东北晚中生代断陷盆地储层次生孔隙形成机制

次生孔隙在东北晚中生代断陷盆地J₃-K₁储层中占有很大比例,主要类型为粒间溶孔、粒内溶孔、铸模孔、胶结物内溶孔和裂缝等。通过对二连、海拉尔、松辽等东北主要含油气断陷盆地储层次生孔隙的研究,总结出其形成机制主要有四种:1与泥岩有机质热演化有关;2与地表水和地下水的渗滤作用有关;3与晚期火山活动有关;4与构造作用和成岩作用有关。明确了寻找次生孔隙发育带的方向为:1成岩强度为早成岩阶段B亚期和晚成岩阶段A、B亚期的砂岩段中;2沉积间断面附近;3地温较高地段岩浆热液影响附近;4在致密砂岩、泥岩和基岩中寻找裂逢发育带。     

东营凹陷南坡沙四上亚段滩坝储层碳酸盐胶结壳发育特征及控制因素

砂-泥岩界面是砂-泥岩互层储层水-岩相互作用的活跃地带。东营凹陷南坡沙四上亚段发育了广泛的滨浅湖滩坝沉积,储层碳酸盐胶结作用强烈,常在砂-泥岩界面富集形成致密胶结壳。综合利用钻井、物性及黏土矿物资料,结合铸体薄片观察,对储层碳酸盐胶结壳的发育规律及控制因素进行了系统的研究。碳酸盐具有多期胶结的特征,砂-泥岩接触界面处胶结物含量高,多为基底式胶结。向砂体内部胶结物含量逐渐减少,砂体中部胶结物含量少且相对稳定,以孔隙式胶结为主。半干旱碱性水体环境形成的滨浅湖泥岩中的高碳酸盐含量流体、泥岩黏土矿物转化和有机质演化析出有机-无机组分、碳酸盐胶结作用发生所需的可容空间、砂-泥岩之间的物质传递能力、砂体的厚度及岩相组合控制了储层胶结壳的发育程度。胶结壳对储层质量并非简单的"破坏性成岩作用",早期碳酸盐胶结对储层的抗压实效应以及致密层构成的异常压力系统对储层后期溶蚀孔隙的发育以及油气的充注和保存提供了有利的条件。     

花岗岩与混凝土胶结面抗剪强度的试验研究

坐落在基岩上的重力式建筑物（重力坝、悬索桥的锚碇等）,依靠基岩与大体积混凝土接触面的摩擦力平衡巨大的水压力或锚索拉力。接触面的摩擦系数有很小的变化,需要混凝土的体积发生大的变化保持摩擦力不变,从而工程造价出现大的差别。针对润扬长江公路大桥南汊悬索桥锚碇接触面抗剪强度取值问题,采用室内控制粗糙度试验的方法,测试了不同风化程度和粗糙度的花岗岩与混凝土接触面的抗剪强度。结合现场编录和现场粗糙度测试结果,获得了混凝土与基岩胶结面摩擦角的分区和面积加权平均值,为锚碇的稳定验算提供了准确的数据。试验结果对其它重力式抗滑结构设计有参考价值。     

东濮凹陷北部沙河街组三段中亚段沉积环境分析

东濮凹陷北部沙三中亚段广泛发育盐岩和烃源岩,这两个看似不能共存的物质却在这里互层共生。该时期研究区沉积特征为多盐韵律与多层烃源岩互层共生、连续沉积,单个盐韵律厚度从几米到十几米,烃源岩有机质丰度高、类型好。平面上,两者在湖盆沉积沉降中心共生;垂向上,高有机质丰度、好干酪根类型与高盐度地层具有较好的对应关系。因而成为恢复古气候和古环境的重要研究对象。通过岩石学、古生物学以及Sr/Ba、B/Ga、(V+Ni+Mn)、Fe/Mn、Sr/Cu、Mg/Ca、V/(V+Ni)、稀土元素含量和氯同位素等方法对凹陷北部沙三中亚段的沉积环境进行研究。结果表明,凹陷北部沙三中亚段为深水沉积的还原环境,古盐度较高,达到半咸水-咸水沉积;微量元素和孢粉化石特征表明研究区沙三中亚段为温暖潮湿的环境。     

