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1.
First record of dinosaur trackway from Tibet,China   总被引:1,自引:1,他引:1  
Three sauropod trackways comprise eight tracks that resemble Brontopodus tracks have been found at the Morong track site in Changdu Prefecture, Tibet, China. These wide- (or sub-wide)-gauge tracks suggest that there was a large sauropod, possibly a member of Titanosauriformes, in Changdu Prefecture during the Early-Middle Jurassic. The sauropod fauna from Changdu Prefecture, Tibet not only has elements in common with the sauropod fauna from the Sichuan Basin, but may include more diverse faunal components.  相似文献   

2.
The Zhaojue(ZJ) tracksites represent multiple steeply-inclined, track-bearing exposures in the clastic Feitianshan Formation of Sichuan Province that have been sequentially, excavated, mapped, expanded and destroyed, by quarrying,erosion or collapse, for almost three decades. The quarried area extends for more almost 1.0 km from north to south and ~0.5 km from east to west. Four important track-bearing surfaces have been identified and identified as ZJ-I, ZJ-II,ZJ-IIN and ZJ-III, some of which are newly exposed surfaces or expanded surfaces that were previously partially described. Others represent surfaces lost since they were first reported in papers published in 2014–2016. The ZJ-II site represents a hugely expanded continuation of a much smaller track-bearing surface described in 2014. It was mapped using drone technology, and now represents the largest tracksite in China, with a minimum count of 933 recognizable tracks, and the longest recorded sauropod and ornithopod trackways from China(~80 m and ~52 m respectively), which also reveal a pronounced change in the direction of trackmaker movement. The ZJ-II surface represents the best Zhaojue paleo-census sample giving a count of 68 individuals from 61 trackways(37 ornithopod, 10 theropod, 14 sauropod) and isolated tracks(representing 7 individuals). Thus, ornithopods(both large and small trackmakers) represent ~54% of the total number of trackways. The smaller ZJ-III surface was mapped using traditional methods, and reveals at least 6 ornithopod-and 4 theropod trackways. Both the ZJ-II and ZJ-III surfaces reveal parallel ornithopod trackways suggestive of social or gregarious behavior. The combined data from all four Zhaojue surfaces reveal a total of 1928 tracks, and include a few previously reported pterosaurs and theropod swim tracks. The Zhaojue quarry complex provide a good example of multiple track-bearing sites(surfaces) that require long term study and monitoring to extract as much trackway data as possible before in situ physical evidence is lost.  相似文献   

3.
The paper describes an early and primitive sauropod dinosaur, Gongxianosaurus shibeiensis (gen. et sp. nov.), from the Dongyuemiao Member of the Lower Jurassic Ziliujing Formation in Shibei Township, Gongxian County, Sichuan Province, China, which is one of the 5 dinosaur fossils discovered in Gongxian in 1997. Except the skull which is incomplete, the fossils are well preserved. It has some features of both sauropods and prosauropods. It is an intermediate type in the evolution of dinosaurs from prosauropods to sauropods and provides materials for the study of the origin and evolution of the sauropod dinosaur fauna. The discovery of this new sauropod furnishes a way for the stratigraphic correlation between the Early Jurassic Ziliujing Formation in the Sichuan basin and the Lower Jurassic Lufeng Formation in the Central Yunnan basin.  相似文献   

4.
China is rich in Middle and Carboniferous fossil corals. The coral faunas in different regions have varying characteristics and can be divided into distinct assemblages. The coral fauna in South China is dominated by the order Caninida and contains numerous endemic elements; that in North China has a lot of Middle Carboniferous corals which are monotonous in species, with Late Carboniferous solitary corals being predominant. The coral fauna in Junggar mainly contains large bi-zoned solitary caninids, while that in southern Khingan is similar to that in South China due to the presence of abundant tri-zoned compound corals. In northern Tibet the coral fauna is also similar to that in South China, but in southern Tibet it is of a cold-water type. Therefore, the Middle and Late Carboniferous coral geography of China can be divided into the Tethys, Boreal and Gondwana Realms.  相似文献   

