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1.
Sheng  J. C.  Chang  L. H. 《古生物学报》1958,(2):210-214
The present brief communication is published in order to demonstrate a small fusulinid faunafound from the Changhsing limestone at the type-locality in the Changhsing coal fields, some 25km northwest of the Changhsing city, northeastern Chekiang Province by W. S. Wu, H. L. Liang,L. H. Lu and the writers in a field trip to Changhsing in the spring of 1956. Although thelimestone and its fauna of this region have been the subject of some studies, the fusulinids have notyet been described.  相似文献   

2.
该文记述了福建大田崆峒山晚二叠世长兴组牙形刺化石4属7种,在长兴组上部建立了Neogondo-lella changxingensis-N.deflecta-N.subcarinata组合带,着重分析了崆峒山长兴组牙形刺的分布规律和组合特征。认为该组合可与浙江煤山长兴阶上部牙形刺组合带对比;福建大田崆峒山长兴组仅大致相当于我国华南长兴阶或浙江煤山长兴组的中、上部,其下伏的原属翠屏山组海相碎屑岩应划归长兴阶。  相似文献   

3.
Summary The roles of Permian colonial corals in forming organic reefs have not been adequately assessed, although they are common fossils in the Permian strata. It is now known that colonial corals were important contributors to reef framework during the middle and late Permian such as those in South China, northeast Japan, Oman and Thailand. A coral reef occurs in Kanjia-ping, Cili County, Hunan, South China. It is formed by erect and unscathed colonies ofWaagenophyllum growing on top of one anotherin situ to form a baffle and framework. Paleontological data of the Cili coral reef indicates a middle to late Changhsing age (Late Permian), corresponding to thePalaeofusulina zone. The coral reef exposure extends along the inner platform margin striking in E-S direction for nearly 4 km laterally and generally 35 to 57 m thick. The Cili coral reef exhibits a lateral differentiation into three main reef facies; reef core facies, fore-reef facies, and marginal slope facies. The major reef-core facies is well exposed in Shenxian-wan and Guanyin-an sections where it rests on the marginal slope facies. Colonial corals are dispersed and preserved in non-living position easward. Sponges become major stabilizing organisms in the eastern part of Changhsing limestone outcrop in Kanjia-ping, but no read sponge reefs were formed. Coral reefs at Cili County in Human are different distinctly from calcisponge reefs in South China in their palaeogeography, lithofacies development, organic constitutuents, palaeoecology and diagenesis. The Cili coral reef also shows differences in age, depositional facies association, reef organisms and diagenesis from coral reefs in South Kitakami of Japan, Khorat Plateau of Thailand, and Saih Hatat of Oman. Although some sponge reefs and mounds can reach up to the unconformable Permian/Triassic boundary, coral reef at Kanjia-ping, Cili County, is the latest Permian reef known. This reef appears to had been formed in a palaeoenvironment that is different from that of the sponge reefs and provides an example of new and unique Permian reef type in South China, and could help us to: 1) understand the significance of colonial corals in Permian carbonate buildups; 2) evaluate the importance of coral community evolution prior to the collapse of reef ecosystems at the Permian/Triassic boundary; 3) better understand the effects of the biotic extinction events in Palaeotethys realm; 4) look for environmental factors that may have controlled reefs through time and space, and 5) provide valuable data for the study of Permian palaeoclimate and global evolutionary changes of Permian reefs and reef community.  相似文献   

4.
Introduction The specimens dealt with here were sent by the geological parties in 1956 to the writer forstudy. They were collected from the Carboniferous and Permian of eight provinces: Szechuan,Hupeh, Hunan, Kiangsi, Kwangsi, Sinkiang, Kansu and Inner Mongolia. Eleven species in fivegenera are described and studied; they are Scenodiscus undulatus(sp. nov.), S. granularis(sp.  相似文献   

5.
广西南部二叠纪长兴期放射虫动物群   总被引:4,自引:2,他引:2  
广西南宁南部柳桥区的长兴组上部硅质岩中存着精美的长兴期晚期放射虫动物群,共有24属39例,其中3个新种,其中以Latentifistularia最为常见,其次是Albaillllidae和Entactiniidae,属于二叠纪晚期的Neoalbaillella optima组合。半生生物有有孔虫、海绵骨针、腕足动物等。多数属在接近二叠纪-三叠世界线附近消失,但生物群中已出现少量三叠纪分子。  相似文献   

