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Subduction of aseismic ridges beneath the Caribbean Plate: implications for the tectonics and seismic potential of the northeastern Carribean
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D. SubmarineGeologyand Geophysics
Geological and geophysical data support the hypothesis that the Adriatic-Po Valley region was detached from the African Plate during the Miocene. Successive collisions of the Adriatic/Eurasian plates produced the Alpine and Dinaric mountain chains, the Apennines, and the Italian peninsula. Structurally the Adriatic can be viewed 'as formed by an axial ridge associated with lateral depressions...or foredeeps [exhibiting] overthrusts of opposite polarity.' Ist. di Geodesia e Geofisica, Univ. di Trieste, Italy. (sir)
84:6130 Giese, Peter, 1984. The crustal strncOn'e along the margin of the Adriatic microplate. Boll. OceanoL teor. appl., II(2):141-150. (In German, English abstract.) The crustal structure varies along the Adriatic microplate. Overthrusting of the Southern Alps' crust onto a continental fragment in the north and 'flake' tectonics in the east have produced a thick crust associated with continental units. In the west, however, the thinner 20-25 km thick crust appears to be situated along the contact between oceanic basins. To the south there is no orogenic belt, only a transition zone to the African plate. Inst. fur Geophys., Wissenschaften, Freie Univ. Berlin, FRG.
(hbf) 84:6131 Hillhouse, J.W. and C.S. Gromme, 1984. Northward displacement and accretion of Wrangellia: new paleomagnetic evidence from Alaska. J. geophys. Res., 89(B6):4461-4477.
84:6132 Huang, Jiqing, Guoming Chen and Bingwei Chen, 1984. Preliminary analysis of the Tethys-Hlmalayan tectonic domain. Acta geol. sin., 58(1): 1-17. (In Chinese, English abstract.) The domain is subdivided into major tectonic regions separated by plate suture zones on the basis of available geological and geophysical data. The plate tectonic history of the area is then traced from its Paleozoic position south of the paleo-Tethys Ocean near the Antarctic through Late Triassic, Jurassic and Cretaceous drifting and rifting in association with the Indian Shield. The Great Tethys and Small Tethys hypotheses are reviewed. It is suggested that the domain has been subjected to an aceordian type of plate movement. Chinese Acad. of Geol. Sei., People's Republic of China. (hbf) 84:6133 Klootwijk, C.T., 1984. A review of Indian Phanerozoic palaeomagnetism: Implications for the
OLR (1984)31 (12)
India-Asia collision. Tectonophysics, 331-353.
105(1/4):
An important feature of the Indian apparent polar wander path is a large-scale Triassic-Jurassic loop, indicating a change from a Late Palaeozoic-Early Mesozoic northward/counterclockwise rotation to a southward/clockwise rotation during Early to Middle Jurassic. Younger magnetic overprints (20-40 m.y.) predominate in external thrust zones; older overprints (50-60 m.y.) are found in more internal zones reflecting a phase of relaxation in the Early Tertiary collision of Greater India with southcentral Asia or island arcs. Subsequent northward movement resulted in large-scale underthrusting of Greater India beneath southern Tibet. Bur. of Min. Res., Geol. and Geophys., P.O. Box 378, Canberra City, ACT 2601, Australia. 84:6134 McCann, W.R. and L.R. Sykes, 1984. Subduction of aseismic ridges beneath the Caribbean Plate: implications for the tectonics and seismic potential of the northeastern Caribbean. J. geophys. Res., 89(B6):4493-4519. The effect on subduction in the Puerto Rico and Lesser AntiUean trenches of a series of aseismic ridges on the North and South American plates is examined. In general, the intersections of the ridges with the trench are marked by a high level of seismicity and deformation in the overriding plate and 'may act as tectonic barriers or asperities during the rupture processes involved in large earthquakes.' Reconstructions of Middle Miocene to Recent plate motions suggest correlations between features of the downgoing plate and jumps in the locus of island arc volcanism. Lamont-Doherty Geol. Observ., Palisades, N.Y. 10964, USA. (amt) 84:6135 Molnar, Peter, 1984. Structure and tectonics of the Himalaya: constraints and implications of geophysical data. A. Rev. Earth planet. Sci, 12:489518. 'The Himalayan range is a product of continental collision between India and Eurasia, and for several reasons it is a logical place to examine the physical causes and mechanisms of mountain building.' This paper presents a comprehensive review of the current geophysical data which constrain models of the structure and tectonics of the Himalaya; several different and conflicting models are examined. 'The geologic structure is divided into slivers separated by major thrust faults that, when active, dipped north...the southward migration of faulting probably occurred because it is energetically more favorable
D. SubmarineGeologyand Geophysics
Geological and geophysical data support the hypothesis that the Adriatic-Po Valley region was detached from the African Plate during the Miocene. Successive collisions of the Adriatic/Eurasian plates produced the Alpine and Dinaric mountain chains, the Apennines, and the Italian peninsula. Structurally the Adriatic can be viewed 'as formed by an axial ridge associated with lateral depressions...or foredeeps [exhibiting] overthrusts of opposite polarity.' Ist. di Geodesia e Geofisica, Univ. di Trieste, Italy. (sir)
84:6130 Giese, Peter, 1984. The crustal strncOn'e along the margin of the Adriatic microplate. Boll. OceanoL teor. appl., II(2):141-150. (In German, English abstract.) The crustal structure varies along the Adriatic microplate. Overthrusting of the Southern Alps' crust onto a continental fragment in the north and 'flake' tectonics in the east have produced a thick crust associated with continental units. In the west, however, the thinner 20-25 km thick crust appears to be situated along the contact between oceanic basins. To the south there is no orogenic belt, only a transition zone to the African plate. Inst. fur Geophys., Wissenschaften, Freie Univ. Berlin, FRG.
