Palaeomagnetism and palaeogeography of Mongolia in the Cretaceous, Permian and Carboniferous—preliminary data

Abstract

The paper reports on the results of palaeomagnetic stability tests of oriented samples of lithologically different types of Cretaceous, Permian and Carboniferous rocks from northern and southern Mongolia. The Permian andesites and tuffites from three localities (Barun Buren, Tel Tin Gol, and Chulut Tsagan Del) have yielded interesting results. Groups of normally and reversely polarized andesite tuffs were found even within a single outcrop by means of thermal field demagnetization and multicomponent analysis of the magnetization. With a view to the number of samples (177) suitable for analysis and the number of localities (9), the reported palaeomagnetic data should be considered as preliminary. The interpreted results indicate a different palaeogeographic evolution of northern and southern Mongolia relative to the Siberian platform and North China in the Permian and Carboniferous. On the other hand, similar apparent polar wander paths for North China (Lin et al., 1985) and the studied regions of northern and southern Mongolia indicate similar palaeogeographic evolution in the Permian to Carboniferous.