5.
The middle Permian Cryptospirifer fauna (brachiopod) has hitherto been found in more than 30 localities in the Yangtze Platform, South China. Examination of data from various localities shows that it occurs stratigraphically in three intervals in the range from the upper Kungurian to Wordian. In the Baoshan block in western Yunnan the fauna occurs in the basal part of the Daaozi Formation and is of possibly an early Wordian age. Outside China the Cryptospirifer fauna has been reported from central and northwest Iran and central Turkey, where the fauna may have an age around the Wordian/Capitanian boundary. Rapid global warming since the late Early Permian and possession of other suitable environmental factors such as proper substrate, clastic input and water depth enabled the Gondwana-derived Baoshan Block and related tectono-stratigraphic units in Iran and Turkey to host the Cryptospirifer fauna, a fauna evolved in the Yangtze Platform that is a type area of the Cathaysian province.  相似文献   

6.
A systematic sedimentological and chronological study of typical Paleogene basins in eastcentral Tibet suggests that the depositional characteristics of extensively developed huge-bedded, purplish-red coarse clastic rocks formed in a tectonic setting of regional thrusting and strike-slipping represent a typical dry and hot subaerial alluvial fan environment formed in a proximal and rapidaccumulating sediment body in debris flows and a fan-surface braided river. Combining results from basin-fill sequences, sequences of coarse clastic rocks, fauna and sporo-pollen associations and thermochronological data, it is conduded that the coarse clastic rocks formed in the period of 54.2- 24.1 Ma, nearly coeval with the formation of Paleogene basins in the northern (Nangqen-Yushu thrust belt), middle (Batang-Lijiang fault belt), and disintegration of large basins in the southern (LanpingSimao fold belt) segments of Tibet. The widespread massive-bedded coarse clastic rocks, fold thrusting and strike-slip, thrust shortening, and igneous activities in the Paleogene basins of eastcentral Tibet indicate that an early diachronous tectonic uplift might have occurred in the Tibetan Plateau from Middle Eocene to Oligocene, related to the initial stage of collision of the Indian and Asian plates.  相似文献   

7.
We describe a new titanosaurian sauropod dinosaur, Borealosaurus wimani gen. et sp. nov., based on a distinctive mid-distal caudal vertebra from the early Late Cretaceous Sunjiawan Formation exposed in the Shuangmiao village of Beipiao in Liaoning, China. We provisionally refer an isolated tooth crown, a middle caudal vertebra, and a right humerus from the same locality and horizon to this taxon. Borealosaurus is distinguished from other sauropods in its possession of opisthocoelous mid-distal caudal vertebrae. The occurrence of opisthocoelous caudals in Borealosaurus and the Mongolian sauropod Opisthocoelicaudia raises the possibility that these taxa pertain to an as-yet unrecognized titanosaurian subclade endemic to the Cretaceous Asia.  相似文献   

8.
A Kubergandian (Kungurian) fusuline fauna from the lower part of the Lugu Formation in the Cuozheqiangma area,central Qiangtang Block is described.This fusuline fauna belongs to the Southern Transitional Zone in palaeobiogeography,and is characterised by the presence of the distinctive bi-temperate genus Monodiexodina and many genera common in lower latitude Tethyan areas such as Parafusulina and Pseudodoliolina.The occurrence of Monodiexodina in the fauna confirms that the seamount-type carbonates of the Lugu Formation did not originate from the Palaeotethys Ocean,but rather from a branch of the Neotethys Ocean after the rifting of the Qiangtang Block from the Tethys Himalaya area in the Artinskian.  相似文献   

9.
Diamond was found in podiform chromitites of ophiolite and harzburgite from Luobusha, Tibet. There are silicate inclusions in some diamond grains from this area. In the present work, the CCD (charge coupled detector) technology of X-ray powder diffraction was applied to the study of the inclusion in diamond from the ophiolite of Tibet. Diffraction patterns are obtained even though the inclusion is only 20 μm in crystal size. The results show that the inclusion in diamond consists of talc and clinochrysotile. Therefore, it is clear that the diamond from the ophiolite of Luobusha, Tibet, is natural diamond rather than a synthetic one.  相似文献   

