Geochemistry of soils derived from black shale, central Hunan, China     

Bo PENG Shurong XIE Meilian XIAO Zhi SONG 《中国地球化学学报》2006,25(B08):85-86

The black shale formed under anoxic conditions usually contains high concentrations of many metals. Weathering of such black shale might cause the emission of many metals. Moreover, soils derived from black shale （SBS） are believed to be affected by black shale weathering. In recent years, many studies such as Lee et al. （2002）, Woo et al. （2002）, Fang et al. （2002）, Pasava et al. （2003）, and Peng et al. （2004） have approached the heavy metal contaminations of SBS, but systematical geochemical study is rare. Presently, the SBS and its corresponding black shales （CBS） were both sampled from central Hunan （China）, and analyzed for a large number of elements, using an Elan6000 ICP-MS/AES machine at Guangzhou Institute of Geochemistry, CAS. In this paper, some preliminary results are reported. The analytical results show that the SBS in central Hunan contains very high concentrations of heavy metals such as Co, Cu, Hg, Mo, Pb, Zn, U, Th, Sb, T1, Cd, Cr, Sc, V, Sn, As, Se, and Ni.  相似文献   

硬致密泥岩钻进的新型复合片钻头的研究与应用          下载免费PDF全文

李雨蔡家品  贾美玲张建元 赵尔信 《探矿工程》2006,33(9):60-61,54

介绍了一种新型齿形的复合片钻头，在硬致密泥岩中钻进，与常规复合片钻头相比，具有很高的钻进效率和高的钻头寿命，解决了泥岩钻进效率低的难题。  相似文献   

Attenuation of aqueous metal transport at two natural acid rock drainage occurrences in the Yukon Territory, Canada     

Y.T. John Kwong 《中国地球化学学报》2006,25(B08):229-230

Naturally acidic drainage associated with pyritic black shale has been observed in many locations in the Yukon Territory. While not necessarily linked to known mineral deposits, most of these natural acid rock drainage occurrences show elevated dissolved concentrations of trace elements, especially zinc, nickel, copper, cadmium and arsenic. Based on field observations, microbial investigation, chemical analyses and geochemical modeling, the fate and transport of potentially deleterious elements at two natural acid drainage occurrences with slightly different settings are examined. The Macintosh Creek is a small, acidic stream （pH 2.98-3.40）, 2 km long, located in the Macmillan Pass area of east-central Yukon amidst known sedimentary exhalative massive sulfide mineralization but remains undisturbed by exploration activities. Its trace metal content is apparently derived from groundwater discharges, which gave as much as 5.0, 2.5, 0.7, 0.13 and 0.03 mg/L ofZn, Ni, Cu and As, respectively. Interaction and sorption reactions with algal mats, biofilms and iron oxyhydroxides appear to be the dominant mechanisms attenuating aqueous contaminant transport along the stream. Cryogenic precipitation further consolidates the ferricrete formation and reduces the mobility of the sorbed metals. The tributaries of the Engineering Creek along the Dempster Highway in northern Yukon drain through a series of dolomite, phyllite, argillite, limestone, black shale, sandstone and conglomerate with no known concentration of mineralization. In this area, the water chemistry fully reflects the local geology with acidic streams invariably associated with black shale occurrences. Groundwater seeps in the headwaters area of the km-180 Creek completely enclosed in black shale gave pH 3.0 and as much as 148, 39, 2.9 and 9.1 mg/L of Zn, Ni, Cu and As, respectively. Sorption with iron oxyhydroxide and organic matter appear to dominate the attenuation of contaminant transport along the stream. However, once entered into carbonate-dominated terrains, secondary carbonate minerals exercise additional geochemical control on the local water chemistry as a result of neutralization.  相似文献   

Petrogenesis of Cretaceous adakitic and shoshonitic igneous rocks in the Luzong area, Anhui Province (eastern China): Implications for geodynamics and Cu–Au mineralization     

Qiang Wang  Derek A. Wyman  Ji-Feng Xu  Zhen-Hua Zhao  Ping Jian  Xiao-Lin Xiong  Zhi-Wei Bao  Chao-Feng Li  Zheng-Hua Bai 《Lithos》2006,89(3-4):424-446

