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1.
J.W. Schopf T.A. Dolnik I.N. Krylov C.V. Mendelson B.B. Nazarov A.V. Nyberg Yu.K. Sovietov M.S. Yakshin 《Precambrian Research》1977,4(3):269-284
Diverse assemblages of cellularly preserved Precambrian microorganisms have been discovered in cherty stromatolitic sediments from six formations in the Soviet Union: Sukhotungusin Fm. (Middle Riphean, Siberia); Valukhtin Fm. (Middle Riphean, Siberia); Shorikha Fm. (Upper Riphean, Siberia); Minyar Fm. (Upper Riphean, Bashkiria); Olkhin Fm. (Upper Riphean, Siberia); and Chichkan Fm. (Vendian, Kazakstan). These cyanophyte-dominated microbial communities, occurring in both stratiform (cf. Stratifera) and columnar stromatolitic deposits (Baicalia hirta and Conophyton gaubitza), are the first stromatolite-building microbiotas to be reported from the Soviet Union; collectively they comprise more than one-fifth of all such Precambrian assemblages now known. 相似文献
2.
Mukund Sharma 《Journal of Earth System Science》2006,115(1):67-98
Mesoproterozoic (∼ 1600 Ma old) Salkhan Limestone (Semri Group) of the Vindhyan Supergroup, exposed in Rohtas district of
Bihar, India, preserves an abundant and varied ancient microbial assemblage. These microfossils are recorded in three distinctly
occurring cherts viz., bedded chert, stromatolitic chert and cherty stromatolites. 27 morphoforms belonging to 14 genera and
21 species have been recognized. Six unnamed forms are also described.
The microbial assemblage, almost exclusively composed of the remnants of cyanobacteria, is dominated by entophysalidacean
members and short trichomes and can be termed as ‘typical Mesoproterozoic microbiotas’. The assemblage includes characteristic
mat-forming scytonematacean and entophysalidacean cyanobacteria.Eoentophysalis is the dominant organism in the assemblage. Ellipsoidal akinetes of nostocalean cyanobacteria(Archaeollipsoides) and spherical unicells also occur; both are distinct from mat forming assemblage, allochthonous and possibly planktic. Co-occurrence
of the microbiotas and precipitates is related to the depositional environment of the Mesoproterozoic tidal flats with high
carbonate saturation. 相似文献
3.
Silicified flake conglomerates and in situ stratiform stromatolites of the Upper Proterozoic (c. 700-800 Ma) Limestone-Dolomite 'Series', central East Greenland, contain well preserved microfossils. Five stratigraphic horizons within the 1200 m succession contain microbial mat assemblages, providing a broad palaeontological representation of late Proterozoic peritidal mat communities. Comparison of assemblages demonstrates that the taxonomy and diversity of mat builder, dweller, and allochthonous populations all vary considerably within and among horizons. The primary mat builder in most assemblages is Siphonophycus inornatum, a sheath-forming prokaryote of probable but not unequivocally established cyanobacterial affinities. An unusual low diversity unit in Bed 17 is dominated by a different builder, Tenuofilum septatum, while a thin cryptalgal horizon in Bed 18 is built almost exclusively by Siphonophycus kestron. Although variable taphonomic histories contribute to observed assemblage variation, most differences within and among horizons appear to reflect the differential success or failure of individual microbial populations in colonizing different tidal flat microenvironments. Twenty-two taxa are recognized, of which two are described as new: Myxococcoides stragulescens n.sp. and Scissilisphaera gradata n. sp. 相似文献
4.
