共查询到17条相似文献，搜索用时 375 毫秒
1.
四川龙门山中段早埃姆斯期生态地层及古环境新认识 总被引：1，自引：0，他引：1
本文讨论了龙门山中段白石 苟家大型飞来峰内早埃姆斯期的甘溪组分布及岩性特征。首次将甘溪组划分为两个生态地层单元 ,即Anetoceras Plectodonta群落及Dicoelostrophia Eosophragmophora群落 ;指定了群落的层型剖面 ,分析了各群落的生物组成、丰富度、生态特征及生态环境。认为区内早埃姆斯期属深水陆棚至深水盆地沉积环境 ,为龙门山区泥盆纪沉积盆地的性质和演化提供了新资料。 相似文献
2.
Orientospirifer正在四川龙门山谢家湾组的发现 总被引：1，自引：0，他引：1
Ｏｒｉｅｎｔｏｓｐｉｒｉｆｅｒ正在四川龙门山谢家湾组的发现Ｏｒｉｅｎｔｏｓｐｉｒｉｆｅｒ一属系侯鸿飞、鲜思远（１９７５）创立，其模式种产于广西下泥盆统那高岭组。该属是我国华南早泥盆世的一个土著分子，包含有Ｏｒｉｅｎｔｏｓｐｉｒｉｆｅｒｎａｋａｏｌｉｎ... 相似文献
3.
文章对早石炭世石燕科Ｆｕｓｅｌｌａ，Ｕｎｉｓｐｉｒｉｆｅｒ，Ｐｒｏｓｐｉｒａ，ｉｍｂｒｅｘｉａ，Ｆｉｎｏｓｐｉｒｉｆｅｒ，Ｃｅｌｓｉｆｏｍｉｘ，Ｇｒａｎｄｉｓｐｉｒｉｆｅｒ，Ｗａｒｓａｗｉａ，Ｇｙｐｏｓｐｉｒｉｆｅｒ，Ｆｒｅｃｈｅｌｌａ，Ｎｅｏｓｐｉｒｉｆｅｒ，Ｂｒａｃｈｙｔｈｙｒｉｎａ，Ｇｕｉｚｈｏｕｓｐｉｒｉｆｅｒ１３个属的分类位置、相互之间的区别特征和演变规律进行了讨论；在此基础上，进而讨论 相似文献
4.
四川龙门山中段早埃姆斯期生态地层及古环境新认识 总被引：1，自引：0，他引：1
本文讨论了龙门山中段白石－苟家大型飞来峰内早埃姆期期的甘溪组分及岩性特征。首次将甘溪组划分为两个生态地层单元,用Ａｎｅｔｏｃｅｒａｓ－Ｐｌｅｃｔｏｄｏｂｏｎｔａ群落及Ｄｉｃｏｅｌｓｔｒｏｐｈｉａ－Ｅｏｓｏｐｈｒａｇｍｏｐｈｏｒａ群落;指定了群落的层型剖面,分析了各群落的生物组成,丰富度,生态特征及生态环境。 相似文献
5.
修水地区志留系殿背组和坟头组腕足类化石自下而上分为：Ｍｅｒｉｃｉｅｌｌａ－Ｚｙｇｏｓｐｉｒａｅｌｌａ组合;Ｎａｌｉｖｋｉｎａ－Ｓｔｒｉｉｓｐｉｒｉｆｅｒ组合;Ｘｉｎａｎｏｓｐｉｒｉｇｅｒ－Ｖａｌｄａｒｉａ组合,与川鄂等地志留纪腕足类生物地层带能很好地对比。通过对腕足类生态分异,共生分子及沉积相的研究,识别出４种腕足类生态类型,确认两组为一套中陆架－内陆架沉积。 相似文献
6.
本文对湖南孟公坳组Ｃｙａｏｐｈｒｅａｔｉｓ－Ｃｈｏｎｅｔｉｐｕｓｔｕｌａ群落和刘家塘组ＦｉｎｏｓｐｉｒｉｆｅｒＭａｒｇｉｎａｔｉａ群落进行了生态演替过程分析．研究表明,化石群落的生态演替体现了当时生活在相同或相似环境中若干生物群落的动态发展．化石群落演替过程的形成和保存与生活环境和沉积环境有直接的关系．分析化石群落的演替过程可以恢复当时沉积环境的变化幅度和变化趋势,有助于研究群落与环境在时空上的变化,有利于提高地层划分和对比的精度． 相似文献
7.
