东营凹陷第三系隐蔽油气藏的地震预测研究

论述了山东省东营凹陷第三系隐蔽油气藏(四大类：岩性型、地层型、裂隙型和复合型)的识别与地震预测技术，应用相干分析、地震属性分析和Stratamagic等地球物理勘探技术，对隐蔽油气藏进行了预测、描述及油气综合评价，为勘探开发提供了井位，取得了显著的效果。     

Palaeomagnetic evidence for Tertiary counterclockwise rotation of Adria

With the aim of obtaining Tertiary palaeomagnetic directions for the Adriatic Foreland of the Dinaric nappe system, we carried out a palaeomagnetic study on platform carbonates from stable Istria, from the northwestern and the Central Dalmatia segment of imbricated Adria. Despite the weak to very weak natural remanences of these rocks, we obtained tectonically useful palaeomagnetic directions for 25 sites from 20 localities. All exhibit westerly declinations, both before and after tilt correction. Concerning the age of the magnetizations, we conclude that five subhorizontal and magnetite bearing Eocene localities from stable Istria are likely to carry primary remanence, whereas three tilted and hematite-bearing ones were remagnetized. In the northwestern segment of imbricated Adria the cluster of the mean directions improved after tectonic correction indicating pre-tilting magnetization. In contrast, Maastrichtian–Eocene platform carbonates from Central Dalmatian were remagnetized in connection with the late Eocene–Oligocene deformation or Miocene hydrocarbon migration. Based on the appropriate site/locality means, we calculate mean palaeomagnetic directions for the above three areas and suggest an alternative interpretation of the data of Kissel et al. [J. Geophys. Res. 100 (1995) 14999] for the flysch of Central Dalmatia. The four area mean direction define a regional palaeomagnetic direction of Dec=336°, Inc=+52°, k=107, α₉₅=9°. From these data we conclude that stable Istria, in close coordination with imbricated Adria, must have rotated by 30° counterclockwise in the Tertiary, relative to Africa and stable Europe. We suggest that the latest Miocene–early Pliocene counterclockwise rotations observed in northwestern Croatia and northeastern Slovenia were driven by that of the Adriatic Foreland, i.e. the rotation of the latter took place between 6 and 4 Ma.     

Age and paleoclimatic significance of late Holocene lakes in the Carson Sink, NV, USA

New dating in the Carson Sink at the termini of the Humboldt and Carson rivers in the Great Basin of the western United States indicates that lakes reached elevations of 1204 and 1198 m between 915 and 652 and between 1519 and 1308 cal yr B.P., respectively. These dates confirm Morrison's original interpretation (Lake Lahontan: Geology of the Southern Carson Desert, Professional Paper 40, U.S. Geol. Survey, 1964) that these shorelines are late Holocene features, rather than late Pleistocene as interpreted by later researchers. Paleohydrologic modeling suggests that discharge into the Carson Sink must have been increased by a factor of about four, and maintained for decades, to account for the 1204-m lake stand. The hydrologic effects of diversions of the Walker River to the Carson Sink were probably not sufficient, by themselves, to account for the late Holocene lake-level rises. The decadal-long period of increased runoff represented by the 1204-m lake is also reflected in other lake records and in tree ring records from the western United States.     

西藏纳木错晚更新世以来湖面变化和藏北高原古大湖的演化

根据西藏纳木错及邻区发现的多处湖岸阶地和高位湖相沉积,确定了藏北高原古大湖的存在。水准测量表明,在纳木错沿岸发育了6级湖岸阶地,以及拔湖48～139.2m的高位湖相沉积;在拔湖26m以下,发育有8～30条湖岸堤;一条明显的湖蚀凹槽则集中出现在拔湖17.5～19.8m的高度上,与纳木错和仁错的分水垭口的高度相当。纳木错沿岸和邻区湖相或湖滨相沉积物的铀系年龄测定表明,高位湖相沉积形成于115.9～71.8kaB.P.的晚更新世早期;第6至第2级阶地形成于53.7～28.2kaB.P.的晚更新世中晚期;与湖蚀凹槽相当的湖滨相沉积则稍早于29.3kaB.P.;第2至第1级阶地,14C测定结果为2350～10390aB.P.。     

Palynological dating of infra- and intertrappean sediments in the Mesozoic succession of Borehole PGD-6, Domra Sub-basin, West Bengal, India

Palynofloras have been examined from infra- and intertrappean sediments of the Panchet and Rajmahal Formations in the Domra Sub-basin of the Damodar Basin, West Bengal, India. Three distinct palynological assemblages are identified and referred to the following palynozones: (i)Lundbladispora–Verrucosisporites(506.60–505.00 m, late Early Triassic, (ii)Murospora florida(501.65–422.20 m. Late Jurassic, Kimmeridgian–Tithonian), and (iii)Cicatricosisporites australiensis(342.00–229.6 m. Early Cretaceous, Tithonian–Berriasian). The first occurrences ofCallialasporites turbatusandC. dampieriare at 501.65 m.Callialasporitesis a dominant element of the succeeding assemblages from the Panchet Formation and indicates a Jurassic age. The FAD ofCicatricosisporites australiensisandC. augustusat 342.00 m, and inconsistent occurrences ofAequitriradites spinulosus,Crybelosporites stylosusin the overlying sediments indicate Jurassic–Cretaceous transition.     

