华南地质与矿产
華南地質與礦產
화남지질여광산
GEOLOGY AND MINERAL RESOURCES OF SOUTH CHINA
2014年
4期
342-351
,共10页
许华%黄炳诚%倪战旭%韩淑朋%黄英%龚云
許華%黃炳誠%倪戰旭%韓淑朋%黃英%龔雲
허화%황병성%예전욱%한숙붕%황영%공운
岩石地球化学%LA-ICP-MS 锆石 U-Pb 年龄%碱性辉长岩体%广西大瑶山
巖石地毬化學%LA-ICP-MS 鋯石 U-Pb 年齡%堿性輝長巖體%廣西大瑤山
암석지구화학%LA-ICP-MS 고석 U-Pb 년령%감성휘장암체%엄서대요산
petrogeochemistry%zircon LA-ICP-MS U-Pb ages%alkaline gabbroic rock%Dayaoshan
古罗碱性辉长岩体包括古罗、黄羌冲两个侵入体,主要由辉长岩、石英辉长岩(或石英闪长岩)组成。岩石以富碱、富集大离子亲石元素(LILE)、轻稀土元素(LREE)和高场强元素(HFSE),无 Nb、Ta 异常,是典型的板内钾玄岩。对古罗辉长岩体进行了高精度的 LA-ICP-MS 锆石 U-Pb 定年,获得石英辉长岩的206Pb/238U 加权平均年龄为165.63±0.95 Ma。研究认为古罗碱性辉长岩体形成于中侏罗世,属典型的板内钾玄岩,形成于大陆地壳伸展拉张减薄的构造背景,为燕山期早期华南后造山阶段的地质记录。
古囉堿性輝長巖體包括古囉、黃羌遲兩箇侵入體,主要由輝長巖、石英輝長巖(或石英閃長巖)組成。巖石以富堿、富集大離子親石元素(LILE)、輕稀土元素(LREE)和高場彊元素(HFSE),無 Nb、Ta 異常,是典型的闆內鉀玄巖。對古囉輝長巖體進行瞭高精度的 LA-ICP-MS 鋯石 U-Pb 定年,穫得石英輝長巖的206Pb/238U 加權平均年齡為165.63±0.95 Ma。研究認為古囉堿性輝長巖體形成于中侏囉世,屬典型的闆內鉀玄巖,形成于大陸地殼伸展拉張減薄的構造揹景,為燕山期早期華南後造山階段的地質記錄。
고라감성휘장암체포괄고라、황강충량개침입체,주요유휘장암、석영휘장암(혹석영섬장암)조성。암석이부감、부집대리자친석원소(LILE)、경희토원소(LREE)화고장강원소(HFSE),무 Nb、Ta 이상,시전형적판내갑현암。대고라휘장암체진행료고정도적 LA-ICP-MS 고석 U-Pb 정년,획득석영휘장암적206Pb/238U 가권평균년령위165.63±0.95 Ma。연구인위고라감성휘장암체형성우중주라세,속전형적판내갑현암,형성우대륙지각신전랍장감박적구조배경,위연산기조기화남후조산계단적지질기록。
Guluo alkaline gabbroic magmatic rocks including Guluo and Huangqiangchong intrusive rocks are comprising of gabbro, quartz-gabbro (or quartz-diorite). These rocks are enriched in alkalies, LILE, LREE and HFSE, characteristed by no Nb and Ta anomalies, which indicates belongs to typical intrapate-shoshonite series. Zircon LA-ICP-MS U-Pb dating of Guluo alkaline gabbroic rocks yields the 206Pb/238U age of 165.63±0.95 Ma. The geochronology data suggests that Guluo alkaline gabbroic rocks as typical intrapate-shoshonite series was formed in the Middle Jurassic Period, and indicated that the magma was generated in the tectonic settings of con-tinental crust extension and thinning, which records post-orogenesis event of South China in the Early Yanshan-nian period.