定结县幅、陈塘区幅地质调查新成果及主要进展

New results and main progress in geological survey of the Dinggyê County and Chentang District sheets

发现上三叠统朗杰学群中产有白垩纪箭石、中侏罗统拉弄拉组产出小型硅化木、下石炭统纳兴组存在重力流沉积。将聂拉木群解体为古元古代马卡鲁杂岩和中—新元古代扎西惹嘎岩组,并在该套变质岩系中发现高压基性麻粒岩和超镁铁岩。厘定了拉轨岗日变质核杂岩,将拉轨岗日群解体为抗青大岩组和拉轨岗日杂岩2部分。确定了晚新生代南北向不同类型的伸展构造和地壳多层次韧性剪切带。

During 1:250000 geological survey of Dinggyê County and Chentang District sheets, the authors found Cretaceous belemnites in the Upper Triassic Langjiexue Group, small petrified wood in the Middle Jurassic Lanongla Formation and gravity-flow deposits in the Lower Carboniferous Naxing Formation. The Nyalam Group is disintegrated into the Paleoproterozoic Makalu complex and Meso- and Neoproterozoic Zhaxirega Formation-complex and high-pressure mafic granulites and ultramafic rocks are found in this metamorphic series. The authors define the Lhagoi Kangri metamorphic core complex and divide it into the Kangqingda Formation-complex and the Lhagoi Kangri complex. In addition, different types of N-S-trending extensional structure and multi-level crustal ductile shear zones are determined.