共查询到20条相似文献，搜索用时 15 毫秒
1.
新疆和田杜瓦地区晚二叠世孢粉组合 总被引：11，自引：0，他引：11
本文论及所研究的新疆塔里木盆地和田地区原来分别属于叶尔羌群(J_(1-2))和二叠—三叠系(杜瓦组上部)两个部分采集的孢粉化石.沉积物中含有多种对地层研究非常重要的生物化石,如介形虫、叶肢介、鱼及孢粉等.根据孢粉组合的研究,这些地层可视为上二叠统,其孢粉组合以裸子植物花粉占主导地位为特征,可与新疆吉木萨尔县大龙口晚二叠世晚期地层梧桐沟组对比,并相当于西欧的镁灰岩统和苏联的鞑靼阶. 相似文献
2.
The aim of the present study is to provide additional information about the properties and depositional environment of the Kipra lignite seam, which was deposited during the regressive stage of development of the Maritza-West basin. Petrographical and mineralogical data, along with ash yields and sulphur contents of 24 samples from a seam profile, have been used to study the vertical variation of the depositional settings during peat accumulation and subsequent coalification.The Kipra lignite is characterized by high ash yields and sulphur contents. It formed in a rheotrophic, low-lying mire with alkaline pH value. Vegetation with low preservation potential dominated within the palaeomire. During peat formation, frequent changes of the water level controlled the depositional environment. During the deposition of units 1 and 2, high water energy caused the transportation of high amounts of inorganic material into the mire, resulting in the formation of weakly gelified mineral-rich lignite. The organic matter from units 3 and 4 is characterized by enhanced gelification, which probably reflects the decreasing energy of the system. Good positive correlation between sulphur contents and the GI values was established in units 4, indicating that the gelification of the tissues was probably mainly controlled by the bacterial activity. In contrast, the gelification of the samples from unit 3 of the Kipra seam was probably governed by the redox conditions. The organic matter deposited under relatively wet conditions, in which the thermal and oxidative destruction of the tissues, was limited.A variety of major, minor and accessory minerals are present in Maritza-West lignite. The mineral composition is dominated mainly by pyrite, gypsum and calcite, and to a lesser extent limonite, quartz, kaolinite, montmorillonite, illite, chlorite and plagioclase. Jarosite, hematite, halloysite, mica, K-feldspar, aragonite, siderite, and dolomite were also determined in very low concentrations. These minerals formed syngenetically and epigenetically. The syngenetic stage is characterized mainly by the formation of pyrite, carbonates, silicates and sulphates, whereas the Fe-oxyhydroxides, partially the carbonates and almost all silicates are of detrital origin. During the epigenetic stage, carbonates, sulphates, clay minerals, pyrite, and Fe-oxyhydroxides were formed. Alteration products like gypsum, jarosite, limonite, chlorite, kaolinite, illite, mica, and calcite were generated due to the transformation of detrital and authigenic minerals. 相似文献
3.
通过巴里坤湖钻孔岩芯沉积相分析、年代学测定、粒度分析、碳酸盐及其稳定同位素测定、孢粉分析等综合研究,建立了巴里坤湖沉积岩芯剖面十五万年来的时间序列、湖水位变化的古水文演化序列,分辨出十五万年来经历的高湖面阶段和低湖面阶段。低湖面阶段对应于冰期阶段,在冰期时,降水主要积累于山地,进入湖泊的水量较少,湖水位降低;高湖面阶段对应于间冰期的到来,山地冰川融化,湖水位迅速上升,但很快达到新的平衡,水位保持稳定。 相似文献
4.
