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在准噶尔盆地南缘上石炭统祁家沟组识别出2种生态类型的四射珊瑚动物群。一种是以小型单体无鳞板类型为主的Cyathoxonia动物群；另一种则是以发育鳞板类型为主的Caniniid–Clisiophyllid动物群。认为祁家沟组四射珊瑚动物群生活于中–高纬度地区温带气候条件下火山口周围类似于环礁的环境中。Cyathoxonia动物群生活于相对闭塞但与外海有连通的低能浅水礁湖（潟湖）环境中并且原地保存，Caniniid–Clisiophyllid动物群则生活于环礁向海一侧适于珊瑚生长的礁坪中–高能环境中。后者不断遭波浪侵蚀，在风暴和重力的作用下，沿着环礁陡峭的前缘斜坡以重力流的形式下滑，在正常浪基面之下的低能环境中保存下来。 相似文献
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《地质科技情报》2017,(1)
塔里木盆地西北缘阿合奇地区石炭系巴什索贡组研究程度较低,鲜有古生物化石的报道,其精确时代一直没有确定。在该套地层中发现四射珊瑚化石共计10属13种,床板珊瑚5属8种。其中四射珊瑚中主要分子有Kueichouphyllum,Palaeosmilia,Dibunophyllum,Arachnolasma,Lithostrotion,根据珊瑚的垂向分布,建立了Kueichouphyllum-Palaeosmilia-Dibunophyllum组合带,该组合带可与前人在华南地区早石炭世地层中建立的Yuanophyllum带进行对比,也能与邻区及中国其他地方相同时期的珊瑚组合对比,进而确定其精确时代为石炭纪密西西比亚纪维宪期至德坞期早期。对该珊瑚动物群的生物古地理研究表明,该动物群具明显的特提斯生物大区和中国北方大区的珊瑚分子特征,属二者的混生带。 相似文献
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新疆哈密地区早泥盆世珊瑚动物群及其地质意义 总被引：2，自引：0，他引：2
新疆哈密地区下泥盆统发育,南部图拉尔根地区下泥盆统为大南湖组,北部三道白杨沟地区为卓木巴斯套组。在大南湖组中共发现四射珊瑚2属5种,床板珊瑚7属12种,并建立四射珊瑚组合Syringaxon moriense和床板珊瑚组合Pseudofavosites giganteus;在卓木巴斯套组共发现四射珊瑚5属7种,床板珊瑚2属2种,并建立四射珊瑚组合Orthopaterophyllum junggarense和床板珊瑚组合Pachyfavosites junggarensis。通过珊瑚在地层中的分布及组合的时代对比,确定前者的时代为早泥盆世埃姆斯期早期,后者的时代为埃姆斯期中晚期。通过与国内外典型的早泥盆世埃姆斯期珊瑚动物群的对比,认为哈密地区的珊瑚动物具有典型的早泥盆世温带动物群特征,在生物古地理区系上属于北方大区准噶尔-兴安省。 相似文献
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滇东曲靖地区志留纪四射珊瑚的动物群特征及地层时代讨论 总被引：4，自引：0，他引：4
本文着重从四射珊瑚动物群的角度讨论了滇东曲靖地区志留系的地层划分及对比问题。并提出曲靖地区的中、晚志留世具有4个珊瑚化石组合。对部分四射珊瑚属种（其中包括9个新种,4个相似种和一个未定属种）进行了描述。 相似文献
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中国兴蒙—新疆北部及邻区中泥盆统发育，含丰富的动植物化石。根据门类生物群综合分析研究，将其古生物地理区划分出１个域，２个省，６个亚省（Ｉ旧世界域；Ｉ１哈萨克斯坦—蒙古—兴安省：Ｉ１１哈萨克斯坦—准噶尔亚省，Ｉ１２萨彦—阿尔泰亚省，Ｉ１３东蒙古—兴安亚省，Ｉ１４北天山来省；Ｉ２南天山省：Ｉ２１土尔克斯坦—阿赖亚省，Ｉ２２艾尔宾山—克孜勒塔格亚省）。哈萨克斯坦—蒙古—兴安省，以床板珊瑚类的土尔干槽珊瑚属广泛发育为主要特征；四射珊瑚以内板—角珊瑚动物群为代表；腕足类具明显的二分特征，早期属群与早泥盆世晚期特征相似，晚期以尖翼尖翼石燕动物群大量发育为主要特征；植物以原始鳞木植物群为特征。南天山省主要特征是全部为海相，没见陆相。床板珊瑚多为世界性分子，缺少土尔干槽珊瑚动物群分子；四射珊瑚以带珊瑚—魏得肯珊瑚动物群大量发育为特征；腕足类则以鹗头贝动物群大量发育为突出特征。此外，尚有丰富的层孔虫，它们与珊瑚多形成礁体。 相似文献
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云南西部施甸地区中泥盆世四射珊瑚 总被引：2，自引：0，他引：2
本文描述的四射珊瑚采自云南省西部施甸地区中泥盆世马鹿塘组及何元寨组。描述了马鹿塘组珊瑚5属5种,2个未定种,并建立1个珊瑚组合:Metrionaxon yunnanense-Neaxon inopinata组合,包括Metrionaxon yunnanense sp.nov.,M.sinense sp.nov.,Neason inopinata(Prantl),Neaxon sp.,Metriophyllum gracile Schluter,Barrandeophyllum?sp.,Amplexocarinia yunnanensisn sp.nov.等。该组合的时代为中泥盆世早期(Eife lian)。描述了何元寨组1属,1个亚种:Peripaedium planum planumBirenheide.本组时代为中泥盆世晚期。这一珊瑚动物群与我国华南区珊瑚动物群截然不同,而与欧洲珊瑚动物群非常相似。 相似文献
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对扬子区中奥陶世至晚志留世四射珊瑚已发表的属种进行全面清理和厘定。现统计扬子区中奥陶世至晚志留世四射珊瑚约有117个属,其中以晚奥陶世和早志留世珊瑚属数最多。117个属中至少有30个属最早出现在扬子区中、晚奥陶世和早志留世地层。因此,扬子区被认为是奥陶纪、志留纪四射珊瑚起源中心之一。完善和修订扬子区中奥陶世至晚志留世四射珊瑚组合序列,使地层时代划分上均与国际通行标准(统、阶)接轨。尤其对扬子区早志留世Rhuddanian晚期,Aeronian早、晚期以及Telychian早、晚期四射珊瑚组合的重新建立和细分。最新资料表明晚奥陶世观音桥四射珊瑚动物群不但有更多的北欧同期的珊瑚分子,而且还产有北美标准属种Salvadorea,Brachyelasmasubregulare等说明两者也存在一定的联系。扬子区早志留世(Llandovery)的众多四射珊瑚属均为世界广布的,但也有许多地方性属(约有22个,占总数的23·4%)。就珊瑚生物古地理关系,它与同期的西伯利亚、哈萨克斯坦和澳大利亚珊瑚群较密切。 相似文献
