岩石矿物学杂志
巖石礦物學雜誌
암석광물학잡지
ACTA PETROLOGICA ET MINERALOGICA
2014年
4期
645-656
,共12页
橄榄玄粗岩%SHRIMP锆石U-Pb年龄%Sr-Nd-Pb-O同位素%广丰、玉山盆地
橄欖玄粗巖%SHRIMP鋯石U-Pb年齡%Sr-Nd-Pb-O同位素%廣豐、玉山盆地
감람현조암%SHRIMP고석U-Pb년령%Sr-Nd-Pb-O동위소%엄봉、옥산분지
shoshonite%SHRIMP zircon U-Pb dating%Sr-Nd-Pb-O isotopes%Guangfeng and Yushan basins
华夏古板块与扬子古板块结合带内的广丰、玉山红色碎屑沉积盆地均有橄榄玄粗岩产出,SHRIMP锆石U-Pb年代学研究表明,橄榄玄粗岩锆石U-Pb年龄为93±1Ma,属晚白垩世早期的产物.广丰盆地橄榄玄粗岩(87Sr/86Sr)i值为0.706 191～0.706 352,εNd(t)值为0.27～0.55,(206pb/204pb)i值为18.045～18.080,(207 pb/204 Pb)i值为15.503～15.543,(208 pb/204 Pb)i值为38.240～38.256;玉山盆地橄榄玄粗岩(87 Sr/86 Sr)i值为0.705 856～0.706 024,εNd(t)值为1.74～1.93,(206pb/24 pb)i值为17.956 ～ 18.063,(207 pb/204 Pb)i值为15.456～15.498,(208pb/204Pb)i值为38.195～38.232.在(87 Sr/86 Sr)i-(206 pb/204 Pb)i、(143 Nd/144 Nd)i-(206 pb/204 Pb)i和(143Nd/144Nd)i-(87S/86Sr)i图解中,广丰、玉山盆地橄榄玄粗岩均位于亏损地幔(DMM)和EMⅡ型富集地幔之间,而且(87Sr/86Sr)i和(206pb/204Pb)i呈正相关,(143Nd/144Nd);和(206pb/204pb)i呈负相关,指示其源区中可能均有DMM和EMⅡ型地幔的贡献;玉山盆地橄榄玄粗岩更偏向DMM端员,指示其DMM端员所占的比例更高.广丰、玉山盆地橄榄玄粗岩具有EMⅡ型地幔的贡献,说明华夏古板块与扬子古板块结合带的岩石圈地幔与华夏古板块的岩石圈地幔属相同类型,为华夏古板块俯冲于扬子古板块之下提供了新的证据.
華夏古闆塊與颺子古闆塊結閤帶內的廣豐、玉山紅色碎屑沉積盆地均有橄欖玄粗巖產齣,SHRIMP鋯石U-Pb年代學研究錶明,橄欖玄粗巖鋯石U-Pb年齡為93±1Ma,屬晚白堊世早期的產物.廣豐盆地橄欖玄粗巖(87Sr/86Sr)i值為0.706 191～0.706 352,εNd(t)值為0.27～0.55,(206pb/204pb)i值為18.045～18.080,(207 pb/204 Pb)i值為15.503～15.543,(208 pb/204 Pb)i值為38.240～38.256;玉山盆地橄欖玄粗巖(87 Sr/86 Sr)i值為0.705 856～0.706 024,εNd(t)值為1.74～1.93,(206pb/24 pb)i值為17.956 ～ 18.063,(207 pb/204 Pb)i值為15.456～15.498,(208pb/204Pb)i值為38.195～38.232.在(87 Sr/86 Sr)i-(206 pb/204 Pb)i、(143 Nd/144 Nd)i-(206 pb/204 Pb)i和(143Nd/144Nd)i-(87S/86Sr)i圖解中,廣豐、玉山盆地橄欖玄粗巖均位于虧損地幔(DMM)和EMⅡ型富集地幔之間,而且(87Sr/86Sr)i和(206pb/204Pb)i呈正相關,(143Nd/144Nd);和(206pb/204pb)i呈負相關,指示其源區中可能均有DMM和EMⅡ型地幔的貢獻;玉山盆地橄欖玄粗巖更偏嚮DMM耑員,指示其DMM耑員所佔的比例更高.廣豐、玉山盆地橄欖玄粗巖具有EMⅡ型地幔的貢獻,說明華夏古闆塊與颺子古闆塊結閤帶的巖石圈地幔與華夏古闆塊的巖石圈地幔屬相同類型,為華夏古闆塊俯遲于颺子古闆塊之下提供瞭新的證據.
화하고판괴여양자고판괴결합대내적엄봉、옥산홍색쇄설침적분지균유감람현조암산출,SHRIMP고석U-Pb년대학연구표명,감람현조암고석U-Pb년령위93±1Ma,속만백성세조기적산물.엄봉분지감람현조암(87Sr/86Sr)i치위0.706 191～0.706 352,εNd(t)치위0.27～0.55,(206pb/204pb)i치위18.045～18.080,(207 pb/204 Pb)i치위15.503～15.543,(208 pb/204 Pb)i치위38.240～38.256;옥산분지감람현조암(87 Sr/86 Sr)i치위0.705 856～0.706 024,εNd(t)치위1.74～1.93,(206pb/24 pb)i치위17.956 ～ 18.063,(207 pb/204 Pb)i치위15.456～15.498,(208pb/204Pb)i치위38.195～38.232.재(87 Sr/86 Sr)i-(206 pb/204 Pb)i、(143 Nd/144 Nd)i-(206 pb/204 Pb)i화(143Nd/144Nd)i-(87S/86Sr)i도해중,엄봉、옥산분지감람현조암균위우우손지만(DMM)화EMⅡ형부집지만지간,이차(87Sr/86Sr)i화(206pb/204Pb)i정정상관,(143Nd/144Nd);화(206pb/204pb)i정부상관,지시기원구중가능균유DMM화EMⅡ형지만적공헌;옥산분지감람현조암경편향DMM단원,지시기DMM단원소점적비례경고.엄봉、옥산분지감람현조암구유EMⅡ형지만적공헌,설명화하고판괴여양자고판괴결합대적암석권지만여화하고판괴적암석권지만속상동류형,위화하고판괴부충우양자고판괴지하제공료신적증거.
