地球科学与环境学报
地毬科學與環境學報
지구과학여배경학보
JOURNAL OF EARTH SCIENCES AND ENVIRONMENT
2014年
1期
141-151
,共11页
花岗岩%氧逸度%锆石U-Pb年龄%钨锡矿%中生代%太平洋板块俯冲%南岭地区
花崗巖%氧逸度%鋯石U-Pb年齡%鎢錫礦%中生代%太平洋闆塊俯遲%南嶺地區
화강암%양일도%고석U-Pb년령%오석광%중생대%태평양판괴부충%남령지구
granite%oxygen fugacity%zircon U-Pb age%W-Sn deposit%Mesozoic%Pacific Plate subduction%Nanling area
华南南岭地区中生代花岗岩钨锡成矿活动十分剧烈。采集了南岭地区清湖岩体、姑婆山岩体（锡矿）、雪花顶岩体、骑田岭岩体（锡钨矿）和九峰岩体5处出露花岗岩锆石样品，并进行锆石 U-Pb年代学和微量元素分析。结果表明：花岗岩年龄主要集中在146～166 Ma之间，与前人所测年龄在误差范围内一致；其锆石Ce4＋/Ce3＋值总体偏低（低于200），EuN/Eu*N值均小于0．4，无论是与锡（钨）矿有关的花岗岩还是普通花岗岩，都显示较低的氧逸度特征，明显低于年龄较老的大宝山铜钼矿、德兴斑岩铜矿的锆石Ce、Eu异常。因此，南岭地区中生代时可能离古太平洋板块俯冲带较远，受到俯冲流体影响较弱，可能形成于古太平洋板块 SW向俯冲背景下。
華南南嶺地區中生代花崗巖鎢錫成礦活動十分劇烈。採集瞭南嶺地區清湖巖體、姑婆山巖體（錫礦）、雪花頂巖體、騎田嶺巖體（錫鎢礦）和九峰巖體5處齣露花崗巖鋯石樣品，併進行鋯石 U-Pb年代學和微量元素分析。結果錶明：花崗巖年齡主要集中在146～166 Ma之間，與前人所測年齡在誤差範圍內一緻；其鋯石Ce4＋/Ce3＋值總體偏低（低于200），EuN/Eu*N值均小于0．4，無論是與錫（鎢）礦有關的花崗巖還是普通花崗巖，都顯示較低的氧逸度特徵，明顯低于年齡較老的大寶山銅鉬礦、德興斑巖銅礦的鋯石Ce、Eu異常。因此，南嶺地區中生代時可能離古太平洋闆塊俯遲帶較遠，受到俯遲流體影響較弱，可能形成于古太平洋闆塊 SW嚮俯遲揹景下。
화남남령지구중생대화강암오석성광활동십분극렬。채집료남령지구청호암체、고파산암체（석광）、설화정암체、기전령암체（석오광）화구봉암체5처출로화강암고석양품，병진행고석 U-Pb년대학화미량원소분석。결과표명：화강암년령주요집중재146～166 Ma지간，여전인소측년령재오차범위내일치；기고석Ce4＋/Ce3＋치총체편저（저우200），EuN/Eu*N치균소우0．4，무론시여석（오）광유관적화강암환시보통화강암，도현시교저적양일도특정，명현저우년령교로적대보산동목광、덕흥반암동광적고석Ce、Eu이상。인차，남령지구중생대시가능리고태평양판괴부충대교원，수도부충류체영향교약，가능형성우고태평양판괴 SW향부충배경하。
W-Sn mineralization of Mesozoic granites in Nanling area of South China is very strong. Five granite zircon samples from Qinghu,Guposhan (Sn deposit),Xuehuading,Qitianling (Sn-W deposit)and Jiufeng plutons in Nanling area were conducted and measured by zircon U-Pb geochronology and trace element analysis.The results show that granite ages are mainly formed at 146-166 Ma,consistent with previous measured ages within errors;all the calculated zircon Ce4+/Ce3+ values are lower than 200,the EuN/Eu*N values are less than 0.4,and granites related with W (Sn)deposit or barren granites have lower oxygen fuga city than that of the older Dabaoshan Mo-Cu-W deposit and Dexing porphyry Cu deposit.Therefore, Nanling area is possible far from subduction zone of Paleo-Pacific Plate in Mesozoic,is weakly influenced by subduction fluids,and is affected by SW-trending subduction of Paleo-Pacific Plate.
