Lithostratigraphy and faunal aspects of marine Jurassic rocks in Thailand

Thai marine Jurassic rocks are well exposed in the Mae Sot, Umphang, and Phop Phra areas, less extensively near Mae Hong Son, Kanchanaburi, Chumphon, Nakhon Si Thammarat and Krabi. Generally they rest unconformably on Permian and Triassic, and are overlain by Quaternary strata. Fourteen lithostratigraphic units are defined (in ascending order): Pa Lan, Mai Hung, Kong Mu formations of the Huai Pong Group-Mae Hong Son area; Khun Huai, Doi Yot, Pha De formations of the Hua Fai Group-Mae Sot area; Klo Tho, Ta Sue Kho, Pu Khloe Khi, Lu Kloc Tu formations of the Umphang Group-Umphang area; and Khlong Min Formation-Chumphon, Nakhon Si Thammarat, and Krabi areas. Dominant widespread mudstones, siltstones and sandstones; limestones are confined to the Mae Sot, Phob Phra, Umphang, Kanchanaburi and Mae Hong Son areas; marls are found only in Mae Sot. Sequences are approximately 900 m thick (Mae Sot), 450 m thick (Umphang) and thinner elsewhere, especially the south. Based on ammonites, brackish to marine bivalves, and foraminifera, the beds are dated mainly as ToarcianEarly Bajocian.     

Non-marine Jurassic rocks of Thailand: A summary

Non-marine Jurassic rocks are widespread in the northeastern part (Khorat Plateau), and partly in the northern, eastern, and southern parts of Thailand. In the Khorat Plateau, the rocks, more than 1000 m thick, are represented by the Phu Kradung and Phra Wihan Formations of the Khorat Group but are less extensive in the north, east, and south. Reddish brown to grayish purple sandstones, siltstones, claystones, conglomeratic sandstones and conglomerates are the main lithologies; calcrete nodules are also present in claystones only in the Phu Kradung Formation. Deposition occurred mostly in meandering and braided rivers in semi-arid and slightly humid conditions for the Phu Kradung and Phra Wihan Formations, respectively, except for the southern rocks, where lacustrine deposits dominate. Age determinations are based mainly on vertebrates, bivalves and palynomorphs indicating reassignment to the Jurassicpossibly Early Cretaceous.     

Non-marine Jurassic rocks of Thailand: A summary

Non-marine Jurassic rocks are widespread in the northeastern part (Khorat Plateau), and partly in the northern, eastern, and southern parts of Thailand. In the Khorat Plateau, the rocks, more than 1000 m thick, are represented by the Phu Kradung and Phra Wihan Formations of the Khorat Group but are less extensive in the north, east, and south. Reddish brown to grayish purple sandstones, siltstones, claystones, conglomeratic sandstones and conglomerates are the main lithologies; calcrete nodules are also present in claystones only in the Phu Kradung Formation. Deposition occurred mostly in meandering and braided rivers in semi-arid and slightly humid conditions for the Phu Kradung and Phra Wihan Formations, respectively, except for the southern rocks, where lacustrine deposits dominate. Age determinations are based mainly on vertebrates, bivalves and palynomorphs indicating reassignment to the Jurassicpossibly Early Cretaceous.     

Middle-Late Jurassic marine dinoflagellate cysts from the eastern Qiangtang Basin in the Qinghai-Tibet Plateau, China

Dinoflagellate cysts from two Middle-Late Jurassic sections in the Wenquan and Yanshiping regions of the Qiangtang Basin comprise 24 genera and 36 species including one new taxon of the genus Tenua. Based on their stratigraphic distribution, six assemblage zones are recognized in ascending order as follows: 1) Tubotuberella egemenii Zone, probably Callovian, in the mid-upper part of the Xiali Formation; 2) Pareodinia ceratophora Zone, probably Oxfordian, in the lower part of the Suowa Formation; 3) Batiacasphaera floralis Zone, probably Oxfordian, in the middle part of the Suowa Formation; 4) Amphorula metaelliptica Zone, probably Early Kimmeridgian, in the upper part of the Suowa Formation; 5) Alisocysta spp. Zone, probably Early Kimmeridgian, in the base of the Xueshan Formation; 6) Tenua wenquanensis sp. nov. -Dichadogonyaulax schizoblata Zone, probably Late Kimmeridgian-Tithonian, in the lower part of the Xueshan Formation. Based on our analysis the Jurassic-Cretaceous Boundary in the Wenquan section is placed higher than previously.     

