保山地块晚石炭世玄武岩古地磁研究及构造归属的新认识  

PALEOMAGNETIC RESEARCH ON THE UPPER CARBONIFEROUS BASALT AND NEW KNOWLEDGE OF THE TECTONIC BELONGING OF BAOSHAN MASSIF IN YUNNAN

作　　者：叶祥华[1] 巩满福[1] 朱夔玉[1] 李家福 

机构地区：[1]成都地质学院

出　　处：《成都地质学院学报》1993年第1期87-92,共6页

基　　金：国家自然科学基金

摘　　要：通过对保山地块晚石炭世玄武岩东、西带代表性剖面的古地磁研究,认为东、西带玄武岩古地磁测量数据的差异是因取样点的古构造古地理背景不同造成的。结合两带玄武岩浆喷溢时所处的构造背景和古地形特征,作者提出西带玄武岩的古地磁数据能较准确地反映地块当时应位于南半球低纬(15.6°)区,而不是过去认为的高纬区。保山地块不是冈瓦纳大陆的一部分,它与扬子地块间不存在古特提斯大洋,而可能是毗邻扬子地块的一个小地块。The recent studies have proved that paleostructural and paleotopographic environment of the east belt was different from that of the west belt in Baoshan massif in the Upper Carboniferous. The east belt was close to the volcanic vent and its paleotopography was very complex. In contrast the west belt was far away from the centre of fracturing-volcanicity and the paleotopography was even. Therefore, paleomagnetic results obtained from basalt of the east belt show that data vary largely, but those from the west belt vary just a little and have higher reliability. The authors consider that Baoshan massif was situated at 15.6° S in the late Carboniferous. It was not a part of Gondwana land and there was not a Paleotethys ocean extending for thousands of kilometers between Baoshan massif and Yangzi massif. Baoshan area might be a small massif adjacent to the Yangzi plate in the late Carboniferous.

关 键 词：地块 晚石炭世 玄武岩 古地磁 构造 

分 类 号：P318.4[天文地球—固体地球物理学]