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新疆东昆仑山阿其克库勒地区下二叠统下部碧云山组,上部喀尔瓦组,两组均含珊瑚、(竹蜓)及腕足化石.对其中的四射珊瑚化石进行了描述.研究结果,该区早二叠世的珊瑚动物群属暖水型的Iranophyllum动物群.推测碧云山组相当栖霞组,喀尔瓦组相当茅口组. 相似文献
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本文通过对黔南、湘中下二叠统(包括链带:Sphoeruschwagerina
带,Panirina m带和misllr-na
带)各个岩相内四射珊瑚及其共生分子的数量统计,探讨了这两个地区本期内四射珊瑚的生态环境分异,并区分出了几个主要岩相中四射珊瑚动物群的典型面貌和特征性分子,为今后岩相古地理研究提供了重要证据。 相似文献
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Thierry Corrge 《Journal of Geochemical Exploration》2006,88(1-3):380
Human-induced pollution in coastal areas can significantly increase the concentration of some trace elements in the marine environment. In the tropics, scleractinian corals incorporate these trace elements in their living parts and skeleton. The potential of corals to monitor pollution through time is reviewed in this contribution. The strength and weakness of corals as pollution indicators are discussed, and a few examples are shown. Although some progress should be made in the understanding of the processes ruling the incorporation of trace elements in coralline aragonite, it is concluded that large environmental changes are well recorded by coral skeletons. 相似文献
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中国兴蒙—新疆北部及邻区早石炭世地层十分发育，动植物化石丰富。根据生物群综合分析，将该研究区归入哈萨克斯坦—西伯利亚域和特提斯域，并进一步划分为３个省，８个亚省。西伯利业省以管孔贝大量发育为特征，缺少大长身贝类，珊瑚不甚发育，植物少见，为安加拉植物群；哈萨克斯坦—蒙古—兴安省以管孔贝类和大长身贝类共同发育为突出特征，珊瑚较发育，但分区特征不明显，并有大量异珊瑚类，植物为安加拉植物群；塔里木北缘—西秦岭省以南方型生物群大量发育为主要特征，大长身贝类最为发育，缺少管孔贝类，珊瑚数量十分丰富，并有假乌拉珊瑚大量发育，植物以华夏植物群为主。早石炭世古生物地理分区与板块关系密切，晚泥盆世末，西伯利亚板块南移，与哈萨克斯坦板块汇聚，到早石炭世早、中期，两大板块基本上处于相近似的古生物地理环境，与此同时，塔里木板块逐渐北移，与哈萨克斯坦板块海水相通，致使哈萨克斯坦板块广大海域出现南、北动物群混生现象。早石炭世末，三大板块海域相连，除各地沉积和构造古地理环境尚有差异外，中石炭世开始，腕足类，类及珊瑚等动物群均显示出明显的一致性。 相似文献
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西藏雅鲁藏布江缝合带含有从砾石级到几十平方千米大小的二叠纪灰岩体，它们没有完整的地层层序，与围岩形成混杂或滑杂堆积，长期以来对其来源的解释存在争论。本文通过对灰岩体的动物群类型、古生物地理区系及其岩石学特征等方面进行研究和比较，认为雅鲁藏布江缝合线一带的二叠纪灰岩体总体上都呈现出冈瓦纳冷水型与华夏暖水型动物群混生特点，应形成于相同或类似的沉积环境。根据珊瑚、筵、腕足类等动物群大致分为与南方冈瓦纳大陆北缘内陆棚相动物群比较接近和与更靠近古赤道区的拉萨地块动物群较为接近两种类型，其时代从早二叠世晚期至长兴期不等。灰岩体主要由肉红色或灰色纯生物碎屑灰岩组成，不含或含有很少的陆源碎屑，均孤立地分散于中生代地层中，与围岩往往呈断层接触，断层带或灰岩夹层中经常有玄武岩或其他火山岩。因此，灰岩体可能为位于冈瓦纳大陆北缘外陆棚上小型碳酸盐台地或新特提斯洋最初裂解带上的海山型碳酸盐岩沉积，受后期印度-欧亚大陆板块碰撞作用而成为外来体夹于缝合带的其他海相沉积中。 相似文献
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Mineralogical, petrological and geochemical analyses of corals and associated skeletal limestones taken from three transects across the Late Quaternary raised coral reefs of the Huon Peninsula, Papua New Guinea, show that tectonic uplift can be related to the degree of subaerial diagenesis of the reefs. Where the uplift rate is high, Pleistocene corals frequently retain their aragonite mineralogy, even though the annual rainfall is relatively high. In contrast, similar age corals from low‐uplift areas are consistently altered neomorphically to calcite. The