库车盆地西北缘下第三系碳、氧同位素特征及成岩环境

库车盆地西北缘及柯坪地区下第三系碳酸盐岩稳定同位素分析结果显示氧同位素组成在相对较小的范围内变化，而碳同位素组成变化很大。沉积学研究表明塔拉克组和小库孜拜组海相地层主要为潮坪、萨布哈和渴湖相沉积，在成岩过程中或成岩期后，沉积物不同程度地受到了淡水作用的影响。所分析的样品大部分形成于大气淡水成岩环境，富集１２Ｃ，δ１３Ｃ为正值的样品一般形成于海水成岩环境。稳定同位素分析是研究成岩作用的有效手段之一。     

Stratigraphy of the upper cretaceous and lower tertiary strata in the Tethyan Himalayas of Tibet (Tingri area,China)

The 1500-m-thick marine strata of the Tethys Himalaya of the Zhepure Mountain (Tingri, Tibet) comprise the Upper Albian to Eocene and represent the sedimentary development of the passive northern continental margin of the Indian plate. Investigations of foraminifera have led to a detailed biozonation which is compared with the west Tethyan record. Five stratigraphic units can be distinguished: The Gamba group (Upper Albian - Lower Santonian) represents the development from a basin and slope to an outer-shelf environment. In the following Zhepure Shanbei formation (Lower Santonian - Middle Maastrichtian), outer-shelf deposits continue. Pebbles in the top layers point to beginning redeposition on a continental slope. Intensified redeposition continues within the Zhepure Shanpo formation (Middle Maastrichtian - Lower Paleocene). The series is capped by sandstones of the Jidula formation (Danian) deposited from a seaward prograding delta plain. The overall succession of these units represents a sea-level high at the Cenomanian/Turonian boundary followed, from the Turonian to Danian, by an overall shallowing-upward megasequence. This is followed by a final transgression — regression cycle during the Paleocene and Eocene, documented in the Zhepure Shan formation (?Upper Danian - Lutetian) and by Upper Eocene continental deposits. The section represents the narrowing and closure of the Tethys as a result of the convergence between northward-drifting India and Eurasia. The plate collision started in the Lower Maastrichtian and caused rapid changes in sedimentation patterns affected by tectonic subsidence and uplift. Stronger subsidence and deposition took place from the Middle Maastrichtian to the Lower Paleocene. The final closure of remnant Tethys in the Tingri area took place in the Lutetian.     

临沧超大型锗矿床有机质与锗矿化的地球化学特征

临沧锗矿床是一产于第三系含煤岩系中的超大型矿床。矿床的最初锗源与盆地西缘的二云母花岗岩有关。主矿体产于下煤组沉积旋回的早期地层中，每一沉积阶段早期形成的褐煤和碳质泥岩中富含锗，最高含量达１４７０×１０＾－６。褐煤和碳质泥岩在矿化过程中平均富集了１６４－１６９倍。根据锗含量，褐煤和碳质泥岩可分为锗含量小于１２×１０＾－６的低锗煤（泥岩）和大于９０×１０＾－６的高锗煤（泥岩）。高锗煤中有机质富含氧官能     

Geochemical constraints on the petrogenesis of basalts from eastern Jiangnan orogen, South China

The basalts crop out widely in the eastern part of late Proterozoic Jiangnan orogen. In terms of their petrographical and geochemical characteristics, they can be divided into two distinct types: low- and high-Ti. basalts. They crystallized from the magmas derived from the depleted upper mantle differing in partial melting degree. Project supported by the National Natural Science Foundation of China.     

岩层离距图法研究沉积岩断裂发育史——以松辽盆地敖古拉断裂为例

利用断裂活动过程中留下的各种地质标记研究断裂发育史是比较困难的 ,已有的研究方法主要可归纳出七种 ,都存在局限性。岩层离距图法是以地震剖面为基础 ,将穿过断裂的各剖面上的标志层投影到沿断裂走向的铅垂面上 ,得到多组标志层的垂向断距数据 ,然后用下部各标志层的断距减去最上部标志层的断距 ,并作多轮次计算 ,直到最后的断距差近似为零或仅剩一个非零标志层。每一轮次计算代表一个活动期次 ,如果出现负值 ,则表示有构造反转。对松辽盆地敖古拉断裂作了实例计算 ,结果为该断裂发育经历了三个正断活动期和一个逆断活动期 ,与盆地区域性活动有些差别。岩层离距图法比起其他已有方法 ,可靠程度大大提高