十万大山地区构造演化和含油气评价   总被引：2，自引：0，他引：2  

尤绮妹  俞广 《海相油气地质》1998,3(1):11-22

十万大山盆地地构造演化过程为：在华夏被动大陆边缘发育的弧间洋盆基础上,经东吴、印支和燕山期碰撞造山运动,形成晚古生代－中生代前陆盆地,又经过短暂的弧后陆内裂谷阶段,形成了喜马拉雅期右列张扭性盆地。共原型盆地经历了镀嵌、交错、披盖、再镶、交错、披盖、再镶嵌等四个叠置过程。其构造发展由正反转向负反转变化,以多次构造运动叠加后保留的基底部分卷入的冲断－推覆构造形成占主导,并发育典型的楔状前陆盆地、斜坡带  相似文献   

遗迹化石与潮控滨线海泛面的识别及准层序相组合──以塔里木盆地下志留统塔塔埃尔塔格组为例   总被引：1，自引：0，他引：1  

齐永安 《矿物岩石》1998,(4)

塔里木盆地下志留统塔塔埃尔塔格组主要由潮坪沉积组成。根据遗迹化石与沉积特征,固底控制的遗迹化石Ｇｙｒｏｌｉｔｈｅｓ常常与沉积性不连续面（海泛面）有关,潮控滨线中的准层序由三类岩相组成,其中含砾砂岩相（相Ａ）为潮道沉积,未见遗迹化石;含交错层理细砂岩相（相Ｂ）为砂坪沉积,仅见少量的遗迹化石Ｓｋｏｌｉｔｈｏｓ;强生物扰动粉砂岩、泥岩相（相Ｃ）为砂、泥混合坪沉积,发育有丰富的遗迹化石,代表Ｓｋｏｌｉｔｈｏｓ－Ｃｒｕｚｉａｎａ混合遗迹相。  相似文献   

中亚干旱区的荒漠化与土地利用   总被引：7，自引：0，他引：7       下载免费PDF全文

杨小平 《第四纪研究》1998,18(2):119-127

笔者在实地考察、航片和卫星影像判读的基础上,参考国际上最新研究成果,以咸海盆地和古丝绸之路沿线地区为例,分析探讨了中亚干旱区荒漠化发生的过程、机制及其对自然和人文环境系统的影响和危害。由于大量从阿姆河和锡尔河引水扩大灌溉、浪费水源及单一农作物种植,使1960年时还为世界第四大湖的威海水面和蓄水大减,在干枯了的湖底和周围耕地上荒漠化快速发展,造成自然环境系统的严重退化和社会经济的巨大损失。虽然在我国丝绸之路沿线地区自古以来就有荒漠化现象,但荒漠化的规模在近40年来发生了根本性变化。塔里木河下游和克里雅河下游及玛纳斯河下游的湖泊干枯,植被退化甚至消失,不少野生动物灭绝。  相似文献   

吉林延边汪清县蛤蟆塘盆地白恶纪地层划分及其演化     

陈跃军  周晓东 《吉林地质》1998,(4)

通过１∶５万区调填图（１９８８～１９９０）,笔者将蛤蟆塘盆地白垩纪地层划分为大拉子组、富兴屯砾岩、龙井组。其中大拉子组下部为山麓冲积扇沉积,上部为湖相沉积;富兴屯砾岩为河流—扇三角洲相沉积;龙井组为浅盆广湖相沉积,其中产有Ｎｉｇｅｒｅｓｔｈｅｒｉａｓｐ等化石,属早白垩世,与延吉盆地等有明显时代差异,具有穿时性。  相似文献   

川西南孔玉—会理地区内生金矿床成矿规律     

葛良胜  李麦兑 《矿产与地质》1998,12(3):145-154

从区域大地构造演化角度阐述了研究区的金矿成矿大地构造环境,及在不同成矿地质环境中产出的主要金矿床类型,代表性金矿床地质特征。从金成矿的地质背景、构造环境和岩浆活动等方面,结合地质事件和成矿作用的时间演化,总结了金矿成矿地层控矿规律、构造控矿规律、岩浆岩控矿规律和矿床时间分布规律。  相似文献   

