A biogeographically mixed late Guadalupian (late Middle Permian) brachiopod fauna from an exotic limestone block at Xiukang in Lhaze county, Tibet

A total of 17 brachiopod species belonging to 15 genera are recorded from a limestone block of about 3×4 km2 in the Indus–Tsangbo suture zone at Xiukang in Lhaze County of Tibet. The brachiopod fauna generally indicates a Late Guadalupian age (late Wordian–Capitanian, late Middle Permian) based on its association with the Timorites-bearing ammonoid fauna and the presence of the brachiopod Urushtenoidea crenulata. Palaeobiogeographically, the fauna exhibits transitional/mixed characters between the warm-water Cathaysian and cold to temperate Gondwanan faunas and may have developed on a carbonate build-up or seamount on the oceanic crust.

Late Middle Permian (Guadalupian) fusuline fauna from the Gyanyima area of Burang County, Tibet, China and its paleobiogeographic implications

Numerous Permian limestone blocks exposed along the Yarlung-Zangbo Suture Zone have been named Tibetan facies exotic limestone blocks or Chitichun-type Permian deposits.The Gyanyima limestone block,one of those limestone blocks,is located in Burang County,southwestern Tibet.Fusulines are abundant in the Gyanyima limestone block especially for Middle Permian Xilanta Formation.The fusuline fauna comprises 10 genera,respectively Neoschwagerina, Yangchienia, Armenina, Verbeekina, Paraverbeekina, Kahlerina, Lantschichites, Codonofusiella,Chusenella, Nankinella.This fauna indicates a Midian age(Late Guadalupian or Lengwuan age of South China) in terms of the coexistence of Kahlerina, Lantschichites, Codonofusiella and Neoschwagerina.

Late Guadalupian (Middle Permian) Fusuline fauna from the Xiala formation in Xainza county, central Tibet : implication of the rifting time of the Lhasa Block

A fusuline fauna consisting of 9 species of 4 genera from the Xiala Formation of the Mujiucuo section, Xainza County, Tibet, China is described. The fusuline fauna is dominated by Nankinella and Chusenella and indicates a Midian (Late Guadalupian) age. The earliest record of fusuline fauna during the Midian in the Lhasa Block suggests that the block rifted later than the Qiangtang Block to the north and the Baoshan and Tengchong blocks to the east, all of which yield much earlier fusuline faunas of Yakhtashian (Artinskian) age, but had drifted away from Gondwana to a relatively warm temperate zone in the Late Guadalupian (Middle Permian).

Discovery of the Early Ordovician strata in Xianza County, Tibet and its significance

There is no any sediments contain fossils which formed earlier than Middle Ordovician in northern Tibet yet. It is very important whether have developed the Cambrian to Early Ordovician sedimentary strata. During geological mapping of Xainza County in 2000, Tetragraptus approximatus, the typical one of graptolite belts which cosmepolitically distributed in the Arenigian of Early Ordovician, was collected from the so-call Pre-Sinian Nianqingtanggula Group. So there is developped the Early Ordovician sediments and we have established Zakang Formation and Taduo Formation which perfected the Plaeozoic sequences in northern Tibet. According to these, we can realize tectonic control, palaeogeographrc pattern as well as palaeobiogeographic distribution of the Qinghai-Tibet Plateau in the early Paleozoic and also provided the materials to the cosmepolitical biostratigraphic contrast.

Middle Permian (Guadalupian) Fusulines from the Xilanta formation in the Gyanyima area of Burang County, southwestern Tibet, China

This paper reports a diversified fusuline fauna from the Middle Permian (Guadalupian) Xilanta Formation in the Gyanyima area, Burang County, southwestern Tibet, China. Nine genera, Lantschichites, Kahlerina, Nankinella, Yangchienia, Chusenella, Verbeekina, Armenina, Paraverbeekina and Neoschwagerina are recognized.Anew species Yangchienia gyanyimaensis n. sp. is established. This fauna indicates a Midian age in terms of the coexistence of Kahlerina, Lantschichites and Neoschwagerina. Paleobiogeographically, the fauna closely resembles that from the Lasaila exotic limestone block of Tibet, both resemble the fusuline assemblages known from the western Cimmerian continents in the Western Tethys Province. However, the absence of Afghanella and Sumatrina in the fauna suggests that the Gyanyima limestone block as well as the Lasaila exotic limestone block, the Batain plain of Oman and the Salt Range of Pakistan, were affected by relatively cool water during the Middle Permian.