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1.
The petrographic and micropaleontological studies of the rocks in the sedimentary cover of the Primorye continental slope in the area of Vladimir Bay in the Sea of Japan made it possible to establish that the sedimentary cover is represented in this area by two different facial complexes of Late Miocene rocks. The first facial complex consists of terrigenous rocks (siltstones, sandstones, and conglomerates) that were accumulated under relatively shallow-water conditions of the shelf and the uppermost part of the continental slope. The second one is formed by diatomaceous-clayey rocks under more deep-water conditions, mainly in the upper part of the continental slope. The carbonate nodules that are widely distributed among the deposits of the first complex but are also recorded in the second one were formed as a result of diagenetic processes in the terrigenous or silicious-terrigenous sediments that had been formed. With respect to their age, the Late Miocene deposits are characterized by a full succession of diatomaceous zones over 10.0–5.5 mln yr. The sediments of the first facial complex accumulated during the first third of the Late Miocene (10.0–8.5 mln yr), while those of the second began to accumulate somewhat later, but their accumulation continued until the late Miocene (9.2–5.5 mln yr). 相似文献
2.
This paper presents the results of geological studies carried out during the two marine expeditions of the R/V Akademik M.A. Lavrent’ev (cruises 37 and 41) in 2005 and 2006 at the underwater Vityaz Ridge. Dredging has yielded various rocks from the basement
and sedimentary cover of the ridge within the limits of three polygons. On the basis of the radioisotope age determinations,
petrochemical, and paleontological data, all the rocks have been subdivided into the following complexes: the volcanic ones
include the Paleocene, Eocene, Late Oligocene, Middle Miocene, and Pliocene-Pleistocene; the volcanogenic-sedimentary ones
include the Late Cretaceous-Early Paleocene, Paleogene undifferentiated, Oligocene-Early Miocene, and Pliocene-Pleistocene.
The determination of the age and chemical composition of the rocks has enabled us to specify the formation conditions of the
extracted complexes and to trace the geological evolution of the Vityaz Ridge. The presence of young Pliocene-Pleistocene
volcanites allows one to come to a conclusion about the modern tectono-magmatic activity of the central part of the Pacific
slope of the Kuril Islands. 相似文献
3.
The results of the complex study of the sedimentary cover (continuous seismic profiling and diatom analysis) in the northeastern
part of the Sea of Japan, including the Bogorov Rise, the adjacent part of the Japan Basin, and the continental slope, are
presented. Two varied-age complexes were distinguished in the sedimentary cover of Primorye’s continental slope, namely, the
Middle Miocene and Late Miocene-Pleistocene; these complexes were formed in a stable tectonic environment with no significant
vertical movements. The depression in the acoustic basement is located along the continental slope and it is divided from
the Japan Basin by a group of volcanic structures, the most uplifted part of which forms the Bogorov Rise. The depression
was formed, probably, before the Middle Miocene. In the Middle Miocene, the Bogorov Rise was already at the depths close to
the modern ones. In the sedimentary cover near the Bogorov Rise, buried zones were found, which probably were channels for
gas transportation in the pre-Pleistocene. Deformations of sediments that occurred in the beginning of the Pleistocene are
established in the basin. 相似文献
4.
5.
琼东南盆地物源和沉积环境变化的重矿物证据 总被引：5，自引：0，他引：5
基于11口钻井岩心样品的重矿物数据,结合古生物学、元素地球化学和地震资料,对琼东南盆地的物源及沉积环境演变进行了分析.结果表明,盆地基底沉积以陆相沉积为主,自渐新世起,盆地逐渐接受海侵,大致经历了海陆过渡→滨浅海→浅海→半深海的沉积环境演变过程,水深总体呈逐渐增大的趋势且在同一时期南部区域水深整体上大于北部.随着沉积环境的变化,各地层(崖城组至莺歌海组)物源呈现出多源性特征,经历了原地→近源→远源的演变过程.在渐新世早期,物源以近源玄武质火山碎屑和邻区陆源碎屑为主,之后演变为远源的陆壳碎屑,物源区包括北部海南岛、南部永乐隆起、东北部神狐隆起、西部红河、西南部中南半岛乃至更广的区域.海南岛物源自早渐新世便开始发育,至中中新世成为盆地最主要的物源,并持续至现今;永乐隆起和神狐隆起物源在晚渐新世至早中新世期间最为发育,于中中新世逐渐消退;红河物源于晚中新世大规模加入,为中央峡谷的主要沉积物源,影响至上新世结束;中南半岛莺西物源自上新世发育,影响至更新世时期.此外,自生组分对盆地(尤其是南部区域)的沉积贡献也不容忽视. 相似文献
6.