Both adakitic and shoshonitic igneous rocks in the Luzong area, Anhui Province, eastern China are associated with Cretaceous Cu–Au mineralization. The Shaxi quartz diorite porphyrites exhibit adakite-like geochemical features, such as light rare earth element (LREE) enrichment, heavy REE (HREE) depletion, high Al₂O₃, MgO, Sr, Sr / Y and La / Yb values, and low Y and Yb contents. They have low ε_Nd(t) values (− 3.46 to − 6.28) and high (⁸⁷Sr / ⁸⁶Sr)_i ratios (0.7051–0.7057). Sensitive High-Resolution Ion Microprobe (SHRIMP) zircon analyses indicate a crystallization age of 136 ± 3 Ma for the adakitic rocks. Most volcanic rocks and the majority of monzonites and syenites in the Luzong area are K-rich (or shoshonitic) and were also produced during the Cretaceous (140–125 Ma). They are enriched in LREE and large-ion lithophile elements, and depleted in Ti, and Nb and Ba and exhibit relatively lower ε_Nd(t) values ranging from − 4.65 to − 7.03 and relatively higher (⁸⁷Sr / ⁸⁶Sr)_i ratios varying between 0.7057 and 0.7062. The shoshonitic and adakitic rocks in the Luzong area have similar Pb isotopic compositions (²⁰⁶Pb / ²⁰⁴Pb = 17.90–18.83, ²⁰⁷Pb / ²⁰⁴Pb = 15.45–15.62 and ²⁰⁸Pb / ²⁰⁴Pb = 38.07–38.80). Geological data from the Luzong area suggest that the Cretaceous igneous rocks are distributed along NE fault zones (e.g., Tanlu and Yangtze River fault zones) in eastern China and were likely formed in an extensional setting within the Yangtze Block. The Shaxi adakitic rocks were probably derived by the partial melting of delaminated lower crust at pressures equivalent to crustal thickness of > 50 km (i.e., 1.5 GPa), possibly leaving rutile-bearing eclogitic residue. The shoshonitic magmas, in contrast, originated mainly from an enriched mantle metasomatized by subducted oceanic sediments. They underwent early high-pressure (> 1.5 GPa) fractional crystallization at the boundary between thickened (> 50 km) lower crust and lithospheric mantle and late low-pressure (< 1.5 GPa) fractional crystallization in the shallow (< 50 km) crust. The adakitic and shoshonitic rocks appear to be linked to an intra-continental extensional setting where partial melting of enriched mantle and delaminated lower crust was probably controlled by lithospheric thinning and upwelling of hot asthenosphere along NE fault zones (e.g., Tanlu and Yangtze River fault zones) in eastern China. Both the shoshonitic and adakitic magmas were fertile with respect to Cu–Au mineralization.  相似文献   

油页岩综合利用对周围环境的影响——以抚顺矿区为例   总被引：3，自引：0，他引：3  

张丽萍曾荣树  徐文东金福杰 《中国煤田地质》2006,18(2):46-48,51

世界能源日益减少的局面为油页岩的开发应用带来广阔的前景，但油页岩工业所带来的环境影响亦不容忽视。以抚顺油页岩为例，从油页岩综合利用和油页岩工业对环境的影响等方面系统讨论了在我国发展油页岩工业时，如何本着节约能源、保护环境、实现可持续发展的观念，利用现有先进技术，科学发展油页岩工业，降低生产过程中的固、液、气污染物对环境的危害。  相似文献   

加水热模拟中深湖与煤系泥岩地化特征比较   总被引：2，自引：0，他引：2  

梁春秀  魏志平等 《沉积学报》2002,20(1):165-168

通过深湖泥岩和煤系泥岩的加水热模拟研究认为,在热模拟实验过程中,深湖泥岩和煤系泥岩显示不同特征,并且其演化有差别。深湖泥岩利于液态原油的生成,并且转化率高于煤系泥岩。深湖泥岩残余可溶有机质饱和烃含量高于煤系泥岩,非烃含量则低于煤系泥岩。深湖泥岩胶质 /沥青质和饱芳比均随温度升高而降低,而煤系泥岩的胶质 /沥青质随温度升高有增加趋势,其饱芳比的变化则不大或有降低趋势。深湖泥岩的T_max难以指示演化阶段,其干酪根碳同位素值明显轻于煤系泥岩,它们的值均随温度的升高而变重。  相似文献   