北山地区早二叠世“哲斯动物群”特征 总被引：2，自引：0，他引：2
北山地区下二叠统以碎屑岩为主，夹碳酸盐岩及火山岩，属活动型滨海－浅海沉积。在弱水以东的巴丹吉林地区称为埋汗哈达组和阿其德组，由下而上共识别为４个腕足群落：（１）Ｓｐｉｒｉｆｅｒｅｌｌａ－Ｋｏｃｈｉｐｒｏｄｕｃｔｕｓ群落；（２）Ｅｌｉｖａ－Ａｌｅｘａｎｉａ群落；（３）Ｐａｒａｍａｒｇｉｎｉｆｅｒａ－Ｔｒａｎｓｅｎｎａｔｉａ群落；（４）Ｗａａｇｅｎｏｃｏｎｃｈａ－Ｌｉｎｏｐｒｏｄｕｃｔｕｓ群落。在弱水以西的马鬃山地区，划分为双堡塘组和金塔组，原定菊石滩组可能应归并于双堡塘组，仅上述的第１个Ｓ．－Ｋ．群落较发育。据生物对比，本区下二叠统的沉积时代，大致相当于华南的栖霞期至茅口期。上述群落具“哲斯动物群”特征，但与哲斯地区不同的是，本区缺失科而富含菊石。其总貌仍属北极海冷水型动物群。 相似文献
8.
丁旋 《吉林大学学报(地球科学版)》1997,(3)
吉林南部晚寒武世凤山期地层出露良好，三叶虫化石丰富，是进行化石群落古生态研究的理想地区。通过埋藏学分析、化石形态功能分析、围岩沉积学研究，在本区建立了六个底栖三叶虫化石群落，自下而上为Ｐｔｙｃｈａｓｐｉｓ－Ｔｓｉｎａｎｉａ群落，Ｑｕａｄｒａｔｉｃｅｐｈａｌｕｓ群落，Ｃｈａｎｇｉａ群落，Ｃａｌｖｉｎｅｌａ群落，Ｍｉｃｔｏｓａｕｋｉａ群落，Ｒｉｃｈａｒｄｓｏｎｅｌａ群落，结合化石群落及其赋存岩性特征，分析本区凤山期沉积环境由前滨－近滨相带渐变为浅海陆棚相带，海水逐渐加深。 相似文献
9.
赵兵 《沉积与特提斯地质》2000,20(4):89-96
龙门山中段白石－苟家地区泥盆纪地层十分发育,根据多条剖面的岩石特征,基本层序,生态环境等所反映的相对海平面变化规律,将区内以泥盆纪为主的沉积地层划分为九个层序,并归之于４个层序组,详细分析了每个层序各体系域的特征并建立了层序地层格架。区内泥盆系总体为一套向上弯浅的沉积层序,埃姆斯早期存在深水盆地环境,中泥盆世早期盆地呈西深东浅的沉积构造格局。 相似文献
10.
姜建军 《沉积与特提斯地质》1997,(21)
滇西保山地区早石炭世生物地层研究姜建军（地质矿产部国际合作司）本文研究了滇西保山早石炭世腕足动物群的分布及特征。笔者根据腕足动物纵向的分布规律，建立了三个腕足类组合，它们分别是岩关阶渔洞组Ｕｎｉｓｐｉｒｉｆｅｒｓｔｒｉａｔｏｃｏｎｖｏｌｕｔｕｓ－Ｍａ... 相似文献
11.
本文分析了Li群落和C-H群落的生物组成,分异度,相对丰富度,生活方式及空间分布等特征;讨论了湘中晚泥盆世群落的演替和取代规律及其空间对比,进一步强调了生物与环境的密切关系及其在地层学上的意义。 相似文献
12.
陈源仁 《沉积与特提斯地质》1990,10(1):19-27
四川龙门山区的泥盆系以其发育完整、出露良好、厚度巨大、化石丰富、地层连续、层序清楚等特点驰名中外,尤其是北川桂溪—甘溪—沙窝子剖面的研究程度不断提高,已成为世界泥盆系分统分阶研究中不可多得的系统剖面。但长期以来对龙门山区泥盆纪时的古地理特点和海侵方向等关键问题,始终没有得到明确的、肯定的和统一的认识。本文就目前作者的认识,提出一些看法以供大家讨论。一、四川龙门山区泥盆系的特点为探讨龙门山区泥盆纪时海侵方向,海水通道,就有必要首先介绍龙门山区泥盆系空间分布格局、生物群特点及其与邻区的关系等,以作为分析的依据。 (一)龙门山区泥盆系的空间分布格局 相似文献
13.
CHEN Yuanren LI Xianghui College of Earth Sciences Chengdu University of Technology Chengdu Sichuan State Key Laboratory of Oil-Gas Reservoir Geology Exploitation Chengdu University of Technology Chengdu Sichuan 《《地质学报》英文版》2005,79(3):313-324
Twelve paleocommunities dominated by benthic brachiopod are recognized in the Givetian-Frasnian stages of the Devonian in the Longmenshan area, southwestern China, in which two kinds of brachiopod community replacement are classified. One is the abrupt replacement, represented by abrupt alternation between the Leiorhynchus community and Zhonghuacoelia-Striatopugnax community in the Frasnian Tuqiaozi Formation. The other is the gradual one, developed in the Givetian Guanwushan Formation, which had been completed by the shift of the Independatrypa lemma-Uncinulus heterocostellis-Emanuella takwanensis community via the SinospongophyUum irregulare-Pseudomicroplasma fongi community to the Clathrocoilona spissa-Hexagonaria composite reef community. According to analyses of the paleocommunities, either the abrupt or gradual paleocommunity replacement of the Middle-Upper Devonian in the Longmenshan area is suggested as a response to the 5th-order sea level fluctuation due to the replacements of the paleocommunities in a tracts-system of depositional sequence. It is supposed that changes of paleocommunity diversity,one of the results of paleocornmunity replacement, are depended on the range and magnitude of sea level fluctuation, but there is not a linear relationship between them. Furthermore, a suggestion is proposed that the concept of paleocommunity succession seem to be abandoned in the paleocommunity analysis because it almost never be practiced to recover the information of community succession in the geological record at present. 相似文献
14.
