地质学报
地質學報
지질학보
ACTA GEOLOGICA SINICA
2014年
8期
1475-1484
,共10页
EBSD技术%组构分析%变形条件%变形岩石%阿尔金山喀腊大湾地区
EBSD技術%組構分析%變形條件%變形巖石%阿爾金山喀臘大灣地區
EBSD기술%조구분석%변형조건%변형암석%아이금산객석대만지구
EBSD system%petro-fabrics analysis%deformation condition%deformed rocks%Kaladawan area of Altun Mountains of NW China
岩石组构是指组成岩石的矿物在岩石中分布的各向异性，EBSD （Electron Back Scattered Diffraction）岩组分析就是运用电子背散射衍射技术测定岩石结构要素---岩石中矿物分布的规律性。本文作者运用EBSD技术方法，对阿尔金山喀腊大湾地区变形岩石的组构分析显示，花岗质糜棱岩和蚀变变形花岗岩中，石英变形机制是以中温I级柱面（10-10）＜0001＞和中高温II 级柱面（10-10）＜0001＞滑移为主，少量为中低温底面（0001）＜11-20＞滑移；而在变形火山岩中，石英变形机制是以中低温底面（0001）＜11-20＞滑移系为主。在区域南北向剖面分布上，接近阿尔金北缘断裂和白尖山断裂的中北部变形温度较高，向南变形温度有逐渐降低的趋势。从岩石组构特点结合宏观构造分析，可以认为本区北段属于中-中深层次（15～25km，t＝350～550℃，P＝0．40～0．60GPa）的韧性变形，而中南段为中浅层次（10～15km，t＝250～350℃，P＝0．25～0．40GPa）的韧脆性变形。结合不同变形特点花岗岩的年代学资料，确定构造变形的时代为早古生代。上述特征与区域上发育板块碰撞带，且北部发育高压榴辉岩和蓝片岩的构造部位以及该构造变形带的演化历史相吻合。
巖石組構是指組成巖石的礦物在巖石中分佈的各嚮異性，EBSD （Electron Back Scattered Diffraction）巖組分析就是運用電子揹散射衍射技術測定巖石結構要素---巖石中礦物分佈的規律性。本文作者運用EBSD技術方法，對阿爾金山喀臘大灣地區變形巖石的組構分析顯示，花崗質糜稜巖和蝕變變形花崗巖中，石英變形機製是以中溫I級柱麵（10-10）＜0001＞和中高溫II 級柱麵（10-10）＜0001＞滑移為主，少量為中低溫底麵（0001）＜11-20＞滑移；而在變形火山巖中，石英變形機製是以中低溫底麵（0001）＜11-20＞滑移繫為主。在區域南北嚮剖麵分佈上，接近阿爾金北緣斷裂和白尖山斷裂的中北部變形溫度較高，嚮南變形溫度有逐漸降低的趨勢。從巖石組構特點結閤宏觀構造分析，可以認為本區北段屬于中-中深層次（15～25km，t＝350～550℃，P＝0．40～0．60GPa）的韌性變形，而中南段為中淺層次（10～15km，t＝250～350℃，P＝0．25～0．40GPa）的韌脆性變形。結閤不同變形特點花崗巖的年代學資料，確定構造變形的時代為早古生代。上述特徵與區域上髮育闆塊踫撞帶，且北部髮育高壓榴輝巖和藍片巖的構造部位以及該構造變形帶的縯化歷史相吻閤。
암석조구시지조성암석적광물재암석중분포적각향이성，EBSD （Electron Back Scattered Diffraction）암조분석취시운용전자배산사연사기술측정암석결구요소---암석중광물분포적규률성。본문작자운용EBSD기술방법，대아이금산객석대만지구변형암석적조구분석현시，화강질미릉암화식변변형화강암중，석영변형궤제시이중온I급주면（10-10）＜0001＞화중고온II 급주면（10-10）＜0001＞활이위주，소량위중저온저면（0001）＜11-20＞활이；이재변형화산암중，석영변형궤제시이중저온저면（0001）＜11-20＞활이계위주。재구역남북향부면분포상，접근아이금북연단렬화백첨산단렬적중북부변형온도교고，향남변형온도유축점강저적추세。종암석조구특점결합굉관구조분석，가이인위본구북단속우중-중심층차（15～25km，t＝350～550℃，P＝0．40～0．60GPa）적인성변형，이중남단위중천층차（10～15km，t＝250～350℃，P＝0．25～0．40GPa）적인취성변형。결합불동변형특점화강암적년대학자료，학정구조변형적시대위조고생대。상술특정여구역상발육판괴팽당대，차북부발육고압류휘암화람편암적구조부위이급해구조변형대적연화역사상문합。
Petro-fabrics means an anisotropy of rock-forming minerals distribution.EBSD petro-fabrics analysis is a method to measure the distribution pattern of rock texture factors-minerals by means of Electron Back Scattered Diffraction system to plane net of a special mineral crystal.Based on the EBSD petro-fabrics analysis of deformed rocks from Kaladawan area,Altun Mountains,NW China,the authors draw the conclusion as follows.①There happens a strong deformation in the rocks from the area.②Quartz in granitic mylotite and altered deformed granite is mainly deformed along its prismatic I and II glide system and partly along its basal or basal-near glide system,while Quartz in deformed volcanic rocks is mainly deformed along its basal or basal-near glide system.③The deformations of the rocks from the northern part of the area happen under a medium and medium-deep depth of 15~25km,a middle and med-high temperature of 350~450℃ and a middle pressure of 0.40~0.60GPa,while the deformations of the rocks from the southern part of the area happen under a low-medium depth of 10~15km,a low-middle of 250~350℃ and a low-middle pressure of 0.25~0.40GPa.④Combine with the age of different deformed granite,the authors conside that the ductile deformation in the area was happened in early Paleozoic era. All features above are identical to specious position that they are located the convergent plate collision belt and the distribution of high-pressure eclogite and glaucophane schist and to their evolution history.
