本文選題：宿松群 + 新元古代�。� 參考：《中國科學技術大學》2015年碩士論文

【摘要】：宿松群位于揚子板塊北緣大別山南麓地區(qū),北面與南大別低溫榴輝巖帶毗鄰被太湖馬廟斷裂帶所分割,南面以襄樊-廣濟斷裂帶為界。宿松群形成于新元古代大致時間為750Ma前后,跟825～740Ma羅迪尼亞超大陸裂解在揚子板塊引發(fā)的陸內裂谷作用有關,期間伴隨弧后盆地的形成,并經歷后期的沉積作用。宿松群巖石類型復雜總的來說主要由變沉積巖和變巖漿巖兩大類巖石組成,其物源組成比較復雜。本次研究選取了宿松變質地體的片巖、片麻巖、變花崗巖和變基性巖樣品,對其進行了鋯石U-Pb定年,鋯石REE,全巖主微量元素和全巖Nd同位素組成的分析。對片巖JH-13-02碎屑鋯石U-Pb年齡范圍在2836Ma到1532Ma,主要集中在2500Ma附近,片巖JH-13-03碎屑鋯石U-Pb年齡范圍在2424Ma到1069Ma,主要集中在2000Ma附近。變花崗巖JH-13-05加權平均年齡為754±15Ma,片麻巖JH-13-06年齡主要集中在767±18Ma,所有樣品的鋯石Th/U大于0.1可見到清晰的巖漿振蕩環(huán)帶顯示典型的巖漿鋯石成因特征,鋯石虧損LREE富集HREE,并且具有不同程度Ce的正異常和Eu的負異常。全巖主量元素特征；片巖具有較高的A1203和Na K含量,片巖SiO2含量57.2%-77.1%。變基性巖SiO2含量在45.6%-50.8%。全巖REE特征顯示富集LREE虧損HREE,片巖和片麻巖具有Eu的不同程度負異常,變基性巖LREE和HREE分異較低不具有Eu的異常。片巖和片麻巖微量元素特征；富集大離子親石元素Rh、Th、Ba虧損Nb、Sr元素。變基性巖也富集大離子親石元素,Nb、Sr虧損不明顯。片巖和片麻巖的初始εNd值變化在-12.0至-2.8之間,Nd模式年齡TDM為1.6-3.1Ga,變基性巖初始εNd值變化在-9.3到1.9,TDM范圍是1.6到2.1Ga。相比海州群云母片巖初始εNd值-2.8到-8.8,TDM為2.1-2.4Ga較為單一的沉積物源,宿松群物源復雜。
[Abstract]:Susong Group is located at the southern foot of Dabie Mountain on the northern margin of the Yangtze Plate. It is adjacent to the southern Dabie cryogenic eclogite belt by the Mamiao fault zone of Taihu Lake and is bounded by the Xiangfan-Guangji fault zone in the south. The Suzong group was formed in the Neoproterozoic around 750Ma, which is related to the intracontinental rift caused by the breakup of the 825~740Ma Rodinia supercontinent in the Yangtze plate, which was accompanied by the formation of the back-arc basin and experienced late sedimentation. The complex rock types of Suzong Group are mainly composed of two types of rocks: metamorphic and metamorphic rocks, and their provenance composition is quite complex. In this study, samples of schist, gneiss, metamorphic granite and metamorphic rocks from the Suzong metamorphic terrane were selected and their zircon U-Pb dating, zircon REE, main trace elements and ND isotopic compositions of the whole rock were analyzed. For schist JH-13-02 zircon, the U-Pb age range is from 2836Ma to 1532 Ma, mainly in the vicinity of 2500Ma, and the U-Pb age range of schist JH-13-03 detrital zircon is from 2424Ma to 1069 Ma, mainly in the vicinity of 2000Ma. The JH-13-05 weighted average age of metamorphic granite is 754 鹵15Ma.The JH-13-06 age of gneiss is mainly 767 鹵18Ma.The zircon Th/U of all samples is greater than 0.1.A clear magmatic oscillation ring shows typical magmatic zircon genesis. Zircon depleted LREE enriches HREE and has positive and negative ce anomalies to varying degrees. The schist has a high content of A1203 and Na K, while the SiO2 content of schist is 57.2-77.1. The SiO2 content of the altered basic rock is between 45.6 and 50.8. The REE characteristics of the whole rock show that the enrichment of LREE depleted hree, the schist and gneiss have negative EU anomalies to varying degrees, and the lower differentiation of LREE and HREE in metamorphic rocks does not have EU anomalies. The microelement characteristics of schist and gneiss are characterized by the enrichment of large ion lithophile element Rhnb Th Ba and depletion of NB + Sr element. Metamorphic rocks are also enriched in large ion lithophile elements, and the depletion of NB ~ (2 +) Sr is not obvious. The initial 蔚 ND values of schist and gneiss vary from -12.0 to -2.8 TDM is 1.6-3.1Ga. the initial 蔚 ND values of basic rocks range from -9.3 to 1.9 ~ 1.1Ga. Compared with the initial 蔚 ND values from -2.8 to -8.8 of mica schist in Haizhou Group, TDM is a single sediment source of 2.1-2.4Ga, and the provenance of Susong Group is complex.
【學位授予單位】：中國科學技術大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：P597;P313

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