Céline Ducassou Michel Ballèvre Hubert Lardeux Cécile Robin 《International Journal of Earth Sciences》2011,100(7):1451-1475
The Palaeozoic sediments from the Mauges Unit (Armorican Massif, France) are the best-preserved pre-orogenic sequences belonging
to the Upper Allochthon. Two coherent sequences are identified. The southern unit (Chateaupanne Unit) represents the cover
of the Proterozoic basement and consists of Ordovician sediments unconformably overlain by Emsian carbonates followed by Emsian
to earliest Eifelian immature sandstones. The northern unit (Tombeau Leclerc Unit) consists of an Hirnantian to Emsian condensed
sequence, in reverse position, that has been thrust over the southern unit. The Devonian unconformity is interpreted as evidence
for an Early Devonian extension, recorded by normal faults affecting both the Early Devonian limestones and the underlying
Ordovician series. This crustal extension, recorded here for the first time, is possibly related to the opening of a back-arc
basin (Saint-Georges-sur-Loire) associated with the subduction of an ocean located further south (Galicia-Brittany-Massif
Central Ocean). 相似文献
15.
Paul Gonez Hung Nguyên HuuPhuong Ta Hoa Gaël ClémentPhilippe Janvier 《Journal of Asian Earth Sciences》2012,43(1):51-63
Several outcrops of the Late Silurian and Devonian of the Ngoc Vung Series, northern Vietnam, yielded plant remains. The Late Silurian localities delivered the earliest known flora of the South China block. Although the fossils are fragmentary, they complement our knowledge about the global composition of the flora. The major components of the flora are plants with dichotomous habit and terminal bivalvate sporangia, which are close relatives to zosterophylls, and zosterophylls. Plants with possible euphyllophyte affinities and bryophytes are occasionally present. This floral composition is similar to that of the rich, younger South China block assemblages from the Posongchong and Xujiachong Formations of China, considered Pragian in age. The South China block flora is therefore likely to have been dominated by zosterophylls and pre-zosterophylls at least from the Late Silurian to the Pragian (i.e. a 20 million years long period). It also strengthens the hypothesis that more derived plants were present on eastern Gondwana earlier that elsewhere, in the first steps of tracheophyte evolution. The Devonian localities of the Ngoc Vung Series delivered a thick fibrous stem fragment and a basal euphyllophyte. These latter plant remains provide some stratigraphic data. The large stem fragment is consistent with an Eifelian age for the Duong Dong Formation (part of the Ngoc Vung Series), as suggested by the brachiopod fauna. The accompanying basal euphyllophyte displays a combination of characters (axes 3-4 mm wide and lateral branchings) that is also consistent with an Eifelian age, but possibly more characteristic of the Emsian flora. It is therefore suggested that the stratigraphic range of the Duong Dong Formation might be extended down to the Emsian. 相似文献
16.
论大槽子组和碳山坪组的地质时代 总被引：2，自引：0，他引：2
《地层学杂志》1989,(2)
<正> 大槽子剖面位于云南省宁蒗县城以南约25km处,是原云南省第二区域地质测量队于70年代发现和测制的,并对泥盆纪地层作了划分、对比和命名。由下而上分别是大瓜坪组、大槽子组、碳山坪组、烂泥箐组和干沟组,其中将大瓜坪组划归早泥盆世晚期,大槽子组和碳山坪组分别与艾菲尔阶和吉维特阶对比,烂泥箐组和干沟组分别与弗拉阶和法门阶对应。大槽子剖面地处泥盆系青藏区和华南区交界处(王钰等1982),且地层发育较 相似文献
17.
吉林省泥盆系层序的新划分 总被引：3，自引：0，他引：3
<正> 吉林省泥盆系露头比较零星,地层资料也比较少。1966年李东津等在永吉县黄榆屯西王家街发现泥盆纪珊瑚,长春地质学院等命名为王家街组。分布在磐石县呼兰镇至黑石镇一带的变质岩系呼兰群经郭鸿俊的研究被划为志留—泥盆系,但至今仍有争议。笔者通过珊瑚化石的研究,肯定了原定为志留系的二道沟灰岩为早泥盆世早期地层,又在王家 相似文献