本文選題：連山關(guān)巖體 + 韌性剪切帶�。� 參考：《地球科學(xué)》2017年12期

【摘要】：韌性剪切帶在巖石圈地殼中廣泛存在,蘊(yùn)含應(yīng)力、應(yīng)變和溫壓等環(huán)境參數(shù),是構(gòu)造解析、流變學(xué)和成因機(jī)制研究的重要對(duì)象.遼吉裂谷帶位于遼寧東部-吉林南部,是華北克拉通重要的古元古代活動(dòng)帶之一.連山關(guān)巖體地處遼吉裂谷帶北緣,經(jīng)歷復(fù)雜變質(zhì)變形作用,巖體南緣發(fā)育NWW向右行走滑韌性剪切帶.糜棱巖顯微結(jié)構(gòu)觀測(cè)分析揭示,剪切帶內(nèi)糜棱巖以S、SL構(gòu)造巖為主,總體呈壓扁型應(yīng)變.運(yùn)動(dòng)學(xué)渦度值為0.91~0.97,均大于0.75,指示簡單剪切為主的變形特征.糜棱巖中云母顯示塑性拉長,石英動(dòng)態(tài)重結(jié)晶明顯,以膨凸重結(jié)晶作用為主.EBSD分析結(jié)果表明,石英發(fā)育中低溫菱面組構(gòu),對(duì)應(yīng)變形溫度450~550℃,暗示糜棱巖形成于低綠片巖相-低角閃巖相.結(jié)合前人研究成果,我們認(rèn)為連山關(guān)韌性剪切帶可能起源于早元古代晚期.連山關(guān)巖體先后經(jīng)歷早期隆起造成的伸展-滑脫作用和晚期與上覆遼河群共同經(jīng)歷的南北向擠壓,從而在巖體南緣形成陡傾的右行韌性剪切帶.
[Abstract]:Ductile shear zones exist widely in the lithospheric crust and contain environmental parameters such as stress strain and temperature and pressure. They are important objects for structural analysis rheology and genetic mechanism research. Liaoji rift belt is one of the important Paleoproterozoic active belts in North China Craton. Lianshanguan rock body is located in the northern margin of Liaoji rift belt and experienced complex metamorphic deformation. The NWW strike-slip ductile shear zone is developed in the southern margin of the rock mass. The observation and analysis of mylonite microstructure indicate that the mylonite in the shear zone is dominated by SzongSL tectonite, and generally shows flattened strain. The kinematic vorticity is 0.91 ~ 0.97, which is more than 0.75, indicating the deformation characteristics of simple shear. The mica in mylonite shows plastic elongation and obvious dynamic recrystallization of quartz. The results of EBSD analysis show that quartz develops at low temperature rhombohedral fabric, corresponding to deformation temperature 450 ~ 550 鈩，

本文編號(hào)：1974141