共查询到20条相似文献，搜索用时 65 毫秒
1.
最近在北羌塘长蛇山地区新发现了晚侏罗世—早白垩世大套油页岩及巨厚膏盐层,该油页岩与近年来作者在胜利河、长梁山地区发现的多处油页岩连成一片,构成了目前我国规模最大的中生代海相油页岩带—北羌塘油页岩带。沉积岩相、古地理研究表明,晚侏罗世—早白垩世时期,北羌塘盆地总体上为一个向北西开口的相对闭塞的巨大海湾,发育了河流-三角洲、海湾(潮坪-潟湖)和浅海-陆棚等沉积相组合。古气候、古环境研究表明,油页岩(段)沉积期,胜利河地区处于潮湿的热带-亚热带环境,大量淡水的注入以及高的生产力等综合因素,控制了油页岩的形成,其分布主要位于局限海湾-潟湖的边缘带;膏盐层(段)沉积则发育于相对干旱、炎热气候条件下的闭塞环境。北羌塘晚侏罗世—早白垩世油页岩及其上覆膏盐层是重要的烃源岩和区域性封盖层。油页岩及含膏盐层沉积组合的发现,对于重新认识羌塘盆地生烃条件及保存条件,具有十分重要的意义。 相似文献
2.
北羌塘盆地索瓦组上段的时代、古气候及石油地质特征 总被引：3，自引：1，他引：2
索瓦组上段是羌塘盆地演化晚期的一套潮坪—潟湖相沉积,分布于北羌塘盆地中部。通过对索瓦组上段区域地层对比,发现索瓦组上段在盆地东部、西部和南部的岩性变化较大,海相油页岩的出露地仅分布于北羌塘坳陷南部胜利河—长蛇山—托纳木一线的局限海湾—潟湖的边缘带,其形成明显受到了古地理条件的控制。根据索瓦组上段以及其下伏地层产出的生物化石组合,并结合油页岩的Re-Os同位素年龄,认为索瓦组上段的时代可能为早白垩世。对该组产出的孢粉化石组合和硅化木分析表明,索瓦组上段在沉积早期和晚期的古气候条件发生了明显的变化,早期为温暖和湿润气候,而晚期为半干旱—干旱气候,这种垂向上的古气候变化特征不仅仅局限于胜利河地区,可能在整个北羌塘盆地都普遍存在。索瓦组上段发育的油页岩及其上部膏岩沉积组合的发现,对于评价羌塘盆地演化晚期的石油地质条件具有重要的意义。 相似文献
3.
提要：北羌塘盆地长蛇山油页岩位于目前中国最大规模的胜利河—长蛇山海相油页岩带北东,长蛇山南麓,其剖面主要岩性为油页岩、泥晶灰岩、黑色页岩和泥灰岩。本文通过对20件样品进行多项地球化学指标测试,详细评价了长蛇山油页岩剖面烃源岩的有机质丰度、类型及成熟度等指标,并分析了其沉积环境。结果表明：长蛇山油页岩的生烃潜力最好,其次为黑色页岩和泥晶灰岩。总有机碳含量在烃源岩中为0.41%~9.49%,平均为4.02%,在油页岩内含量最高,达到4.53%~9.49%,平均为7.74%;氯仿沥青“A”含量为0.0252%~0.3403%,在油页岩内平均为0.27%,总体为中等—较好烃源岩;有机元素和有机显微组分分析显示干酪根类型以Ⅱ1型为主,少数为Ⅱ2和Ⅲ型;Ro的分布范围为1.08%~1.43%,平均值为1.27%,有机质热演化程度为成熟—过成熟,且在垂向上有机质演化程度逐渐变高。该剖面的烃源岩沉积于盐度较高的还原环境,有机质母质主要以低等水生生物为主。 相似文献
4.
北羌塘盆地晚中生代地层:早白垩世海相地层的发现 总被引：5，自引：0，他引：5
针对羌塘盆地是否存在早白垩世海相沉积,以那底岗日地区主干剖面为依托,结合胜利河、托纳木、长蛇山等已初步判断为早白垩世的油页岩剖面为辅助剖面,采用古生物化石定年和同位素定年相结合的研究方法,对胜利河-托纳木地区原初步定为晚侏罗世-早白垩世的海相地层时代作了进一步研究,结果表明,其时代为早白垩世。这些海相地层在胜利河-托纳木地区广泛分布,但岩性组合存在一定的差异,在胜利河-长蛇山地区为油页岩,厚度最大,向东逐渐变薄,过渡为页岩沉积,向西过渡为灰岩沉积。区域上该套地层对下伏油气藏的保存具有重要意义。 相似文献
5.
