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1.
Volcanic tuff deposits near Daohugou village, Ningcheng County of Inner Mongolia have yielded many wellpreserved fossils. Here we briefly introduce our recent findings of invertebrates from the Daohugou fauna: mainly insects, conchostracans, anostracans, and spiders. The age of the Daohugou fauna is considered to be Middle Jurassic on the basis of an analysis of various invertebrates especially insects and conchostracans, showing strong similarities to the Yanliao fauna of north China and the Karatau fauna of Kazakhstan.  相似文献   

2.
SHRIMP U-Pb zircon dating was carried out for the Daohugou Biota near Ningcheng of Inner Mongolia and for lavas overlying or underlying sala-mander-bearing strata at Reshuitang in Lingyuan of West Liaoning. The results suggest that the Dao- hugou Biota occurred at an interval from 168 Ma to 164―152 Ma. Both the Daohugou Biota and the salamander-bearing fossil assemblage are the same biota and thus developed from 168 to 152 Ma, i.e. from late Middle Jurassic to the early Late Jurassic. The Daohugou Biota-bearing rocks, resting on the Jiulongshan Formation in disconformity and being overlain in unconformity by Late Jurassic Tuchengzi Formation and Early Cretaceous rocks containing the Jehol Biota, are mainly composed of volcanic-sedi- mentary rocks in a normal sequence. It is recom- mended that the Daohugou Biota and the related stratigraphy should be correlated with the Tiaojishan Formation (Lanqi Formation in West Liaoning) or its synchronous rocks. It is suggested that the Dao- hugou Biota and the Jehol Biota would be neither taken into one biota nor considered as the earliest elements of the Jehol Biota. The Daohugou Biota and the related rocks and the Yixian Formation were respectively formed in different periods of volcanic-sedimentary tectonics.  相似文献   

3.
Stratigraphy and age of the Daohugou Bed in Ningcheng, Inner Mongolia   总被引:6,自引:0,他引:6  
Recent fieldwork has extended the distribution of the Daohugou Bed deposits from the Daohugou Village to its several neighboring areas. The fossil-bearing Daohugou deposits uncomformably overlie complex bedrocks, and comprise three major parts. The red shales in the lower part were misidentified as belonging to the Tuchengzi Formation. Field excavation has indicated that the shales of upper part of the bed are the major fossil-bearing horizon. Due to strong tectonic activities, sediments were often folded with the sequences inverted in the region. Some newly recognized contacts between the Daohugou Bed and the volcanic rocks showed that the ignimbrite of the Tiaojishan Formation (159-164 Ma) underlies the Daohugou deposits, rather than overlying the latter as previously proposed. Thus, the age of the Daohugou deposits should be younger than the age of the ignimbrite, and thus it was incorrect to correlate the Daohugou Bed with the Middle Jurassic Jiulongshan Formation. Although biostratigraphic studies based on conchostracans and insects support a Middle Jurassic-early Late Jurassic age for the Daohugou deposits, vertebrate fossils such as Liaoxitriton, Jeholopterus and feathered maniraptorans show much resemblance to those of the Yixian Formation. In other words, despite the absence of Lycoptera, a typical fish of the Jehol Biota, the Daohugou vertebrate assemblage is closer to that of the Early Cretaceous Jehol Biota than to any other biota. We propose that the Daohugou fossil assemblage probably represents the earliest evolutionary stage of the Jehol Biota based on both vertebrate biostratigraphy and the sedimentological and volcanic features which suggest the Daohugou deposit belongs to the same cycle of volcanism and sedimentation as the Yixian Formation of the Jehol Group.  相似文献   

4.
A zircon U-Pb age of (916±16) Ma is measured for grantoid gneisses from the Yagan-Onch Hayrhan metamorphic core complex and represents the crystallization age of the grantoid magma. This age provides evidence for the existence of the South Mongolian microcontinent, which is consistent with the analysis of the regional geology.  相似文献   

