安塞油田杏河地区长6油层沉积微相研究     

秦敬  张金亮 《西北地质》2004,37(4):15-21

在岩心描述的基础上，对杏河地区长6油层沉积相进行了分析，提出了该区主要沉积相为湖泊环境的河控三角洲体系，主要为三角洲前缘亚相沉积，主要沉积微相有水下分流河道、分流河口砂坝、前缘砂席和分流间等，分流河道和河口砂坝是本区占主导地位的骨架砂体。该区长6油层的三角洲体系是安塞三角洲体系最早发育的一支，早期分流来自于北部，后期分流转由东北方向进入，由于各期分流河道迁移、袭夺、决口以及因压实的均衡调整等，从而形成三角洲复合体内部各分流三角洲砂体的相互叠置交错。根据岩心微相分析、小层砂体形态和测井剖面对比分析，对该区长6油层砂组及小层的沉积微相进行了研究，掌握了沉积微相的时空展布和变化规律。  相似文献   

胜利油区孤南洼陷古、新近系充填层序与沉积环境   总被引：6，自引：0，他引：6       下载免费PDF全文

鲁广军 《沉积与特提斯地质》2004,24(1):97-104

孤南洼陷是济阳坳陷沾化凹陷的一个新生代次级洼陷。边界断层的活动差异性造成洼陷形态为典型的南超北断的箕状洼陷；多次的构造运动形成了湖盆的多次抬升剥蚀和沉降。充填序列可以划分为4个构造层序；沉积体系可划分出河流、扇三角洲、三角洲及湖泊体系等4种；洼陷的沉积受同沉积构造活动及物源补给状况的控制。  相似文献   

沉积有机相的研究现状及其应用   总被引：5，自引：0，他引：5       下载免费PDF全文

李君文  陈洪德  田景春  侯中健 《沉积与特提斯地质》2004,24(2):96-100

沉积有机相是近年来国内外广泛运用于油气勘探的一种有效的研究方法。本文介绍了沉积有机相的概念、划分方案，及其在油气勘探、盆地分析和层序地层学中的应用，指出了沉积有机相与层序地层分析相结合对油气资源评价和预测烃源岩有广阔的发展前景。  相似文献   

陕西金矿床类型及其找矿方向   总被引：1，自引：2，他引：1  

齐文  侯满堂 《陕西地质》2004,22(2):1-8,106

通过对陕西金矿资源的分析、总结，将陕西金矿成因类型划分为7类14亚类；与金矿有关的成矿系列划分为3个矿床成矿系列组合，7个成矿系列类型，10个成矿系列和4个亚系列；金矿床空间分布严格受隐伏基底和出露基底，隐伏岩体、重磁吻合构造，构造和成矿时代的控制；与金成矿有关的Ⅲ级成矿区(带)有4条，有关的Ⅳ级成矿区(带)有10条，有关的Ⅴ级主要金成矿区(带)有16条；提出了金矿新的找矿方向，为今后本区金矿地质找矿的新突破提供信息。  相似文献   

Genesis of the Shear Zone-related Gold Vein Mineralization of the Lega Dembi Gold Deposit, Adola Gold Field, Southern Ethiopia     

Solomon Tadesse 《Gondwana Research》2004,7(2):481

The Lega Dembi Primary Gold Deposit in southern Ethiopia is related to the shear zone-hosted vein in the Neoproterozoic metamorphosed volcano-sedimentary succession of greenschist- to amphibolite-facies metamorphism. The rocks consists of a sequence of biotite-feldspar-quartz schists, carbonaceous mica-schists, amphibolites and basic to ultrabasic rocks. This unit is separated from a foot wall biotite gneiss by a major shear zone. The ore bodies are hosted in the volcano-sedimentary sequence and consist of swarms of quartz veins, lenses, and stockworks that propagated along mesoscale ductile to brittle-ductile shear zones.The mineralization is defined by a complex paragenesis of gold in association with Cu-Pb-Zn-Fe sulphides, tellurides and sulphosalts. The presence of Ni-bearing minerals in amphibolites of the host sequence, together with the ore mineral association, suggests an origin related to mafic volcanism.  相似文献   

Character of Terrestrial Sequence Stratigraphy and Depositional System in Incised Valley, Outcrop Area of Karamay Oilfield, Junggar Basin, China   总被引：1，自引：0，他引：1  

JiaoYangquan YanJiaxin LiSitian YangRuiqi LangFengjiang YangShengke 《中国地质大学学报(英文版)》2004,15(3):324-334

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Deep seismic reflection profiling in the Archaean northeastern Yilgarn Craton, Western Australia: implications for crustal architecture and mineral potential     

B.R. Goleby  R.S. Blewett  R.J. Korsch  D.C. Champion  K.F. Cassidy  L.E.A. Jones  P.B. Groenewald  P. Henson 《Tectonophysics》2004,388(1-4):119