An integrated (petrographical and micropaleontological) study of the sedimentary cover samples dredged from the lower slopes of the Kuril deep-sea basin was carried out. The Pliocene-Pleistocene sediments are mainly represented by tuffaceous sedimentary rocks (tuffites, tuffaceous muds, tuffaceous diatomites, tuffaceous silts, tuffaceous sandstones, etc.). Significant admixtures of pyroclastic matter, especially of volcanic glasses, indicates that the sedimentation process was accompanied by explosive volcanism. The data obtained give evidence about the intensification of the tectonomagmatic regime within the region under study during the Pliocene-Pleistocene time. By the beginning of the Pliocene, a deep-sea basin with a well-manifested continental and/or island slope and a narrow shelf already existed. The Pliocene-Pleistocene deposits accumulated in a cold well-aerated deep-sea basin under oxic conditions and downslope sediment transport. 相似文献
7.
A basin modeling system was used to numerically reconstruct the burial, thermal, and catagenesis histories of the rocks in
the sedimentary sections of four boreholes in the Kaigan-Vasyukan part of the Sakhalin-5 area on the northeastern shelf of
Sakhalin. The sedimentary section of the basin includes the Late Cretaceous complex in addition to the Cenozoic one. The region
of the shelf considered here is located within the Okhotsk block margin near to the East Sakhalin accretion complex in the
region subjected to active fault tectonics. Consequently, two limiting versions of the basin’s development are analyzed in
this paper: the first with the local-isostatic response of the basin’s lithosphere during the basin’s entire history and the
second with the isostatic behavior of the lithosphere beginning from the time of the Kuril Island Arc’s formation (about 34
Ma BP). The modeling suggests a rather high thermal mode of the basin at intensive sedimentation during the last 10 Ma. The
rocks of the upper half of the Late Cretaceous formation; the Eocene, Machigar, and Daekhurin formations; and the lower half
of the Uinin complex could generate oil up to the present time. In contrast, the rocks of the upper half of the Uinin complex
and the Dagi, Okobykai, and Lower and Upper Nutov formations are interesting only as the reservoir and cap rocks for the hydrocarbons
generated in the lower levels. 相似文献
8.
N. G. Vashchenkova 《Oceanology》2008,48(6):855-863
Sedimentary rocks from the northern slope of the Kuril Deep-Water Basin are examined. Four different-age lithological units are distinguished, and inferences about the probable conditions of their formation are made. The Paleogene-Lower Miocene deposits (lithological units I and II) are represented by the purest varieties of siliceous rocks, which implies their accumulation far away from the source areas under quiet hydrodynamical conditions of the waters. The composition of the microfossils suggests a relatively shallow-water marine basin. The Pliocene-Pleistocene deposits of lithological units III and IV were formed in an active hydrodynamical environment under conditions of synchronous explosive volcanism at bathyal depths. The presence of porcelanite outcrops on the continental slope of the basin, together with the micropaleontological data about the paleodepths of the sedimentation, allows us to assume that, in the region studied, the continental slope was formed as a result of vertical motions in the post-Middle Miocene time. 相似文献
9.
北康盆地构造特征及其构造区划 总被引：3，自引：0，他引：3
北康盆地是位于南沙中部海城的新生代沉积盆地，新生代沉积盖层在盆地内广泛发育，根据地震反射特征及地震反射界面的区域对比，盆地基层可进一步划分为3个构造层。北康盆地西南边界发育延贾断裂，该断裂西起万安盆地，向东直于加里曼丹。从渐新世始，廷贾断裂先后经历了3次规模较大的构造活动。南沙海槽西北缘断裂位于北康盆地的东南边界，该断裂把北康盆地和南沙海槽盆地分隔开来。北康盆地内断裂主要有北东、北西和南北向三组，其中南北、北西向断层往往错断北东向断层。在详细讨论断层特征和沉积盖层布规律的基础上，对北康盆地的二级构造单元进行了划分。 相似文献
10.
Original results of igneous rock studies are presented. The rocks were dredged during a marine expedition (cruise 37 of R/V Akademik M.A. Lavrent’ev in August–September, 2005) in the region of the submarine Vityaz Ridge and Kuril Arc outer slope. Several age complexes (Late Cretaceous, Eocene, Late Oligocene, Miocene, and Pliocene-Pleistocene) are recognizable on the Vityaz Ridge. These complexes are characterized by a number of common geochemical features since all of them represent the formations of island arc calc-alkali series. At the same time, they also have individual features reflecting different geodynamic settings. The outer slope of the Kuril Arc demonstrates submarine volcanism. The Pliocene-Pleistocene volcanic rocks dredged here are similar to the volcanites of the Kuril-Kamchatka Arc frontal zone. 相似文献
11.