10.
From 1985 to 1987, four new localities with abundant fossil mammals were dis-covered by Cao, Tian and others in the Zhoukoudian (Choukoutien) area, Beijing. They are theEast, West, Shangdian and Donglingzi caves. The East Cave fauna consists of 28 speices ofmammals and its age is middle Early Pleistocene. The East Cave assemblage shows that a tem-perature-falling event took place at around 1.20 Ma B.P. at Zhoukoudian. Sixteen species ofmammals were collected from the West Cave, which are mainly forms of late Early Pleistoceneage. The West Cave fauna represents a transitional fauna from the East Cave fauna (dry-cold)to the fauna (warm) at locality 9. The Shangdian Cave fauna is composed of four forms, beingMiddle Pleistocene in age. The Donglingzi Cave fauna contains 21 Late Pleistocene forms. Inthe cave two fossil horizons may be distinguished. The age of the lower horizon is early LatePleistocene, which is equivalent to that of the New Cave fauna; while the fauna of the upper ho-rizon may be correlated with the Upper Cave fauna.  相似文献   

11.
A probable theropod dinosaur crouching trace and associated tracks from the Tuchengzi (Houcheng) Formation of Siliang Mountain, Chicheng County, Hebei Province, China are the largest theropod tracks currently known from the formation. Although the crouching trace lacks manus and tail marks, the traces are interpreted as made by a crouching theropod because they include a left metatarsal impression and associated ischial, and possibly pubic, callosity traces. This represents the third known example of an asymmetric crouching position adopted by a theropod.Key words: crouching theropod trace;Therangospodus isp.;cf. Megalosauripus isp.;Tuchengzi Formation;Jurassic-Cretaceous boundary  相似文献   

12.
In spite of tremendous discoveries of dinosaur eggs and nests over the world, dinosaur embryonic remains are rare. Until today, dinosaur embryos associated with eggshells are only known in about 20 cases, most of which were recovered from broken or crushed eggs. Here we report intact dinosaur eggs in a partial clutch with preserved embryonic remains in eggs from the Upper Cretaceous Nanxiong Formation of Ganzhou in the southern Jiangxi Province of China. Based on macro- and microscopic features of eggs and eggshells, these eggs were identified as Elongatoolithus sp., and possibly belong to oviraptorosaurs. A CT scanning topography revealed that all the eggs contain accumulations of embryonic bones, including possible femur and tibia. Our discovery suggests that dinosaur embryos might be preserved more than we have recognized, because intact eggs potentially confine embryonic remains.  相似文献   

13.
Three new genera and species of perleidid fishes from the Middle Triassic strata of Yunnan Province, i.e., Fuyuanperleidus dengi gen. et sp. nov., Luopingperleidus sui gen. et sp. nov., and Diandongperleidus denticulatus gen. et sp. nov., are described in this paper. Fuyuanperleidus dengi is distinguishable from other perleidids by the shape of the maxilla, the big teeth, the ornamentation of the skull bones, maxilla fused with the first infraorbital and the deepened flank scales. Luopingperleidus sui is distinguishable from other perleidids by the following features: the triangular main branchiostegal rays, four horizontal rows of deepened flank scales anterior to the pelvic fin, and three anal scales. Diandongperleidus denticulatus is distinguishable from other perleidids by the following features: the anterior border of some anterior fin rays of both the paired fins and the dorsal and anal fins bearing denticles, and posterior strongly serrated scales. The new discoveries not only add to the diversity of perleidid fishes in South China, but also shed new light on the radiation of Triassic perleidid fishes in the world.  相似文献   

14.
The fossil specimens discussed in this paper were collected from the grayish green mudstone and shale in the upper part of Lower Member of Middle Triassic Tongchuan Formation (T2t) in Shaanxi Province, China. Venationary feature correlation with old families and taxonomic discussion show that, among them, one specimen can be assigned to a new family - Sunopteridae fam. nov., which includes a new genus and species and can be referred to Order Protorthoptera Handlirsch, 1906 in taxonomic position, thus belonging to a new member of the Tongchuan Entomoassemblage of Shaanxi Entomofauna (belonging to Shaanxi Biota). The discovery of the new family and its new genus and species has certain reference values as follows: ① The discovery of the new family and its new genus and species fills firstly the vacancy in the protorthopterous field of China; ② In the meantime, it fills also the gaps of the valuable Middle Triassic protorthopterous fossil specimens between Late Carboniferous and Late Triassic Epochs in the world; ③ Judging from venationary features and taxonomic position, especially in the course of the formation of the merged vein of M and Cu, it formed a new unique and particular style of merged vein M+Cu. It not only is unique and simple, but also can be distinguished from the above mentioned 10 old families, thus providing important taxonomic evidence.  相似文献   

