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101.
CHEN Lei 《地球空间信息科学学报》2008,11(3):228-234
A review was conducted on the environmental evolvement and environmental archaeological research since the 1980s in the Yangtze Delta. Former environmental evolvement and environmental archaeological research results can be summed up into 4 aspects: 1) Formation and evolution of the Taihu Lake; 2) Transgression and sea-level changes in the Holocene epoch; 3) Reconstruction of the pre-historical environment; and 4) Impacts of environmental variations on the rise and fall of human civilization (formation of the cultural interruptions). Based on this review, some limitations in the present research methods and possible outcomes are pointed out in this paper. 相似文献
102.
103.
辽宁东五家子金矿的矿脉由蚀变岩和石英脉透镜体构成,可采矿体均为硫化物石英脉型.工业矿脉中,石英为烟灰色,发育他形、半自形的细粒黄铁矿等硫化物,有较大规模的矿体.矿化脉中,石英为乳白色,发育粗粒、自形的浅色黄铁矿,无可采矿体.在工业矿脉、次要矿脉、矿化脉的蚀变岩和石英脉样品中,Au,Hg与其他元素的相关性有明显区别.用石英脉样品的As-Ni-Ba图解和蚀变岩样品的Au-Ag-Ba图解预测,矿区外围的西沟1号脉和西沟3号脉属于工业矿脉. 相似文献
104.
Benthic nutrient fluxes in the intertidal flat within the Changjiang (Yangtze River) Estuary 总被引:1,自引:0,他引:1
GAO Lei LI Daoji WANG Yanming YU Lihua KONG Dingjiang LI Mei LI Yun and FANG Tao State Key Laboratory of Marine Geology Tongji University Shanghai China State Key Laboratory of Estuarine Coastal Research East China Normal University Shanghai China 《中国地球化学学报》2008,27(1):58-71
In an annual cycle from March 2005 to February 2006, benthic nutrient fluxes were measured monthly in the Dongtan intertidal flat within the Changjiang (Yangtze River) Estuary. Except for NH4^+, there always showed high fluxes from overlying water into sediment for other four nutrients. Sediments in the high and middle marshes, covered with halophyte and consisting of macrofauna, demonstrated more capabilities of assimilating nutrients from overlying water than the low marsh. Sampling seasons and nutrient concentrations in the overlying water could both exert significant effects on these fluxes. Additionally, according to the model provided by previous study, denitrification rates, that utilizing NO3- transported from overlying water (Dw) in Dongtan sediments, were estimated to be from -16 to 193 μmol·h^-1·m^-2 with an average value of 63 μmol·h^-1·m^-2 (n=18). These estimated values are still underestimates of the in-situ rates owing to the lack of consideration of DN, i.e., denitrification supported by the local NO3^- production via nitrification. 相似文献
105.
Treatment with metallic copper for the removal of elemental sulfur from bitumen extracted from sedimentary rocks or petroleum is the most widely used method. Little attention has been paid, however, to its disadvantages. It was observed that copper can interact with some polar organic substances during conventional sulfur removal, which can strongly influence the quantitative and qualitative determination of bitumen, as has been confirmed by interaction of long-chain fatty acids with copper. The copper soap generated was analyzed by element analysis, inductively coupled plasma optical emission spectrometry (ICP-OES), thermal analysis (TG-DSC) and Fourier Transform Infrared spectroscopy (FFIR). Mechanism of the interaction was investigated and elucidated. Our experimental results would necessitate improvement of the present method for sulfur removal and/or a search for a new one. 相似文献
106.
Subtle traps or oil pools have become an important exploration play in the Dongying Depression, Bohai Bay Basin, east China. Despite recent successes in exploration, the formation mechanisms of subtle traps are still not well understood. The majority of subtle oil pools in the Dongying Depression are developed in the middle interval of the Es3 Member of the Paleogene Shahejie Formation with the subtle traps being primarily of lenticular basin-floor turbidite sands encompassed in mudstones. Oil in the subtle traps was previously thought to have migrated directly from the surrounding source rocks of the same formation (Es3). Detailed geochemical investigation of 41 oils and 41 rock samples from the depression now indicates that the oils from the subtle traps cannot be correlated well with the surrounding Es3 source rocks, which are characterized by high Pr/ Ph (〉1), low Gammacerane/C30hopane, representing a freshwater lacustrine setting. In contrast the oils features low Pr/Ph (〈1) and relatively high Gammacerane content, showing a genetic affinity with the underlying Es4 source rocks, which also have the same qualities, indicating a brackish lacustrine setting. Oils in the Es3 subtle traps are probably derived from mixed sources with the contribution from the upper Es4 source rocks predominating. Therefore unconventional oil migration and accumulation mechanisms need to be invoked to explain the pooling of oils from the ES4 source rocks, which probably came through a thick low interval of the Es3 source rocks with no apparent structural or stratigraphic pathways. We suggest that the subtle oil migration pathway probably plays an important role here. This finding may have significant implications for future exploration and the remaining resource evaluation in the Dongying Depression. 相似文献
107.
