摘要
松潘—甘孜复理石带（位于中国中部）呈巨大的三角形区域，面积2．0×10^5 km^2。以上，其周围分别是华南板块、华北板块以及青藏高原大陆地块。从该带中部采集了六个砂岩样品，用U-Pb法对其中的锆石逐个进行分析。碎屑锆石的有较大的年龄变化范围，其年龄主要集中在元古代，并且含少量的晚太古代（25～26亿年）物质，其它年龄反映从四堡期到三叠纪的印支期岩浆喷发事件。低U含量的锆石不协和性与铅丢失型式表明可能是由于后来岩浆喷发事件所致。加里东期锆石年龄峰值表明碎屑沉积物的源区可能来自北秦岭，其它的主要为扬子克拉通北缘、南秦岭。
The Songpan-Ganze basin （Central China） covers a huge triangular area of more than 200,000km^2 and is bounded by the continental blocks of South China, North China and the Tibetan plateau. The six sandstone samples collected from this belt were analyzed grain-by-grain using SHRIMP U-Pb method. The detrital zircons yield a wide range of ages, which are focused on Proterozoie with minor contribution from late Arehean material. The discordance and Pb loss patterns from low U zircons indicate that they might be resulted from the subsequent magmatism events, including the Sibao to the Indosinian periods. The Caledonian appearance of zircons indicates that the origin of these elastic sediments might originate from the Northern Qinling belt, other zircons originated mainly from the north margin of the Yangtze eraton and the south Qinling belt.
出处
《沉积学报》
CAS
CSCD
北大核心
2006年第3期321-332,共12页
Acta Sedimentologica Sinica
基金
国家自然科学基金(批准号:40234052)
教育部重点科研项目(重点03032)共同资助