Middle-Late Jurassic marine dinoflagellate cysts from the eastern Qiangtang Basin in the Qinghai-Tibet Plateau, China

Dinoflagellate cysts from two Middle-Late Jurassic sections in the Wenquan and Yanshiping regions of the Qiangtang Basin comprise 24 genera and 36 species including one new taxon of the genus Tenua. Based on their stratigraphic distribution, six assemblage zones are recognized in ascending order as follows: 1) Tubotuberella egemenii Zone, probably Callovian, in the mid-upper part of the Xiali Formation; 2) Pareodinia ceratophora Zone, probably Oxfordian, in the lower part of the Suowa Formation; 3) Batiacasphaera floralis Zone, probably Oxfordian, in the middle part of the Suowa Formation; 4) Amphorula metaelliptica Zone, probably Early Kimmeridgian, in the upper part of the Suowa Formation; 5) Alisocysta spp. Zone, probably Early Kimmeridgian, in the base of the Xueshan Formation; 6) Tenua wenquanensis sp. nov. -Dichadogonyaulax schizoblata Zone, probably Late Kimmeridgian-Tithonian, in the lower part of the Xueshan Formation. Based on our analysis the Jurassic-Cretaceous Boundary in the Wenquan section is placed higher than previously.     

四川盆地西部海相碎屑岩-陆相碎屑岩的转换过程

四川盆地是一个叠合盆地,经历了海相碳酸盐岩到海相碎屑岩、海相碎屑岩到陆相碎屑岩的转换和变迁.这两个转换过程最终结束均发生在四川盆地西部.海相碎屑岩到陆相碎屑岩的转换发生在晚三叠世末,相对应的地层单位为上三叠统须家河组.通过对须家河组厚度和沉积相变化,以及龙门山前砾岩的分布特征研究,认为这一转换主要发生于须家河组沉积末期(T_3x~4-T_3x~6),时间上随地区不同而不同,空间上具有由北往南的先后顺序.这揭示龙门山造山带的造山隆升过程具有由北往南的特点.这一转换过程导致川西前陆盆地内南、北段油气地质条件存在差异.寻找河口沙坝、三角洲平原河道砂等形成的优质储层应是须家河组油气勘探的关键.     

柴达木盆地德令哈拗陷中侏罗统烃源岩有机地球化学特征

柴达木盆地德令哈拗陷中侏罗统广泛发育,是该区主要的烃源岩层系.野外地质调查及有机地球化学分析表明,中侏罗统烃源岩主要以油页岩、泥岩、碳质泥岩和煤为主.油页岩有机碳的质量分数平均为7.95%,有机质类型属Ⅰ-Ⅱ型,为好生油岩;泥岩的有机质丰度交化大,但80%以上的样品有机碳的质量分数大于1%,65%样品的有机碳的质量分数...     

Influences of marine floor hydrothermal activity on organic matter abundance in marine carbonate rocks——A case study of middle-upper Proterozoic in the northern part of North China

FOR A LONG TIME, RESEARCHERS HAVE BEEN REGARDING THE BIOLOGICAL PRODUCTIVITY, THE SEDIMENTATION RATE, THE DEPOSITION ENVIRONMENT, AND THE PRESERVATION CONDITION OF THE DEPOSITIONAL ORGANIC MATTER AS THE CONTROLLING FACTORS OF ORGANIC MATTER ABUNDANCE IN T…     

The potential of vertebrate microfossils for marine to non-marine correlation in the Late Jurassic

Fish (cartilaginous: elasmobranch and bony: osteichthyan actinopterygian) and reptile (crocodile) microfossils comprising scales and teeth have been examined from a series of limestone samples in the Upper Jurassic of France and Germany to gauge the possibilities of using them for correlation between fully marine and hypo-or hyper-saline (non-marine) deposits.     

