Extensional collapse of orogens

Tectonics - Tập 7 Số 6 - Trang 1123-1139 - 1988
John Dewey

Tóm tắt

Lithospheric extension is sited, preferentially, along orogenic belts because they have a thicker continental crust, contain structural inhomogeneities, and suffer extensional orogenic collapse caused by body forces resulting from isostatically compensated elevation and sharp elevation gradients. Collapse occurs especially where rapid advective thinning of the shortened thermal boundary conduction layer occurs beneath an orogen and causes rapid uplift. Where boundary forces are compressional, extension is balanced by radial thrusting to form oroclinal loops around collapsed extensional basins. Where, as in the disruption of Pangea, boundary forces change rapidly from compressional to tensional, body force collapse is continued by general extension which may lead to continental splitting. Even where overall convergence is continuing, orogenic collapse may be enhanced by subduction rollback into small remnant oceans. The extensional collapse of orogens offers a partial explanation for why oceans cyclically close and reopen in roughly the same places, preservation of very high pressure metamorphic rocks, for the return of orogenic large crustal thicknesses to normal without very much erosional denudation with the widespread preservation of supracrustal sequences, high temperature metamorphic assemblages and the minimum‐melting granite suite.

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Tài liệu tham khảo

10.1130/0016-7606(1970)81[3513:IOPTFT]2.0.CO;2

10.1029/TC005i003p00375

10.1130/0091-7613(1976)4<686:SDOEAS>2.0.CO;2

10.1029/TC005i001p00049

10.1130/0091-7613(1976)4<661:SRAMOC>2.0.CO;2

10.1029/JB083iB10p04975

10.1029/JB084iB13p07561

Bird P., Formation of the Rocky Mountains, western United States: A continuum computer model, Science, 240, 1501

10.1098/rsta.1982.0039

10.1016/0040-1951(84)90190-2

10.1016/0040-1951(80)90106-7

10.1130/0091-7613(1987)15<142:TDOTSM>2.0.CO;2

Buck R., 1988, Flexural rotation of normal faults to produce abandoned horizontal detachments, E. Trans. AGU, 69, 465

10.1038/333247a0

Carey S. W., 1955, The orocline concept in geotectonics, Proc. Pap. R. Soc. Tasmania, 89, 255

10.1144/gsjgs.140.6.0893

10.1111/j.1525-1314.1985.tb00327.x

10.1144/GSL.SP.1987.028.01.13

10.1130/0091-7613(1984)12<550:CMCCCE>2.0.CO;2

10.1016/0012-821X(87)90224-X

10.1016/0012-821X(81)90174-6

10.1016/0040-1951(79)90303-2

Dewey J. F., 1980, Episodicity, sequency and style at convergent plate boundaries, The Continental Crust and its Mineral Deposits, edited by D.W. Strangway, Spec. Pap., Geol. Assoc. Can., 20, 553

10.1144/gsjgs.139.4.0371

10.1144/GSL.SP.1988.037.01.03

10.1086/627920

10.1029/TC004i001p00071

10.1130/0016-7606(1979)90<84:AASRCM>2.0.CO;2

10.1130/0016-7606(1973)84<3137:PTATEO>2.0.CO;2

10.1144/GSL.SP.1986.019.01.01

10.1098/rsta.1988.0135

10.1144/GSL.SP.1989.045.01.15

10.1098/rsta.1988.0089

10.1111/j.1365-246X.1982.tb04969.x

10.1144/GSL.SP.1987.028.01.12

Hills E. S., 1956, A contribution to the morphotectonics of Australia, J. Geol. Soc. Aust., 3, 1

10.1029/JB086iB07p06115

10.1029/JB076i014p03246

10.1130/0016-7606(1971)82[323:SHOTMI]2.0.CO;2

10.1144/GSL.SP.1987.028.01.34

10.1038/323147a0

10.1038/215578a0

10.1098/rsta.1981.0068

10.1029/TC006i003p00275

10.1126/science.189.4201.419

10.1130/0016-7606(1986)97<1037:DOOWAT>2.0.CO;2

10.1029/TC002i001p00091

10.1029/TC002i001p00063

10.1016/0040-1951(78)90107-5

10.1029/TC004i007p00739

10.1029/TC007i001p00087

10.1038/279590a0

10.1144/GSL.SP.1986.019.01.19

10.1130/0016-7606(1971)82[2039:ADATOA]2.0.CO;2

10.1144/GSL.SP.1987.028.01.14

10.1016/0012-821X(86)90045-2

10.1144/GSL.SP.1987.028.01.15

Wezel F. C., 1982, The Tyrrhenian Sea: A rifted Krikogenic‐Swell basin, Mem. Geol. Soc. Italy, 24, 531

Williams D. M., 1988, Tectonic denudation of Dalradian rocks, Connemara, Ireland, Tectonics

10.1038/211676a0

Zwart H. J., 1967, The duality of orogenic belts, Geol. Mijnbouw, 46, 283

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Tectonics

Tập 7 Số 6

1123-1139

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