Caractérisation des paragenèses et des paléocirculations fluides dans l'indice d'or de Bleı̈da (Anti-Atlas,Maroc)Characterization of the paragenesis and the fluid palaeo-circulations in the gold showings of Bleida (Anti-Atlas,Morocco)     

Ahmed Barakat  Christian Marignac  Marie-Christine Boiron  Mohamed Bouabdelli 《Comptes Rendus Geoscience》2002,334(1):35-41

The gold showings at Bleida are hosted in Late Pan-African N50–80 °E quartz–hematite–chlorite 1 tension lenses that are related to the activity of major sinistral sub-east–west thrusts. Ores result from three superimposed stages of fluid migration. Gold occurs in microcracks offsetting the earlier minerals. Fluids evolved from COHN compositions with a saline component to boiling aqueous fluids. Pressure and temperature decreased from 50 MPa and 300 °C to less than 4 MPa and 150 °C. Thus, the gold showings at Bleida were formed in a typical geothermal (epithermal) setting, likely controlled by the Late Pan-African magmatism. To cite this article: A. Barakat et al., C. R. Geoscience 334 (2002) 35–41  相似文献   

台湾西南部泥岩土地利用型态与环境劣化趋势之分析   总被引：5，自引：2，他引：5  

林信辉  张俊斌  周跃 《云南地理环境研究》2003,15(3):40-47

台湾泥岩恶地因其特殊之土壤理化性质及区域微气候的相互恶性循环，衍生生态环境等问题。在以往之35年，裸化面积从1967年的2532hm^2，至2001年11月已扩大为15539hm^2。其表土大量流失、崩塌、河川含砂量激增、植被退化与微气候变异等破坏，更显示泥岩之环境劣化问题。以SPOT卫星影像判识泥岩裸露面积，探讨不同时期之地景变异，并应用地景生态理论量化泥岩地表不同土地利用之空间结构变化，分析地景结构变迁之生态内涵与生态指标意义。因子分析结果其主要变异为多样性因子与形状破碎型因子所影响，而应用马可夫链模式计算出不同时期之土地利用变迁内涵，此结果搭配指标分析可解释泥岩裸露面积与竹林面积皆持续扩大，乃由人为土地利用之活动及植被变迁所引起。  相似文献   

遵义市城区及周边地带制砖页(泥)岩地质特征和开发前景     

王祁仑  金华英 《贵州地质》2003,20(1):50-55

文章对遵义市城区及周边地带各地质时代的页（泥）岩已有资料进行了系统收集、归纳和适当的野外调研，认为区内制砖页（泥）岩层位可分为三类，第一、二类利用价值小或仅有部分可以利用，第三类则易于露采，大部分可利用，其层位为下奥陶统湄潭组和下三叠统夜郎组九级滩段，是区内可作制砖页（泥）岩利用最有开发前景的层位。同时对页（泥）岩的形成沉积环境作了简要分析，对其资源量进行了概略估算，经优化筛选，提出了10个供制砖厂企设置布局和矿源地选择之前需进行地质勘查的区块。  相似文献   

遵义牛蹄塘组发现的多水硫磷铝石   总被引：2，自引：0，他引：2  

罗泰义  李晓彪  姚林波  朱丹 《矿物学报》2003,23(3):205-210

遵义牛蹄塘组黑色岩系发现的多水硫磷铝石主要产出在Ni-Mo多金属层的微裂隙中，偶尔在多金属层下部的黑色粉砂岩中以脉体形式产出。该矿物结构不稳定，结构中一部分水分子很容易失去，在X射线衍射鉴定时其特征谱线变化较大；在自然条件下存放一定时间后，样品具有稳定的X射线衍射特征。此外，对这些样品进行了红外光谱、热重和差热分析、TEM观测、化学分析和晶胞参数计算，与纤磷铝石进行了对比和讨论。  相似文献