Zircon geochronology of the Klyuchevskoi gabbro-ultramafic massif and the problem of the age of the Mohorovicic paleoboundary in the Central Urals

The Klyuveskoi gabbro-ultramafic massif is the most representative ophiolite complex on the eastern portion of the Uralian paleoisland arc part. The massif is composed of dunite-harzburgite (tectonized mantle peridotites) and dunite-wehrlite-clinopyroxenite-gabbro (layered part of the ophiolite section) rock associations. The U-Pb age was obtained for the accessory zircons from the latter association using a SHRIMP-II ion microprobe at the Center for Isotopic Research at the Karpinskii Russian Geological Research Institute. The euhedral zircon crystals with thin rhythmic zoning from dunites are 441.4 ± 5.0 Ma in age. Zircons from olivine clinopyroxenite show three age clusters with sharply prevalent grains 449.0 ± 6.8 Ma in age. Two points give 1.7 Ga, which is probably related to the age of the mantle generating the layered complex. One value corresponds to 280 Ma, which possibly reflects exhumation of ultramafic rocks in the upper crust during the collision of the Uralian foldbelt. Thus, dunites and olivine pyroxenites from the Klyuchevskoi massif are similar in age at 441–449 Ma. The bottom of the layered part of the ophiolite section corresponds to the M paleoboundary and, consequently, the age of the Mohorovicic discontinuity conforms with the Ordovician-Silurian boundary in this part of the Urals.     

广昆铁路复线秀宁隧道大皮坡—中村段岩溶塌陷成因

塌陷灾害的发生直接影响着秀宁隧道大皮坡-中村段沿线工农业生产和城镇居民生活,本研究以地质环境与隧道建设活动为基础,分析了区内塌陷的发育特征,揭示本区塌陷在隧道建设前后存在三个发生期:缓慢出现期、集中爆发期、后续影响期;本区塌陷发育存在四个阶段:初始稳定阶段、应力初步变化阶段、塌陷阶段、阶段性稳定阶段,并得出月累积降雨量210～290 mm为本区塌陷发生的临界降雨强度;进一步对本区岩溶富水带塌陷发育模式、断裂带塌陷发育模式进行了讨论,并通过引入塌陷斜率因子μ对区内不同地段潜在塌陷能力进行了对比分析,据此提出了防治措施。     

Investigating the spatial pattern of the characteristics of the onset and cessation of the rains in Nigeria

The characteristics of the onset and cessation of the rains investigated in this study are early, normal and late onset and cessation. The spatial pattern of these parameters were investigating for Nigeria using rainfall and potential evapotranspiration data analyzed for the period between 1959– 1990. Furthermore, 4 major rainfall producing mechanisms that could be responsible for the observed pattern of these parameters in Nigeria were also investigated using the stepwise multiple regression analysis. It was found that Inter-Tropical Discontinuity appeared as the most significant rainfall producing factor for predicting the spatial variation in the characteristics of the onset and cessation of the rains in Nigeria. This finding corroborates the zonal (north-south) pattern evident in the spatial distribution of the early, normal and late onset and cessation of the rains in the country. However, it was found that the combination of ITD and disturbance line together proved significant for explaining the spatial variation in the characteristics of the onset and cessation of the rains in Nigeria. Consequently, a south-northeast trend in the spatial pattern of each of early, normal and late onset and cessation of the rains is evident for the country. The combination of the 3 factors-ITD, disturbance line and relief were found to be significant for predicting the late onset and early cessation of the rains. However, the contribution due to relief factor is extremely low. It is observed that the occurrence of onset and cessation of the rains in Nigeria is generally erratic. The study showed further that the probability of the deviation of onset and cessation of the rains from normal is higher in the north than the southern part of the country. The significance of the observations of the study to selection of crops for cultivation and schedule of planting dates have been noted.     