Advancements in hydrology proceeded slowly until the late 1800's when new ventures created a surge of interest and accomplishment. Progress waned again until the middle 20th century when an International Hydrological Decade was conceived, eventually receiving wide multinational support from governmental agencies and nongovernmental institutions.Organized by UNESCO, the Decade program was launched January 1, 1965. Participation included 107 nations, six United Nations agencies, and more than a dozen international scientific organizations. The initial program emphasized scientific research, and international cooperation; the second half of the Decade, emphasized technical assistance and technology transfer, largerly through education, training and demonstration.The success of the Decade led to the establishment of the International Hydrological Program, again under the aegis of UNESCO, to continue the work of the Decade indefinitely. The five major program activities, now involving about 90 countries and several international organizations, include: the scientific program, the promotion of education and training, the enhancement of information exchange, support of technical assistance, and the enlargement of regional cooperation.A significant amount of activity related to hydrological data networks and forecasting is carried on in an Operational Hydrology Programme by the WMO, chiefly through its Commission for Hydrology.Other international governmental organizations with a strong interest in water include the UN, the UN Development Programme, the FAO, the WHO, the International Atomic Energy Agency, the UN Environment Programme, the International Standardization Organization, and developmental institutions such as the World Bank.The specialized interests of researchers outside of the governmental structure, are met through association in various scientific and technical organizations which are world wide in scope and membership.Notwithstanding a sometimes bewildering variety of organizations, there certainly exists, for any nation, group, or individual, a demonstrated mechanism for almost any conceivable form of international cooperation in hydrology and water resources.Dr. Heindl, L.A., formerly US Geological Survey, died on October 18, 1978 (see In Memoriam at the end of the paper) before he could finish the final version. His colleagues, James R. Jones, Robert M. Beall and Ennio V. Giusti, Office of International Hydrology, US Geological Survey, Reston, VA. 22092, USA, kindly prepared the paper for publication and wrote In Memoriam. Approved for publication by the Director, US Geological Survey. 相似文献
5.
6.
J. -Y. Yu 《Environmental Geology》1996,27(4):286-299
Osheepcheon Creek running through the Dogyae area is being polluted by the influx of the abandoned coal mine drainage. Generally, the more polluted water has lower pH and Eh and higher conductivity values. The concentrations of Mg, Ca, Fe, SO4, and some trace elements, such as Cd, Co, Cr, Mo, Ni, Pb, Rb, Sr, U and Zn, are tens to hundreds of times more concentrated in the abandoned coal mine drainage than in the unpolluted streamwater. However, most immobile toxic pollutants from the mine drainage are quickly removed from the streamwater by the precipitation of amorphous Fe hydroxide and sorption on the precipitated Fe hydroxide. The fast removal of the pollutants from the streamwater maintains the water quality of the creek as acceptable at most places along the stream path, except where the abandoned coal mine drainage flows in. However, the creek has the potential of deteriorating quickly if the mine drainage is allowed to be continuously combined with the streams. A function of pH, Eh, and conductivity has been developed with discriminant function analysis for the purpose of easy, fast, and inexpensive measurement of the degrees of pollution of the streams. The estimated pollution of the streams with the discriminant function are consistent with what the chemical compositions of the water samples indicate. The pollution map of the study area was constructed from the calculated scores with the discriminant function. The pollution map suggests that the pollutants mainly come from the west side of Osheepcheon Creek. Thus, the abandoned coal mine drainage from the west side has to be appropriately treated as soon as possible to prevent Osheepcheon Creek from being further polluted. Considering the topography, climate, and the amount of the mine drainage, an active treatment method is recommended. 相似文献
7.
通过城门山矿田矿床地质、矿体走向及倾向上的厚度及品位变化情况总结其矿化特征,根据成矿温度及地球化学成矿条件研究该矿体矿化富集规律的控制因素,并从矿化特征方面佐证讨论该类矿床的成因及外围找矿方向。研究表明,矿体矿化沿水平及垂向上均具有分带特征,大致表现为沿热液中心向外为Mo、Cu、Zn、Pb、Ag、Au元素的分带,从地表向下为TFe、Au、Ag、Pb、Zn、Cu元素的分带。除此之外,矿化还具有差异特征,表现为走向上矿体两端发育的不一致性、倾向上的局部豆荚状发育特征。本次工作厘定的分带性及差异性分别佐证了矿床的热液成因与沉积成因,并预测外围具有较好的多金属找矿前景,且东段好于西段。 相似文献
8.
