عنوان

Structural styles and tectonic evolution of the Bandar Abbas area, southern Iran:

TLpq303955220

انگلیسی

Structural styles and tectonic evolution of the Bandar Abbas area, southern Iran:

[Thesis]

M. N. Bushara

A model based on geologic, satellite, and geophysical data

C. Craddock

The University of Wisconsin - Madison

1991

424

Ph.D.

The University of Wisconsin - Madison

1991

The structural styles in the Bandar Abbas area are dominantly controlled by two major tectonic features. The first is two sets of extension faults in the basement--an older NW-SE-trending set that is probably of late Precambrian age, and a younger, N-S-trending set perhaps of Permo-Triassic age. The first set is interpreted as incipient continental rifting which is not well-developed, but which has formed widespread zones of weakness throughout the Afro-Arabian continent and Iran. These zones are demarcated by discrete axial lineaments such as the Main Zagros Thrust (MZT), the proto-Red Sea trend, and the Najd Shear Zone of Arabia. The N-S basement faults were apparently fully developed rift basins, along one of which Iran separated from Arabia to form the Neo-Tethyan Ocean during Late Triassic-Early Jurassic time. The second major tectonic feature is a set of N-trending fracture zones (e.g. Oman Line and Kazerun fault), whose effects are manifest as dextral strike-slip faults within the Phanerozoic sedimentary rocks. The observed surface structural styles, such as whaleback folds, faults, salt diapirism, and scattered magmatic intrusions and outpourings, are regarded as the result of intermittent reactivation of basement structures. Results from studies of these data, along with pertinent evidence from the literature, suggest that a major continental collision between Arabia and Iran may have occurred just after ophiolite obduction in Oman and Iran at 84-75 Ma; and that the dextral separation of the Oman landmass from Iran must have accompanied this suturing. The intense shortening and thickening of the Zagros Mountains in late Tertiary time can be attributed to a renewed cycle of convergence between Iran and Arabia in order to accommodate the opening of the Red Sea and the Gulf of Aden. Post-collisional deformation in southern Iran is dominated by strong right-lateral strike-slip faults coupled with high-angle thrusting. Surface features such as the NE-trending sinistral faults on Landsat imagery indicate clockwise rotation of the N-S-oriented basement faults, which still show sinistral strike-slip faults along their original trends within the sedimentary section. (Abstract shortened with permission of author.)

Applied sciences

Earth sciences

Geology

Geology

Remote sensing

satellite data

C. Craddock

M. N. Bushara

p

[Thesis]

276903

a

Y