翠宏山铁多金属矿床成矿流体包裹体及硫同位素特征   总被引：1，自引：0，他引：1  

杜美艳  李超  杨乃峰  孙珍军  王春光  于赫楠 《世界地质》2011,30(4):538-543

对翠宏山铁多金属矿床成矿早期阶段钨钼矿体中的石英、成矿晚期阶段铅、锌、铜矿体中的萤石流体包裹体特征及均一温度、盐度的研究表明,从早期钨钼成矿阶段至晚期铅、锌、铜成矿阶段,侵入体内接触带至外接触带,经历了一个温度剧降和盐度显著增加的过程。钨钼成矿阶段成矿流体主要为岩浆热液流体,成矿过程为单一的成矿流体冷却过程; 在晚期铅、锌、铜成矿阶段,来自岩浆中的温度较高的热流体与围岩地层中的大气降水等低温、高盐度流体混合,使成矿流体温度剧降和盐度增高,导致铅、锌、铜等成矿物质的沉淀。辉钼矿和方铅矿的δ34S ( × 10-3 ) 测试结果表明,侵入体内接触带钨钼矿体的成矿物质主要来自岩浆热液; 围岩地层中铅、锌、铜矿体的成矿物质,除岩浆热液来源外,部分可能来自雨水对地层中硫酸盐岩中硫及其他成矿物质的淋滤。  相似文献   

锑矿区水体水环境锑污染及硫同位素示踪研究   总被引：4，自引：0，他引：4  

宁增平  肖唐付  杨菲  贾彦龙  孙嘉龙  何立斌 《矿物岩石地球化学通报》2011,30(2):135-141

本文系统研究了贵州省半坡锑矿区水环境锑污染现状,用硫同位素指示采矿活动对矿区水体的影响,以查明锑矿区水环境中Sb的释放迁移过程和水污染程度。研究发现,矿区水体中Sb和SO42-含量分别高达1377μg/L和1926 mg/L;岔河下游近10 km处仍保持较高水平(182.5μg/L Sb和59.8 mg/L SO42-)。岔河水体中,δ34S-Sb、δ34S-SO42-和Sb-SO42-间均具显著正相关,相关系数分别为r=0.68(p<0.05)、r=0.89(p<0.01)、r=0.72(p<0.05)。表明岔河水体中,δ34S和SO42-能很好地指示矿业活动引起的Sb污染程度和扩散范围。根据同位素质量平衡原理估算,发现矿区下游水体中的硫主要来自矿山,表明矿区下游水体污染受采矿活动影响显著。  相似文献   

山东济宁高硫煤与低硫煤煤层剖面地球化学特征研究     

姜尧发  代世峰  王西勃  赵蕾  周国庆  张丽莉  艾丽琴 《中国煤炭地质》2011,(4):1-10

运用电感耦合等离子质谱（ICP-MS）、X射线荧光光谱（XRF）、离子选择电极（ISE）、显微镜光度计和煤化学等方法,对山东济宁矿区的高硫煤（太原组16号煤层）与低硫煤（山西组3上煤层）剖面的煤岩、煤质和煤地球化学特征进行研究。高硫煤中微量元素在垂向上呈现显著的变化规律：（1）Sr含量从煤层底板到顶板呈增高趋势,而Ba含量则相反;因而Sr/Ba比值从下向上呈逐渐变大趋势（0.04～47.7）;（2）Th/U比值从下向上也呈逐渐变大趋势（0.2～37.1）;（3）As含量在煤层顶板石灰岩（26.1μg/g）、透镜状黄铁矿夹层（14.7～19.3μg/g）中较高;（4）V、Cr、Co、Ni、Cu、Pb、Zn等元素在煤层底部和顶部分层中含量较高,而在煤层中部分层中含量较低;（5）Nb、Ta、Zr、Hf、Ga等元素从煤层的底部到顶部呈逐渐降低趋势;（6）煤中稀土元素总量（REE）,除透镜状黄铁矿夹层（第2、4、11分层）外,其它分层（第1、3、5、6、7、8、9、10分层）显示从上往下逐渐增高之规律性。低硫煤中微量元素的分布和垂向变化与高硫煤明显不同：As含量在14个煤分层中都较低（1.03～3.37μg/g）,Sr/Ba比值从下向上变化不大（0.4～2.2）,各个煤分层中稀土元素总量（REE）呈现随灰份含量增高而增高的变化趋势,低硫煤与高硫煤的稀土元素分布模式差别很大。上述研究结果表明济宁矿区高硫煤与低硫煤在地球化学特征上的差别,反映了上石炭统太原组与下二叠统山西组沉积环境和聚煤条件的差别,具有指相意义;太原组16号煤层中富集的硫及有害微量元素,对环境具有潜在危害。  相似文献   