通过对秭归地区闪长岩岩体风化壳中微量元素的分布规律研究,将该风化剖面中的微量元素划分为3类。第一类包括Sc、V、Cr、Co、Ni、Cu、Zn、Zr、Hf、Nb、Ta、U、Th、Mo、W,基本属于非活动性元素,在风化过程中得以有效保留,其中U、Cr、Cu等受氧化还原条件的影响,有时呈局部富集现象,规律性不明显。第二类以Ca、Rb、Cs、Sr、Ba、Pb、Ga、Gd、Tl为代表,随着风化作用的进行而逐步从风化壳中淋失,属活动性元素。第三类以稀土元素为代表,在风化壳内部发生局部的再分配,从剖面上层随风化溶液向下淋滤亏损,到剖面中下部沉淀富集,其中重稀土元素的淋失程度大于轻稀土元素。由于母岩中斜长石的风化淋滤,Eu在氧化环境下逐渐从正异常变为负异常。Ce在地表氧化条件下很容易生成四价氧化物（方铈石）,并在表层明显富集,剖面介质中氧化还原条件的变化导致Ce的波动变化。 相似文献
9.
In the old mining area of Rodalquilar, mine wastes, soil and sediments were characterized and the results revealed high concentration
of Au, Ag, As, Bi, Cu, Fe, Mn, Pb, Se, Sb and Zn in tailings and sediments. The contaminant of greatest environmental concern
is As. The mean concentration in the tailings was 679.9, and 345 mg/kg in the sediments of Playazo creek. The groundwater
samples from the alluvial aquifer showed high concentration of Al, As, Cd, Fe, Hg, Mn, Ni, Pb, Se, Sb and Zn and very high
concentration of chloride and sulfate, which were above the concentration defined in the European standards for drinking water.
The presence of As in groundwater may be caused by the oxidation of arsenian pyrite, the possible As desorption from goethite
and ferrihydrite and the jarosite dissolution. Groundwater concentrations of Cd, Fe, Mn, and possibly Cu, were associated
with low values of Eh, indicating the possible dissolution of oxy-hydroxides of Fe and Mn. The mobility of metals in the column
experiments show the release of Al, Fe, Mn, Cr, Cu, Ni, V and Zn in significant concentrations but below the detected values
in groundwater. However, As, Cd, Sb, Se Pb and Au, are generally mobilized in concentrations above the detected values in
groundwater. The possible mass transfer processes that could explain the presence of the contaminants in the aquifer and the
leachates was simulated with the PHREEQC numerical code and revealed the possible dissolution of the following mineral phases:
jarosite, natrojarosite, arsenian pyrite, alunite, chlorite, kaolinite and calcite. 相似文献
10.
系统分析青藏高原新生代中新世50余个沉积盆地的类型、构造背景、岩石地层序列,对青藏高原中新世构造岩相古地理演化特征进行分析和探讨。中新世,青藏高原海相沉积已经全面退出,全部转为陆相沉积,约23Ma时高原及周边不整合面广布,标志高原整体隆升。塔里木、柴达木及西宁-兰州、羌塘、可可西里等地区主体表现为大面积的构造压陷湖盆沉积。约17.2Ma左右,阿尔金山显著隆升,使柴达木盆地西叉沟一带再无生物礁灰岩出现,且在盆地西部出现了短暂的沉积间断。这一时期,柴达木盆地西部开始进入湖退期,而东南部则快速湖进;同时,大约17.7Ma索尔库里山间盆地初始凹陷形成。另外,高原腹地五道梁-沱沱河盆地受南部唐古拉山的挤压抬升,在16Ma左右结束了五道梁组的沉积,在可可西里—唢呐湖一带则再次凹陷接受唢呐湖组沉积,形成高原腹地的大型压陷湖盆。13～10Ma期间,藏南南北向断陷盆地的形成,是高原隆升到足够高度开始垮塌的标志;约8Ma以来,高原东北部几乎所有湖盆均进入湖退期,普遍出现冲积扇、辫状河和水下扇砂砾岩堆积。 相似文献
11.