Arubam C.Khelen C.Manikyamba Li Tang M.Santosh K.S.V.Subramanyam Th Dhanakumar Singh 《地学前缘(英文版)》2020,11(1):229-242
Oldest rocks are sparsely distributed within the Dharwar Craton and little is known about their involvement in the sedimentary sequences which are present in the Archean greenstone successions and the Proterozoic Cuddapah basin.Stromatolitic carbonates are well preserved in the Neoarchean greenstone belts of Dharwar Craton and Cuddapah Basin of Peninsular India displaying varied morphological and geochemical characteristics.In this study,we report results from U-Pb geochronology and trace element composition of the detrital zircons from stromatolitic carbonates present within the Dharwar Craton and Cuddapah basin to understand the provenance and time of accretion and deposition.The UPb ages of the detrital zircons from the Bhimasamudra and Marikanve stromatolites of the Chitradurga greenstone belt of Dharwar Craton display ages of 3426±26 Ma to 2650±38 Ma whereas the Sandur stromatolites gave an age of 3508±29 Ma to 2926±36 Ma suggesting Paleo-to Neoarchean provenance.The U-Pb detrital zircons of the Tadpatri stromatolites gave an age of 2761±31 Ma to1672±38 Ma suggesting Neoarchean to Mesoproterozoic provenance.The Rare Earth Element(REE)patterns of the studied detrital zircons from Archean Dharwar Craton and Proterozoic Cuddapah basin display depletion in light rare earth elements(LREE)and enrichment in heavy rare earth elements(HREE)with pronounced positive Ce and negative Eu anomalies,typical of magmatic zircons.The trace element composition and their relationship collectively indicate a mixed granitoid and mafic source for both the Dharwar and Cuddapah stromatolites.The 3508±29 Ma age of the detrital zircons support the existence of 3.5 Ga crust in the Western Dharwar Craton.The overall detrital zircon ages(3.5-2.7 Ga)obtained from the stromatolitic carbonates of Archean greenstone belts and Proterozoic Cuddapah basin(2.7-1.6 Ga)collectively reflect on^800-900 Ma duration for the Precambrian stromatolite deposition in the Dharwar Craton. 相似文献
5.
Zhang Yun 《Precambrian Research》1985,30(3):277-302
A relatively diverse microbiota, preserved in-situ, has been discovered in cherty stratiform stromatolites of the middle Proterozoic Wumishan Formation (c. 1200–1300 Maold), Jixian Group, in the Ming Tombs area of Beijing. This microfossil assemblage consists of two parts: (1) the mat-building and mat-dwelling benthos which mostly belong to “long-lasting” taxa and are mostly common with those of other Proterozoic microbiotas; and (2) allochthonous elements including some plankton and peculiar structures which are either new forms first described here or taxa shared with some contemporaneous or penecontemporaneous microbiotas elsewhere. The latter may have more stratigraphic significance.Bivariate analysis on two characters measured (length and width) has been used in the classification of the elongate microfossils, and the results demonstrate that biometrical methods are effective in the taxonomy of some Precambrian microfossils.The following new taxa are described:Archaeoellipsoides obesus sp. nov., Archaeoellipsoides conjunctivus sp. nov., Bactrophycus oblongum gen. et sp. nov., Bactrophycus dolichum gen. et sp. nov., Callosicoccus crauros gen. et sp. nov. 相似文献
6.
7.
Most of the Proterozoic carbonate formations of Peninsular India, and the so-called ‘unfossiliferous’ carbonates of the Sub- and Lesser Himalaya, contain abundant columnar and branching stromatolites. Systematic study of some of these stromatolites supports their use in biostratigraphy and reveals their Riphean—Proterozoic affinity. A synthesis of stromatolite studies in India has been attempted. A biostratigraphic correlation of the stromatolitic formations of Sub- and Lesser Himalaya extending from Jammu in the west to Buxa in the eastern Himalaya has been established. A probable correlation of those of Peninsular India has been indicated, based on available information. A bibliography on Indian stromatolites is appended. 相似文献
8.
天津蓟县中元古界雾迷山组是一套厚度超过3000,m的叠层石碳酸盐岩沉积序列,在该序列中潮下相叠层石生物层、凝块石生物丘与潮坪相泥晶白云岩、潟湖相白云质泥页岩一起构成若干个环潮坪型米级旋回——"雾迷山旋回层"。在雾迷山组下部发育微指状叠层石,并被古生物学家定义为"Pseudogymnosolen mo-panyuensis-Scuphus-Yangzhuang columnaris"组合,即假裸枝叠层石科叠层石,沉积学家将其解释为元古代文石(灰华)海底沉淀物所构成的叠层石,代表从太古代海底结壳状文石沉淀物组成的叠层石到新元古代碎屑结构相的泥晶碳酸盐岩叠层石过渡时期的特殊产物。因此,雾迷山组巨厚的叠层石碳酸盐岩沉积序列,记录了元古代文石(灰华)海底沉淀物所构成的特殊的叠层石大规模消亡的层位,为研究前寒武纪以叠层石为代表的微生物碳酸盐岩所经历的漫长而复杂的地质历史演变提供了宝贵的材料。 相似文献
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V N Sergeev A H Knoll S P Kolosova P N Kolosov 《Stratigraphy and Geological Correlation》1994,2(1):19-33
Silicified shallow-water marine carbonate deposits of the Proterozoic Debengda Formation (the Olenek Uplift, northeastern Siberia) contain well preserved microfossils. One or two distinct assemblages consists only of filamentous Siphonophycus microfossils, which are presumably the extracellular sheaths of hormogonium cyanobacteria. The other is dominated by coccoidal microfossils, first by the entophysalidacean cyanobacterium Eoentophysalis. The coccoidal assemblage was recognized in the layered carbonate precipitate structures of a superficially stromatolite appearance. Despite its simple composition, the microfossil assemblage supports the generally accepted Mesoproterozoic (middle Riphean) age of the Debengda Formation. This conclusion corresponds to the available data on isotopic geochronology, and to the composition of columnar stromatolites from the Dehengda Formation. Both the structural features and carbon isotopic composition of its rocks are comparable to those of rocks of known Mesoproterozoic age, but differ from the characteristics of definitely Neoproterozoic deposits. 相似文献
11.
