资源调查与环境
資源調查與環境
자원조사여배경
RESOURCES SURVEY & ENVIRONMENT
2012年
3期
152-157
,共6页
黄水保%毛大华%狄永军%魏英文%罗平%李伯春
黃水保%毛大華%狄永軍%魏英文%囉平%李伯春
황수보%모대화%적영군%위영문%라평%리백춘
流纹斑岩%铅锌矿%梨子坑火山盆地%北武夷
流紋斑巖%鉛鋅礦%梨子坑火山盆地%北武夷
류문반암%연자광%리자갱화산분지%북무이
rhyolite porphyries%lead-zinc mineralization%Lizikeng volcanic basin%northern Wuyishan
摘要:梨子坑火山盆地位于北武夷中生代月凤山-梨子坑火山岩带东段,已知铅锌(铜、银)矿体或矿化呈细脉-浸染型、脉状,产于流纹斑岩脉的内外接触带及其外侧围岩中,发育钾化、绿泥石化、硅化、绿帘石化等围岩蚀变。地球化学特征显示流纹斑岩为钙碱性系列,岩石具有高SiO2、富碱、高K2O、高钙铁、低镁、K2O/Na2O值偏高的特点,为强过铝质岩石。w(∑REE)值为76.28×10^-6~222.54×10&-6(∑LREE/∑HREE)比值较大,为4.08-12.30,属于轻稀土元素富集型。成矿流纹斑岩形成于1372=2.1Ma(SHRIMP锆石U—Pb法)~138.8±1.4Ma(LA-MC—ICPMS锆石U—Pb法),属早白垩世。铅锌矿属于次火山斑岩脉型铅锌(银铜)成矿系列,划分为次火山斑岩脉型和次火山热液破碎带型两种矿床成因类型。
摘要:梨子坑火山盆地位于北武夷中生代月鳳山-梨子坑火山巖帶東段,已知鉛鋅(銅、銀)礦體或礦化呈細脈-浸染型、脈狀,產于流紋斑巖脈的內外接觸帶及其外側圍巖中,髮育鉀化、綠泥石化、硅化、綠簾石化等圍巖蝕變。地毬化學特徵顯示流紋斑巖為鈣堿性繫列,巖石具有高SiO2、富堿、高K2O、高鈣鐵、低鎂、K2O/Na2O值偏高的特點,為彊過鋁質巖石。w(∑REE)值為76.28×10^-6~222.54×10&-6(∑LREE/∑HREE)比值較大,為4.08-12.30,屬于輕稀土元素富集型。成礦流紋斑巖形成于1372=2.1Ma(SHRIMP鋯石U—Pb法)~138.8±1.4Ma(LA-MC—ICPMS鋯石U—Pb法),屬早白堊世。鉛鋅礦屬于次火山斑巖脈型鉛鋅(銀銅)成礦繫列,劃分為次火山斑巖脈型和次火山熱液破碎帶型兩種礦床成因類型。
적요:리자갱화산분지위우북무이중생대월봉산-리자갱화산암대동단,이지연자(동、은)광체혹광화정세맥-침염형、맥상,산우류문반암맥적내외접촉대급기외측위암중,발육갑화、록니석화、규화、록렴석화등위암식변。지구화학특정현시류문반암위개감성계렬,암석구유고SiO2、부감、고K2O、고개철、저미、K2O/Na2O치편고적특점,위강과려질암석。w(∑REE)치위76.28×10^-6~222.54×10&-6(∑LREE/∑HREE)비치교대,위4.08-12.30,속우경희토원소부집형。성광류문반암형성우1372=2.1Ma(SHRIMP고석U—Pb법)~138.8±1.4Ma(LA-MC—ICPMS고석U—Pb법),속조백성세。연자광속우차화산반암맥형연자(은동)성광계렬,화분위차화산반암맥형화차화산열액파쇄대형량충광상성인류형。
Lizikeng volcanic basin is located in the east section of the Mesozoic Yuefengshan-Lizikeng volcanic rock belt, northern Wuyishan. The known lead-zinc(copper, sliver) ore-bodies or mineralizations which are shown as veinlet-disseminated and vein ores are mainly occurred in internal or external contact zones and wall rocks of rhyolite porphyries, where wall-rock alterations such as potassic alteration, chloritiza- tion, silicification and epidotization are well developed. The results of geochemical analyses show that the rhyolite porphyries belong to strongly peraluminous calc-alkaline series rocks with high contents of alkali, SiO2,K2O, Ca, Fe, high ratios of K20/Na20 and low contents of Mg, w(EREE)values vary from 76.28×10^-6to 222.54× 10^-6, w(S.LREE/Y.HREE) values are relatively high(4.08-12.30),suggesting a strongly right-inclined LREE enrichment type. Ore-forming rhyolite poyphyries are occurred in 137 4-2.1 Ma (SHRIMP zircon U-Pb)-138.8±1.4 Ma(LA-MC-ICPMS zircon U-Pb), belong to the Early Cretaceous. The lead-zinc deposit can be genetically divided into subvolcanic porphyry vein type and subvolcanic hy- drothermal fracture zone type, belonging to subvolcanic porphyry vein type lead-zinc (copper, sliver) metallogenic series.