台湾海峡西部沉积物中碳的来源及埋藏   总被引：4，自引：1，他引：3  

叶翔  陈坚  王爱军  黄财宾  汪卫国  李东义 《海洋学报》2011,33(5):73-82

根据2005年夏季航次观测的沉积物中总有机碳(TOC)、无机碳(CaCO3)、总氮(TN)、悬浮体颗粒有机碳(POC)、沉积物粒度数据得出,台湾海峡西部表层沉积物TOC质量分数的范围为0.01～1.79,平均值为0.37±0.24,略高于20多年前台湾海峡南部海区,而低于台湾海峡中、北部海区;TOC的质量分数湾内比湾外...  相似文献   

舟山海域陆源溶解有机质变化及其对近岸羽状流的响应   总被引：5，自引：1，他引：4       下载免费PDF全文

黄清辉  吴加学  蒋愉林  李建华 《海洋学报》2011,33(1):66-73

2007年夏季在东海舟山海域河口锋区开展了陆源溶解有机质的调查研究。测定了有色溶解有机质(CDOM)在激发波长370 nm/发射波长460 nm处的荧光强度和在λ=355 nm处的吸收系数,用于代表陆源CDOM浓度,并测定了荧光指数以指示CDOM来源。结果表明,CDOM的荧光值和紫外吸收系数之间呈显著正相关性,陆源CDOM浓度大体有向海方向降低的趋势,但是纵向上存在一些"突跃"现象。在舟山海域东北角不时观测到表层水体含有高浓度的CDOM,但变异性很大,推测可能该海区受到长江口羽状流的影响。在连续观测站发现陆源CDOM浓度在低平潮时往往比高平潮时要高。河海水在混合过程中CDOM浓度与盐度呈显著的线性负相关关系。在低盐度的悬沙锋区(S<24)CDOM浓度明显低于理论稀释值,而在较高盐度的羽状锋区,CDOM浓度接近于理论稀释值。在盐度为24~31范围内,大部分水样的荧光指数在1.50上下波动,表明其中CDOM来源以陆地来源为主;在较低盐度(S<24)的水样中荧光指数在1.70至1.90以上,表明CDOM以海洋来源为主,这与其陆源组分在高浊度的低盐度区存在显著的去除过程有关。研究表明,舟山海域水质存在着显著的变异性,与近岸羽状流密切相关,陆源溶解有机质的分布特征对此有较好的响应。  相似文献   

长江口水下三角洲沉积物记录的古环境演化   总被引：4，自引：0，他引：4  

张瑞虎  谢建磊  刘韬  赵宝成 《海洋地质与第四纪地质》2011,(1):1-10

长江口水下三角洲60 m的HYZK5钻孔,揭示了末次冰期以来河流相、滨海湖沼相、河口湾-浅海相(前三角洲相)和水下汉道相的沉积环境演化.泥炭层形成于末次冰期的冷湿气候环境;有孔虫丰度的变化反映了12 000 cal.aBP以来海平面迅速上升,但在11 200～10 000 cal.aBP出现短暂的停顿.沉积物的粒度、磁...  相似文献   

The chemical changes of DOM from black waters to coastal marine waters by HPLC combined with ultrahigh resolution mass spectrometry     

Zhanfei Liu  Rachel L. Sleighter  Junyan Zhong  Patrick G. Hatcher 《Estuarine, Coastal and Shelf Science》2011

How dissolved organic matter (DOM) undergoes chemical changes during its transit from river to ocean remains a challenge due to its complex structure. In this study, DOM along a river transect from black waters to marine waters is characterized using an offline combination of reversed-phase high performance liquid chromatography (RP-HPLC) coupled to electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS), as well as tandem ESI-FTICR-MS. In addition, a water extract from degraded wood that mainly consists of lignins is used for comparison to the DOM from this transect. The HPLC chromatograms of all DOM samples and the wood extract show two major well-separated components; one is hydrophilic and the other is hydrophobic, based on their elution order from the C₁₈ column. From the FTICR-MS analysis of the HPLC fractions, the hydrophilic components mainly contain low molecular weight compounds (less than 400 Da), while the hydrophobic fractions contain the vast majority of compounds of the bulk C₁₈ extracted DOM. The wood extract and the DOM samples from the transect of black waters to coastal marine waters show strikingly similar HPLC chromatograms, and the FTICR-MS analysis further indicates that a large fraction of molecular formulas from these samples are the same, existing as lignin-like compounds. Tandem mass spectrometry experiments show that several representative molecules from the lignin-like compounds have similar functional group losses and fragmentation patterns, consistent with modified lignin structural entities in the wood extract and these DOM samples. Taken together, these data suggest that lignin-derived compounds may survive the transit from the river to the coastal ocean and can accumulate there because of their refractory nature.  相似文献   

The effect of the dominant polychaete Scolelepis squamata on nematode colonisation in sandy beach sediments: An experimental approach     