滇西北地区早更新世时全面隆起,中更新世发生陆内裂谷作用,云南高原面解体,晚更新世是地堑系发育的全盛时期,全新世这一过程仍在进行。断块的差异隆升运动造成该区自北、西向南、东呈台阶状降低,形成了玉龙山等断块山。断裂活动控制了盆地、河流、湖泊、冰川、温泉及其沉积。青藏高原隆升产生向南偏东的推挤使川西-云南的断裂活动具相同的方式,断陷盆地发育主要受近南北向左行剪切-拉张活动控制。 相似文献
12.
湖北宜昌黄花场中/下奥陶统界线附近几丁虫组合及其地层学意义 总被引：4，自引：1，他引：4
对宜昌黄花场大湾组下段牙形石 Oepikodus evae带至 Baltoniodus triangularis带系统采集与分析几丁虫样品 ,共发现几丁虫 6属 12种 ,其中包括 1个相似种、1个未定种 ,它们是 Conochitina raymondii,C.ordinaria,C.primitiva,C.langei,C.brevis,C.poumoti,C.decipiens,Belonechitina cf.micracantha,L agenochitina esthoni-ca,L.sp.,Eremochitina baculata和 Cyathochitina dispar等。根据上述几丁虫的地质和地理分布特征 ,自下而上可划分为 Conochitina langei带和 Eremochitina baculata带 ,讨论并指出了他们与相关笔石、牙形石生物带的关系 相似文献
13.
The formation and distribution of fractures are controlled by paleotectonic stress field,and their preservative status and effects on development are dominated by the modern stress field. Since Triassic,it has experienced four tectonic movements and developed four sets of tectonic fractures in the extra low-permeability sandstone reservoir at the south of western Sichuan depression. The strikes of fractures are in the S-N,NE-SW,E-W,and NW-SE directions respectively. At the end of Triassic,under the horizontal compression tectonic stress field,for which the maximum principal stress direction was NW-SE,the fractures were well developed near the S-N faults and at the end of NE-SW faults,because of their stress concentration. At the end of Cretaceous,in the horizontal compression stress fields of the NE-SW direction,the stress was obviously lower near the NE-SW faults,thus,fractures mainly developed near the S-N faults. At the end of Neogene-Early Pleistocene,under the horizontal compression tectonic stress fields of E-W direction,stress concentrated near the NE-SW faults and fractures developed at these places,especially at the end of the NE-SE faults,the cross positions of NE-SW,and S-N faults. Therefore,fractures developed mostly near S-N faults and NE-SW faults. At the cross positions of the above two sets of faults,the degree of development of the fractures was the highest. Under the modern stress field of the NW-SE direction,the NW-SE fractures were mainly the seepage ones with tensional state,the best connectivity,the widest aperture,the highest permeability,and the minimum opening pressure. 相似文献
14.
Geochemical fractionation of heavy metals in Chilka Lake (east coast of India)—a tropical coastal lagoon 总被引：1，自引：0，他引：1
Chilka lake, the largest coastal lagoon of Asia is one of the most dynamic ecosystems along the Indian coast. Historically the lagoon has undergone a considerable reduction in surface area due, in part, to input from natural processes but mostly due to human activities. The purpose of this investigation is to document the heavy metals' affinity for specific geochemical phases in the recently deposited sediments in the lagoon. Thirty-three samples were collected and analyzed for different geochemical phases of Fe, Mn, Cu, Cr, Ni, Pb, and Zn utilizing a sequential extraction scheme. In the nonlithogenous fraction, the exchangeable fraction was not geochemically significant, having <2% of the total metal concentration for all the elements. However, the carbonate fraction contained the following percentages of the total concentration: <1% Fe, 13% Mn, 6% Cu, 4% Cr, 8% Ni, 13% Pb, and 12% Zn, suggesting the detrital origin of the sediments. Reducible and organic matter-bound fractions were the significant phases in the nonlithogenous fraction, containing 9% Fe, 16% Mn, 15% Cu, 16% Cr, 16% Ni, 14% Pb, and 14% Zn in the former and 4% Fe, 3% Mn, 17% Cu, 3% Cr, 14% Ni, 15% Pb, and 14% Zn in the latter. The phenomenon has been attributed to the scavenging affinity of Fe-Mn oxides and affinity for sorption into organic matter of the lagoon sediments. The lithogenous, residual fraction generally considered as a guide for natural background values was determined to contain 87% Fe, 67% Mn, 61% Cu, 77% Cr, 61.3% Ni, 56% Pb, and 60% Zn of the total concentrations. 相似文献
15.