波拿巴盆地油气资源十分丰富.新生界千余米的浅海碳酸盐岩背景下,中新统底部发育一套12～52 m硅质碎屑与碳酸盐混合沉积,其中硅质碎屑作为潜在的良好储集体,尚未引起足够重视.综合运用录井、测井及三维地震等资料,认为盆地北部研究区内该套混合沉积是由陆棚浅海台地生物滩、坝碳酸盐和三角洲平原和前缘硅质碎屑混合而成,以相在空间上... 相似文献
12.
为了更好地揭示南海北部陆坡琼东南盆地晚中新世以来的沉积物输送样式,本次研究将盆地裂后期加速沉降阶段以来的沉积物充填样式作为研究对象,基于前人对这一区域潜在物源区的分析,通过对已有勘探成果的总结和归纳,对深水沉积体的类型进行识别,建立具有成因关系或相同来源的深水沉积体组合,尝试对沉积物输送样式进行划分和归类。研究结果认为,晚中新世以来,琼东南盆地主要存在海南岛物源、莺西物源、南部隆起带物源和神狐隆起物源等4个潜在物源区,沉积物输送样式可划分为垂向沉积物输送、轴向沉积物输送和转向沉积物输送3种类型。 相似文献
13.
Particular features of the tectonic structure and anomalous distribution of the geothermal, geomagnetic, and gravity fields in the region of the Sea of Okhotsk are considered. On the basis of heat flow data, the ages of large-scale structures in the Sea of Okhotsk are estimated at 65 Ma for the Central Okhotsk Rise and 36 Ma for the South Okhotsk Basin. The age of the South Okhotsk Basin is confirmed by the data on the kinematics and corresponds to a 50-km thickness of the lithosphere. This is in accordance with the thickness value obtained by magnetotelluric soundings. A comparative analysis of the model geothermal background and the measured heat flow values on the Akademii Nauk Rise is performed. The analysis points to an abnormally high (by approximately 20%) measured heat flow, which agrees with the high negative gradient of gravity anomalies. The estimates of the deep heat flow and the basement age of the riftogenic basins in the Sea of Okhotsk were carried out in the following areas: the Deryugin Basin (18 Ma, Early Miocene), the TINRO Basin (12 Ma, Middle Miocene), and the West Kamchatka Basin (23 Ma, Late Oligocene). The temperatures at the boundaries of the main lithological complexes of the sedimentary cover are calculated and the zones of oil and gas generation are defined. On the basis of geothermal, magnetic, structural, and other geological-geophysical data, a kinematic model of the region of the Sea of Okhotsk for a period of 36 Ma was calculated and constructed. 相似文献
14.
台西南盆地的构造演化与油气藏组合分析 总被引：14，自引：2，他引：14
杜德莉 《海洋地质与第四纪地质》1994,14(3):5-18
本文根据台西南盆地的地质、地球物理资料，对台西南盆地的地壳结构、基底特征、沉积厚度、断裂构造等基本地质构造特征＾［１］作了研究，探讨了台西南盆地的构造发展演化及及油气藏组合。认为该盆地的构造演化为幕式拉张。幕式拉张可分为三大张裂幕，相应的热沉降作用使盆地在不同的张裂幕时期发展为断陷，裂陷，裂拗－拗陷。它们分别与板块作用下的区域构造运动阶段相对应，说明区域构造运动不但控制了盆地的发展演化，同时也制约 相似文献
15.
Amlia and Amukta Basins are the largest of many intra-arc basins formed in late Cenozoic time along the crest of the Aleutian Arc. Both basins are grabens filled with 2–5 km of arc-derived sediment. A complex system of normal faults deformed the basinal strata. Although initial deposits of late Micocene age may be non-marine in origin, by early Pliocene time, most of the basinfill consisted of pelagic and hemipelagic debris and terrigenous turbidite deposits derived from wavebase and subaerial erosion of the arc's crestal areas. Late Cenozoic volcanism along the arc commenced during or shortly after initial subsidence and greatly contributed to active deposition in Amlia and Amukta Basins.Two groups of normal faults occur: major boundary faults common to both basins and ‘intra-basin’ faults that arise primarily from arc-parallel extension of the arc. The most significant boundary fault, Amlia-Amukta fault, is a south-dipping growth fault striking parallel to the trend of the arc. Displacement across this fault forms a large half-graben that is separated into the two depocentres of Amlia and Amukta Basins by the formation of a late Cenozoic volcanic centre, Seguam Island. Faults of the second group reflect regional deformation of the arc and offset the basement floor as well as the overlying basinal section. Intra-basin faults in Amlia Basin are predominantly aligned normal to the trend of the arc, thereby indicating arc-parallel extension. Those in Amukta basin are aligned in multiple orientations and probably indicate a more complex mechanism of faulting. Displacement across intra-basin faults is attributed to tectonic subsidence of the massif, aided by depositional loading within the basins. In addition, most intra-basin faults are listric and are associated with high growth rates.Although, the hydrocarbon potential of Amlia and Amukta Basins is difficult to assess based on existing data, regional considerations imply that an adequate thermal history conducive to hydrocarbon generation has prevailed during the past 6-5 my. The possibility for source rocks existing in the lower sections of the basins is suggested by exposures of middle and upper Miocene carbonaceous mudstone on nearby Atka Island and the implication that euxinic conditions may have prevailed during the initial formation of the basins. Large structures have evolved to trap migrating hydrocarbons, but questions remain concerning the preservation of primary porosity in a sedimentary section rich in reactive volcaniclastic debris. 相似文献
16.