近年来,在羌塘盆地胜利河、长梁山、长蛇山、托纳木等地发现的油页岩为目前我国规模最大的海相油页岩矿床,具有重要的工业开采价值。海相油页岩的主要矿物成分为碳酸盐、粘土矿物和石英,并见有黄铁矿、石膏、菱镁矿等矿物。粘土矿物以伊利石为主,少量高岭石,不含蒙脱石。有机地球化学分析表明,这些油页岩的有机质丰度较高,有机质类型较好。胜利河油页岩TOC含量在4.31%~21.37%之间,均值为8.40%;托纳木油页岩的TOC含量也较高,最大值为25.68%,平均为9.32%;长梁山剖面油页岩的TOC含量在2.96%~23.47%之间,平均值为9.56%;长蛇山油页岩的TOC含量在4.53%~9.49%之间,平均值为7.74%。长蛇山油页岩干酪根类型主要为Ⅱ1型,少数为Ⅱ2和Ⅲ型;胜利河油页岩主要为Ⅱ1和Ⅱ2型干酪根,而托纳木油页岩的干酪根类型主要为Ⅱ1型和Ⅰ型。白垩系海相油页岩的形成受多方面因素控制,包括缺氧富氧状态、古生产力、古气候、粘土矿物的混积作用、古地形条件以及海平面变化等。其中,油页岩的总有机碳含量(TOC)与古环境元素指标Mo、V存在较强的相关关系,相关系数分别为0.975和0.917,而与古生产力指标P/Ti、Ba/Al之间为弱相关或无相关关系,相关系数分别为0.481和-0.739。因此,本文认为海相油页岩的形成以"保存模式"为主,有机质沉积时的水体环境对高有机质含量的油页岩的形成起主导作用,并在此基础上建立了海相油页岩的形成演化模式。 相似文献
6.
胜利河油页岩位于北羌塘盆地南部, 走向长超过34 km, 宽9 km。笔者对该油页岩各岩系干酪根进行了分离、镜鉴、元素分析和碳同位素分析, 结果表明, 该油页岩干酪根为Ⅱ型干酪根, 油页岩中干酪根含量较高, 介于15.79%~20.37%, 具有富氢少氧的特征, 其H/C和O/C比率分别为1.11~1.19和0.08~0.25, 为胜利河地区非常好的烃源岩。油页岩层干酪根13C相对富集, 具有相对较高的δ13CPDB值(-20.79‰~ -21.78‰), 与胜利河地区油页岩母源为较单一的藻类有关。藻类的大量繁殖造成了该类生物死亡埋藏速率远大于氧化速率, 在还原环境下大部分藻类还未被氧化就被埋藏, 从而保留了原始藻类略富13C的特征。胜利河油页岩的空间展布以及规模明显受古泻湖环境的控制。 相似文献
7.
羌塘盆地半岛湖—东湖地区主力烃源岩及油气资源潜力 总被引：1，自引：0，他引：1
羌塘盆地中部新发现很多液态油苗,生物标志化合物指示这些液态油苗和BAPS古油藏的原油来自早侏罗世Toarcian油页岩。下侏罗统海相油页岩TOC含量高、生烃潜量大、有机质成熟度适中,是羌塘盆地侏罗系优质烃源岩和主力生油层。地震反射剖面结合钻探标定揭示,下侏罗统Toarcian油页岩稳定分布于北羌塘凹陷,厚度110～150m,大部分地区埋深4500～3000m,半岛湖背斜两翼埋深3000～1000m。由于逆冲推覆及构造改造,下侏罗统Toarcian富碳页岩在半岛湖背斜核部埋深变浅为522～675m,在比洛错、胜利河、长蛇山、托纳木藏布等地表形成油页岩露头。应用氯仿沥青法和成烃率法,采用不同地点Toarcian油页岩及生烃参数,估算面积2万km~2半岛湖—东湖地区初次生烃形成原油资源量为50～100亿吨,新生代二次生烃形成原油资源量为24.4亿吨。北羌塘凹陷Toarcian海相油页岩经过初次生烃和二次生烃形成了巨量油气资源,具有巨大的油气勘探前景。 相似文献
8.
9.
10.