治岭头金矿位于浙江省遂昌县,是我国东南沿海的一座大型金矿床。该矿床围岩蚀变发育,类型有硅化、绢云母化、绿泥石化、黄铁矿化、方解石化和菱锰矿化。从矿体到围岩可以划分为4个蚀变带:强硅化带、弱硅化-黄铁绢英岩化带、绢云母化带和绿泥石化带。沿矿体走向,蚀变强度整体上呈波动性变化,与矿体呈透镜状产出特征一致。硅化、黄铁矿化、菱锰矿化与金矿化关系最密切,而且这些蚀变具有相似的变化趋势。绢云母化和绿泥石化与硅化的变化趋势不同,且与矿化关系不密切。另外,矿区还发育方解石化,且强度较弱。金矿化及围岩蚀变均发育在古元古界八都群变质岩中,未进入上覆中生代火山岩盖层,证明治岭头金矿成矿作用与中生代火山活动无关。定量计算结果显示:蚀变过程中Al_2O_3、TiO_2、P_2O_5为惰性组分;SiO_2、CaO、MnO、Au、Ag、Cu、Pb、Zn等为明显带入组分;Fe_2O_3、FeO、MgO、K_2O、Na_2O、Ba、Sr等为明显带出组分。根据围岩蚀变和稳定同位素分析,推断治岭头金矿原始成矿热液流体应是富含Si、Ca、Mn、Au、Ag、Cu、Pb、Zn等组分的岩浆热液,后期有大气降水的加入。 相似文献
16.
Mohamed A. Morsy 《Mathematical Geology》1993,25(7):833-850
Geochemical reconnaissance survey of Wadi Umm Khariga in the southern part of the Eastern Desert of Egypt was carried out in an area of 30 Km2. The results of 79 stream sediment samples analyzed for Co, Cr, Cu, Fe, K, Li, Mn, Ni, Pb, Rb, Ti, and Zn after hot extraction with aqua regia were treated with simple and multivariate statistical methods. Titanium, Cu, Co, Ni, and Cr show lognormal distribution, whereas the other elements are normally distributed. The correlation between Fe and Mn and most of the analyzed elements suggest coprecipitation process that could be significant in controlling the distribution of these elements. Regression analysis was effective in correcting the effects of Fe and Mn by calculating the residuals. R-mode factor analysis produced a four-factor model, which accounts for 79.1% of the total variance in the data. Factor 1 (rCr, rCo, Ni) scores are correlated spatially with the area underlain by the serpentinites, metarhyolites, and metadacites. Factor 2 (rLi, rZn, rTi, Rb, K) scores are correlated with the metarhyolites, metadacites, and metapyroclastics. Factor 3 (Cu, rTi, Pb) scores characterize the metabasalts, meta-andesites, metarhyolites, and metadacites, thus reflecting the parent rocks as dominant influencing factors. Factor 4 (Mn, Fe) scores reflect the secondary environment effects. Discriminant analysis delineated an anomalous area for Co, Ni, Cr, Cu, Ti, Mn, Pb, and Li with probable occurrence of economic mineral deposits. 相似文献
17.
Daiani Kochhann Everton Rodolfo Behr Adilson de Chaves Marcia F. Mesko Valderi L. Dressler Erico M. M. Flores Bernardo Baldisserotto 《Environmental Earth Sciences》2013,70(4):1727-1733
The water quality of the Vacacaí River was assessed at different sites in the period between winter 2005 and autumn 2006. All samples were analyzed for 52 elements (Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Th, Li, Be, Mg, Al, Ca, V, Cr, Mn, Fe, Ni, Co, Cu, Zn, Ga, As, Se, Rb, Sr, Ag, Cd, In, Cs, Ba, Tl, Pb, Bi, U, Na, K, Hg, B, Mo, Sn, Te, Ti), temperature, pH, ammonia, and alkalinity levels. Water from the Vacacaí River ranged from slightly acidic to alkaline. No difference was observed in the chemical composition at different sites of the Vacacaí River. Levels of Ba, Ca, Sr and Mg increase in the dry seasons and reach their highest concentrations in autumn; Be and U decrease in the dry season and reach their highest concentration in spring. Al, Fe, Cr, Ni, Th, U Mn, Ca and Mg are highly positively related, indicating a common origin. Se and Cu are probably from anthropogenic source, from the rice crops of the margins of the river. Waterborne Al and Fe levels were above the desirable level for drinking water at all sites during all seasons. These results demonstrate the need for constant monitoring of water parameters, which is crucial to ensure water quality for the population of this region. 相似文献
18.