The potential of vertebrate microfossils for marine to non-marine correlation in the Late Jurassic

Fish (cartilaginous: elasmobranch and bony: osteichthyan actinopterygian) and reptile (crocodile) microfossils comprising scales and teeth have been examined from a series of limestone samples in the Upper Jurassic of France and Germany to gauge the possibilities of using them for correlation between fully marine and hypo-or hyper-saline (non-marine) deposits.     

海相碳酸盐岩和泥岩生烃动力学特征对比分析

选取三塘湖灰岩和下马岭页岩分别代表海相泥岩和海相碳酸盐岩开展开放体系下的生烃动力学实验,动力学模拟结果表明三塘湖灰岩成油、成气活化能基本为单一活化能分布,下马岭页岩活化能呈现多活化能分布的特点。将两样品的动力学参数结合塔里木盆地满东1井区埋藏史-热史进行地质应用,结果表明海相碳酸盐岩的生油门限（2000m）较海相泥岩的生烃门限（3000m）浅,但在5000m以前,海相泥岩的生油速率较慢;而海相碳酸盐岩的生气门限比海相泥岩的生气门限大,在6000m左右二者都达到生气高峰,但碳酸盐岩的成气转化率增加速率比较大。     

Chronostratigraphic units in the Jurassic and their boundaries: Definition, recognition and correlation, causal mechanisms

The historical development of the chronostratigraphic classification of the Jurassic into series, stages and zones is summarised. Traditionally, the series and stages are defined hierarchically in terms of the standard (ammonite) zones they contained but since Hedberg (1976)［1］ they have been defined by a basal boundary stratotype (GSSP). To date four Jurassic Stages have ratified GSSPs; progress with the others is outlined. The primary marker for the definition of the Stage boundaries is biochronology based on evolution of ammonites, with secondary markers based on biostratigraphy of other fossil groups, chemostratigraphy and magnetostratigraphy. Causal mechanisms for the environmental changes that caused ammonite evolution are reviewed and possible methods of correlation with nonmarine successions are briefly discussed.     

Chronostratigraphic units in the Jurassic and their boundaries: Definition, recognition and correlation, causal mechanisms

The historical development of the chronostratigraphic classification of the Jurassic into series, stages and zones is summarised. Traditionally, the series and stages are defined hierarchically in terms of the standard (ammonite) zones they contained but since Hedberg (1976)［1］ they have been defined by a basal boundary stratotype (GSSP). To date four Jurassic Stages have ratified GSSPs; progress with the others is outlined. The primary marker for the definition of the Stage boundaries is biochronology based on evolution of ammonites, with secondary markers based on biostratigraphy of other fossil groups, chemostratigraphy and magnetostratigraphy. Causal mechanisms for the environmental changes that caused ammonite evolution are reviewed and possible methods of correlation with nonmarine successions are briefly discussed.     

Kinetic study of the hydrocarbon generation from marine carbonate source rocks characterization of products of gas and liquid hydrocarbon

The kinetic parameters of hydrocarbon generation from the marine carbonate source rocks were determined and calibrated through kinetic simulating experiment. The kinetic parameters of hydrocarbon generation then were extrapolated to geological condition by using the relative software. The result shows that gaseous hydrocarbons (C_1, C_2, C_3, C_(4-5)) were generated in condition of 150℃相似文献   

Geochronology of source materials from high-pressure and ultrahigh-pressure metamorphic rocks in Jurassic sedimentary rocks of Hefei Basin

