The geometry of structures in the Zagros cover rocks and its neotectonic implications
Published:January 01, 2002
Yosef Sattarzadeh, John W. Cosgrove, Claudio Vita-Finzi, 2002. "The geometry of structures in the Zagros cover rocks and its neotectonic implications", The Tectonic and Climatic Evolution of the Arabian Sea Region, P. D. Clift, D. Kroon, C. Gaedicke, J. Craig
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The Zagros Mountains are situated along the NE margin of the Arabian plate and are the product of complex deformation which began in Late Cretaceous time as a result of the collision between the Arabian and Central Iranian plates. During Pliocene time, deformation increased when plate convergence was accelerated by the opening of the Red Sea. This stimulated the migration of a deformation front from the collision zone towards the SW into the undisturbed Zagros basin and led to the creation of the Zagros Mountain Belt. The type and distribution of the deformation in the Zagros are controlled mainly by plate velocity, which is linked to the anticlockwise rotation of the Arabian plate around a pole in Syria, and the regional stratigraphy. The sedimentary cover and the underlying metamorphic basement decouple along an important detachment horizon, the Hormuz Salt Formation, and the uneven thickness and distribution of this salt plays a key role in determining the geometry of the deformation belt. Analysis of the distribution and geometry of the folds provides evidence for the southwestwards migration of the deformation front into the Arabian plate. The analyses are consistent with field evidence for serial folding, which indicates that each fold takes c. 600 ka to develop fully, and with the model of a southwestward advancing deformation front driven by the processes of serial folding and footwall collapse.
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The Tectonic and Climatic Evolution of the Arabian Sea Region
Over long periods of time the tectonic evolution of the solid Earth has been recognized as the major control on the development of the global climate system. Tectonic activity acts in one of two different ways to influence regional and global climate: (i) through the opening and closing of oceanic gateways and its effect on the circulation patterns in the global ocean; (ii) through the growth and erosion of orogenic belts, resulting in changes in oceanic chemistry and disruption of atmospheric circulation. The Arabian Sea region has several features that make it the best area for studies of climate and palaeoceanographic responses to tectonic activity, most notably in the context of the South Asian monsoon and its relationship to the growth of high topography in the adjacent Himalayas and Tibet.
The Tectonic and Climatic Evolution of the Arabian Sea Region brings together a collection of recent studies on the area from a wide group of international contributors. The paper range from high resolution, Holocene palaeoceanographic studies of the Pakistan margin to regional tectonic reconstructions of the ocean basin and surrounding margins throughout the Cenozoic. Marine geophysics, stratigraphy, isotope chemistry and neotectonics come together in a multidisciplinary approach to the study of interactions of land and sea. while much work remains to be done to understand fully the tectonic and climatic evolution of the Arabian Sea, a great deal has been achieved since the last major review, as detailed in the 26 contributions. This volume is essential reading for palaeoceanographers, sedimentologists and geophysicists. It will also be interest to structural geologists and those working in the petroleum industry.