Geodynamics of the Riphean stage in the evolution of the northern passive margin of the East European Craton

The nearly parallel northwest-trending Onega-Kandalaksha, Kerets-Leshukonsky, and Barents paleorift zones located in the northeastern part of the East European Platform are interpreted as a common structural assemblage that was formed in the Middle-Late Riphean as a result of horizontal extension of the continental margin. Therefore, it is reasonable to combine these paleorift structural features into the common White Sea Rift System instead of subdividing them into two or more systems as done previously. The White Sea Rift System originated owing to the breakup of the ancient Paleopangea supercontinent 1300–1240 Ma ago. The latter event occurred as a result of the divergence of the Baltia and Laurentia continental plates that most probably was caused by mantle spreading within the hot equatorial belt of the Earth. The diffuse rifting of that time occurred in the form of near-parallel rifts developing progressively from the inner part of the continental plate toward its margin. A pericratonic sedimentary basin eventually formed at the passive margin of Baltia as a system of roughly parallel rift zones. The geologic and geophysical data show that the passive margin of the East European Platform formed in the Riphean, a phenomenon that corresponds with a model of large-scale extension of the lithosphere after the stage of early ocean-floor spreading. In the course of this process, the brittle upper crust was detached from the ductile lower crust. The geodynamic regime of the Riphean passive margin of the East European Platform probably was similar to the regime of the present-day Atlantic-type passive margins. The White Sea Rift System differs from the transverse Mid-Russian Paleorift System both in origin and age. The Mid-Russian Paleorift System is considered to have formed in the Late Riphean as a result of transtension along a mobile zone in the ancient basement. The lithosphere of northeastern Fennoscandia has experienced horizontal extension since the Middle Riphean, a phenomenon that is closely related to the evolution of the White Sea Rift System, i.e., to the formation of the passive margin of the Baltia continent.     

江西修水地区早震旦世末期冰碛相分析

<正> 修水地区属于扬子地台江南台褶带的一部分,南频华南加里东褶皱系。早震旦世末期冰碛岩分布较广,出露齐全,沉积岩相类型多样。过去,对该区冰碛岩相的研究较贫乏,对其地层的划分和对比一直存有分歧,最突出的焦点是南沱组内是否存在间冰期及是否存在多期间冰期沉积。此外,在扬子地台区的湘、黔、桂等地的间冰期地层中赋藏丰富的     

准噶尔盆地南缘郝家沟剖面下侏罗统三工河组辫状河三角洲沉积特征

对准噶尔南缘郝家沟剖面下侏罗统三工河组的沉积相与层序地层特征进行了详细的研究,确认三工河组发育辫状河三角洲沉积。辫状河三角洲包括辫状河三角洲平原亚相、辫状河三角洲前缘亚相和前辫状河三角洲亚相。辫状河三角洲前缘亚相又可进一步划分为水下分流河道、水下分流河道间、席状砂和河口坝等微相类型。三工河组辫状河三角洲沉积除一些层位的辫状河道沉积物颗粒较粗外,主体沉积物以砂岩、粉砂岩和泥岩为主,为砂质辫状河三角洲。运用高分辨率层序地层学基准面旋回划分原理,将三工河组划分为2个中期基准面旋回,下部中期基准面旋回又可划分为4个短期基准面旋回,上部中期基准面旋回发育不完整。     

New data on the structure of the Kas Block in the basement of the West Siberian Plate

A new concept concerning the structure and stages of evolution of the Kas Block of the West Siberian Plate is stated in this paper. The Kas Block is traditionally considered to be a subsided western margin of the Siberian Platform. The new concept is based on the results of the interpretation of the geophysical data recently obtained along the reference and regional profiles in this territory. The geological interpretation of the deep dynamic sections obtained by reprocessing of the CDP seismic reflection records has been performed for the first time. The structural features of the Kas Block, as well as the character of its junction with the Siberian Platform and the Paleozoic framework, are discussed. The tectonic scheme of the territory and the scheme of the pre-Late Devonian surface of the Kas Block have been compiled. The Baikalian age of the basement of the Kas Block is substantiated. The Salairian allochthonous ophiolite-basalt tectonic nappe is localized for the first time within the sedimentary cover of the Kas Block. The available information allowed us to reconstruct the development of the western margin of the Siberian continent in the Riphean and Early Paleozoic before and after the Baikalian Orogeny, respectively. The informational background of the geological and geophysical interpretation involves the results of the CDP seismic reflection profiling, including the deep dynamic seismic sections and parameters of the P-wave velocities along the reference 1-SB seismic line and the regional Vostok 10, 12, 15, and 16 seismic lines; the results of the deep seismic and magnetotelluric soundings; the gravity measurements; the magnetic exploration; and the new coherent physical geological models.     

