ネパール中央部,タコーラ地域Thini Kholaにおけるペルム・3畳紀境界

The Permian and Triassic boundary was examined at Thini Khola area and precise columnar sections were obtained at three localities. The succession near the Permian and Triassic boundary is divisible into the calcareous sandstone part of the lower, orange dolomite part of the middle and thin-bedded limestones with mudstone seams of the upper, and the Permian and Triassic boundary is reasonably drawn between the middle and upper parts on the basis of already known occurrences of ammonites and newly found some conodonts. It was also discussed that extreme shallowing and regression of the sea at the end of the Permian occurred in most Tethyan realm and that transgression at the biginning of the Triassic was rather uniform and simultaneous.