THE PALEOSEISMIC SURFACE RUPTURE AT SOUTH OF CENTRAL ALTYN TAGH FAULT AND ITS TECTONIC IMPLICATION          下载免费PDF全文

SHAO Yan-xiu  YUAN Dao-yang  LIU-ZENG Jing  Jerome Van der Woerd  LI Zhi-gang  WU Lei  LIU Fang-bin 《地震地质》1979,42(2):435-454

In this study, we described a 14km-long paleoearthquakes surface rupture across the salt flats of western Qaidam Basin, 10km south of the Xorkol segment of the central Altyn Tagh Fault, with satellite images interpretation and field investigation methods. The surface rupture strikes on average about N80°E sub-parallel to the main Altyn Tagh Fault, but is composed of several stepping segments with markedly different strike ranging from 68°N~87°E. The surface rupture is marked by pressure ridges, sub-fault strands, tension-gashes, pull-apart and faulted basins, likely caused by left-lateral strike-slip faulting. More than 30 pressure ridges can be distinguished with various rectangular, elliptical or elongated shapes. Most long axis of the ridges are oblique(90°N~140°E)to, but a few are nearly parallel to the surface rupture strike. The ridge sizes vary also, with heights from 1 to 15m, widths from several to 60m, and lengths from 10 to 100m. The overall size of these pressure ridges is similar to those found along the Altyn Tagh Fault, for instance, south of Pingding Shan or across Xorkol. Right-stepping 0.5~1m-deep gashes or sub-faults, with lengths from a few meters to several hundred meters, are distributed obliquely between ridges at an angle reaching 30°. The sub-faults are characterized with SE or NW facing 0.5~1m-high scarps. Several pull-apart and faulted basins are bounded by faults along the eastern part of the surface rupture. One large pull-apart basins are 6~7m deep and 400m wide. A faulted basin, 80m wide, 500m long and 3m deep, is bounded by 2 left-stepping left-lateral faults and 4 right-stepping normal faults. Two to three m-wide gashes are often seen on pressure ridges, and some ridges are left-laterally faulted and cut into several parts, probably owing to the occurrence of repetitive earthquakes. The OSL dating indicates that the most recent rupture might occur during Holocene.
Southwestwards the rupture trace disappears a few hundred meters north of a south dipping thrust scarp bounding uplifted and folded Plio-Quaternary sediments to the south. Thrust scarps can be followed southwestward for another 12km and suggest a connection with the south Pingding Shan Fault, a left-lateral splay of the main Altyn Tagh Fault. To the northeast the rupture trace progressively veers to the east and is seen cross-cutting the bajada south of Datonggou Nanshan and merging with active thrusts clearly outlined by south facing cumulative scarps across the fans. The geometry of this strike-slip fault trace and the clear young seismic geomorphology typifies the present and tectonically active link between left-lateral strike-slip faulting and thrusting along the eastern termination of the Altyn Tagh Fault, a process responsible for the growth of the Tibetan plateau at its northeastern margin. The discrete relation between thrusting and strike-slip faulting suggests discontinuous transfer of strain from strike-slip faulting to thrusting and thus stepwise northeastward slip-rate decrease along the Altyn Tagh Fault after each strike-slip/thrust junction.  相似文献   

Transgressions-régressions, variations eustatiques et influences tectoniques de l'Aptien au Maastrichtien dans le Bassin de Paris occidental et sur la bordure du Massif armoricain     

P. Juignet 《Cretaceous Research》1980,1(4):341-357

La série sédimentaire du Crétacé moyen et supérieur étudiée dans l'Ouest du Bassin de Paris et sur la bordure du Massif armoricain comporte sept pulsations transgressives qui peuvent être reconnues en fonction de la disposition géomètrique des dépôts et de l'enchaînement vertical des faciès.Les épisodes transgressifs atteignent leur phase paroxysmale, en alternance avec des stades de régression, successivement:

1. (1) à la fin de l'Aptien supérieur —(régression début Albien)

2. (2) au milieu de l'Albien supérieur —(régression fin Albien-début Cénomanien)

3. (3) au milieu du Cénomanien inférieur —(régression fin Cénomanien inférieur)

4. (4) à la fin du Cénomanien moyen —(régression fin Cénomanien)

5. (5) au milieu du Turonien inférieur —(régression du Coniacien)

6. (6) au Santonien puis Campanien —(régression fin Campanien)