transformation of reef skeletal limestones shows a similar, but less pronounced, trend to the corals. Chemical analysis shows that the neomorphic calcite crystals of coral skeletons from the low‐uplift areas have relatively higher Sr and Mg concentrations, compared with those in high‐uplift areas. This may indicate that neomorphism of corals in the low‐uplift terraces takes place at a relatively higher rate and an earlier stage than that in the high‐uplift areas. The pattern of diagenesis of the Huon reefs can be explained by the effects of tectonic uplift on the regional hydrological regime. First, lower uplift rates allow a raised reef or any part of it to remain in the meteoric phreatic zone for a relatively long time. Second, river gorge slopes from low‐uplift regions have lower gradients and reef terraces in these areas have more extensive raised lagoon depressions than in high‐uplift areas. Thus, there is less runoff and consequently more extensive vadose percolation in the former areas. Third, the resulting low‐relief topography in low‐uplift areas prompts formation of soils on the terraces, and further increases the ability of interaction between coral reefs and formation water. 相似文献
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Recognizing extinction events and determining their cause at the Triassic/Jurassic (T/J) transition and near the Pliensbachian–Toarcian (Lower Jurassic) boundary is a field of growing interest. We provide arguments for these events through a literature based new evaluation of coral diversity from Triassic to Dogger and a new palaeobiogeographical map. The T/J extinction of corals is clearly related to the breakdown of reef environments. Origination curves show that Hettangian (the lowest Jurassic stage) was not only a survival phase but already rather a recovery phase. Post-extinction evolution of reefs and their survival only in the northernmost margin of the Tethys support the hothouse hypothesis for the T/J extinction event. During Pliensbachian, many new taxa appear, but mostly solitary corals, not really framebuilders. Many of these taxa do not occur anymore during the following stages. The new increase in diversity is related to the development of Bajocian (Middle Jurassic) reefs. 相似文献
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中国中、晚石炭世珊瑚化石丰富。各地珊瑚群特征不同,故可分出不同的珊瑚组合。华南地区珊瑚群以犬齿珊瑚目为主,出现大量地区性分子。 相似文献
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自泥盆纪埃姆斯期, 广西受陆内裂陷影响, 形成碳酸盐台地与台沟间列的构造格局.吉维特期开始, 六景及相邻的黎塘一带逐渐形成孤立台地的沉积背景.吉维特期, 六景剖面的民塘组为以竹节石为特色的礁前斜坡生态系, 尽管目前没有出露生物礁, 从礁前角砾岩可以恢复曾经存在的礁生态系.而黎塘一带塘家湾组为以珊瑚、层孔虫、腕足类为主要特色的台地生态系.弗拉斯期, 六景剖面的谷闭组则为少量珊瑚、腕足、层孔虫为特色的局限-半开放台地生态系.黎塘一带的桂林组仍为以珊瑚、层孔虫、腕足类为主要特色的台地生态系.六景、黎塘地区自法门期开始发生生态系突变, 六景剖面的融县组和黎塘一带的东村组发育藻礁丘或藻席为特色的藻生态系.该生态系的突变是F-F生物群集绝灭造成的生物类群突变的结果.生态系的特征也与吉维特-弗拉斯期烃源岩的形成、演化密切相关. 相似文献
