CAJ | 학술논문

南岭地区钼成矿与花岗质岩浆活动关系密切,“成钼”岩体常呈小岩株或岩瘤状产出,出露面积多数＜3.5 km2,以钾长石花岗岩/普通花岗岩类-二长花岗岩类-花岗闪长岩类系列为主。根据近年来南岭地区钼矿及其相关花岗岩的最新研究成果初步总结了“成钼”岩体的成矿专属性。结果表明,南岭地区“成钼”岩体具有以下特征：(1)极强的时代专属性和地域差异性,即成矿岩体集中形成于燕山期的150~171 Ma、129~140 Ma和90~105 Ma 3个主要阶段。其中,高峰期为150~171 Ma,主要分布在南岭中东段的赣南、粤北和湘南地区。早白垩世岩体以南岭东段的闽西南地区为主(90~140 Ma),其次为南岭西段(90~105 Ma)；(2)化学成分专属性不显著, SiO2含量范围较广(58.04%~78.68%),呈双峰式分布(峰值分别为62%~70%和72%~78%),但当岩体具有不同矿化组合时,其 SiO2含量、碱含量(K2O+Na2O)、K2O/Na2O 比值和分异指数(DI)具有不同的特征范围,表现出一定的专属性：一般具不太高的 SiO2含量(65%~71%)、高碱(6%~9%)、高 K2O/Na2O比值(＞6)、高氧化态(磁铁矿系列)和适度演化(70＜DI＜90)的岩体对形成较大规模的(独立)钼矿最为有利；(3)富集Rb、Th、U、K、Pb、Nd等元素,亏损Ba、Sr、P、Ti、Nb、Zr、LREE等,具不同矿化组合的岩体稀土元素组成差异比较大：当与铜矿有关时,各时代岩体稀土元素配分曲线呈右倾,具有不明显的Eu负异常(0.6＜δEu＜1)；独立钼矿与含铜矿化岩体特征相似,但Eu负异常更不明显(0.8＜δEu＜1)；与钨、铅、锌、锡矿等相关的岩体稀土元素配分模式呈平卧海鸥状,具有明显的Eu负异常(δEu＜0.45)；(4)岩石成因类型可以是I型、A型和S型,以后两者为主,当岩体为I型花岗岩时,往往发育铜矿化,当有幔源物质参与成岩时往往对成钼矿十分有利。
남령지구목성광여화강질암장활동관계밀절,“성목”암체상정소암주혹암류상산출,출로면적다수＜3.5 km2,이갑장석화강암/보통화강암류-이장화강암류-화강섬장암류계렬위주。근거근년래남령지구목광급기상관화강암적최신연구성과초보총결료“성목”암체적성광전속성。결과표명,남령지구“성목”암체구유이하특정：(1)겁강적시대전속성화지역차이성,즉성광암체집중형성우연산기적150~171 Ma、129~140 Ma화90~105 Ma 3개주요계단。기중,고봉기위150~171 Ma,주요분포재남령중동단적공남、월북화상남지구。조백성세암체이남령동단적민서남지구위주(90~140 Ma),기차위남령서단(90~105 Ma)；(2)화학성분전속성불현저, SiO2함량범위교엄(58.04%~78.68%),정쌍봉식분포(봉치분별위62%~70%화72%~78%),단당암체구유불동광화조합시,기 SiO2함량、감함량(K2O+Na2O)、K2O/Na2O 비치화분이지수(DI)구유불동적특정범위,표현출일정적전속성：일반구불태고적 SiO2함량(65%~71%)、고감(6%~9%)、고 K2O/Na2O비치(＞6)、고양화태(자철광계렬)화괄도연화(70＜DI＜90)적암체대형성교대규모적(독립)목광최위유리；(3)부집Rb、Th、U、K、Pb、Nd등원소,우손Ba、Sr、P、Ti、Nb、Zr、LREE등,구불동광화조합적암체희토원소조성차이비교대：당여동광유관시,각시대암체희토원소배분곡선정우경,구유불명현적Eu부이상(0.6＜δEu＜1)；독립목광여함동광화암체특정상사,단Eu부이상경불명현(0.8＜δEu＜1)；여오、연、자、석광등상관적암체희토원소배분모식정평와해구상,구유명현적Eu부이상(δEu＜0.45)；(4)암석성인류형가이시I형、A형화S형,이후량자위주,당암체위I형화강암시,왕왕발육동광화,당유만원물질삼여성암시왕왕대성목광십분유리。
Molybdenum mineralization is closely associated with granitic magmatism in the Nanling region. Ore-bering plutons generally occur as small stocks or bosses with outcrop areas of <3.5 km2. The lithologies are mainly potassium feldspar granite-monzonitic granite-granodiorite. Based on the recently published data, metallogenic specialization of the granitic rocks related to molybdenum mineralization is discussed in this paper. The characteristics of metallogenic specialization can be concluded as follows: (1) Strong age specialization and geographical differences: ages of these granitoids related to the Mo deposits are mainly Yanshanian which can be subdivided into three stages: 150-171 Ma, 129-140 Ma, and 90-105 Ma. Inbeing the peak granitic magmatism, the 150-171 Ma plutons mainly distribute in the southern Jiangxi province, the northern Guangdong province, and the southern Hunan province; the early Cretaceous plutons distribute in the southwestern Fujian province (90-140 Ma) and the western part of Nanling (90-105 Ma); (2) Unobvious specialization of chemical composition:The SiO2 contents change in a wide range of 58.04%to 78.68%with bimodal distribution (two peaks are 62%-70% and 72%-78%, respectively). SiO2, K2O+Na2O contents, K2O/Na2O ratios, and differentiation indices (DI) have different characteristics for different combinations of metallogenetic elements showing somewhat specialization. In general, the plutons with high SiO2 contents (65%-71%), high alkali (6%-9%), high K2O/Na2O values (>6), high oxidation state (magnetite series) and moderate DI (70<DI<90) commonly relate to large-scale (independent) Mo ore deposits;(3) The plutons are relatively enriched in Rb, Th, U, K, Pb, and Nd, but depleted in Ba, Sr, P, Ti, Nb, Zr, and LREE. REE compositions are different for ore-bearing granitiods of different ages with different combinations of metallogenetic elements. Chondrite normalized REE patterns of the rocks with Cu mineralization show right-dipping patterns with insignificant negative Eu anomalies (0.6<δEu<1);Chondrite normalized REE patterns of the Mo mineralized rocks are similar to those of Cu mineralized rocks with even less significant Eu anomalies (0.8<δEu<1); whereas the chondrite normalized REE patterns of the rocks associated with W, Pb, Zn, Sn mineralization show flat seagull shapes with obvious negative Eu anomalies (δEu<0.45);(4) Three genetic types (I-, A-, S-types) of ore-bearing granitiods were discerned, however, most of which are either A- or S-type. It is strikely noteworthy that the Cu mineralization commonly related to I-type granites, while mantle involvement in the granite magma processes is crucial for Mo mineralization.