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51.
黔中隆起在地质构造上属于扬子地块的滇黔隆褶带.南华纪晚期初现雏形,震旦纪—奥陶纪为水下隆起,燕山运动使其整体抬高,喜马拉雅运动时急剧隆升,构造地貌长期相对隆起。地表油苗油样分析结果显示,在红外吸收谱图中缩合芳烃结构及含氧基团吸收明显,有机质热成熟度高,且遭受了氧化蚀变:震旦系以上地层大量暴露,地表水溶蚀下渗深度在黔西南地区可达3000-4000m;作为长期存在的古隆起,经历了多次抬升,直至挽近仍处于严重剥蚀阶段。地腹可能存在酸性岩浆热源使有机质过度热演化、保存条件不佳以及缺少勘探目的层,是黔中隆起油气勘探的三大壁垒。兼谈了碳酸盐岩烃源岩问题.认为形成大油气田的烃源岩主要是泥质岩系,“碳酸盐岩烃源岩”只是从属性的.分布在泥质烃源岩系的边缘或局部范围。 相似文献
52.
Conservation and community in the new South Africa: A case study of the Mahushe Shongwe Game Reserve 总被引:1,自引:0,他引:1
Brian H. King 《Geoforum》2007,38(1):207-219
The idealization of natural landscapes and peoples during colonialism, coupled with the popularity of sustainable development in the postcolonial era, has contributed to the expansion of conservation planning throughout the African continent. Concerns surrounding the promotion of national and international conservation agendas at the expense of local livelihood needs have generated interest in community conservation projects that attempt to include local participation and knowledge in natural resource management. The early excitement associated with community conservation has waned in light of recent assessments that it has been unsuccessful in meeting its ecological and social goals. This parallels other research that suggests communities are understood in generic or homogenous ways that influence how these initiatives are understood. Using a case study of the Mahushe Shongwe Game Reserve, this paper evaluates how rural households access environmental and economic resources to produce livelihoods, and how these access patterns impact their views of the project. It is argued that there are significant livelihood variations within the community that shape the ways households engage with, and benefit from, conservation planning. Rather than strictly viewing Mahushe Shongwe as a constraint to environmental resource access or site for limited employment, community members identify a number of benefits from its existence including education and development opportunities. Additionally, transformations in governance systems in the region impact community views of the project since younger residents are less likely to engage with the Matsamo Tribal Authority, which participates in managing the reserve. The consequence is that conservation has various impacts and meanings within a specific community that remain tied to the livelihood and governance systems being renegotiated in the post-apartheid era. 相似文献
53.
根据两次资源评价结果的分析和对比,认为值得对古生界进行大规模油气勘探。分析了中国海相油气勘探滞后的原因是地史发展的顺序为先海后陆和海相沉积深度比陆相的大。归纳阐述了适用于海相沉积与陆相沉积的10条基本石油地质认识,指出了我国海相沉积深度大、年代老、生油争议多、气比油多、遭破坏多等特点,建议开展区域地质、碳酸盐岩生油、古隆起带、逆掩断层带、盐下油气、碳酸盐岩储集性、油藏破坏与保存的关系、新技术与新方法等8个方面的研究。 相似文献
54.
论述了塔里木盆地的地球动力学演化过程,指出震旦-三叠纪和侏罗-第四纪是两个构造巨旋回.在这类旋回中,盆地经历了由伸展到聚敛的完整发育过程塔里木盆地的演化总体上表现为强伸展-聚敛-微伸展-强聚敛的特点盆地动力学旋回决定了油气的生运聚散过程.提出含油气系统旋口的概念.在分析寒武-奥陶系含油气系统旋回、石炭系-下二叠统含油气系统旋回和侏罗系含油气系统旋回的基础上,指出对含油气系统旋回的形成期与调整再分配期的研究更具实际意义. 相似文献
55.
Dynamics and relationships of Ca, Mg, Fe in litter, soil fauna and soil in Pinus koraiensis-broadleaf mixed forest 总被引:1,自引:0,他引:1
The Liangshui Natural Reserve in Heilongjiang Province of China was selected as the study area. The authors collected the samples of forest litter (Tilia amurensis, Fraxinus mandshurica, Pinus koraiensis, Acer mono, Betula costata, and mixed litter), soil in humus horizon (0--5cm) and soil horizon (5-20cm), and soil macrofauna (Oligochaeta, Geophiloporpha and Juliformia) from 2001 to 2002. The role of soil macrofauna in the material cycle was analyzed through comparing the macro-element contents among various parts of the subsystems and using enrichment index (El). The results indicate that dynamic changes of various litters are very complicated. The contents of Fe in each kind of litter increase firstly, and then decrease in the study period. The changes of macro-element contents are greater in the broad-leaf litter than in the coniferous litter, and the mixed litter is in the middle level, but the differences among them are not significant. The contents of Mg and Fe in humus are higher than those in soil, but the contents of Ca in soil are higher than that in humus. The dynamic changes of macro-element contents in soil and soil fauna are not consistent with those in litter. The diplopod presented obvious enrichment of Ca and Mg (E1〉1), but it does not significantly enrich Fe. Earthworm has a stronger enrichment ability of Fe than diplopod and scolopendra, but E1〈1. Soil fauna can make great influences on the material cycle of the subsystems. 相似文献
56.