6.
The following new species are described: Commiphora arenaria from bushland on sand in south-central Somalia, C. gardoensis from limestone slopes in the Qardho area in north-eastem Somalia, C. stellatopubescens from bushland on limestone outcrops or stony ground in the Hiiraan Region in south-central Somalia, C. spinulosa from limestone rocks on the escarpment along the Gulf of Aden in northeastern Somalia, C. lobatospathulata from bushland on sand in central and south-central Somalia, C. quercifoliola from bushland on shallow soil over limestone near Eil in north-eastem Somalia, C. chiovendana from bushland in northern and central Somalia, C. multifoliolata from limestone hills and ridges in south-westem Somalia, C. murraywatsonii from limestone outcrops near Hobyo in central Somalia, and C. kucharii from bushland on shallow soils over limestone in central and southern Somalia.  相似文献   

7.
Many vascular plant species are unable to colonize calcareous sites. Thus, the floristic composition of adjacent limestone and acid silicate soils differs greatly. The inability of calcifuge plants to establish in limestone sites seems related to a low capacity of such plants to solubilize and absorb Fe or phosphate from these soils. Until now, mechanisms regulating this differing ability of plants to colonize limestone sites have not been elucidated. We propose that contrasting exudation of low-molecular organic acids is a major mechanism involved and show that germinating seeds and young seedlings of limestone plants exude considerably more di- and tricarboxylic acids than calcifuges, which mainly exude monocarboxylic acids. The tricarboxylic citric acid is a powerful extractor of Fe, and the dicarboxylic oxalic acid a very effective extractor of phosphate from limestone soils. Monocarboxylic acids are very weak in these respects. The study is based on ten species from limestone soils and ten species from acid silicate soils.  相似文献   

8.
论五峰页岩   总被引:9,自引:1,他引:8  
Y.T.HOU 《古生物学报》1954,(2):246-264
一.引言五峯页岩是一个很薄的地层单位,分布在长江流域,介於奥陶系与志留系的交界处。由岩性上看来,和上面的下志留纪地层同为黑色笔石页岩,非常相似,很像同一的建造;但是所含的化石,许多是上奥陶纪的标准化石。因此,多少年来五峯页岩的时代问题一直未能解决。有人认为五峰页岩应当是下志留系的底部,也有人认为应当是上奥陶系的顶部。由於五峯页岩的时代不能确定,中国奥陶系与志留系之间的界线便无从划分。  相似文献   

9.
NEW MATERIAL OF SINOHELICOPRION FROM CHANGXING, ZHEJIANG PROVINCE   总被引:1,自引:0,他引:1  
Thenewmateria1describedinthispaperisarowofcontinual1lteethandgentlyarciform,itslengthmeasuresaboutl2Omm-Thevariationsinsizeoftheteetharesomewhatirregularffomendtoend.Atoothmayberegardedasconsi-stingofthreeparts:acuttingblade,alatera1part(wing)andabase.Thereisnointerdenticalspacebetweenadjacentteeth.Thecuttingbladeistriangu1arinlateralview,itformsabouthalfofthetota1lengthofthetooth-Therearemanydenticlesonitsanteriorandposterioredges,whicharel8averagelyinnumberoneachside.Thetopsofthedenticlesa…  相似文献   

10.
张以春  王玥 《古生物学报》2019,58(3):311-323
西藏雅鲁藏布江缝合带蛇绿混杂岩中混杂着大小不一的二叠纪灰岩块体,它的来源一直颇有争议,这些灰岩块体中动物群的古生物地理面貌是判断其来源的重要手段。姜叶玛灰岩体是位于西藏普兰县境内混杂在中生代蛇绿混杂岩中的一个大型二叠纪灰岩块体。其中,中二叠世西兰塔组中含有丰富的非?有孔虫化石,它们主要由Neodiscus,Climacammina,Pachyphloia和Lysites组成,伴生有Dagmarita,Deckerella,Globivalvulina,Neoendothyra,Lasiodiscus,Lasiotrochus,Tetrataxis,Geinitzina,Ichthyofrondina,Nodosaria,Nodosinelloides,Agathammina,Septoagathammina和Shanita,时代相当于中二叠世Capitanian期。古生物地理上,Lysites和Shanita的出现表明这个动物群属于基墨里生物区,它们从古生物地理上以及生物多样性上和印度板块北缘的巴基斯坦盐岭地区以及藏南喜马拉雅区的同时代动物群有显著差别。结合前期?类动物群古生物地理的研究,姜叶玛灰岩块体很可能位于拉萨地块与喜马拉雅之间的新特提斯洋海山上,与两个地块之间都有一定的隔离。这也说明新特提斯打开的时间早于中二叠世。  相似文献   

