地质学报2018，Vol.92Issue(6)：1240-1263,24.
新疆哈尔里克山石城子地区钠铁闪石花岗斑岩岩墙的发现及构造背景示踪
Arfvedsonite Granitic Porphyry Dykes Discovered in the Shichengzi Area of Harlik Mountain, Xinjiang and Their Tectonic Significance
摘要
Abstract
One set of the arfvedsonite granitic porphyry dykes exposed widely in the Shichengzi area of Harlik Mountain,Xinjiang,NW China,was discovered.The dykes intrude into Late Paleozoic monzonitic granite plutons.The dykes are of porphyritic texture and massive structure.Phenocrysts consist dominantly of perthite and antiperthite,with matrix composed of albite,orthoclase,quartz,arfvedsonite and aegirine.The main elements analysis shows that arfvedsonite granitic porphyry has high contents of SiO2 and Na2O +K2O,and low contents of Al2O3,MgO and CaO.These samples have a high ∑REE value and distinct fractionation between LREE and HREE,especially enrichment in LREE.The chondrite-normalized REE patterns show obvious right-leaning pattern with strong Eu negative anomaly.In addition,the primitive mantle-normalized trace elements pattern shows show high 104 Ga/A1,Zr and (Zr+Nb+Ce+Y) values,and the depletion of Ba,Sr,P,and Ti and enrichment of Th,U,Zr,and Hf.The petrographic and geochemical data above indicate that the arfvedsonite granitic porphyry dykes are A-type granite.Positive εNd(t) (4.13～4.75) values and young Nd model ages (tDM2) indicate that arfvedsonite granitic porphyry was derived from juvenile crust.LA-ICP-MS zircon U-Pb dating suggests that the dykes emplaced at Late Permian (259.7±4.5 Ma).The ages of two old zircons in country rocks concentrate around two peaks (2168 to 2635Ma and 1677 to 1973Ma),respectively,which indicate the existence of Precambrian basement in Harlik Mountain,but was reformed by juvenile crust.Combined with regional geologic background,the Harlik Mountain area was in tectonic setting of post-collision during Carboniferous and early Permian and then entered the intracontinental extension during Late Permian.关键词
钠铁闪石/花岗斑岩岩墙/地球化学特征/石城子地区/哈尔里克山Key words
arfvedsonite/granitic porphyry dikes/geochemistry/Shichengzi area/Harlik Mountain引用本文复制引用
南云,柳益群,周鼎武,周小虎,焦鑫,李哲萱..新疆哈尔里克山石城子地区钠铁闪石花岗斑岩岩墙的发现及构造背景示踪[J].地质学报,2018,92(6):1240-1263,24.基金项目
本文为国家自然科学基金(41272116)、教育部科技发展中心高等学校博导基金(20106101110020)、西北大学研究生创新教育项目(YZZ13008)联合资助的成果. （41272116）
