地质通报
地質通報
지질통보
GEOLOGICAL BULLETIN OF CHINA
2014年
6期
841-849
,共9页
南卡俄吾%贾群子%李文渊%郭周平%李金超%孔会磊%栗亚芝%代岩
南卡俄吾%賈群子%李文淵%郭週平%李金超%孔會磊%慄亞芝%代巖
남잡아오%가군자%리문연%곽주평%리금초%공회뢰%률아지%대암
石英闪长岩%LA-ICP-MS%锆石U-Pb年龄%哈西亚图%东昆仑造山带
石英閃長巖%LA-ICP-MS%鋯石U-Pb年齡%哈西亞圖%東昆崙造山帶
석영섬장암%LA-ICP-MS%고석U-Pb년령%합서아도%동곤륜조산대
quartz diorite%LA-ICP-MS%zircon U-Pb dating%Haxiyatu%East Kunlun orogenic belt
东昆仑地区是青海省重要的夕卡岩型铁多金属矿成矿带,哈西亚图铁多金属矿是近年来首例在东昆仑金水口岩群中发现的与中酸性岩体有关的夕卡岩型矿床,目前铁、金、锌矿已达中型。其成矿作用与矿区东北部石英闪长岩关系密切,矿体产于石英闪长岩的外接触带。采用LA-ICP-MS同位素测定技术,测得石英闪长岩锆石U-Pb年龄为246.8±1.8Ma(MSWD=0.074),形成于早三叠世,表明东昆仑地区早三叠世存在夕卡岩成矿作用。地球化学研究表明,石英闪长岩为高钾钙碱性系列,具有安第斯型活动大陆边缘火成岩的构造属性。研究认为,石英闪长岩是阿尼玛卿洋盆向北俯冲,致使壳幔岩浆发生混合,后经侵位、结晶分异形成的。
東昆崙地區是青海省重要的夕卡巖型鐵多金屬礦成礦帶,哈西亞圖鐵多金屬礦是近年來首例在東昆崙金水口巖群中髮現的與中痠性巖體有關的夕卡巖型礦床,目前鐵、金、鋅礦已達中型。其成礦作用與礦區東北部石英閃長巖關繫密切,礦體產于石英閃長巖的外接觸帶。採用LA-ICP-MS同位素測定技術,測得石英閃長巖鋯石U-Pb年齡為246.8±1.8Ma(MSWD=0.074),形成于早三疊世,錶明東昆崙地區早三疊世存在夕卡巖成礦作用。地毬化學研究錶明,石英閃長巖為高鉀鈣堿性繫列,具有安第斯型活動大陸邊緣火成巖的構造屬性。研究認為,石英閃長巖是阿尼瑪卿洋盆嚮北俯遲,緻使殼幔巖漿髮生混閤,後經侵位、結晶分異形成的。
동곤륜지구시청해성중요적석잡암형철다금속광성광대,합서아도철다금속광시근년래수례재동곤륜금수구암군중발현적여중산성암체유관적석잡암형광상,목전철、금、자광이체중형。기성광작용여광구동북부석영섬장암관계밀절,광체산우석영섬장암적외접촉대。채용LA-ICP-MS동위소측정기술,측득석영섬장암고석U-Pb년령위246.8±1.8Ma(MSWD=0.074),형성우조삼첩세,표명동곤륜지구조삼첩세존재석잡암성광작용。지구화학연구표명,석영섬장암위고갑개감성계렬,구유안제사형활동대륙변연화성암적구조속성。연구인위,석영섬장암시아니마경양분향북부충,치사각만암장발생혼합,후경침위、결정분이형성적。
Eastern Kunlun region is an important skarn-type iron-polymetallic metallogenic belt in Qinghai Province, and the Haxi-yatu iron-polymetallic deposit is related to the intermediate intrusive body discovered in recent years in the area of Jinshuikou rock group. The iron, gold and zinc reserves of the deposit have reached a medium-size deposit. The mineralization has a close relation-ship with quartz diorite in northeast mining area, and the orebody occurs in the outer contact zone of quartz diorite. LA-ICP-MS isotope dating of zircons from the quartz diorite yielded an age of 246.8 ± 1.8Ma (MSWD=0.074), suggesting that the quartz diorite was formed before Early Triassic and that there existed skarn mineralization in Eastern Kunlun area in Early Triassic. Geochemical studies indicate that quartz diorite is of high-K calc-alkaline series and has the attribute of Andean type epicontinental igneous tecton-ics. It is thus held that the quartz diorite was formed after the northward subduction of Animating ocean basin which caused the mix-ing, emplacement and crystallization differentiation of the crust mantle magma.