Tectonic inferences of paleomagnetic data from some Mesozoic formations in Central Iran

Abstract

Material for paleomagnetic research has been collected from sedimentary rocks of Mesozoic age from four localities in Central Iran. Detailed paleomagnetic analyses have been carried out using partial progressive demagnetization procedures both with alternating magnetic fields and with heating in order to isolate the characteristic remanence. The following results were obtained: Early Triassic Sorkh Shales with D = 289°, I = 21°, α₉₅= 14°; Late Jurassic Garedu Red Beds with D = 4°, I = 42°, α₉₅ = 14°; Late Jurassic - Early Cretaceous Bidou Beds with D = 48°, I = 32.5°, α₉₅ = 19°; Middle Cretaceous Dehuk Sandstones with D = 326°, I = 38.5°, α₉₅ = 21°. The large α₉₅ values are due to the rather small collections of specimens, roughly 50 each. From the paleomagnetic data we conclude that in Early Triassic times Central Iran, which forms part of the Iranian-Afghan micro-continent, belonged to Gondwana; since Early Jurassic times the area has been positioned close to the Eurasian continent. The scatter in the declination of the remanence directions can be explained in terms of rotations of individual blocks along the main Central-Iranian fault systems.

          ARK: https://n2t.net/ark:/88439/y021734

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