北羌塘凹陷沃若山、长蛇山、胜利河、西长梁地区出露海相含油泥页岩,以油页岩、暗色泥岩、黑色页岩、泥灰岩为主,TOC含量高、生烃潜力大,属优质烃源岩。在西长梁和长蛇山油页岩剖面,分别发现丰富的腕足和双壳化石。西长梁泥页岩含双壳类化石Limea(Pseudolimea)cf.duplicata(J.de C.Sowerby,1827),Integricardium(Integricardium)cf.bannesianum(Contejean,1860),Radulopecten laminates(J.Sowerby,1818),Pholadomya(Bucardiomya)lirata(J.Sowerby)及腕足类化石Holocothyris-Burmirhynchia组合,指示沉积时代为早中侏罗世,层位不高于下巴通阶,地层单元归属雀莫错组。长蛇山油页岩含双壳类化石Chlamys(Chlamys)textoria(Schlotheim),Radulopecten fibrosus(J.Sowerby),Cercomya(Capillimya)striata(Agassiz,1843)及腕足类化石Burmirhynchia obessa Buckman,B.asiatica Buckman,B.hpalaiensis Buckman,指示沉积时代为中侏罗世巴通期—卡洛期,地层单元归属夏里组。沃若山及邻区那底岗日组火山岩与凝灰岩的锆石U-Pb年龄为215~218Ma,指示其下伏肖茶卡组及烃源岩形成时代为晚三叠世卡尼期,上覆沃若山组暗紫色碎屑岩沉积时代为晚三叠世诺利期—瑞替期。 相似文献
11.
Police, politics, and the right to the city 总被引：1，自引：0，他引：1
Mustafa Dikeç 《GeoJournal》2002,58(2-3):91-98
Space and spatiality have recently been at the core of debates concerning the political possibilities of the city. The arguments advanced in this paper might be seen as an attempt to contribute to these debates through a reflection on the spatiality of (in) justice, politics, and the right to the city. The case of French urban policy, with its focus on distressed urban areas, and the `suburban problem' in France are used as examples to make arguments more concrete. 相似文献
12.
E. M. Prasolov S. A. Sergeev B. V. Belyatsky E. S. Bogomolov K. A. Gruzdov I. N. Kapitonov R. Sh. Krymsky V. O. Khalenev 《Geochemistry International》2018,56(1):46-64
This paper reports the first results of a study of 11 isotope systems (3He/4He, 40Ar/36Ar, 34S/32S, 65Cu/63Cu, 62Ni/60Ni, 87Sr/86Sr, 143Nd/144Nd, 206–208Pb/204Pb, Hf–Nd, U–Pb, and Re–Os) in the rocks and ores of the Cu–Ni–PGE deposits of the Norilsk ore district. Almost all the results were obtained at the Center of Isotopic Research of the Karpinskii All-Russia Research Institute of Geology. The use of a number of independent genetic isotopic signatures and comprehensive isotopic knowledge provided a methodic basis for the interpretation of approximately 5000 isotopic analyses of various elements. The presence of materials from two sources, crust and mantle, was detected in the composition of the rocks and ores. The contribution of the crustal source is especially significant in the paleofluids (gas–liquid microinclusions) of the ore-forming medium. Crustal solutions were probably a transport medium during ore formation. Air argon is dominant in the ores, which indicates a connection between the paleofluids and the atmosphere. This suggests intense groundwater circulation during the crystallization of ore minerals. The age of the rocks and ores of the Norilsk deposits was determined. The stage of orebody formation is restricted to a narrow age interval of 250 ± 10 Ma. An isotopic criterion was proposed for the ore-bearing potential of mafic intrusions in the Norilsk–Taimyr region. It includes several interrelated isotopic ratios of various elements: He, Ar, S, and others. 相似文献
13.
I. M. Gorokhov M. A. Semikhatov M. M. Arakelyants E. A. Fallick N. N. Mel’nikov T. L. Turchenko T. A. Ivanovskaya T. S. Zaitseva E. P. Kutyavin 《Stratigraphy and Geological Correlation》2006,14(3):260-274
Clay subfractions (SFs) of <0.1, 0.1–0.2, 0.2–0.3, 0.3–0.6, 0.6–2 and 2–5 μm separated from Middle Riphean shales of the Debengda Formation are studied using the TEM, XRD, K-Ar and Rb-Sr isotopic methods. The oxygen and hydrogen isotope compositions in the SFs are studied as well. The low-temperature illite-smectite is dominant mineral in all the SFs except for the coarsest ones. The XRD, chemical and isotopic data imply that two generations of authigenic illite-smectite different in age are mixed in the SFs. The illite crystallinity index decreases in parallel with size diminishing of clay particles. As compared to coarser SFs, illite of fine-grained subfractions is enriched in Al relative to Fe and Mg, contains more K, and reveals higher K/Rb and Rb/Sr ratios. The Rb-Sr age calculated by means of the leachochron (“inner isochron”) method declines gradually from 1254-1272 Ma in the coarsest SFs to 1038-1044 Ma in finest ones, while the K-Ar age decreases simultaneously from 1225–1240 to 1080 Ma. The established positive correlation of δ18O and δD values with dimensions of clay particles in the SFs seems to be also consistent with the mixing systematics. The isotopic systematics along with data on mineral composition and morphology lead to the conclusion that mixedlayer illite-smectite was formed in the Debengda shales during two periods 1211–1272 and 1038–1080 Ma ago. The first period is likely close to the deposition time of sediments and corresponds to events of burial catagenesis, whereas the second one is correlative with the regional uplift and changes in hydrological regime during the pre-Khaipakh break in sedimentation. 相似文献
14.
