【摘要】：瀘水-怒江斷裂帶位于喜馬拉雅東構(gòu)造結(jié)南緣高黎貢構(gòu)造帶中段,西臨高黎貢剪切帶,東鄰瀾滄江構(gòu)造帶及崇山剪切帶,是研究調(diào)節(jié)與印度-亞洲碰撞相關(guān)的陸內(nèi)變形的重要場所之一。本文以構(gòu)造解析理論為指導(dǎo),通過野外構(gòu)造觀測及顯微構(gòu)造、運(yùn)動(dòng)學(xué)渦度估計(jì),地球化學(xué)分析、鋯石U-Pb同位素年代學(xué)等研究,認(rèn)為該斷裂帶變形物質(zhì)與岡底斯S型花崗巖同源,并厘定出三期構(gòu)造變形。D1:始新世-漸新世,在東西向擠壓應(yīng)力下純剪切主導(dǎo)的收縮構(gòu)造,發(fā)育緊閉同斜褶皺,南北向線理;D2:漸新世-中新世,由應(yīng)變分解作用形成簡單剪切主導(dǎo)的右旋擠壓走滑韌性剪切變形,糜棱面理陡立傾向東西,線理均南北向延伸,發(fā)育大規(guī)模直立A型褶皺;D3:伸展背景下發(fā)育晚中新世的左行正走滑斷層,具脆韌性-脆性構(gòu)造變形。變質(zhì)礦物組合的相平衡模擬與石英EBSD組構(gòu)表明,該帶經(jīng)歷了三期變質(zhì)作用:(1)高角閃巖相(580℃-720℃,8.5-10.8Kbar);(2)高角閃巖相-麻粒巖相(730℃-820℃,5.8-7.7Kbar);(3)綠片巖相(440-680℃,3-5.5Kbar)。變質(zhì)鋯石的U-Pb分析表明D1純剪切主導(dǎo)的收縮構(gòu)造變形不晚于42.9±2.1Ma,D2擠壓走滑韌性剪切變形不晚于30.86Ma,且剪切作用至少延續(xù)到20.62Ma,D3期脆韌性-脆性變形不早于11Ma。結(jié)合前人研究成果,本文認(rèn)為該帶經(jīng)歷了早期加壓環(huán)境地殼加厚過程,后經(jīng)歷應(yīng)變分解過程啟動(dòng)擠壓走滑剪切運(yùn)動(dòng)來調(diào)節(jié)地塊碰撞引起的陸內(nèi)變形,最后作為騰沖地塊邊界,發(fā)育伸展走滑斷裂并被剝露抬升至淺部發(fā)生脆韌性-脆性變形。
[Abstract]:The Lushui-Nujiang fault zone is located in the middle section of the Goligong structural belt on the southern margin of the eastern Himalayan tectonic junction, the Goligong shear zone in the west, the Lancangjiang structural belt and the Chongshan shear zone in the east. It is one of the important places to study the intercontinental deformation associated with India-Asia collision. Guided by the structural analysis theory, through field structural observation and microscopic structure, kinematic vorticity estimation, geochemical analysis, zircon U-Pb isotopic chronology, it is considered that the deformed material in this fault zone is homologous to Gangdis S-type granite. The three tectonic deformations. D1: Eocene to Oligocene, shearing dominated by pure shearing under east-west compressive stress, developed closed syncline folds, south-north alignment D2: Oligocene to Miocene, By strain decomposition, a simple shear-dominated strike-slip ductile shear deformation is formed, and the surface of the mylonium tends to move steeply in the direction of east-west, and the alignment extends from the south to the north. A large scale erect A-type fold D3: developed in the late Miocene Left-line strike-slip fault with brittle ductile and brittle structural deformation in the extensional setting. The facies equilibrium simulation of the metamorphic mineral assemblage and quartz EBSD fabric indicate that the zone has undergone three stages of metamorphism: (1) the high-amphibolite facies (580 鈩，

本文編號(hào)：2141242