7. (7) au Maestrichtien —(régression fin Maastrichtien)

Ces dépôts crétacés présentent une succession de séquences séparées par des discontinuités et des surfaces d'érosion plus ou moins marquées. Les caractères et la répartition de ces séquences sont analysés en domaine de sédimentation terrigène littorale et dans le bassin envahi par la craie. Il est alors tenté d'interpréter les variations bathymétriques d'une part en fonction d'évènements tectoniques locaux, d'autre part en relation avec des variations eustatiques plus générales.Middle and Upper Cretaceous deposits studied in the western Paris Basin and on the Armorican Massif margin show seven transgressive pulses that can be detected in the geometrical arrangement of the sedimentary bodies and the vertical succession of facies.The transgressive episodes, each delimited by a regressive phase, reached their peak during:

1. (1) late Late Aptian —(Early Albian regression)

2. (2) mid Late Albian —(Late Albian-Early Cenomanian regression)

3. (3) mid Early Cenomanian —(late Early Cenomanian regression)

4. (4) late Middle Cenomanian —(Late Cenomanian regression)

5. (5) mid Early Turonian —(Coniacian regression)

6. (6) Santonian-Campanian —(Late Campanian regression)

7. (7) Maastrichtian —(Late Maastrichtian regression)

The Cretaceous sediments occur as a series of sequences, separated by more or less important discontinuities and erosion surfaces. The features and distribution of these sequences have been studied in the nearshore region of terrigenous sedimentation and in the Chalk basin. An attempt is made to relate the bathymetric changes to either tectonic movements or more widespread eustatic oscillations.  相似文献   

Cretaceous transgressions and regressions on the Russian Platform, in Crimea and Central Asia     

D. P. Naidin  I. G. Sasonova  Z. N. Pojarkova  M. R. Djalilov  G. N. Papulov  Yu. Senkovsky  V. N. Benjamovsky  L. F. Kopaevich 《Cretaceous Research》1980,1(4):375-387

This paper is a brief explanation of the diagrams of the Cretaceous transgressions and regressions on the Russian Platform, in the Crimea (Figures 1–3) and some regions of central Asia—the western flanks of the Tien Shan mountains, the Fergana basin, the Zeravshan-Gissar and Alaj mountains, and the Northern Pamirs (Figures 5–7).Internationally recognized stages are employed. They are interpreted by Sasonova (1967) for the Lower Cretaceous (K₁) of the Russian Platform, by Naidin (1977) for the Upper Cretaceous (K₂) of the Platform and the Crimea, by Djalilov (1971) and Pojarkova (1976) for the Upper Cretaceous of central Asia. General data on the stratigraphy of the Cretaceous of central Asia may be found in Anon 1977.  相似文献   

Theoretical analysis of telluric anomaly of a basin structure     

Rakesh Kumar 《Pure and Applied Geophysics》1980,119(2):339-348

The solution of a boundary value problem modelling a two-dimensional basin structure has been obtained by using the Schwartz-Christoffel conformal transformation technique and numerical methods of solving non-linear differential equations. Utilizing this solution, the telluric field and its first horizontal derivative have been theoretically computed for field directions perpendicular to the strike of the structure. On the basis of systematic analysis of a large number of such anomaly curves, two nomograms have been prepared to be used in the quantitative interpretation of telluric data. An interpretation procedure to evaluate the geometric parameters of the basin from the observed telluric data is outlined. This procedure is demonstrated on an actual field example.  相似文献   

Correlation of T-log with E-log in coal-bearing formations     

J. R. Kayal 《Pure and Applied Geophysics》1980,119(2):349-355

The profile of temperature gradient versus depth (T-log) has been found to be very useful for correlation with electrical resistivity log (E-log) in coal-bearing formations. A positive correlation between electrical resistivity and thermal resistivity is observed in coal sections whereas a negative correlation is found in sandstone/shale beds, thus helping in coal prospect evaluation. T logs have been used to correct the location of coal bed which had apparently been misinterpreted by the E-log. Hole to hole correlation of T-log and E-log is found to be excellent and it is observed that thermal resistivity characteristics of given formations remain fairly uniform. A rough estimation of coal grade is possible from the detailed study of the T-logs. Abrupt changes of temperature gradient as also its reversals have been observed in burnt coal sections.  相似文献