Tatiana F. Maria  André M. EstevesJan Vanaverbeke  Ann Vanreusel 《Estuarine, Coastal and Shelf Science》2011,94(3):272-280

The effect of an abundant sandy beach polychaete, Scolelepis squamata, on the colonisation of defaunated sediments by marine nematodes indicates that sandy beach fauna can be partially controlled by biological interactions within and across size groups. Experimental cores, equipped with windows allowing infaunal colonisation, were filled with defaunated sandy beach sediment containing two different treatments with and without S. squamata. These cores were inserted into microcosms filled with sediment with indigenous meiofauna collected from the field. The treatments were incubated in the laboratory at ambient temperature and salinity for 2, 7, 14 and 21 days, in order to follow the colonisation process of the defaunated sediments by the indigenous nematode fauna over time. Nematodes initially colonised both treatments, with abundances of up to 10% of the densities in the control; after 2 weeks, nematode densities in the cores without S. squamata surpassed the control densities. Nematode assemblages in both treatments were not species rich, and also differed in composition from the natural assemblages. The most successful colonising species, Enoplolaimus litoralis, was rare in the surrounding sediment, suggesting that colonisation was determined by species-specific characteristics such as body size, motility and feeding strategy. Initially the presence of macrofauna did not affect the nematode community composition, but after 2 weeks of the experiment, the presence of the polychaete seemed to facilitate the earlier establishment of non-opportunistic species.  相似文献   

Origin and biochemical cycling of particulate nitrogen in the Mandovi estuary   总被引：2，自引：0，他引：2  

Loreta Fernandes 《Estuarine, Coastal and Shelf Science》2011,94(3):291-298

Mandovi estuary is a tropical estuary strongly influenced by the southwest monsoon. In order to understand, sources and fate of particulate organic nitrogen, suspended particulate matter (SPM) collected from various locations, was analyzed for particulate organic carbon (POC) and particulate organic nitrogen (PON), δ¹³C_POC, total hydrolysable amino acid enantiomers (l- and d- amino acids) concentration and composition. δ¹³C_POC values were depleted (−32 to −25‰) during the monsoon and enriched (−29.6 to −21‰) in the pre-monsoon season implying that OM was derived from terrestrial and marine sources during the former and latter season, respectively. The biological indicators such as C/N ratio, d-amino acids, THAA yields and degradation indices (DI) indicate that the particulate organic matter (POM) was relatively more degraded during the monsoon season. Conversely, during the pre-monsoon, the biological indicators indicated the presence of relatively fresh and labile POM derived from autochthonous sources. Amino acids such as alanine, aspartic acid, leucine, serine, arginine, and threonine in monsoon and glutamic acid, glycine, valine, lysine, and isoleucine in pre-monsoon were relatively abundant. Presence of bacterial biomarker, d-amino acids in the SPM of the estuary during both the seasons signifies important contribution of bacteria to the estuarine detrital ON pool. Based on d-amino acid yields, bacterial OM accounted for 16-34% (23.0 ± 6.7%) of POC and 29-75% (47.9 ± 18.7%) of PON in monsoon, and 30-78% (50.0 ± 15%) of POC and 34-79% (51.2 ± 13.3%) of the PON in pre-monsoon in the estuary. Substantial contribution of bacterial-N to PON indicates nitrogen (N) enrichment on terrestrial POM during the monsoon season. Transport of terrestrial POM enriched with bacterial OM to the coastal waters is expected to influence coastal productivity and ecosystem functioning during the monsoon season.  相似文献   

Longitudinal and depth variation of bacterioplankton productivity and related factors in a temperate estuary     

Benjamin L. Peierls  Hans W. Paerl 《Estuarine, Coastal and Shelf Science》2011

Bacterioplankton productivity (BP) spatial variation was investigated in relation to potential resources, including primary productivity and dissolved organic matter, in the micro-tidal Neuse River–Pamlico Sound estuarine system, North Carolina, USA. Estuarine BP was predicted to correlate with the trophic gradient, decreasing along the salinity gradient in parallel with the decrease in organic matter and primary productivity. This prediction was tested over four years at spatial scales ranging from kilometers to meters along the riverine axis and with depth. The general pattern of BP across the salinity gradient was unimodal and matched the phytoplankton patterns in peak location and variability. Peak locations varied with discharge, especially in 2003 when above average discharge moved peaks downstream. Spatial coherence of BP with other variables was much less at short time scales. The effect of temperature, nutrients, and phytoplankton on BP varied by location, especially fresh versus brackish stations, although only temperature explained more than 20% of the BP variation. Depth variation of BP was as great as longitudinal variation and bottom samples were often higher than surface. BP was strongly correlated with particulate organic carbon at the pycnocline and bottom, highlighting the importance of particulate matter as a resource. Station-averaged BP and phytoplankton data corresponded well with two published meta-analyses, although the offset of the freshwater station suggested longitudinal differences in community composition or resource availability.  相似文献