5.
Using the data of ULF/ELF electric and magnetic wave field measured on board AUREOL-3 satellite, by the high resolution spectral analyses, one obtained for the first time the spatial measurement on the evidence of ionospheric alfvén resonator. The result of the measurement indicates that there are 7. 8 Hz for fundamental frequency, 14 Hz for second resonant frequency in the electric field component, and also the spectral resonance structure, but not in the magnetic vertical component for the magnetic field components.  相似文献   

6.
梁玉红 《科技信息》2013,(17):241-241,297
As the unique heritage of culture,humor has its own characteristics.Whether the translation of verbal humor can convey the original culture accurately is vital.In this thesis,the author will make a study on the translation of verbal humor in Yu Hua 's novel Brothers from the perspective of Functional Equivalence Theory,which examines whether the translation version reproduces the style of the original text accurately and adequately.  相似文献   

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irectly the development of regional economy,forefront production and common life of the people.Its education focuses more or less on the teaching,training and research on t  相似文献   

9.
The Mesoproterozoic Changcheng System is widely distributed in the North China Craton. Determining its time of deposition and sources is important to understand the Precambrian crustal evolution of the North China Craton. This paper suggests age distribution patterns for detrital zircons from clastic sediments of the Changcheng System in the Ming Tombs area, Beijing. Samples of feldspar-bearing sandstone (CHc-2) and pure sandstone (CHc-9) were collected from the Changzhougou Formation, which constitutes the basal part of the Changcheng System. Detrital zircons show an age range from 2.35 to 2.60 Ga. However, sample CHc-9 in the upper Changzhougou Formation also contains some zircons with ages of 1.9-1.8 Ga and 2.3-2.1 Ga. The age patterns lead to the following conclusions: (1) Most of the detrital material came from a source area composed predominantly of -2.5 Ga continental crust of the North China Craton; (2) 1.9--1.8 Ga reflects the age record of Palaeoproterozoic continent-continent collisional event in the North China Craton; and (3) the oldest age for deposition of the Changcheng System is 1.8 Ga.  相似文献   

10.
Large-scale granitic plutons are exposed in the Ergun block in the northern part of the Da Hinggan Range, but their emplacement age and petrogenesis remain unknown. Of these plutons, the Tahe pluton is composed mainly of porphyritic syenogranite and monzogranite, with minor hornblende alkali feldspar granite and gabbro, which have affinities to post-orogenic granitoids. Laser-ablation Inductively Coupled Plasma Mass-spectroscope (LA-ICP-MS) analysis shows that the major rock types of the Tahe pluton formed at 494- 480 Ma ago, indicating its emplacement in the Early Paleozoic. It is concluded, therefore, that the collision between the Ergun and the Xing'an blocks ended in Early Paleozoic. Considering the geochronological data of the plutons in the adjacent areas, the Early Paleozoic evolutionary history of the Ergun block is similar to the central Mongolia and the Tuvino blocks in Mongolia, and the Ergun block should be a part of the accretionary continental margin in the southern Siberian Craton.  相似文献   

11.
贾真真 《科技信息》2009,(18):127-128
This essay analyzes the famous French writer's novel Candide from the perspective of gender roles. It introduces some literary terms related to gender, and explains my understanding of the gender roles some characters have played from the aspects of wars and masculinity, Candide and masculinity, female characters and femininity, and Candide related to feminism.  相似文献   

12.
Evidence for the existence of primitive life forms such as lichens and fungi can be based upon the formarion of oxalates. Oxalates are most readily detected using Raman spectroscopy. A comparative study of a suite of natural oxalates including weddellite, whewellite, moolooite,humboldtine, glushinskite, natroxalate and oxammite has been undertaken using Raman spectroscopy. The minerals are characterised by the Raman position of the CO stretching vibration which is cation sensitive. The band is observed at 1468 cm^-1 for weddellite, 1489 cm^-1 for moolooite, 1471cm^-1 for glushinskite and 1456 cm^-1 for natroxalate. Except for oxammite, the infrared and Raman spectra are mutually exclusive indicating the minerals are bidentate. Differences are also observed in the water OH stretching bands of the minerals. The significance of this work rests with the ability of Raman spectroscopy to identify oxalates which often occur as a film on a host rock. As such Raman spectroscopy has the potential to identify the existence or pre-existence of life forms on planets such as Mars.  相似文献   