Youngho Yoon Gwang H. Lee Sanghoon Han Dong G. Yoo Hyun C. Han Kyungsik Choi Keumsuk Lee 《Marine and Petroleum Geology》2010
The petroleum system of the Kunsan Basin in the Northern South Yellow Sea Basin is not well known, compared to other continental rift basins in the Yellow Sea, despite its substantial hydrocarbon potential. Restoration of two depth-converted seismic profiles across the Central Subbasin in the southern Kunsan Basin shows that extension was interrupted by inversions in the Late Oligocene-Middle Miocene that created anticlinal structures. One-dimensional basin modeling of the IIH-1Xa well suggests that hydrocarbon expulsion in the northeastern margin of the depocenter of the Central Subbasin peaked in the Early Oligocene, predating the inversions. Hydrocarbon generation at the dummy well location in the depocenter of the subbasin began in the Late Paleocene. Most source rocks in the depocenter passed the main expulsion phase except for the shallowest source rocks. Hydrocarbons generated from the depocenter are likely to have migrated southward toward the anticlinal structure and faults away from the traps along the northern and northeastern margins of the depocenter because the basin-fill strata are dipping north. Faulting that continued during the rift phase (∼ Middle Miocene) of the subbasin probably acted as conduits for the escape of hydrocarbons. Thus, the anticlinal structure and associated faults to the south of the dummy well may trap hydrocarbons that have been charged from the shallow source rocks in the depocenter since the Middle Miocene. 相似文献
17.
18.
Keith A. W. Crook 《Geo-Marine Letters》1987,6(4):203-209
Sedimentary rocks from the northern margin of the Trobriand Platform, the north wall of the New Britain Trench, and the floor of the Solomon Sea Basin are volcaniclastics, mudrocks, and neritic and bathyal limestones. Arc-volcanic debris from calc-alkaline or high-K magmatic sources is present at each locality. A minor metamorphic component occurs at one site on the Trobriand Platform which yielded Early Eocene to Middle Miocene material, and at the New Britain Trench site, which yielded Miocene or older and post-Miocene samples. Solomon Sea Basin samples are mudrocks which are apparently no older than Late Pliocene. 相似文献
19.
Eleven seismic reflection profiles across Shirshov Ridge and the adjacent deep-water sedimentary basins (Komandorsky and Aleutian Basins) are presented to illustrate the sediment distribution in the western Bering Sea. A prominent seismic reflecting horizon, Reflector P (Middle—Late Miocene in age), is observed throughout both the Aleutian and Komandorsky Basins at an approximate subbottom depth of 1 km. This reflector is also present, in places, on the flanks and along the crest of Shirshov Ridge. The thickness of sediments beneath Reflector P is significantly different within the two abyssal basins. In the Aleutian Basin, the total subbottom depth to acoustic basement (basalt?) is about 4 km, while in the Komandorsky Basin the depth is about 2 km.Shirshov Ridge, a Cenozoic volcanic feature that separates the Aleutian and Komandorsky Basins, is an asymmetric bathymetric ridge characterized by thick sediments along its eastern flank and steep scarps on its western side. The southern portion of the ridge has more structural relief that includes several deep, sediment-filled basins along its summit.Velocity data from sonobuoy measurements indicate that acoustic basement in the Komandorsky Basin has an average compressional wave velocity of 5.90 km/sec. This value is considerably larger than the velocities measured for acoustic basement in the northwestern Aleutian Basin (about 5.00 km/sec) and in the central Aleutian Basin (5.40–5.57 km/sec). In the northwestern Aleutian Basin, the low-velocity acoustic basement may be volcaniclastic sediments or other indurated sediments that are overlying true basaltic basement. A refracting horizon with similar velocities (4.6–5.0 km/sec) as acoustic basement dips steeply beneath the Siberian continental margin, reaching a maximum subbottom depth of about 8 km. The thick welt of sediment at the base of the Siberian margin may be the result of sediment loading or tectonic depression prior to Late Cenozoic time. 相似文献