对地质和矿产资源研究的贡献betway亚洲

文摘:中国内蒙古白云鄂博矿床是世界上已知最大的稀土矿床;矿床中还含铁、铌矿。中元古界白云鄂博群上部的白云岩大理岩单元(H8)中稀土、铁矿石层控富集，并发生了变质作用。H8寄主岩不是岩浆碳酸盐岩，而可能是沉积物。由于该大型矿床的矿物学性质复杂，区域变质历史复杂，矿化过程多，必须综合研究多种证据，才能对矿床进行描述和成因解释。结合野外和微观结构分析、地代学矿物年龄和不同世代矿物的化学成分，推断了矿物的年代演化序列。白云鄂博稀土矿床建立的总体矿物共生序列为:(1)中元古代H8碳酸盐岩沉积，白云石化为主;(2)变质成因的早期gofeo镁砂长岩(最小K-Ar类人猿802±19ma和724±17Ma);(3)在横切白云鄂博群下部(1200Ma)的热液脉中发现早期镁铝镁玄武岩;(4) 628 Ma以前白云岩中的早期独居石; (5) Mn-rich mag-nesio-arfvedsonite (minimum K-Ar age of 628±15Ma); (6) disseminated high-Nd monazite(~(232)Th/~(208)Pbmodel op of 596--592Ma); (7) monazite in banded ore (~(232)Th/~(208)Pb internal isochron age473±2Ma); (8) FeOMgO alkali amphiboles (minimum K-Ar age of 442±11a); (9) early mag-netite; (10) low-Nd monazite, bastnaesite, and apatite associated with aegirine and fluorite in bandedores; and alkali amphiboles in sheared dolomite (~(232)Th/~(208)Pb mineral isochron ages and ~(40)Ar/~39(Ar)plateau ages of about 425Ma); (11) granular hematite replacing fine-grained monazite (post--423Ma); (12) late magnetite; (13) aegirine-rich veins containing huanghoite and aeschynite (~(232)Th/~(208)Pbmineral isochron age of 438±25Ma) crosscuturg banded ores; and (14) Hercynian ape late stage min-eralization. The Bayan Obo ore deposit is concluded to be of epigenetic, hydrothermal, metasomatic orign. In- termittent hydrothermal activity began about 1,200 Ma and diminished after 400Ma. Intermittentprincipal mineralizatiuon started before 628Ma and reached peak activity between 473 and 400Ma.Three periods of regional metamorphism and two periods of subduction are thought to have producedthe fracures and hydrothermal solutions responsible for fomation of the deposit.

文摘:石门斯钨多金属矿床位于下扬子成矿省江南地块中生代铜钼金银铅锌矿带中。根据该矿床的区域地质背景和成矿地质特征，详细分析了工作区围岩、赋矿岩和裂缝等控矿因素。国岩为晋宁晚期黑云母花岗闪长岩，认为是在新元古代未成熟大陆地壳基础上发育的同碰撞火山弧中的s型花岗岩;赋矿岩为燕山期斑状黑云母花岗岩、细粒黑云母花岗岩、钙碱系列Si、Al饱和岩的花岗岩，s型花岗岩是九岭基在大陆内碰撞挤压作用下熔融同源演化而成该断裂为控矿断裂，其交点控制着含矿花岗岩的侵位和w -多金属矿床的分布。

文摘:滇东南燕山晚期的个旧岩体、伯珠山岩体和老君山岩体控制了3个超大型和部分中、小型多金属矿床。矿床多数产于花岗岩体内部或周围，矿床有用元素相似，成矿金属可能多来源于花岗岩体，锶、铜多产于花岗岩体接触带附近，银、铅、锌多位于形成的断裂中通过侵入花岗岩岩浆