| 湖南中部早石炭世腕足动物组合及几个问题的讨论 |
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| 引用本文： | 史晓颖.湖南中部早石炭世腕足动物组合及几个问题的讨论[J].现代地质,1988,2(3):342. |
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| 作者姓名： | 史晓颖 |
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| 作者单位： | China University of Geosciences, |
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| 摘 要： | 对湘中下石炭统腕足动物群的系统研究表明,该地区的腕足动物群自下而上可划分为6个组合带;1.“plicatifera” tenuiplicaia Hou Ass.（Lower Toumaisian）,2.Unispiri-fer tournaicensis（Kon.）—Eochoristites alatus（Ching）Ass.（Middle Tournaisian）; 3．Finosp-irifer shaoyangensis（Ozaki）—Marginatia vaughani（Muir--Wood）Ass.（Upper Tournasian）;4.（?）itiliproductus groberi（Kren.）——Pugilis hunanensis（Ozaki）Ass.（Lower Visean）;5.Para-kansuella subrhomboidea Sp·nov.——Kansuella——Gigantoproductus maximus （M’coy）Ass．（UpperVisean）;6.Latiproductus latissimus（Sow.）—Gigantoproductus edelburgensis（Phillips）Ass.（Lower Namurian or Serpukhovian）.这些腕足动物大部分是特提斯区广泛分布的属种,能够与西欧,苏联等地的同时期动物群进行很好的对比.对邵东组腕足动物的研究表明,该组的地质时代属晚泥盆世末期.其所产腕足动物能很好地与西欧及苏联同期地层的腕足动物比较.研究表明,在湘中杜内与维宪阶的生物地层界线,根据腕足动物,应置于Finospirifer-marginatia动物群和Delepinea subcarinata—Megachonetes zimmermanni组合带之间,而不是过去认为的Eochoristives—Martiniella动
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| 关 键 词： | 湘中 下石炭统 腕足动物群 生物地层 |
THE LOWER CARBONIFEROUS BRACHIOPOD FAUNA OF CENTRAL HUNAN PROVINCE AND THE DISCUSSION ON SOME RELATED STRATIGRAPHICAL PROBLEMS |
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| Shi Xiaoying.THE LOWER CARBONIFEROUS BRACHIOPOD FAUNA OF CENTRAL HUNAN PROVINCE AND THE DISCUSSION ON SOME RELATED STRATIGRAPHICAL PROBLEMS[J].Geoscience——Journal of Graduate School,China University of Geosciences,1988,2(3):342. |
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| Authors: | Shi Xiaoying |
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| Abstract: | The marine lower Carboniferous of central Hunan was very well deve-loped and is rich in brachiopod fossils. The present study shows that the bra-chiopods there can be biostratigraphically grouped into the following six assemblage zones, from the bottom upwards.
1. "Plicatifera" tenuiplicata Hou Ass. (Lower Tournasian); 2. Unispirifer tournaicensis (Kon.)-Eochoristites alatus (Ching) Ass. (Middle Tournais-ian); 3. Finospirifer shaoyangensis (Ozaki) -Marginatia vaughani (Muir-Wood) Ass. (Upper Tournaician); 4. Vitiliproductus groberi(Kren.)-Pugi-lis hunanensis (Ozaki) Ass. (Lower Visean); 5. Parakansella subrhombo-idea sp. nov.-Kansuella-Gigantoproductus submaximus (Bolk.) Ass. (Upper Visean); 6. Latiproductus latissimus (Sow.)-Gigantoproductus edelbergensis (Phillips) Ass. (Lower Namurian or Serpukhovian).
The brachiopods of the central Hunan are mostly the widespread forms in the Tethys and can be correlated quite well with those from Europe and the Soviet Union.
The study shows that the brachiopods of the Shaodong Formation are very similar to those from the Etroeungtian or its equivalents of Europe and Russia, the age of the shaodong Formation, therefore, can be determined as Devonian rather than Carboniferous as it was thought before.
The biostratigraphical boundary between the Yanguanian and the Datangian of the south China, based on the brachiopods, was put previously between the Eochoristites-Martiniella fauna and the Megachonetes zimmermani -Delepinea subcarrinata Ass. The present study shows that Finospirifer shaoyangensis-Marginalia vaughani Ass. represents the uppermost horizon of the Yanguanian in South China, while the Megachonetes zimmermani-Delepinea subcarinata Ass. can not be used as the lowerest assemblage zone of the Da-tangian, which may be only correlated with the Arundian of England.
By studying the brachiopods of the Zimenqiao Formation, the present author is quite sure that the deposits equivalent to the Serpukhovian are present in central Hunan and the Zimenqiao Fm. is composed of the Upper Visean and the Serpukhovian. The brachiopod fauna collected from this Fm. represents two different stages of development in the brachiopod evolution.
In this paper, one new genus Neoyanguania,with type-species N. quadrata sp.nov. and three new species Mesoplica shaodongensis, Marginatia multispinosa and Neoyanguania quadrata have been described.
Genus Neoyanguania gen. nov.
Type-species..Neoyanguania quadrata gen. et sp.nov.
Diagnosis: Shell medium, elongated, geniculated, tail long;both valves no interareau, no teeth in vental valve;ventral valve ornamented with irregular rugae posteriorly and with irregular Tines anteriorly, spines in a row along cardinal margin and in group at ears. Dorsal valve concaved slightly, geniculated anteriorly, no ornaments.
Cardinal process trilobated, middle lobe notched slightly;no ridges along cardinal margin, medium ridge long, about 2/3 of posterior valve and notched posteriorly;adductor muscle scars dendritic, two short lateral ridges located posterior to the scars, about 45 degree to meddle ridge; brachial ridges ear-like, enveloping two oval elevations.
Age and Distribution:Late Tournaisian, Hunan province, south China.
Comparision: The new genus is mostly similar to Yanguania Yang 1978, but the latter has narrow interareas on both valves and teeth in ventral valve, the cardinal process of Yanguania is bilobated; cardinal ridges are present, along the cardinal margin, adductor muscle scars are very small and simple. Semiproductus Boblitschenko 1956 is also similar to the new genus, but it has clear cardinal ridges along the posterior margin, no lateral short
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:idges located at posterior to the muscle scars. It is different from the new genus in exteriors. |
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| Keywords: | : Central Hunan province Lower Carboniferous braehiopodfauna biostratigrphy |
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