V. N. Sergeev M. A. Semikhatov M. A. Fedonkin A. F. Veis N. G. Vorob’eva 《Stratigraphy and Geological Correlation》2007,15(2):141-160
Expounded in this work are the results of critical consideration of published and original data on biologic nature and appearance chronology of different groups of Archean and Lower Proterozoic (3.5–1.65 Ga) paleontological remains known from geological record. Conclusions are substantiated by morphological analysis of structurally preserved microfossils, their facies distribution, and by inferable genesis and principal evolutionary trends of Archean stromatolites. A special attention is paid to variations of organic and carbonate carbon isotope composition in sedimentary successions with paleontological remains and to recent information about discovered, most ancient biomarkers of large groups of organic world. As a result of this approach, a detailed model of Precambrian organic world evolution is suggested. 相似文献
12.
M. E. Raaben 《Stratigraphy and Geological Correlation》2006,14(2):150-163
Columnar stromatolites representing more than a half of species described in Precambrian stromatolite assemblages reveal a regular trend of size variations during the Proterozoic and Early Paleozoic. Their dimensional parameters grew gradually during the Paleoproterozoic to attain peak values in the Early Riphean and to decline steadily afterward during the Middle-Late Riphean, Vendian, and Cambrian. Size variations are established based on statistically averaged maximum diameters of columns calculated for 230 taxa and on percentages of large, medium and small species occurring in successive units of stratigraphic scale. The units correspond to three Paleoproterozoic subdivisions (time span from 2.3 to 1.65 Ga) and to five subdivisions of the Riphean, Vendian and Early Paleozoic jointly spanning a comparable period of geologic time. The results of calculation depict a unimodal variation curve with one infliction point designating inversion of ascending and descending trends in the Early Riphean time. The inversion and cardinal changes in taxonomic composition of the entire stromatolite community across the Riphean lower boundary appear to be interrelated. Abiotic events, which certainly influenced diversity of all, especially columnar stromatolites, have no manifestation however in the size-variation curve lacking perceptible oscillations in both the ascending and descending branches. Consequently, dimension parameters of columnar stromatolites appear to be independent of direct influence of abiotic events. 相似文献
13.
MEI Mingxiang 《《地质学报》英文版》2008,82(2):295-309
In the long Precambrian period, stromatolitic carbonate successions were very common. However, the non-stromatolitic carbonate succession that is marked by subtidal deposits shows a sharp contrast to the stromatolitic carbonate succession. Both the non-stromatolitic and the stromatolitic carbonate successions are important clues for the further understanding of the evolving carbonate world of the Precambrian. The Mesoproterozoic Gaoyuzhuang Formation at the Qiangou section in northwestern suburb of Beijing is a set of more than 1000 m-thick carbonate strata that can be divided into four members （or subformations）, in which a non-stromatolitic carbonate succession marked by the scarcity of stromatolites makes up the third member of the formation. This non-stromatolitic carbonate succession can further be subdivided into three third-order sequences that are marked by the regular succession of sedimentary facies. In third-order sequences, a lot of subtidal carbonate meter-scale cycles made up of medium-bedded leiolite limestones and thin-bedded marls constitute their transgressive system tracts （TSTs） and the early high-stand system tracts （EHSTs）, a lot of meter- scale cycles made up by thin-bedded limestones and marls constitute their condensed sections （CSs）, and thick-bedded to massive dolomitic limestones or lime dolomites make up the late high-stand system tracts （LHSTs）. The particularly non-stromatolitic carbonate succession making up the third member of the Mesoproterozoic Gaoyuzhuang Formation at the Qiangou section might be the representative of the non-stromatolitic carbonate succession of the Precambrian because of its special lithological features and particular sedimentary structures, and its general sedimentary features are helpful and meaningful for the further understanding of the evolution rules of the sophisticate and evolving carbonate world of the Precambrian. The time scale of the Gaoyuzhuang Formation is deduced as that from 1600 Ma to 1400 Ma; thus, the non-stromatolitic 相似文献
14.
