准噶尔盆地第三纪磁性地层柱的建立

通过对新疆准噶尔盆地第三系３个剖面古地磁样品的分析、测试，在生物地层学研究的基础上，建立了一条较为完整的第三纪磁性地层柱，标定了各组地质年代，为在不同盆地进行对比，提供了新的依据。     

南平花岗伟晶岩中铯沸石的研究

目前在中国已发现两种铯矿物，即南平石和铯沸石，其中铯沸石主要分布在新疆、陕西、河南省的花岗伟晶岩中，在华南，南平花岗伟晶岩是迄今所报道的铯沸石的唯一产地。我们将南平钩沸石分成原生和次生两类，本文详细报道了南平铯沸石的产状、物性和光性、化学成分、Ｘ射线衍射特征、红外光谱、差热分析和形成过程。     

新矿物—彭志忠石的发现及研究

彭志忠石产于湖南安化白钨矿区,是一种富含镁、锡、铝的复杂氧化物。矿物为浅黄褐色、浅黄色,少量无色,晶体呈六方板状。晶体化学式为:(Mg,Zn,Fe,Al)_4(Sn,Fe)_2(Al,□)_(10)O_(22)(OH)_2,空间群P_3ml,a=5.692(5)A,c=13.78(2)A,V=386.7A~3,Z=1。D=4.22(3)g/cm~3,H≥8,一轴正晶,ω=1.802(2),ε=1.814(2)。     

新疆柯坪巴立克立克组腕足动物群

报道和首次描述巴立克立克组腕足动物共30属39种,其中1新属7新种.该动物群具有石炭、二叠系过渡的性质,时代属于阿舍尔末期至萨克马尔最初期.Choristites qiudaisaiensis-Costifrina indicus 带分为 Postamartinia granulipwa-Rugivestis kutorgae 上亚带和 Costiferina punilus-Meckella hemiplicata 下亚带.下亚带属于阿舍尔末期,上亚带属于萨克马尔最初期,石炭、二叠乐界线置于下、下亚带之间,该动物群生物地理区系属古地中海大区,次级区系特征不明显,具混合性质。     

A method for quantifying living roots of Spartina (cordgrass) and Juncus (needlerush)

Quantifying living roots in a marsh is a necessary but difficult task in wetland research. The two main difficulties usually encountered are distinguishing living from dead roots and processing a dense mat of fine roots. We found that living roots of salt-marsh plants release much more dissolved organic carbon (DOC) in boiling water than dead roots. Based on the finding, we developed a DOC procedure to quantify living roots of Spartina alterniflora and Juncus roemerianus. The DOC released in boiling water is a function of root activity, and the amount released can be used to calculate the living root biomass of a sample. The amount of living roots determined by the DOC method correlated well with the amount of living roots determined by the manual, sorting method (r² = 0.78, p<0.01). The DOC method is more objective, precise, and much less tedious than the manual sorting method.     

断陷湖盆浅水三角洲沉积特征:以Muglad盆地Unity凹陷Aradeiba组为例

浅水三角洲是沉积学和油气勘探开发领域的热点,目前研究主要集中在大型坳陷型盆地内,部分学者研究证明在断陷湖盆萎缩期或裂陷初期也存在浅水三角洲沉积,但研究较为薄弱.本文利用岩心、测井、地震以及分析化验资料,对Muglad盆地研究区内Aradeiba组浅水三角洲的沉积有利条件、沉积特征以及垂向演化特征进行了深入剖析,结合湖平...     

华南燕山晚期构造-岩浆事件与成矿作用——来自广西大瑶山龙头山金矿床的地球化学约束

广西贵港大瑶山成矿带位于华南东南沿海成矿带西南端,对矿带内龙头山金矿黄铁矿化斑岩进行定年的结果为96.1±3.0 Ma,与区域内邻近的平天山侵入岩体(96.2±0.4 Ma)相同.龙头山矿床的Sr同位素组成与其锆石的REE特征表明,成矿作用伴随有大量的流体参与;矿化斑岩与区内侵入相岩石相同的形成时代以及矿化斑岩中锆石C...     

岔路口特大型钼多金属矿床的发现及其意义

黑龙江岔路口矿床是近年来在大兴安岭地区北部找到的一处特大型斑岩钼多金属矿床,其产出规模已居中国北方钼多金属矿床之首.钼多金属矿化大部分在侏罗系火山-沉积岩中,呈细脉状、细脉浸染状产出,并与晚侏罗世石英斑岩、花岗斑岩和隐爆角砾岩具有密切的时空分布关系.初步研究表明,该矿床无论是在产出环境、地质特征上,还是在含矿侵入岩岩石...     

Chemical and Strontium Isotopic Compositions of the Hanjiang Basin Rivers in China: Anthropogenic Impacts and Chemical Weathering

The Hanjiang River, the largest tributaries of the Changjiang (Yangtze) River, is the water source area of the Middle Route of China’s South-to-North Water Transfer Project. The chemical and strontium isotopic compositions of the river waters are determined with the main purpose of understanding the contribution of chemical weathering processes and anthropogenic inputs on river solutes, as well as the associated CO₂ consumption in the carbonate-dominated basin. The major ion compositions of the Hanjiang River waters are characterized by the dominance of Ca²⁺ and HCO₃ ⁻, followed by Mg²⁺ and SO₄ ²⁻. The increase in TDS and major anions (Cl⁻, NO₃ ⁻, and SO₄ ²⁻) concentrations from upstream to downstream is ascribed to both extensive influences from agriculture and domestic activities over the Hanjiang basin. The chemical and Sr isotopic analyses indicate that three major weathering sources (dolomite, limestone, and silicates) contribute to the total dissolved loads. The contributions of the different end-members to the dissolved load are calculated with the mass balance approach. The calculated results show that the dissolved load is dominated by carbonates weathering, the contribution of which accounts for about 79.4% for the Hanjiang River. The silicate weathering and anthropogenic contributions are approximately 12.3 and 6.87%, respectively. The total TDS fluxes from chemical weathering calculated for the water source area (the upper Hanjiang basin) and the whole Hanjiang basin are approximately 3.8 × 10⁶ and 6.1 × 10⁶ ton/year, respectively. The total chemical weathering (carbonate and silicate) rate for the Hanjiang basin is approximately 38.5 ton/km²/year or 18.6 mm/k year, which is higher than global mean values. The fluxes of CO₂ consumption by carbonate and silicate weathering are estimated to be 56.4 × 10⁹ and 12.9 × 10⁹ mol/year, respectively.