Influences of the unsaturated,saturated, and riparian zones on the transport of nitrate near the Merced River,California, USA 总被引：1，自引：0，他引：1
Joseph L. Domagalski Steven P. Phillips E. Randall Bayless Celia Zamora Carol Kendall Richard A. WildmanJr Janet G. Hering 《Hydrogeology Journal》2008,16(4):675-690
Transport and transformation of nitrate was evaluated along a 1-km groundwater transect from an almond orchard to the Merced River, California, USA, within an irrigated agricultural setting. As indicated by measurements of pore-water nitrate and modeling using the root zone water quality model, about 63% of the applied nitrogen was transported through a 6.5-m unsaturated zone. Transport times from recharge locations to the edge of a riparian zone ranged from approximately 6 months to greater than 100 years. This allowed for partial denitrification in horizons having mildly reducing conditions, and essentially no denitrification in horizons with oxidizing conditions. Transport times across a 50–100-m-wide riparian zone of less than a year to over 6 years and more strongly reducing conditions resulted in greater rates of denitrification. Isotopic measurements and concentrations of excess N2 in water were indicative of denitrification with the highest rates below the Merced River. Discharge of water and nitrate into the river was dependent on gradients driven by irrigation or river stage. The results suggest that the assimilative capacity for nitrate of the groundwater system, and particularly the riverbed, is limiting the nitrate load to the Merced River in the study area. 相似文献
15.
扬子北缘马元铅锌矿床闪锌矿微量元素及S-Pb-He-Ar-C同位素地球化学研究 总被引：7，自引：3，他引：4
马元铅锌矿床是近年扬子陆块北缘铅锌找矿的新突破。矿体呈层状、似层状产于碑坝隆起翼部震旦系灯影组角砾状白云岩层间构造带中,围岩蚀变很弱。矿石中硫化物以闪锌矿、方铅矿为主,中粗粒晶质结构,充填于白云岩角砾间。闪锌矿富集Cd、Ge、Ag,贫In、Tl、Se,Ga/In为6~132,Ge/In多1000,成矿温度以中-低温为主。金属硫化物ε~(34)S值相对集中,为12.9‰~19.4‰,平均为17.4‰,来自于海相硫酸盐的还原。铅同位素组成稳定,~(206)Pb/~(204)Pb为17.858~17.918:~(207)Pb/~(204)Pb为15.603~15.694;~(208)Pb/~(204)Pb为37.756~38.046,具有造山带和上地壳铅的特征,震旦系可能提供了金属成矿物质。闪锌矿中流体包裹体的~3He/~4He为0.03Ra~1.05Ra,~(40)Ar/~(36)Ar为326.1~765.1,~(38)Ar/~(36)Ar为0.183~0.204,表明成矿流体主要为地壳流体和饱和大气水(大气降水或海水)的混合。闪锌矿内流体包裹体挥发分δ~(13)C_(CH_4)值为-36.01‰~-28.80‰,δ~(13)C_(C_2H_6)值为-27.72‰~-22.44‰,δ~(13)C_(CO_2)值为-23.24‰~-9.68‰,表明有机流体参与了成矿作用。石英、方解石的H-O同位素结果表明具有海水和有机水混合的特征。可见,成矿流体具有两种流体混合的特征,一为蒸发海水与围岩反应所形成的盆地卤水,二为有机流体。推测矿区可能存在一个古油气藏,由于TSR生成一高硫气藏,为区内还原性有机流体的主要来源。当富含Pb、Zn等成矿物质的成矿流体运移至富含CH_4和H_2S的还原性流体的矿区角砾岩带时,两种流体混合,Pb、Zn等遇到H_2S发生反应而沉淀成矿,并伴生热液白云石等,形成了马元铅锌矿床。综上所述,我们认为马元矿床属MVT型铅锌矿床。 相似文献
16.