<正>The Mesoproterozoic Wumishan Formation at the Jixian section in Tianjin is a set of more than 3000-m-thick stromatolitic carbonate succession.In this succession,several lithofacies units,that is,the subtidal stromatolitic biostrome,the thrombolitic bioherm,tidal-flat micritic dolomite and lagoon dolomitic shale,make up many meter-scale cycles of the peritidal carbonate type that have been nominated as the Wumishan cycles.Importantly,many microdigital stromatolites make up the stromatolitic biostrome unit of the Wumishan cycles in the lower part of the Wumishan Formation. These microdigital stromatolites have been grouped as a stromatolitic assemblage by paleontologists, that is,"Pseudogymnosolen mopanyuensis-Scuphus-Yangzhuang columnaris"assemblage.These microdigital stromatolites had also been interpreted as the aragonite(tufa) sea-floor precipitates by sedimentologists,and has further been thought as the special products of the transitional period from the sea-floor aragonite precipitates of the Archean to the clastic and muddy carbonates of the Neoproterozoic.Although there are some restrictions for the stratigraphic meaning of the concept of the stromatolitic assemblage,detailed studies on classification by paleontologists provide an important clue to understand the sedimentological meaning of the microdigital stromatolites.Furthermore,an important and obvious horizon for the end of the microdigital stromatolites was recorded in the Mesoproterozoic Wumishan Formation at the Jixian section,which provides useful information to understand the stromatolite decline occurred at c.1250 Ma and the evolving carbonate world of the Precambrian. 相似文献
15.
北京延庆千沟中元古代高于庄组第三段:一个典型的前寒武纪非叠层石碳酸盐岩沉积序列 总被引：2，自引：0，他引：2
在前寒武纪碳酸盐岩中,最为普遍的是叠层石碳酸盐岩沉积序列,而以潮下相沉积为主的非叠层石碳酸盐岩沉积序列与前者形成了较大的差异;因此,与叠层石碳酸盐岩沉积序列一样,非叠层石序列成为了解前寒武纪复杂多变的碳酸盐世界的重要线索。燕山地区中元古代高于庄组为一套厚度千余米的碳酸盐沉积序列,包括四大部分:第一段（或称为官地亚组）为发育在海侵砂岩上的叠层石白云岩地层;第二段（或称为桑树鞍亚组）为发育少量叠层石的含锰白云岩地层;第三段又称为张家峪亚组,为一套以发育灰岩为主的非叠层石碳酸盐岩沉积序列;第四段以叠层石岩礁和叠层石礁白云岩为特征。延庆千沟剖面的高于庄组第三段的非叠层石碳酸盐岩沉积序列,贫乏叠层石是其基本特点,包含3个三级层序,在三级层序的海侵体系域和早期高水位体系域中,层面上发育席底构造的中层均一石灰岩（隐藻泥晶灰岩）和灰黑色薄层泥灰岩组成若干潮下型米级旋回,晚期高水位体系域则以厚层块状纹理石灰质白云岩和白云质灰岩为特征;三级层序的凝缩段单元则以薄层泥灰岩和泥页岩构成的L-M型米级旋回为特征。因此,每一个三级层序均以一个有序的沉积相序列为特征。高于庄组的分布时限大致为200 Ma（1 600～1 400 Ma）,考虑到下伏的大红峪组和高于庄组之间的地层间断时限大致为50 Ma至100 Ma,所以推断高于庄组的堆积作用时限为100 Ma（1 500～1 400 Ma）左右,其中高于庄组第一段与第二段的分界线正好处于该组的中部而可以推断该界线的大致为1 450 Ma左右;因此,高于庄组第三段非叠层石碳酸盐岩沉积序列的发育表明,在1 450 Ma左右可能发生过一次可以与前寒武纪其他已经被识别出的三次叠层石衰减事件（2 000 Ma、1 000 Ma和675 Ma）相比拟的又一次叠层石衰减事件。延庆千沟剖面高于庄组第三段的非叠层石碳酸盐岩沉积序列,可以大致与北美地区的起始时限为1 450 Ma左右、Belt超群中的Helena组非叠层石碳酸盐岩沉积序列相对比,表明了1 450 Ma左右的叠层石衰减事件具有全球性,从而赋予高于庄组第三段非叠层石碳酸盐岩沉积序列重要的沉积学意义。延庆千沟剖面高于庄组第三段非叠层石碳酸盐岩沉积序列,特别的岩石类型和沉积构造,成为前寒武纪碳酸盐岩沉积中非叠层石碳酸盐岩沉积序列的典型代表,由其所代表的沉积学特点将有助于深入理解漫长的前寒武纪碳酸盐沉积作用的变化规律而具有重要意义。 相似文献
16.