Geology of the northern side of the Gulf of Edremit and its tectonic significance for the development of the Aegean grabens

This paper describes the Neogene evolution of northwestern Anatolia based on geological data collected in the course of a new mapping program. The geological history of the region, as recorded by the Neogene sedimentary and magmatic rocks that overlie the Paleozoic–Triassic basement, began after a lake invasion during the Early Miocene period with the deposition of shale-dominated successions. They were accompanied by calc-alkaline intermediate lavas and pyroclastic rocks ejected through NNE trending fractures and faults. The Lower–Middle Miocene successions were deformed under a compressional regime at the end of the Middle Miocene. The deposition of the overlying Upper Miocene–Lower Pliocene successions was restricted to within NE–SW trending graben basins. The graben bounding faults are oblique with a major strike-slip displacement, formed under approximately the N–S extension. The morphological irregularities formed during the Miocene graben formations were obliterated during a severe erosional phase to the end of the deposition of this lacustrine succession. The present E–W graben system as exemplified from the well-developed Edremit graben, postdates the erosional phase, which has formed during the Plio-Quaternary period.     

悬板开孔对排沙漏斗流场特性的影响

排沙漏斗的水沙分离性能取决于其流场特性,为了弄清楚悬板开孔对流场特性的影响,利用粒子图像测速技术和数值模拟方法,分别对悬板溢流段和非溢流段同时均匀布孔、仅在非溢流段布孔和无孔时的排沙漏斗流场特性开展研究。结果表明：①布孔位置不影响涡流性质但影响其强度,均匀布孔时涡流强度最小,不利于水沙离心分离;②无孔和仅在非溢流段布孔时的流场特性有利于泥沙径向输移、沉降和排出,均匀布孔径向速度和二次流流速减小不利于泥沙输移和排出;③仅在悬板非溢流段布孔时悬板表面速度大于其他方案,泥沙不易淤积于悬板。为减少悬板上的泥沙淤积量且同时要保证较高的泥沙截除率时可采用仅在悬板非溢流段布孔的方案优化悬板体型。     

悬板开孔对排沙漏斗流场特性的影响

排沙漏斗的水沙分离性能取决于其流场特性,为了弄清楚悬板开孔对流场特性的影响,利用粒子图像测速技术和数值模拟方法,分别对悬板溢流段和非溢流段同时均匀布孔、仅在非溢流段布孔和无孔时的排沙漏斗流场特性开展研究。结果表明:①布孔位置不影响涡流性质但影响其强度,均匀布孔时涡流强度最小,不利于水沙离心分离;②无孔和仅在非溢流段布孔时的流场特性有利于泥沙径向输移、沉降和排出,均匀布孔径向速度和二次流流速减小不利于泥沙输移和排出;③仅在悬板非溢流段布孔时悬板表面速度大于其他方案,泥沙不易淤积于悬板。为减少悬板上的泥沙淤积量且同时要保证较高的泥沙截除率时可采用仅在悬板非溢流段布孔的方案优化悬板体型。     

Palaeoenvironment of the Karelian Isthmus, the easternmost part of the Gulf of Finland, during the Litorina Sea stage of the Baltic Sea history

The palaeoenvironment of the Karelian Isthmus area during the Litorina Sea stage of the Baltic Sea history, between 8.0 and 4.5 kyr BP (8.8-5.2 cal. kyr BP), was reconstructed by studying four sites located on the Karelian Isthmus in Russia. Methods included diatom and pollen analyses, sediment lithostratigraphical interpretation and ¹⁴C dating. The brackish-water (Litorina) transgression began c. 7.7 kyr BP (8.45 cal. kyr BP) in the Karelian Isthmus area. The transgression maximum occurred between 6.7 and 5.7 kyr BP (7.6-6.5 cal. kyr BP), depending on the glacio-isostatic land uplift rate. Regarding the vegetation, the maximum occurrence of temperate deciduous trees took place at the same time. The transgression was interrupted by a short-lived sea-level standstill during the middle phase of the main transgression, c. 6.3 kyr BP (7.2 cal. kyr BP), on the eastern part of the isthmus. The highest Litorina shoreline is located between 8 and 13 m above present sea-level and the amplitude of the Litorina transgression has varied between 5 and 7 m. The 8.2-kyr cold event is not evident, but the sea-level standstill around 6.3 kyr BP (7.2 cal. kyr BP) could reflect a cool episode at that time in the Karelian Isthmus area.     

