Mineralogical and geochemical characteristics of scheelite-bearing skarns,and genetic relations between skarn mineralization and petrogenesis of the associated granitoid pluton at Sargipali,Sundergarh District,Eastern India

Skarn rocks occur at the contact between calcite-bearing dolomitic marbles and granitoids (massive varieties with pegmatites) in close spatial association with the mica schist-hosted Proterozoic Pb–Cu–Ag sulfide deposits at Sargipali, Sundergarh District, Eastern India. The exoskarn (pyroxene–garnet) of variable width (1 to 30 m) occurs in marble proximal to the granitic intrusion, and endoskarn (pyroxene–epidote) is variably developed (< 1 to 10 m). Molybdenum-free scheelite with minor pyrrhotite (0.2%) is found only in late garnet–clinopyroxene exoskarn assemblages.     

吉林省四平山门银金矿成因机理及成矿模式

奥陶系上统矿源层残存在花岗岩内。矿源层历经三次花岗岩的高温、高压气热流体的渗透，其银、金元素迁移再富集，丰度约是同类岩石Ａｇ的７倍，Ａｕ的３倍。发育在上述地质体内的剪切带活动时产生的富温、高压及的气水热液萃取其银、金元素向邻侧低温，低压扩容空间迁移富集成矿。     

界牌岭锡矿床蚀变矿化分带及其成因探讨

湖南界牌岭锡矿床蚀变矿化可分为条纹状云母萤石岩化—铍矿化带,细脉状云母萤石化—铅锌矿化带、黄玉—萤石—云英岩化—锡铜锌多金属矿化带和弱—无蚀变矿化带.不同蚀变矿化带物质组分迁移规律有不同的特点.其成矿物质主要来源于花岗斑岩,该矿床是与陆壳重熔型花岗岩类斑岩体有成因联系的斑岩型锡矿床.     

http://www.sciencedirect.com/science/article/pii/S1674987111000168

Actual granitoid analytical data of 767 composited samples are presented here.The data source is 6080 samples collected mainly from 750 large- to middle-sized granitoid bodies across China. Data from the composited samples,which includes that of 70 elements,is analyzed according to geological age—Archeozoic(Ar),Proterozoic(Pt),Eopaleozoic(Pz_1),Neopaleozoic(Pz_2),Mesozoic(Mz), and Cenozoic(Cz)—and three major compositional varieties,e.g.alkali-feldspar granite,syenogranite and adamellite.Petrochemical pa...     

吉林省西部草地土壤的化学元素含量及其特征研究

对吉林省西部草地土壤化学元素含量研究表明，吉林省西部草地土壤中富钾少磷；钙、镁含量丰富；硼、铜、铁、锰含量在剖面上表现为向下增加；土壤中氮、磷、钾、钙、铜含量随草地退化程度的加深而减少；土壤中硅、钠含量丰富，显示出较强的沙化、盐碱化趋势，其含量随草地退化程度的加深而增加，钴含量随草地退化程度加深而降低；钡含量随草地退化程度的加深有增加的趋势；而稀土元素总量低于土壤背景值，并随着草地退化程度的加深其含量有减少的趋势。     

云南铂族元素找矿基础问题

云南省铂族元素矿床成矿地质条件较好，已有不少已知矿床、矿点、找矿信息及地球化学异常。找矿重点以基性超基性岩型为主，也应考虑其它类型，如热液型、黑色页岩型、煤岩型等。找矿重点地区除在峨眉山玄武岩分布区及其周边外，应注意康滇地轴中部及边缘中新生代断裂带通过的地区。峨眉山玄武岩分布区外围的卡林型金矿和浅成低温热液型矿床分布区亦值得重视，如滇东南地区。此外，寒武系黑色岩系及含磷层位的含铂性是一个具有挑战性的新课题，值得加强研究。云南铂族元素矿床的成矿时代，可能从元古代到新生代均有，对云南找铂来说非常有利，其它省区无法与之相比。新生代构造可能将深埋的矿体错动到浅部，找矿中需要特别注意。不妨“沿河找矿”。第四纪的风化壳中是否有铂族元素的富集也可探索。     

Digital Element Earth

The resources and environmental problems are the two most fundamental issues facing all nations in the world. Everything in and on the Earth – minerals, animals and plants – is made from one, or generally some combination of, chemical elements, which are scientifically listed in the periodic table. Thus it is important to understand the present abundance and spatial distribution of all the elements across the Earth’s surface. Such kinds of data can only be obtained at present and for the foreseeable future by on-earth geochemical mapping at all scales. The 30-year efforts made by Chinese geochemists in carrying out multi-element, multi-media, multi-scale geochemical mapping projects to delineate 39–76 element distribution at home and abroad culminated in a successful case of high-quality geochemical data acquirement. The new idea for a four-level plan for global geochemical mapping was advanced to obtain global data in the foreseeable future and the collection of updated geochemical information. Such information needs to be easily accessible not only by the science community, but also by industry, agriculture, governments, and even individuals, by all who would make an effort to promote sustainable living on our planet. The concept of a Digital Element Earth (DEE) fulfills the aims.     

皖南姚村岩体花岗岩风化壳稀土元素赋存特征

皖南地区花岗岩风化壳中稀土元素普遍富集，局部已成为矿床，其中，郎溪县姚村岩体风化壳富集程度较高。LA- ICP- MS锆石U- Pb定年表明，姚村花岗岩体的形成年龄为127.9±1.4 Ma，属于皖南地区燕山期晚期岩浆作用的产物。风化壳可细分为残坡积层（A）、强半风化层（C1）、过渡层（C2）、弱风化层（C3）和基岩（D）五层。稀土总量在纵向剖面上呈“波浪式”分布，各层稀土分布型式表现出对原岩的继承性。风化壳稀土配分型式与基岩一致， 富集LREE，轻重稀土分馏明显(La/Yb)N=15.6），但总含量明显更高。基岩∑REE为338×10-6，半风化层∑REE最高达642×10-6，富集约两倍。风化壳物质由风化残余主矿物（石英、钾长石、斜长石、黑云母）、黏土矿物（高岭石、埃洛石、伊利石、三水铝石等）和副矿物（锆石、磷灰石、榍石等）等组成。黏土矿物以伊利石含量最高，指示风化壳发育不成熟。REE与埃洛石含量明显正相关，与其他黏土矿物关系不明显。（含）稀土矿物（尤其是榍石）对风化壳中稀土元素的贡献量超过百分之五十，其次为斜长石，是风化壳中REE的重要来源。