15.
鄂尔多斯奥陶系碳酸盐岩碳氧同位素特征及其意义*   总被引:1,自引:1,他引:0       下载免费PDF全文
鄂尔多斯古生代海相地层沉积厚度巨大。鄂尔多斯奥陶系碳酸盐岩的碳氧同位素组成受后期成岩作用影响较小,基本保留了原始海洋的同位素组成: δ13C值分布于-7.30‰~2.26‰之间,均值-0.30‰;δ18O值分布于-13.14‰~-1.94‰之间,均值-6.38‰,碳氧同位素组成与全球基本一致。区域上,鄂尔多斯西缘具有相对较高的δ13C值,南缘次之,而东缘最低。纵向上,碳同位素组成逐渐增重,并在中晚奥陶世发生明显的正向偏移,δ13C均值由马家沟组的-0.36‰增加到平凉组的0.15‰,至背锅山组增加至0.68‰。碳同位素的区域分布差异表明鄂尔多斯西缘水体相对较深,南缘次之,东缘相对较浅,由早奥陶世至晚奥陶世水体逐渐加深,碳同位素组成反映的海平面变化趋势与沉积相演化一致。鄂尔多斯西南缘中晚奥陶世碳同位素组成的正向偏移,标志着较高的生产力和有机碳埋藏率,具有重要的石油地质学意义,西南缘的平凉组/乌拉力克组和背锅山组是下古生界最重要和有效的烃源岩层。  相似文献   

16.
工程区受地质构造运动影响强烈,属高山峡谷地貌,地质条件复杂。发育面上湾崩坡积体,原设计方案采用明线通过,受特大暴雨、开挖等影响,地质条件发生变化;通过定性、定量分析得出在暴雨、地震工况下不满足安全要求。为规避其对公路的不良地质影响,改线采用隧道洞内小角度交岔口设计,将大断面交岔口段分为护壁区、减跨区、扩挖区,并分别进行开挖支护参数设计,结构简单经济易施工,并得以成功实施,希望本文为今后类似工程的处理提供一些经验和参照意义。  相似文献   

17.
强夯法施工实践中加固深度问题浅析   总被引:34,自引:4,他引:30  
张平仓  汪稔 《岩土力学》2000,21(1):76-80
在论述和分析强夯加固深度研究现状和影响因素的基础上, 建立量纲统一的加固深度公式: , 并对其运用范围进行了讨论。  相似文献   

18.
毛天鹏 《工程地质学报》2006,14(S1):269-271
在岩溶勘察工作实践中,结合工程实际情况,在勘察与复查工作的基础上,通过稳定性评价分析,进行危险性分区,将治理与勘察相结合,治理过程进一步揭露溶洞发育及分布状态,达到治理目的。  相似文献   

19.
顺层蠕动边坡变形破坏机理及稳定性动态分析   总被引:16,自引:5,他引:11  
本文以阜新海州露天矿边坡为例, 分析了边坡变形规律和破坏机制。在弱层流变试验的基础上, 建立了弱层流变力学模型, 通过确定加速蠕变阶段来临的极限应变量和应变速率, 建立了弱层长期强度的时间效应方程, 对于不同边坡工况进行了动态稳定性评价, 为采取抗滑措施控制蠕动边坡的变形破坏发展提供了科学依据。最后提出了一个边坡加速蠕变阶段来临的预测预报方法, 分析结果和实测资料较为一致。  相似文献   

20.
李振  任武刚  张爱军 《岩土力学》2006,27(Z1):183-188
结合某在建水库大坝的粘土直心墙和斜心墙两种坝型方案,分别在静力和地震力作用下对坝体在竣工期和运行期的变形、应力及坝体的稳定性进行了计算,从应力、变形和安全的角度对两种坝型的优劣进行了比较分析,得出了一些有益的结论,可以为类似工程及设计提供参考。  相似文献   

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