11.
The new genus Yushanograptus described in the present paper is a monotypic genuswith Yushanograptus separatus gen.et sp.nov.as the genotype which is represented by5 specimens securd by one of the writers(Han)in the summer of 1961 from the NingkuoShale at the locality near Lijiapeng of the Yushan district,northeastern Jiangxi(Kiangsi)Province(Field No.F61001).The marked features of the new genus are the two long and slender primary stipesand the Goniograptid type in branching.The young forms of this new graptolite bear astriking resemblance to the slender Didymograpti,such as Didymograptus gracilis T(?)rn-quist,D.cognatus Harris et Thomas etc.The same is the case in Zygograptus,particul-arly in Zygograptus irregularis Harris et Thomas.In the mode of branching of the  相似文献   

12.
The effect of granular coral limestone and Leca as adsorbents for removing Acid Cyanine 5R (AC5R) from aqueous solution was studied. The optimum pH and adsorbent particles size in both adsorbents were determined to be 3 and 297 μm, respectively. The optimum dosages of coral limestone and granular Leca were 0.150 and 0.145 g/mg of dye, respectively. Also, results have shown that the adsorption efficiency by both coral limestone and Leca increased with the decreasing adsorbent particles size. Moreover, under similar conditions, the maximum removal efficiency by granular coral limestone and Leca was 94% and 88%, respectively. The results revealed that the performance of granular coral limestone was better in AC5R removal than that of Leca granulated under such condition. In total, granular coral limestone and Leca act as suitable adsorbents for removing dye pollutants from an aqueous solution.  相似文献   

13.
The new species Abrus baladensis , from fixed sand dunes near Mogadishu in south-central Somalia, and A. gawenensis , from limestone or sand over limestone in central Somalia, are described.  相似文献   

14.
Sixty limestone monuments in Central London, UK, with copper staining from brass or bronze attachments, were surveyed. Severe spalling was noted at some copper-stained sites. The survey suggests that copper initially protects the surface, but causes stone deterioration after around 70 years. Samples from four limestone monuments were analysed microbiologically and using ESEM/EDX. EDX analyses suggested the build-up of salts below a basic copper carbonate skin (salting) as the most probable explanation of the observed deterioration. Copper-stained stone was free of photosynthetic microorganisms and yielded relatively few other microorganisms. ESEM and EDX analyses of a well-conserved limestone monument surface free of copper showed the almost complete conversion of surface limestone to gypsum. The grey/brown biofilms consisted of actinomycetes and filamentous fungi. The results indicate that copper initially prevents and then enhances limestone deterioration, and that atmospheric pollutants are far less harmful than phototrophic biofilms, since surface areas completely converted to gypsum are well preserved after more than 100 years.  相似文献   

15.
The material upon which this paper is based was collected by Messrs. S. C. Kwan and S. T.Che from the Zhuozishan limestone in southwestern part of Inner Mongolia during their fieldinvestigation in 1953. A part of specimens were procured by Messrs. Y. H. Lu, A. T. Mu andJ. T. Chang from the same district in 1954. The lower Ordovician strata of the Zhuozishan region was divided by Messrs. S. C. Kwanand S. T. Che (1955, Acta Geological Sinica, vol. 35, no. 2, p. 98--101) into three parts,namely: the Sandaokan formation in the lower part, the Zhuozishan limestone in the middle partand the Klimli limestones in the upper part. The gastropods are largely procured from theZhuozishan limestone. This limestone series consists mainly of greyish blue, massive limestons  相似文献   

16.
The new species Kleinia tuberculata , from open deciduous bushland on gypsum hills and gypseous limestone in northern and north-eastern Somalia, K. curvata , from evergreen bushland on limestone in northern Somalia, K. sabulosa , from deciduous bushland on sand in central Somalia, K. ogadensis , from deciduous bushland in eastern Ethiopia, K. gracilis , from dwarf bushland on limestone in north-eastern Somalia, and K. tortuosa , from alkaline plains in northern Somalia, are described, and for some of them illustrations are provided. The new combinations K. nogalensis and K. lunulata are made, and the recently described K. isabellae from eastern Ethiopia is placed in synonymy of K. lunulata.  相似文献   