西秦岭北带泥盆纪Nereites遗迹相及其环境分析 总被引：4，自引：1，他引：3
西秦岭北带泥盆系舒家坝组下一中上部的巨厚陆源碎屑岩系中含有极丰富的遗迹化石,它们可为解释该组沉积环境提供重要信息:（1）由大量典型深水遗迹化石组成的Nereites遗迹相,可与世界各地浊积岩系和复理石相中的Nereites遗迹相进行对比,该遗迹相主要发育在浊流沉积区直至深海平原,其沉积水深最大可超过2000m;（2）舒家坝组的遗迹群落中,除大量属深水型分子外,还见有典型的浅水分子,两种水深性质不同的遗迹组合共生在一个沉积剖面,正是浊积岩系和复理石相才具有的独特分布特征;（3）根据沉积层序和遗迹组合的对比确认舒家坝组不存在风暴岩。 相似文献
19.
地表钙华,是喀斯特地区普遍存在的一种沉积体,是陆相碳酸钙沉积的重要类型。长期以来陆相碳酸钙沉积的水动力成因观点为大多数人所熟悉(1)（2）,生物成因观点则研究较少,在实际中生物作用过程也是不可忽略的,特别是藻类的沉积作用。论文以几种典型的蓝藻为例,通过对自然界水动力条件的模拟,对蓝藻藻类进行了几种水动力条件下的碳酸钙生物沉积试验研究,对比研究了在不同水动力条件下,蓝藻钙化沉积过程。试验得出了钙藻生长与钙化沉积的最适宜水动力为0~60 rpm,在过强的水动力条件下,蓝藻的生长将受到抑制,从而降低蓝藻的钙化沉积速率。文章讨论了在瀑布条件下的陆相碳酸钙沉积是以水动力成因为主导,而在水动力条件较弱的河流中以生物成因为主导,从而提出了,陆相碳酸钙沉积的水动力-生物双成因观点。文章还探讨了在静止状态下,藻类沉积对碳酸钙沉积的贡献大小,叠层石所指示的安静的沉积环境。 相似文献
20.
乌伦布拉克铜矿床位于新疆东准北塔山地区,是中亚-兴蒙斑岩铜矿带的一部分,近年来在该成矿带的境外发现了多处大型铜矿床。我国新疆北部斑岩型铜矿床也取得突破,相继发现了希勒库都克、哈腊苏、琼河坝等斑岩型铜矿床,具有良好的找矿前景,因此乌伦布拉克铜矿床值得进一步深入研究。本文通过对新疆乌伦布拉克铜矿床15种微量元素和9种常量元素含量的系统研究,总结出元素富集贫化特征,并对这些元素含量随着主成矿元素Cu含量变化的规律性进行了探讨,筛选出指标元素,对这些元素进行迁移量计算。以试验区K04勘探线剖面为例,以多维异常体系为指导,对元素空间分布特征和成矿与未成矿地段的地球化学特征差异进行初步讨论。结果表明:赋矿闪长岩体中元素带入带出特征明显。成矿阶段发生明显带入的元素包括S、Cu、Ag、As、Sb、Mo、W和Se,以及H2O+等,发生明显带出的元素包括Ba、Sr、Rb、Fe2O3等,带出元素形成的负异常范围更大,涵盖了带入元素形成的正异常。综合利用不同属性的异常,不仅可以直接有效地指示矿(化)体产出位置,也为试验区进一步找矿提供了方向。 相似文献