|
|
|
| Main Progress and Achievements in Supplemental Regional Geological Survey of 1∶250 000 Yumenzhen Sheet |
| LIANG Ming-hong1, HUO Qin-zhi1, LI Hai-lin2 |
1. Gansu Institute of Geological Survey, Lanzhou, Gansu 730000,China;
2. Gansu Bureau of Geology and Mineral Exploration and Development, Lanzhou, Gansu 730000, China |
|
|
|
|
Abstract The regional geological survey project of 1∶250 000 Yumenzhen sheet (K47C004001) has got some progress and achievements. In this project, we have found that the Dunhuang Group was mainly composed of a series of Paleoproterozoic khondalite rocks, and a set of epimetamorphic volcanic rocks, epimetamorphic fine clastic rocks and carbonate rocks. Combining with a large number of microfossil evidence, we confirmed that the three rock units were corresponding to the Qianluzigou group of Changcheng period, the Pingtoushan and Yema formation of Jixian, respectively. By using the innovative technology of finite strain measurement, five deformation events in the Dunhuang Group were identified on the basis of a detailed analysis of the ductile shear zone in this region. Through the statistics of the sedimentary grains, seven grain coarsening events in Changma alluvial fan were identified. Combining with a large number of ESR dating data, we suggested that the sediment grain size abrupt event and uplift of the plateau had a positive connection. In addition, we also found out the spatial-temporal distribution and evolution sequence of intrusive rocks in this region, and divided these intrusions into four types: homologous, heterologous, tectonic melange, and metamorphic.
|
|
Received: 29 September 2014
|
|
|
|
|
|
[1] 梁明宏,霍勤知,王云斌,等.1∶25玉门镇幅区域地质调查报告[R].兰州:甘肃省地质调查院,2005.
[2] 霍勤知,梁明宏,刘土改,等.敦煌地块前寒武纪变质基底物质组成及构造演化[R].兰州:甘肃省地质调查院,2005.
[3] 李增,梁明宏,霍勤知,等.青藏高原北外缘第四纪沉积特征、环境演化及与高原隆升耦合关系——以玉门镇地区昌马扇为研究核心[R]. 兰州:甘肃省地质调查院,2005.
[4] 王云斌,梁明宏,霍勤知,等.利用变形花岗岩体中的长石矿物进行有限应变测量初探[J].西北地质,2004,37(2):19-24.
[5] 郑亚东,常志忠.岩石有限应变测量及韧性剪切带[M].北京: 地质出版社,1985.
[6] 单文琅,宋鸿林,傅昭仁,等.构造变形分析的理论方法和实践[M].武汉:中国地质大学出版社,1991.
[7] 李增,王云斌,梁明宏,等. 粒度统计分析方法在青藏高原隆升研究中的运用及效果——以昌马洪积扇为例 [J].西北地质,2005,38(2):16-20.
[8] 宋春晖,方小敏,李吉均,等.青藏高原北缘酒西盆地13 Ma以来沉积演化与构造隆升[J].中国科学:D辑,2001,31(B12):155-162.
[9] 于庆文.青藏高原东北缘新生代隆升沉积气候演化及其耦合:区域地质调查方法实践[M].武汉:中国地质大学出版社,2001. |
|
|
|
2014, Vol. 1 