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Soft corals and black corals are useful proxy tools for paleoceanographic reconstructions. However, most work has focused on deep-water taxa and few studies have used these corals as proxy organisms in shallow water (<200 m). To facilitate the use of stable nitrogen and carbon isotope (δ15N and δ13C) records from shallow-water soft coral and black coral taxa for paleoceanographic reconstructions, quantification of the inherent variability in skeletal isotope values between sites, across depth, and among taxa is needed. Here, skeletal δ15N and δ13C values were measured in multiple colonies from eleven genera of soft corals and two genera of black corals from across a depth transect (5-105 m) at two sites in Palau located in the tropical western Pacific Ocean. Overall, no difference in skeletal δ15N and δ13C values between sites was present. Skeletal δ15N values significantly increased and δ13C values decreased with depth. This is consistent with changes in isotope values of suspended particulate organic matter (POM) across the photic zone, suggesting that the primary food source to these corals is suspended POM and that the stable isotopic composition of POM controls the skeletal isotopic composition of these corals. Thus, to compare the isotope records of corals collected across a depth range in the photic zone, first order depth corrections of −0.013‰ m−1 and +0.023‰ m−1 are recommended for δ15N and δ13C, respectively. Average depth-corrected δ15N values were similar between black corals and soft corals, indicating that corals in these orders feed at a similar trophic level. In contrast, average depth-corrected δ13C values of black corals were significantly lower than that of soft corals, potentially resulting from metabolic processes associated with differing skeletal compositions among the orders (i.e., gorgonin vs. chitin based). Thus, a correction of +1.0‰ is recommended for black corals when comparing their δ13C-based proxy records to soft corals. After correcting for both the depth and order effects, variability in δ15N values among corals within each genera was low (standard deviation (SD) of the mean <±0.5‰), with the exception of Acanthorgorgia. The calculated SD of <±0.5‰ provides a first order guideline for the amount of variability that could be expected in a δ15N record, and suggests that these corals may be useful for δ15N-based paleoceanographic reconstructions. Variability in δ13C values among corals within genera was also low (standard deviation of the mean <±0.5‰) with the exception of Rhipidipathes and Villogorgia. Similar to δ15N, records from the genera studied here with the exception of Rhipidipathes and Villogorgia may be useful for δ13C-based paleoceanographic reconstructions. Overall, using the recommendations developed here, stable isotope records from multiple sites, depths and taxa of these corals can be more rigorously compared. 相似文献