CAJ | 학술논문

德兴斑岩铜矿位于扬子地块江南隆起带东缘,含矿斑岩类型为花岗闪长斑岩。岩石主矿物组合为斜长石(中长石、更长石)+石英+钾长石+角闪石+黑云母,常见副矿物为磁铁矿、磷灰石、榍石、钛铁矿和锆石。斑岩主量元素具有高硅(SiO 2=63.59%)、高铝(Al2 O 3=15.54%)、低镁(MgO=2.2%)的特征,岩石富钾贫钠(K2 O=3.06%；Na2 O=3.67%),高 K2 O/Na2 O(0.89)比；ALK=6.66%,A/CNK=1.086,σ=2.18,A.R=2.07,显示岩石为弱过铝质高钾钙碱性系列；稀土元素特征表现为轻稀土富集(121.81×10-6),重稀土亏损(8.8×10-6),具有较大的 LREE/HREE 比值(13.93)；微量元素表现为富集大离子亲石元素 LILE(Rb、Ba、La、Sr)和亏损高场强元素 HFSE(Nb、Ta、Y),具低 Y(11.21×10-6)和 Yb(1.23×10-6)含量特征,有较高 Sr/Y(57.29)、La/Yb(28.93)比值,具较高的87 Sr/86 Sr 比值(>0.7040),弱的负 Eu 异常(δEu=0.91),以及负εNd 值等特征,表明德兴花岗闪长斑岩为“C”型高钾钙碱性埃达克岩,埃达克岩浆来源于活动陆缘加厚下地壳的部分熔融。
덕흥반암동광위우양자지괴강남륭기대동연,함광반암류형위화강섬장반암。암석주광물조합위사장석(중장석、경장석)+석영+갑장석+각섬석+흑운모,상견부광물위자철광、린회석、설석、태철광화고석。반암주량원소구유고규(SiO 2=63.59%)、고려(Al2 O 3=15.54%)、저미(MgO=2.2%)적특정,암석부갑빈납(K2 O=3.06%；Na2 O=3.67%),고 K2 O/Na2 O(0.89)비；ALK=6.66%,A/CNK=1.086,σ=2.18,A.R=2.07,현시암석위약과려질고갑개감성계렬；희토원소특정표현위경희토부집(121.81×10-6),중희토우손(8.8×10-6),구유교대적 LREE/HREE 비치(13.93)；미량원소표현위부집대리자친석원소 LILE(Rb、Ba、La、Sr)화우손고장강원소 HFSE(Nb、Ta、Y),구저 Y(11.21×10-6)화 Yb(1.23×10-6)함량특정,유교고 Sr/Y(57.29)、La/Yb(28.93)비치,구교고적87 Sr/86 Sr 비치(>0.7040),약적부 Eu 이상(δEu=0.91),이급부εNd 치등특정,표명덕흥화강섬장반암위“C”형고갑개감성애체극암,애체극암장래원우활동륙연가후하지각적부분용융。
The Dexing porphyry copper deposit is located to the eastern part of Jiangnan paleouplift in the Yangtze landmass,and the rock type of copper-bearing porphyries is granodiorite porphyry with the major mineral assemblage consisted of plagioclase(andesine,oligoclase)+ quartz + potassium feldspar +hornblende + biotite and some accessory minerals consisted of magnetite,apatite,titanite,ilmenite and zir-con.The granodiorite porphyries are geochemically characteristic of higher silicon (SiO 2 =63.59%),high-er aluminum (Al2 O 3 =15.54%),lower magnesium (MgO=2.2%),and are rich in potassium and poor in sodium (K2 O=3.06%;Na2 O=3.67%)with higher K2 O/Na2 O ratio(0.89),rocks belong to weak peralu-minous high-K calc-alkaline series,ALK=6.66%,A/CNK=1.086,σ=2.18,A.R=2.07,showing that the rocks belong to weak peraluminous high-k calc-alkaline series.The granodiorite porphyries are obviously rich in LREE (LREE=121.81 ×10-6 )and LILE(Rb,La,Ba,Sr),and depleted in HREE(HREE=8.8 × 10-6 )and HFSE(Nb,Ta,Y),with higher LREE/HREE ratio(13.93).The geochemical characteristics of trace elements are show by lower Y(1 1.21×10-6 )and Yb(1.23×10-6 ),and with higher Sr/Y (57.29)and La/Yb(28.93),higher 87 Sr/86 Sr (>0.7040)and weakly negative Eu anomaly (δEu:=0.91 )negativeεNd .Through the analysis of petrological and geochemical characteristics,it is considered that the Dexing granodiorite porphyries belong to the “C”type high-K calc-alkaline adakites,which were formed from par-tial melting of the thickened lower crust at active continental margin.