التفاصيل البيبلوغرافية
| العنوان: |
Cenozoic geodynamic evolution of the Andaman–Sumatra subduction margin: Current understanding. |
| المؤلفون: |
Chakraborty, Partha P.1,2 parthageology@gmail.com, Khan, Prosanta K.3 |
| المصدر: |
Island Arc. Mar2009, Vol. 18 Issue 1, p184-200. 17p. 3 Black and White Photographs, 1 Diagram, 1 Chart, 2 Graphs, 2 Maps. |
| مصطلحات موضوعية: |
*STRUCTURAL geology, *CENOZOIC stratigraphic geology, *GEODYNAMICS, *EOCENE paleoclimatology, *VOLCANIC activity prediction, *MIOCENE paleoecology, *VOLCANISM, *GEOLOGICAL basins |
| مصطلحات جغرافية: |
ANDAMAN Sea |
| مستخلص: |
The Andaman–Sumatra margin displays a unique set-up of extensional subduction–accretion complexes, which are the Java Trench, a tectonic (outer arc) prism, a sliver plate, a forearc, oceanic rises, inner-arc volcanoes, and an extensional back-arc with active spreading. Existing knowledge is reviewed in this paper, and some new data on the surface and subsurface signatures for operative geotectonics of this margin is analyzed. Subduction-related deformation along the trench has been operating either continuously or intermittently since the Cretaceous. The oblique subduction has initiated strike–slip motion in the northern Sumatra–Andaman sector, and has formed a sliver plate between the subduction zone and a complex, right-lateral fault system. The sliver fault, initiated in the Eocene, extended through the outer-arc ridge offshore from Sumatra, and continued through the Andaman Sea connecting the Sagaing Fault in the north. Dominance of regional plate dynamics over simple subduction-related accretionary processes led to the development and evolution of sedimentary basins of widely varied tectonic character along this margin. A number of north–south-trending dismembered ophiolite slices of Cretaceous age, occurring at different structural levels with Eocene trench-slope sediments, were uplifted and emplaced by a series of east-dipping thrusts to shape the outer-arc prism. North–south and east–west strike–slip faults controlled the subsidence, resulting in the development of a forearc basins and record Oligocene to Miocene–Pliocene sedimentation within mixed siliciclastic–carbonate systems. The opening of the Andaman Sea back-arc occurred in two phases: an early (∼11 Ma) stretching and rifting, followed by spreading since 4–5 Ma. The history of inner-arc volcanic activity in the Andaman region extends to the early Miocene, and since the Miocene arc volcanism has been associated with an evolution from felsic to basaltic composition. [ABSTRACT FROM AUTHOR] |
| قاعدة البيانات: |
Academic Search Index |
