[51]  S. Handa,et al.  Crustal electrical conductivity in north-central Saskatchewan: the North American Central Plains anomaly and its relation to a Proterozoic plate margin , 1984 .

[52]  R. A. Price,et al.  Regional cross section of the Southern Province adjacent to Lake Huron, Ontario: implications for the tectonic significance of the Murray Fault Zone , 1984 .

[53]  M. St-Onge.  Geothermometry and geobarometry in pelitic rocks of north-central Wopmay Orogen (early Proterozoic), Northwest Territories, Canada , 1984 .

[54]  S. Bowring,et al.  Short-lived 1.9 Ga continental margin and its destruction, Wopmay orogen, northwest Canada , 1984 .

[55]  D. Gough.  Electromagnetic geophysics and global tectonics , 1983 .

[56]  N. Saraçoğlu,et al.  Geology of the McClean Uranium Deposits , 1983 .

[57]  A. Sinha.  Deep Transient Electromagnetic Soundings Over the McClean Uranium Deposits , 1983 .

[58]  T. Sibbald.  Geology of the Crystalline Basement, NEA/IAEA Athabasca Test area , 1983 .

[59]  C. Beaumont,et al.  A comparison of foreland and rift margin sedimentary basins , 1982, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[60]  J. Lewry,et al.  Thermotectonic evolution of the churchill province in Northern Saskatchewan , 1980 .

[61]  H. Jenkyns.  Cretaceous anoxic events: from continents to oceans , 1980, Journal of the Geological Society.

[62]  M. Seguin.  Exploration of magnetic taconite and itabirite with integrated aeroelectromagnetic and magnetic methods , 1978 .

[63]  Ben K. Sternberg,et al.  Electrical resistivity structure of the crust in the southern extension of the Canadian Shield , 1977 .

[64]  D. Gough,et al.  A possible Proterozoic plate boundary in North America , 1977 .

[65]  D. Gough,et al.  The North American Central Plains Conductivity Anomaly , 1975 .

[66]  S. Graham,et al.  Himalayan-Bengal Model for Flysch Dispersal in the Appalachian-Ouachita System , 1975 .

[67]  J. D. Hays,et al.  Lithospheric Plate Motion, Sea Level Changes and Climatic and Ecological Consequences , 1973, Nature.

[68]  I. Reddy,et al.  Crustal conductivity anomaly under the Black Hills: a magnetotelluric study , 1973 .

[69]  M. Seguin.  Interpretation quantitative de donnees obtenues a partir d'un systeme electromagnetique et magnetique heliporte dans la recherche de taconites magnetiques rentables , 1973 .

[70]  D. Gough,et al.  Convergent geophysical evidence of a metamorphic belt through the Black Hills of South Dakota , 1972 .