中国地质
中國地質
중국지질
CHINESE GEOLOGY
2015年
2期
556-569
,共14页
丁正江%孙丰月%李国华%纪攀%孔彦
丁正江%孫豐月%李國華%紀攀%孔彥
정정강%손봉월%리국화%기반%공언
锆石U-Pb年龄%燕山早期%钼钨矿床%邢家山%胶东地区
鋯石U-Pb年齡%燕山早期%鉬鎢礦床%邢傢山%膠東地區
고석U-Pb년령%연산조기%목오광상%형가산%효동지구
zircon U-Pb age%Early Yanshanian%molybdenum-tungsten deposit%Xingjiashan%Jiaodong Peninsular
对从幸福山花岗岩中挑出的岩浆锆石进行了LA-ICP-MS分析,得出了由15个点组成的加权平均值为(157±2) Ma的年龄。此15个测试点均处于岩浆锆石的振荡环带上,且此年龄与邢家山钼钨矿辉钼矿Re-Os年龄一致,代表该花岗岩的结晶年龄。本次测试所得到的另外2组捕获锆石年龄(2798±13) Ma和(2250±18) Ma暗示该岩浆源区可能存在的新太古代-古元古代侵入岩基底,(230±6) Ma则可能暗示着该区存在三叠纪的岩浆活动。中生代以来(190~110 Ma),中国东部构造岩浆活动特征较为一致,与之相对应存在多期成矿作用。胶东地区广泛出露的玲珑花岗岩与幸福山花岗岩岩石地球化学特征及年龄基本一致,可能该区也存在着大规模的钼多金属成矿作用,只是大部分为后期构造抬升所剥蚀,邢家山钼钨矿是保存下来的代表。也说明,栖霞—福山地区中生代以来剥蚀程度相对较小,矿床保存条件较好,故应重视该区中浅成矿床(斑岩-矽卡岩型、卡林型、造山型浅成矿床等)的寻找。
對從倖福山花崗巖中挑齣的巖漿鋯石進行瞭LA-ICP-MS分析,得齣瞭由15箇點組成的加權平均值為(157±2) Ma的年齡。此15箇測試點均處于巖漿鋯石的振盪環帶上,且此年齡與邢傢山鉬鎢礦輝鉬礦Re-Os年齡一緻,代錶該花崗巖的結晶年齡。本次測試所得到的另外2組捕穫鋯石年齡(2798±13) Ma和(2250±18) Ma暗示該巖漿源區可能存在的新太古代-古元古代侵入巖基底,(230±6) Ma則可能暗示著該區存在三疊紀的巖漿活動。中生代以來(190~110 Ma),中國東部構造巖漿活動特徵較為一緻,與之相對應存在多期成礦作用。膠東地區廣汎齣露的玲瓏花崗巖與倖福山花崗巖巖石地毬化學特徵及年齡基本一緻,可能該區也存在著大規模的鉬多金屬成礦作用,隻是大部分為後期構造抬升所剝蝕,邢傢山鉬鎢礦是保存下來的代錶。也說明,棲霞—福山地區中生代以來剝蝕程度相對較小,礦床保存條件較好,故應重視該區中淺成礦床(斑巖-矽卡巖型、卡林型、造山型淺成礦床等)的尋找。
대종행복산화강암중도출적암장고석진행료LA-ICP-MS분석,득출료유15개점조성적가권평균치위(157±2) Ma적년령。차15개측시점균처우암장고석적진탕배대상,차차년령여형가산목오광휘목광Re-Os년령일치,대표해화강암적결정년령。본차측시소득도적령외2조포획고석년령(2798±13) Ma화(2250±18) Ma암시해암장원구가능존재적신태고대-고원고대침입암기저,(230±6) Ma칙가능암시착해구존재삼첩기적암장활동。중생대이래(190~110 Ma),중국동부구조암장활동특정교위일치,여지상대응존재다기성광작용。효동지구엄범출로적령롱화강암여행복산화강암암석지구화학특정급년령기본일치,가능해구야존재착대규모적목다금속성광작용,지시대부분위후기구조태승소박식,형가산목오광시보존하래적대표。야설명,서하—복산지구중생대이래박식정도상대교소,광상보존조건교호,고응중시해구중천성광상(반암-석잡암형、잡림형、조산형천성광상등)적심조。
This paper presents the magma zircon LA-ICP-MS U-Pb isotopic dating results of the Xingfushan granites. The weighted mean age (157±2 Ma) was obtained from 15 test points on the oscillatory zones. Inferred from the same test positions and the coincident dating result with Re-Os isotopic age of molybdenite from the Xingjiashan molybdenum-tungsten deposit, the granites here crystallized in this period. The other two captured zircons from the same assay at the separate age of (2798±13) Ma and (2250 ± 18) Ma imply possible existence of Neoarchean-Paleoproterozoic intrusive basement, whereas No. 7 point at the age of (230±6) Ma implies possible Triassic magmatic activity. The consistent features of the tectono-magmatic activities in eastern China since Mesozoic (190?110 Ma) produced the corresponding varied metallogenesis here. The common granites of Linglong and Xingfushan units in Jiaodong Peninsular share almost the same geochemical features and ages, suggesting that this area might have hosted large-scale molybdenum polymetallic metallogenesis. Under heavy regional denudation by late tectonic uplifting, the left Xingjiashan molybdenum-tungsten deposit typically shows less denudation in Qixia-Fushan area since Mesozoic and better metallogenic condition, so more importance should be attached to the prospecting for hypabyssal deposits (porphyry-skarn, Carlin and organic hypabyssal deposits) here.