(hbf) 84:6131 Hillhouse, J.W. and C.S. Gromme, 1984. Northward displacement and accretion of Wrangellia: new paleomagnetic evidence from Alaska. J. geophys. Res., 89(B6):4461-4477.
84:6132 Huang, Jiqing, Guoming Chen and Bingwei Chen, 1984. Preliminary analysis of the Tethys-Hlmalayan tectonic domain. Acta geol. sin., 58(1): 1-17. (In Chinese, English abstract.) The domain is subdivided into major tectonic regions separated by plate suture zones on the basis of available geological and geophysical data. The plate tectonic history of the area is then traced from its Paleozoic position south of the paleo-Tethys Ocean near the Antarctic through Late Triassic, Jurassic and Cretaceous drifting and rifting in association with the Indian Shield. The Great Tethys and Small Tethys hypotheses are reviewed. It is suggested that the domain has been subjected to an aceordian type of plate movement. Chinese Acad. of Geol. Sei., People's Republic of China. (hbf) 84:6133 Klootwijk, C.T., 1984. A review of Indian Phanerozoic palaeomagnetism: Implications for the
OLR (1984)31 (12)
India-Asia collision. Tectonophysics, 331-353.
105(1/4):
An important feature of the Indian apparent polar wander path is a large-scale Triassic-Jurassic loop, indicating a change from a Late Palaeozoic-Early Mesozoic northward/counterclockwise rotation to a southward/clockwise rotation during Early to Middle Jurassic. Younger magnetic overprints (20-40 m.y.) predominate in external thrust zones; older overprints (50-60 m.y.) are found in more internal zones reflecting a phase of relaxation in the Early Tertiary collision of Greater India with southcentral Asia or island arcs. Subsequent northward movement resulted in large-scale underthrusting of Greater India beneath southern Tibet. Bur. of Min. Res., Geol. and Geophys., P.O. Box 378, Canberra City, ACT 2601, Australia. 84:6134 McCann, W.R. and L.R. Sykes, 1984. Subduction of aseismic ridges beneath the Caribbean Plate: implications for the tectonics and seismic potential of the northeastern Caribbean. J. geophys. Res., 89(B6):4493-4519. The effect on subduction in the Puerto Rico and Lesser AntiUean trenches of a series of aseismic ridges on the North and South American plates is examined. In general, the intersections of the ridges with the trench are marked by a high level of seismicity and deformation in the overriding plate and 'may act as tectonic barriers or asperities during the rupture processes involved in large earthquakes.' Reconstructions of Middle Miocene to Recent plate motions suggest correlations between features of the downgoing plate and jumps in the locus of island arc volcanism. Lamont-Doherty Geol. Observ., Palisades, N.Y. 10964, USA. (amt) 84:6135 Molnar, Peter, 1984. Structure and tectonics of the Himalaya: constraints and implications of geophysical data. A. Rev. Earth planet. Sci, 12:489518. 'The Himalayan range is a product of continental collision between India and Eurasia, and for several reasons it is a logical place to examine the physical causes and mechanisms of mountain building.' This paper presents a comprehensive review of the current geophysical data which constrain models of the structure and tectonics of the Himalaya; several different and conflicting models are examined. 'The geologic structure is divided into slivers separated by major thrust faults that, when active, dipped north...the southward migration of faulting probably occurred because it is energetically more favorable