Eclogite cobbles were discovered by Wang et al. (2001) in the Fenghuangtai Formation of the northern margin of Dabie Mountains in the Dushan area of Anhui Province, China[1]. They proposed that after the formation during the Triassic, the high-pressure (HP) and ultra-high-pressure (UHP) metamorphic rocks reached the sur-face through exhumation and uplifting before the late Ju-rassic. However, they have not provided any evidence about isotopic ages. One kind of cobbles of HP-UHP rocks w…     

Stratigraphy and paleontology of the marine Jurrassic strata in Vietnam

Marine Jurassic strata in Vietnam have yielded characteristic ammonites and occur in: (1) west Quang Binh Province located in the eastern margin of the Nam Theun Basin (the main part of which is located in Middle Laos); (2) the Nong Son Basin situated in the north of the Kon Tum Geoblock; (3) the Da Lat Basin, the largest Jurassic basin in Vietnam, extending from the southern margin of the Kon Tum Geoblock to southeast of Ho Chi Minh City. In the first two, Lower Jurassic marine beds occupy the lower part of the section and grade up into Middle Jurassic red beds. In central Da Lat Basin the section consists completely of marine strata containing many ammonite levels dated from Early Sinemurian to Bajocian, whereas the marginal basin section is like the first two areas. Based particularly on biostratigraphical evidence, a marine transgression is considered to have entered the Indochina Block as early as the Late Hettangian. During the early transgression the fauna was distinctly endemic, showing the separate character of the basins, but since the Late Sinemurian, communication between the Da Lat and other basins was established; the marine regime in Da Lat Basin ended around the Late Bathonian.     

Stratigraphy and paleontology of the marine Jurrassic strata in Vietnam

Marine Jurassic strata in Vietnam have yielded characteristic ammonites and occur in: (1) west Quang Binh Province located in the eastern margin of the Nam Theun Basin (the main part of which is located in Middle Laos); (2) the Nong Son Basin situated in the north of the Kon Tum Geoblock; (3) the Da Lat Basin, the largest Jurassic basin in Vietnam, extending from the southern margin of the Kon Tum Geoblock to southeast of Ho Chi Minh City. In the first two, Lower Jurassic marine beds occupy the lower part of the section and grade up into Middle Jurassic red beds. In central Da Lat Basin the section consists completely of marine strata containing many ammonite levels dated from Early Sinemurian to Bajocian, whereas the marginal basin section is like the first two areas. Based particularly on biostratigraphical evidence, a marine transgression is considered to have entered the Indochina Block as early as the Late Hettangian. During the early transgression the fauna was distinctly endemic, showing the separate character of the basins, but since the Late Sinemurian, communication between the Da Lat and other basins was established; the marine regime in Da Lat Basin ended around the Late Bathonian.     

历史上的中泰友好关系

中国和泰国自古以来就有着传统的友好往来，泰国也一直同中国保持着长期友好的交往。文章通过对历史上中泰关系的回顾，阐述了双方之间的友好交往及其对泰国社会经济发展的贡献。     

印度、泰国和越南生物多样性概况

首先涉及到印度、泰国和越南３国陆生生物多样性主要栖息地──森林及自然保护区的概况，然后对３国的物种多样性以及生物多样性的就地保护，迁地保护及持续利用的情况作了介绍，并与我国的情况作些比较。     

豫南,皖西晚期中生代地层的对比

豫南、皖西晚期中生代地层可以划分为上侏罗统、下白垩统及上白垩统。属于晚侏罗世的有毛坦厂组、黑石渡组、南召组及西谭楼组下段。白湾组下段可能也应归于此期。下白垩统是这一地区的主要沉积层,有晓天组、锦湾组、西谭楼组上段、马市坪组及白湾组上段。上白垩统则分布零星。该地区有发育较好的侏罗系-白垩系剖面,对它们的研究必将为解决侏罗纪、白垩纪的界线提供重要的证据。