THE DISCOVERY OF WUCHIAPINGIAN FOSSILS FROM THE XIALA FORMATION IN THE XAINZA AREA(TIBET)AND ITS SIGNIFICANCE
THE DISCOVERY OF WUCHIAPINGIAN FOSSILS FROM THE XIALA FORMATION IN THE XAINZA AREA(TIBET)AND ITS SIGNIFICANCE
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发表时间：
2014
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通讯作者：
Zhang Yu-ji
中科院分区：
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作者：
Zhang Yu-ji
对西藏申扎地区木久错剖面下拉组的再研究表明，木久错剖面下拉组是连续的，与下伏的昂杰组页岩和上覆的木久错组白云岩呈整合接触，其沉积时代为昆古尔期至乌恰坪期。木九错剖面下拉组可划分为三段，下、中段在下拉地区也可识别，其时代为晚昆古尔世至卡匹坦期，上段为厚层瘤状灰岩，仅出现在木九错地区。根据牙形石Clarkina liangshanensis（Wang）和纺锤虫Codonofusiella schubertelloides Sheng的存在，将下拉组上段的沉积时代归属于吴家坪阶，首次证实了申扎地区下拉组可上溯至吴家坪阶。
A restudy of the Xiala Formation at the Mujiucuo section in the Xainza area,Tibet(Xizang), shows that the Xiala Formation at the Mujiucuo section is continuous,with conformable contacts with the underlying shales of the Angjie Formation and dolostones of the overlying Mujiucuo Formation.Its depositional age is from the Kungurian to the Wuchiapingian.Different from stratigraphic sections in the Xiala area,the Xiala Formation at the Mujiucuo section can be divided into three members.The lower and middle members are also recognizable in the Xiala area and ranges from the late Kungurian to the Capitanian, whereas the upper member consisting of thick-bedded nodular limestone only occurs in the Mujiucuo area. The depositional age of the upper member of the Xiala Formation is ascribed to the Wuchiapingian based on the presence of the conodont Clarkina liangshanensis(Wang)and the fusulinid Codonofusiella schubertelloides Sheng.It is the first time to confirm that the Xiala Formation in the Xainza area can range upper into the Wuchiapingian Stage.