The Cuu Long Basin (Mekong Basin) is a rift basin off southern Vietnam, and the most important petroleum producing basin in the country. However, information on petroleum type and characteristics has hitherto been largely unavailable to the public. This paper presents petroleum geochemical data on nine oil samples from four different producing fields in the Cuu Long Basin: the Dragon (Rong), Black Lion (Sutu-Den), Sunrise (Rang ?ong) and White Tiger (Bach Ho) Fields. The oils are highly paraffinic with bimodal normal alkane distributions and show moderate pristane to phytane ratios and a conspicuous hyperbolic decrease in abundance with increasing carbon number of hopane homologues from C30 to C35. The TPP-index of Holba et al. (Holba, A.G., Dzou, L.I., Wood, G.D., Ellis, L., Adam, P., Schaeffer, P., Albrecht, P., Greene, T., Hughes, W.B., 2003. Application of tetracyclic polyprenoids as indicators of input from fresh–brackish water environments. Organic Geochemistry 34, 441–469) is equal to 1 in all samples which in combination with tricyclic triperpane T26/T25 ratios >1 and the n-alkane and hopane distributions mentioned above provide a strong indication of an origin from lacustrine source rocks. This is supported by the absence of marine C30 desmethyl steranes (i.e. 24-n-propylcholestanes) and marine diatom-derived norcholestanes. Based on the overall biological marker distributions, the lakes probably belonged to the overfilled or balanced-fill types defined by Bohacs et al. (Bohacs, K.M., Carroll, A.R., Neal, J.E., Mankiewicz, P.J., 2000. Lake-basin type, source potential, and hydrocarbon character. An integrated sequence-stratigraphic–geochemical framework. AAPG Studies in Geology 46, 3–34). The oils were generated from source rocks at early- to mid-oil-window maturity, presumably Oligocene lacustrine shales that are present in the syn-rift succession. Oils from individual fields may, however, be distinguished by a combination of biological marker parameters, such as the oleanane index, the gammacerane index, the relative abundance of tricyclic terpanes, the proportions of diasteranes and 28-norspergulane, complemented by other parameters. The oils of the Cuu Long Basin show an overall similarity to the B-10 oil from the Song Hong Basin off northern Vietnam, but are markedly different from the seepage oils known from Dam Thi Nai on the coast of central Vietnam. 相似文献
57.
The Kazhdumi Formation of the Bangestan Group is a well-known source rock that has produced abundant oil in most petroleum fields in the Zagros Basin, which stretches from northwest to southwest Iran over hundreds of kilometres. The formation reaches a thickness of 230 m at the type section in northwest Zagros but thins out to 40–50 m in wells studied from the South Pars giant petroleum field, where it comprises mainly grey shales with occasional intercalations of marls and sandstones. South Pars, best known as the Iranian part of the world's largest non-associated gas field, contains small quantities of oil above and below the Kazhdumi Formation. 相似文献
58.
Since the first drill in 1957, three oil, 19 gas and condensate fields have been discovered in the Thrace Basin. However, any petroleum system with its essential elements and processes has not been assigned yet. This study consists of two parts, (1) geochemical overview of the previous work in order to get a necessary help to construct a petroleum system and (2) calculation of quantitative undiscovered hydrocarbon resources generated from this system. An extensive overview study showed that the primary reservoir and source rocks in the Thrace Basin are the Middle Eocene Hamitabat sandstones and shales, respectively, hence it appears that the most effective petroleum system of the Thrace Basin becomes the Hamitabat (!) petroleum system. Currently, 18.5 billion m3 of in-place gas, 2.0 million m3 (12.7 million bbl) in-place waxy oil as well as minor amount of associated condensate were discovered from this system. This study showed that the regional distribution of the oil and gas fields almost overlapped with the previously constructed pod of active Hamitabat shales implying that short and up-dip vertical migration pathway of hydrocarbons from the source to trapping side was available. Thermal model demonstrated that hydrocarbon generation from the Hamitabat shales commenced in the Early Miocene. The amount of quantitative gas generation based on the mean-original TOC = 0.94 wt%, mean-original HI = 217 HC/g TOC and the volume of the pod of active source rock = 49 km3 is approximately 110 billion m3 of gaseous hydrocarbons that results in a high generation–accumulation efficiency of 17% when 18.5 billion m3 of already discovered hydrocarbons are considered. 相似文献
59.
F. Rodriguez Monreal H.J. Villar R. Baudino D. Delpino S. Zencich 《Marine and Petroleum Geology》2009
In the Altiplanicie del Payún area (Neuquen Basin, Argentina), immature source rock sections intruded by up to 600 m thick Tertiary laccoliths show full spectrum maturity aureoles over hundreds of meters from the contacts. Commercial oil accumulations (20–33°API) and oil shows are located along the entire column, both in sandstone/carbonate and fractured igneous reservoirs. A challenging numerical model that included the emplacement of the intrusive bodies, with extreme temperature ranges and unusually short calculation time steps, has been done with the aim to better understand hydrocarbon generation and migration processes related to these thermal anomalies. 相似文献
60.
Models for petroleum generation used by the industry are often limited by (a) sub-optimal laboratory pyrolysis methods for studying hydrocarbon generation, (b) over-simple models of petroleum generation, (c) inappropriate mathematical methods to derive kinetic parameters by fitting laboratory data, (d) primitive models of primary migration/expulsion and its coupling with petroleum generation, and (e) insufficient use of subsurface data to constrain the models. Problems (a), (b) and (c) lead to forced compensation effects between the activation energies and frequency factors of reaction kinetics that are wholly artificial, and which yield poor extrapolations to geological conditions. Simple switch or adsorption models of expulsion are insufficient to describe the residence time of species in source rocks. Yet, the residence time controls the thermal stresses to which the species are subjected for cracking to lighter species. 相似文献