1:250 000 Mayer Kangri Sheet in Xizang
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摘要: 发现了有化石依据的早古生代地层;在果干加年山发现大量的古生物化石;在中浅变质岩解体出早二叠世地层;否定了羌塘中部隆起区存在中元古界变质基底;羌北发现石炭—二叠纪较为连续的类化石序列;发现上泥盆统;厘定了新近系康托组与唢呐湖组的对应关系;在尼玛县绒玛乡温泉附近和古木乡南西采集了大量头足类、笔石、竹节石等化石;补充、厘定完善了羌南、羌北岩石地层序列;石炭纪基性岩墙群和羌塘中部面积最大的复合岩基———本松错岩体以及新近纪火山岩研究取得进展;在角木日地区发现一套保存完整的蛇绿岩;发现和确定了果干加年山构造混杂岩体;进一步探讨了羌塘基底和南北向构造问题。Abstract: The findings obtained in the geological survey within the extent of the 1:250 000 Mayer Kangri Sheet include the discrimination of fossil-based Early Palaeozoic strata throughout the Sheet; abundant biotic fossils in the Guoganjianian Mountains; presence of the Early Permian strata in the low-grade metamorphic rocks; absence of the Mesoproterozoic metamorphic basement in the central Qiangtang uplifted area; discovery of a continuous Carboniferous-Permian fusulinid fossil sequence in northern Qiangtang; presence of the Upper Devonian strata throughout the Sheet; correlation of the Neogene Kangtog Formation and Suonahu Formation; collection of abundant fossils such as cephalopods, graptolites and tentaculites near Rongma Village and in southwestern Gumu Village, Nyima, and implement of the lithostratigraphic sequences in northern and southern Qiangtang. In addition, advances also include the examination of the Carboniferous basic dike swarms and Bunsumco massif, a large-sized composite batholith in central Qiangtang; discovery of well-preserved ophiolites in the Jiaomuri region and tectonic mélanges in the Guoganjianian Mountains. The basement and NS-trending structures in Qiangtang are dealt with as well.
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Keywords:
- 1:250 000 /
- geological survey /
- Mayer Kangri Sheet /
- development /
- Xizang
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