Delivery of Trace Metals (Al,Fe, Mn,V, Co,Ni, Cu,Cd, Ag,Pb) from the Trinity River Watershed Towards the Ocean 总被引：2，自引：0，他引：2
The Trinity River (Texas, USA) contains in its watershed 23 different reservoir lakes, the largest one being Lake Livingston
situated in the lower Trinity River watershed and two potentially polluting metroplexes, Dallas and Houston. In order to determine
fluxes of nutrients and trace metals to Galveston Bay, a survey that included 24 discreet samples collected over a year and
at various stages of discharge was carried out during 2000–2001. Geochemical (i.e., sorption by Fe oxyhydroxides), biological
(i.e., seasonal uptake by sinking algae in Lake Livingston), and hydrological (i.e., dilution effects by increasing flow rates)
controls were found to be mainly responsible for variations in dissolved trace metal concentrations rather than pollution
sources. The Trinity River loads of suspended sediments and pollutant trace metals entering Galveston Bay at Anahuac were
<20% of those reaching Lake Livingston, and only a few percent of the total upstream trace metal load is entering the Gulf
of Mexico. Thus, during the transit through the 23 man-made lakes and an estuary, >96% of the pollutant trace metal load is
lost to sediments. 相似文献
17.
V. Yu. Prokof’ev L. D. Zorina V. A. Kovalenker N. N. Akinfiev I. A. Baksheev A. N. Krasnov G. A. Yurgenson N. V. Trubkin 《Geology of Ore Deposits》2007,49(1):31-68
The mineral composition of the Talatui gold deposit has been studied with modern methods. Previously unknown minerals (ilmenite, siegenite, glaucodot, wittichenite, matildite, hessite, pilsenite, zircon, tremolite, cummingtonite, hercynite, and goethite) have been identified in the ore. A high Re content has been detected in molybdenite. The spatiotemporal separation of Au and Ag is caused by different mineral species of these elements and their diachronous precipitation during the ore-forming process. Gold crystallized along with early mineral assemblages, beginning from virtually pure gold (the fineness is 996). Silver precipitated largely at the end of the process as hessite (Ag2Te) and matildite (AgBiS2). The temperature of ore deposition varied from 610 to 145°C, the pressure was 3370–110 bar, and the salt concentration ranged from 56.3 to 0.4 wt % NaCl equiv. The heterogeneous state (boiling) of fluid at the early stages has been documented. The chemical and isotopic compositions of the fluid testify to its magmatic nature and the participation of meteoric water at late stages in the ore-forming process. Thermodynamic modeling reproduces the main specific features of ore formation, including separation of Au and Ag. A physicochemical model of the gold mineralization in the Darasun ore district has been proposed. On the basis of several attributes, the Talatui deposit has been referred to the prophyry gold-copper economic type. 相似文献
18.
19.
山西五台山区滹沱群变质玄武岩岩石学、地球化学特征及其成因意义 总被引：10，自引：0，他引：10
在野外地质调查的基础上，选取滹沱群豆村亚群底部四集庄组玄武岩、顶部青石村组玄武岩和东冶亚群中下部河边村组玄武岩，进行岩石学和地球化学研究。分析结果表明：玄武岩主量元素高TiO2、TFeO，低MgO，具有演化的基性岩浆的特征。稀土元素含量相对较高，具有弱—中等程度的轻稀土元素富集，中等程度的轻重稀土元素分异，轻微的Eu异常；玄武岩中Cr、Ni含量变化较大，但与Mg#具有很好的正相关性。微量元素配分图解中具有明显的Sr负异常，部分样品具有Nb、Ta和Ti负异常，无Zr、Hf负异常，与岛弧火山岩不同；同时Nb、Ta无分异，Zr/Hf值较高，具有板内玄武岩浆的特征。综合分析认为，滹沱群玄武岩可能形成于板内裂谷环境。在岩浆上升过程中发生橄榄石与尖晶石的分离结晶作用，同时不同程度地受到地壳的混染。 相似文献
20.
海南大坡岩体位于五指山褶皱带内,主要受昌江—琼海构造带、琼西构造带与潭爷断陷构造带控制.岩石地球化学及岩石学研究表明,大坡岩体形成于海西-印支晚期,岩性单一,主要为中细粒似斑状黑云母二长花岗岩.岩体显示为Ⅰ型花岗岩与S型花岗岩的混合,主体以地壳物质部分熔融为主,形成过程有少量地幔物质加入.元素对的比值及稀土元素配分特征说明岩体钨锡等多金属含矿性可能较差. 相似文献