Multifractal Analysis of Element Distribution in Skarn-type Deposits in the Shizishan Orefield, Tongling Area, Anhui Province, China 总被引:3,自引:1,他引:2
Wang Qingfei Deng Jun Wan Li Zhao Jie Gong Qingjie Yang Liqiang Zhou Lei Zhang Zhijun 《《地质学报》英文版》2008,82(4):896-905
A series of element concentrations sampled from four drill cores with a length about 1000 m into different skarn-type deposits were selected from the Shizishan orefield, central Tongling, southeastern part of Anhui Province. Using the multifractal method, the distribution and migration characteristics of the major and trace elements are analyzed. The multifractal spectrum of the major elements is left-skewed, whereas the spectrum of the trace elements is right-skewed, which shows that in the process of skarn formation, the trace elements were enriched only locally, and major elements transported within a much larger range. The correlation coefficients of the multifractal parameters Aa (width of the multifractal spectrum) of the four drill cores are relatively low, but the correlation coefficients of the multifractal parameters R (spectrum symmetry parameter) and Af are relatively higher, indicating that although the non-homogeneous intensity of the distribution of elements is inconsistent, their spatial accumulation patterns are almost the same during the ore-forming process. The statistics of the mnltifractal parameters of various elements in the different locations show that the ore-forming processes and element migration pattern in the Shizishan orefield are consistent, and that the migrations of trace elements and major elements exhibit some differences. 相似文献
108.
湖子地区位于NNE向诸广-新兴铀成矿带与近EW向大东山-漳州大断裂复合部位,是华南早、晚两期铀成矿热液活动叠加区、放射性高场区,既有"硅化带大脉"型铀矿产出,又有"交点"型铀矿存在,找矿前景良好.文章在论述下庄矿田铀成矿地质环境、铀成矿特征及铀矿定位条件基础上,分析了湖子地区铀成矿条件与找矿前景,指出该区今后铀矿找矿方向是:① 6009号硅化断裂带,在其北段找硅化带大脉型铀矿,在其南段找"交点"型铀矿;②新桥-下庄硅化断裂带和6009号带之间成矿部位,寻找硅化带型和"交点"型铀矿;③NW向、近EW向辉绿岩脉与NNE向、NE向构造交汇部位(交点),寻找"交点"型铀矿. 相似文献
109.
胶东地区晚中生代岩浆活动及对大地构造的制约 总被引:16,自引:1,他引:15
应用近十几年来胶东地区及其周边岩浆岩体的同位素测年资料,结合几个岩体的新的SHRIMP测年数据(牙山岩体117.7Ma,院格庄岩体113.4Ma,正长斑岩脉115.7Ma),系统研究了该区晚中生代以来的岩浆活动规律,结果表明,该区可分为4个岩浆活动期;(1)晚侏罗世构造-岩浆热事件(150~160Ma),以玲珑-滦家河型岩体为代表,是在区域挤压构造应力作用下侵入的,属同构造或同造山时期的岩浆作用。(2)早白垩世早期构造-岩浆热事件(135~125Ma),以郭家岭岩体为典型,该时期的岩浆活动均具有双峰式岩浆作用特征,反映了伸展动力学背景。(3)早白垩世中晚期构造-岩浆热事件(125~105Ma),以崂山花岗岩为特征,该阶段对应于中国东部岩石圈大规模的减薄时期,是大陆裂谷作用的高峰期。(4)晚白垩世-古新世基性-超基性火山作用。本文还探讨了岩浆活动的地球动力学因素及其对大地构造的制约。 相似文献
110.