Statistical analysis of the reasons for the varying magnetization of the granitoids of the Verkhoyansk-Chukotka fold region and the Okhotsk-Chukotka volcanic belt

The granitoid intrusions are classified into nonmagnetic, weakly magnetic, and strongly Magnetic groups. Various characteristics of the intrusions are examined and an attempt is made to statistically relate these characteristics of the intrusions to the intensity of magnetization. The conclusionsreached are: 1) the intensity of magnetization is closely related to the tectonic environment of emplacement. Intrusions emplaced into residual massifs and fold belts where fracturing is common tend to be magnetic. Those emplaced in regions of prolonged subsidence where fracturing is not common tend to be nonmagnetic. 2) Petrography of the intrusion does not seem to affect magnetization; nor does thetype of country rock. 3) The most highly magnetic intrusions are those emplaced at a depth of about 1 km. The intensity of magnetization drops off sharply for those emplaced at depths less than 1 km; a more gradient drop off is noticed for those emplaced at depths greater than 1 km. 4) The intensity of magnetization is dependent upon the magnetic content in the intrusion. However, totaLiron oxide content is about the same in highly magnetic and nonmagnetic intrusions. 5) Tin deposits seem to be associated with nonmagnetic intrusions and gold deposits with magnetic intrusions. — J. R. Hayes.     

塔里木盆地塔中地区奥陶系地层沉积特征

新疆塔里木盆地塔中地区是重要石油天然气产区。奥陶系是烃源岩，也是主要勘探层系之一，具有分布广，纵、横向变化大的特点。下奥陶统与寒武系相似，碳酸盐台地发育，以灰岩、白云岩为主。中上奥陶统岩性分区以塔中Ⅰ号断裂为界，分为两大地层、岩性区。为碳酸盐台地与外源碎屑岩同时发育时期。寒武－下奥陶统是该区分布最广的烃源岩，中上奥陶统烃源岩只分布在浅海台地区。     

四套降水资料在喀喇昆仑山叶尔羌河上游流域的适用性分析

分析了2003-2009年基于卫星观测的降水数据CMORPH、 TMPA 3B42 v6、 中国科学院青藏高原研究所的融合数据ITPCAS和基于地面台站的APHRODITE (2003-2007)四套降水数据集在叶尔羌河上游流域的时空分布特征, 并以这四套降水数据为驱动, 利用VIC分布式水文模型对叶尔羌河上游流域的降水径流进行模拟.结果表明: 在空间分布上, 四套降水资料在叶尔羌河上游流域的差异较大, ITPCAS的空间分布与流域冰川的分布较一致, 基于冰川区即为大降水区的基本认知, 初步认为ITPCAS的空间分布比较合理; 其次是TMPA 3B42 v6和APHRODITE; 在流域的年降水量和季节分配量上, 由于缺乏高海拔地区的实测降水资料, 无法准确回答各套降水资料在量级上是否合理; 在时间序列上, 四套降水资料与流域站点降水(库鲁克栏杆站和塔什库尔干站的平均降水)存在着不同程度的差异.但从整体上看, CMORPH数据在一定程度上能够反映流域的月降水变化过程, 而APHRODITE和ITPCAS只能在个别年份对流域的降水描述较好; 在径流模拟上, 卫星降水数据CMORPH显示了作为水文模型输入数据的较大潜力; 而其他降水资料在叶尔羌河径流模拟中, 与实测径流在量和季节分配上可能存在较大偏差.     

Peculiarities of the kinematics of the South Uralian suture zones as a cause of the formation of the convergent structure of the East Uralian megazone

The structure of the suture zones surrounding the East Uralian megazone in the South Urals is reviewed. The analysis of mesoscale structures allowed us to prove their strike-slip nature. Their kinematics changed from left-lateral in the Early Carboniferous into right-lateral in the Mesozoic. The age of these dislocations was determined after the age of synkinematic intrusions. The suture zones have divergent structures in contrast to the convergent East Uralian megazone that is located between them.