13.
Fission track (FT) ages of apatite and zircon from four granite batholiths from Lhasa and Shannan areas are measured.The FT ages of apatite range from 3.2±8.3 Ma, corresponding to the uplift rates of 0.12±0.20 mm·a~(-1) during this period. The upliftheight is 580m, showing that there is not large-scale rapid uplifting in southern Tibet from 3.2 to 8.3 Ma. The zircon FT ages of Lhasabatholith are 25.9±1.7 and 32.7±2.8 Ma, yielding an uplift rate of 0.08 mm·a~(-1) between 26 and 33 Ma. Combining this work withother studies, it is suggested that the average uplift rate in southern Tibet is low from the time of collision between India and Asian conti-nents to ~3Ma. The uplift of Tibetan Plateau seems to have finished in multi-stage processes with varied rates.  相似文献   

14.
After the disintegration of the pro-Sinian System, the choice of the stratotype section of the newly established Nanhua System and determination of its lower boundary age have been one of the most important problems in Neoproterozoic stratigraphy[1—3]. In the Yangtze Gorge area in Yichang of Hubei Province where the standard section of the pro-Sinian System is located, the newly established Nanhua System consists only of the Nantuo formation (tillite) and the Liantuo Formation with tuf-…  相似文献   

15.
Brain evolution is one of the most important aspects of human evolution,usually studied through endocasts.Analysis of fossil hominid endocasts allows inferences on functional anatomy,physiology,and phylogeny.In this paper,we describe the general features of endocast studies and review some of the major topics in paleoneurology.These are:absolute and relative brain size evolution;brain shape variation;brain asymmetry and lateralization;middle meningeal vessels and venous sinuses;application of computed tomography and virtual imaging;the history of Chinese brain endocast studies.In particular,this review emphasizes endocast studies on Chinese hominin fossils.  相似文献   

16.
The sedimentary strata and deposition ages of the “old red sand” distributed along the coasts of south Fujian and west Guangdong are determined by lithostratigraphy, magnetic stratigraphy and earth chemistry combined with TL, ESR and14C-dating techniques. The research shows that the “old red sand” was aeolian sediments deposited from 55 400 to 9 000 aBP, the last glacial period in the middle and later age of Late Pleistocene. Most of them deposited in two periods of 56-42 ka and 30-10 ka. The “old red sand” deposited in the period of 30-10 ka, the later Würm glacier substage (Q 3 3 ), developed on the largest scale with the widest distribution.  相似文献   

17.
学习胡锦涛在庆祝中国共产党成立90周年大会上的讲话,借鉴延安整风的历史经验,在全党范围内,加强马克思主义理论学习和党性修养,克服"精神懈怠"的危险;大兴调查研究及理论联系实际之风,提升党的执政能力;坚持密切联系群众的作风及以人为本的执政理念,以防"脱离群众";从领导干部做起,进行批评与自我批评,敲响"消极腐败"的警钟。通过加强党的建设,保持党的先进性和纯洁性,提高党的执政能力,巩固党的执政地位。  相似文献   

18.
Brain evolution is one of the most important aspects of human evolution, usually studied through endocasts. Analysis of fossil hominid endocasts allows inferences on functional anatomy, physiology, and phylogeny. In this paper, we describe the general features of endocast studies and review some of the major topics in paleoneurology. These are: absolute and relative brain size evolution; brain shape variation; brain asymmetry and lateralization; middle meningeal vessels and venous sinuses; application of computed tomography and virtual imaging; the history of Chinese brain endocast studies. In particular, this review emphasizes endocast studies on Chinese hominin fossils.  相似文献   

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