Deep seismic reflection data across the Archaean Eastern Goldfields Province, northeastern Yilgarn Craton, Western Australia, have provided information on its crustal architecture and on several of its highly mineralised belts. The seismic reflection data allow interpretation of several prominent crustal scale features, including an eastward thickening of the crust, subdivision of the crust into three broad layers, the presence of a prominent east dip to the majority of the reflections and the interpretation of three east-dipping crustal-penetrating shear zones. These east-dipping shear zones are major structures that subdivide the region into four terranes. Major orogenic gold deposits in the Eastern Goldfields Province are spatially associated with these major structures. The Laverton Tectonic Zone, for example, is a highly mineralised corridor that contains several world-class gold deposits plus many smaller deposits. Other non crustal-penetrating structures within the area do not appear to be as well endowed metallogenically as the Laverton structure. The seismic reflection data have also imaged a series of low-angle shear zones within and beneath the granite–greenstone terranes. Where the low-angle shear zones intersect the major crustal-penetrating structures, a wedge shaped geometry is formed. This geometry forms a suitable fluid focusing wedge in which upward to subhorizontal moving fluids are focused and then distributed into the nearby complexly deformed greenstones.  相似文献   

The role of leaf inclination,leaf orientation and plant canopy architecture in soil particle detachment by raindrops     

Kirsten Foot  R. P. C. Morgan 《地球表面变化过程与地形》2005,30(12):1509-1520

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A study on the focal parameters of Shidian M =5.9 earthquake sequences in 2001     

Qin Jia-zheng  Qian Xiao-dong  Ye Jian-qing 《地震学报(英文版)》2005,18(3):269-279

On the basis of about 300 earthquake wave forms observed in the Shidian M _S=5.9 sequences on April 12, 2001 recorded in Kunming Digital Seismic Network, the spectra of shear wave have been used to estimate the focal parameters of these earthquake sequences. The results show that within the magnitude range of 1.5–5.3, the seismic moments are 10¹⁰–10¹⁶ N·m, the corner frequencies are 0.2–0.8 Hz, radii of the focal rupture are 200–2 500 m and the stress drops are 0.1×10⁵–20×10⁵Pa. Through the statistical analyses of variation of corner frequency f _c and stress drop Δσ with time, it is discovered that the average corner frequency of the foreshock sequences is obviously lower than that of the aftershock sequences. Contrarily, the average stress drops Δσ of the foreshock sequences are clearly higher than that of the aftershocks. It is considered that these variation characteristics of average corner frequency and stress drops before and after the main shock have index significance to the precursory information before a strong earthquake. The higher stress drops for the foreshock sequences show that the higher shear stresses have been stored in the area of main shock. After the main shock, most of the stresses have been released, so the aftershock sequences show a rupture process of lower stresses. Foundation item: Scientific and Technological Key Project of Yunnan Province (2001NG46)  相似文献   

Normal faulting as a control on the stratigraphic development of shallow marine syn-rift sequences: the Nukhul and Lower Rudeis Formations, Hammam Faraun fault block, Suez Rift, Egypt   总被引：2，自引：0，他引：2  

C. A. L. JACKSON  R. L. GAWTHORPE  I. D. CARR  I. R. SHARP 《Sedimentology》2005,52(2):313-338

Tectono-stratigraphic analysis of the East Tanka fault zone (ETFZ), Suez Rift, indicates that the evolution of normal fault segments was an important control on syn-rift depositional patterns and sequence stratigraphy. Sedimentological and stratigraphic analysis of the Nukhul Formation indicates that it was deposited in a narrow (ca 1–2 km), elongate (ca 5 km), fault-bounded, tidally influenced embayment during the low subsidence rift-initiation phase. The Nukhul Formation is composed of transgressive (TST) and highstand (HST) systems tract couplets interpreted as reflecting fault-driven subsidence and the continuous creation of accommodation in the hangingwall to the ETFZ. The overlying Lower Rudeis Formation was deposited during the high subsidence rift-climax phase, and is composed of forced regressive systems tract (FRST) shallow marine sandbodies, and TST to HST offshore mudstones. Activity on the ETFZ led to marked spatial variability in stratal stacking patterns, systems tracts and key stratal surfaces, as footwall uplift, coupled with regressive marine erosion during deposition of FRST sandbodies, led to the removal of intervening TST–HST mudstone-dominated units, and the amalgamation of FRST sandbodies and the stratal surfaces bounding these units in the footwall. This study indicates that the evolution of normal fault segments over relatively short (i.e. <1 km) length-scales has the potential to enhance or suppress a eustatic sea-level signal, leading to marked spatial variations in stratal stacking patterns, systems tracts and key stratal surfaces. Crucially, these variations in sequence stratigraphic evolution may occur within time-equivalent stratal units, thus caution must be exercised when attempting to correlate syn-rift depositional units based solely on stratal stacking patterns. Furthermore, local, tectonically controlled variations in relative sea level can give rise to syn-rift stacking patterns which are counterintuitive in the context of the structural setting and perceived regional subsidence rates.  相似文献