17.
Li W  Yu LJ  Wu Y  Jia LP  Yuan DX 《Bioresource technology》2007,98(4):950-953
Three experimental systems were set up to investigate whether carbonic anhydrase (CA) from microorganisms actually plays the driving role in limestone dissolution. In one, redistilled water served as negative control. In a second, microbial origin CA enzyme solution supplemented with CA special inhibitor acetazolamide (AZ) served as positive control. A third contained a crude enzyme solution of microbial CA. The results showed that the amount of released Ca2+ from limestone in a CA non-inhibited system increased by 2.4 times compared to a CA inhibited system, and increased by 11.7 times compared to the redistilled water control. These experiments demonstrated that microbial origin CA significantly enhanced Ca2+ release from limestone (P < 0.01), and therefore, proved the significant driving effect of microbial CA on limestone dissolution. The results also suggested that microbially derived CA might exert an important influence on biokarst process.  相似文献   

18.
The new species Jatropha miskatensis , from limestone slopes of the Cal Miskaat Range in north-eastern Somalia, and J. marmorata , from bushland on shallow soil over limestone just south of the Nugaal valley in north-eastern Somalia, are described. An illustration is provided for J. miskatensis.  相似文献   

19.
Subsurface karst aquifers receiving sulfidic water can host complex chemolithotrophic microbial communities that are capable of dissolving limestone, forming new karstic habitat. Neutrophilic sulfur-oxidizing bacteria use reduced sulfur compounds as energy rich substrate, potentially producing sulfuric acid as a geochemically reactive byproduct. The physicochemical relationship between a biofilm forming on a limestone surface and the extent of microbial influence on dissolution rate, however, are unknown. We investigated the rate of Madison limestone dissolution by sulfur-oxidizers both in the field at Lower Kane Cave, WY (LKC), and in the laboratory using continuous flow culture reactors and microbial mat collected from LKC. In the field, a microbial consortium rapidly colonized limestone chips forming a thick biofilm, with deep etching of mineral surfaces underneath. In the laboratory we found that a microbial biofilm oxidizing thiosulfate on the limestone surface accelerated dissolution rate up to 7 times faster than the abiotic baseline rate. In contrast, experiments done with H2S or a mixture of H2S and thiosulfate had no effect on dissolution rate. We hypothesize that the laboratory mat community dominated by Thiothrix sp. oxidizes thiosulfate to sulfate and H+, while H2S is partially oxidized to S°. When all sulfur substrate is withheld, the community oxidizes stored intracellular sulfur, briefly accelerating limestone dissolution even in the absence of external supplied substrate. Accelerated corrosion occurs only in the reactive micro-environment under the biofilm, disconnected from the bulk reactor solution. When experiments are repeated where the microbial population is separated from the limestone by a dialysis membrane barrier, measured pH drop is greater, but there is only slight enhancement of rate. This work confirms our working hypothesis that neutrophilic sulfur-oxidizers colonize and rapidly dissolve limestone surfaces, possibly to buffer the production of excess acidity.  相似文献   

20.
We studied the effects of limestone sand additions in Bear and Rock runs, two chronically and episodically acidified streams in southwestern Pennsylvania, U.S.A. Linn Run, a nearby episodically acidified stream, served as a reference stream. Our objectives were to evaluate the effects of doubling recommended limestone sand amounts on water quality and macroinvertebrates on Bear and Rock runs and to assess substrate changes resulting from limestone sand inundation. Approximately 23 and 6 tonnes of limestone sand were added annually to the headwaters of Bear and Rock runs, respectively, from 1999 to 2001. In 2002, amounts were doubled. Macroinvertebrate communities were assessed from 1999 to 2003 at points above and below the sand additions on Bear Run and Rock Run. Small, plastic substrate samplers were used to assess sand substrate effects. Doubling annual limestone sand amounts resulted in significantly improved pH and acid‐neutralizing capacity; however, total dissolved aluminum increased significantly downstream (α≤ 0.05). Macroinvertebrate density and diversity were not significantly affected, but an increase in acid‐sensitive taxa was observed at a site 3,500 m downstream. Substrate sampler data indicated a significant negative relationship between amount of sand deposited and density of macroinvertebrates. The mixed water quality and benthic macroinvertebrate results were reasonably consistent with earlier work and call into question the use of limestone sand in the restoration of chronically and episodically acidified waters.  相似文献   

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