Black smoker chimneys and biological vent communities have been identified at many sites on the deep seafloor, particularly along oceanic spreading centers. We report the largest and oldest known, microbe-rich sub-meter-sized black smoker chimneys and mounds from a 1.43 billion-year old sulfide deposit in a continental graben in northern China. These chimneys are especially well preserved, with characteristic morphology, internal textures and internal cylindrical mineralogical zonation. Four main types of chimneys are distinguished on textural and mineralogical criteria, exhibiting either Zn–Fe-sulfide or Pb–Zn–Fe-sulfide internal cylindrical mineralogical zones. The chimneys mark vent sites in submarine grabens indicating focused flow-venting processes. The fossil chimneys have mineralogical and geological evolutionary features similar to their counterparts on the modern seafloor and other submarine hydrothermal vents. Black smoker vent fluids and seafloor tectonism played important roles for formation of the massive sulfide deposits in the Mesoproterozoic.We also report the first known, remarkably diverse assemblage of fossil microbialites from around and inside Precambrian vent chimneys, demonstrating that Proterozoic life flourished around submarine hot vents and deep within the chimney vent passages. Filamentous, spherical, rod, and coccus-shaped fossil microbes are preserved preferentially on sulfide precipitates. Based on the depth and setting of the fossil biota, the organisms that produced the microbialites were likely sulfate-reducing chemosynthetic and thermophyllic microbes. Textural and mineralogical evidence shows that biomineralization processes enhanced chimney growth and sulfide precipitation.Close association of microorganisms with sulfide chimneys in modern deep-sea hydrothermal vents and younger ophiolites has sparked speculation about whether life may have originated at similar vents. However, little is known about fossil equivalents of vent microfossils and black smoker chimneys from Earth's early evolution. The fossilized microorganisms from the Gaobanhe black smoker chimney sulfide deposits include thread-like filaments with branching and twisted forms and preserved organic carbon, representing fossilized remnants of microbial mats metabolized at high temperatures characteristic of venting fluids. The preservation of fossil microorganisms provides evidence that microbial populations were closely associated with black smoker chimneys in Earth's early history. The microbial population clearly constitutes the site for mediating mineral formation. These ancient microbial fossils lead to a much better understanding of early life on the deep seafloor. The discovery of the Mesoproterozoic microfossils within black-smoker hydrothermal chimneys indicates that hydrothermal activity around sea-floor vents supported dense microbial communities, and supports speculation that vent sites may have hosted the origin of life. 相似文献
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梅冥相 《中国地质大学学报(英文版)》2007,18(3):191-209
A particular non-stromatolitic carbonate succession making up the third member of the Mesoproterozoic Gaoyuzhuang (高于庄) Formation might demonstrate that a stromatolite decline of the Mesoproterozoic occurring at ca. 1 450 Ma besides other three events of the Proterozoic,respectively,occurred at ca. 2 000 Ma,ca. 1 000 Ma,and ca. 675 Ma. The forming duration of this non-stromatolitic carbonate succession can be generally correlative to that of a similar depositional succession in North America,i.e. a non-stromatolitic carbonate succession made up by the Helena Formation of the Belt Supergroup,which suggests that the stromatolite decline occurring at ca. 1 450 Ma may be a global event. This information endows the non-stromatolitic carbonate succession making up the third member of the Gaoyuzhuang Formation in the Yanshan (燕山) area with important significance for the further understanding of Precambrian sedimentology. The Mesoproterozoic Gaoyuzhuang Formation in Yanshan area is a set of more than 1 000 m thick carbonate strata that can be divided into four members (or subformations). The first member (or the Guandi (官地) subformation) is marked by a set of stromatolitic dolomites overlying a set of transgressive sandstones; the second member (or the Sangshu'an (桑树鞍) subformation) is a set of manganese dolomites with a few stromatolites; the third member (or the Zhangjiayu (张家峪) subformation) is chiefly made up of leiolite and laminite limestones and is characterized by the development of molar-tooth structures in leiolite limestone; the fourth member (or the Huanxiusi (环秀寺) subformation) is composed of a set of dolomites of stromatolitic reefs or lithoherms. Sequence-stratigraphic divisions at two sections,i.e. the Jixian (蓟县) Section in Tianjin (天津) and the Qiangou (千沟) Section of Yanqing (延庆) County in Beijing (北京),demonstrate that a particularly non-stromatolitic succession making up the third member of the Mesoproterozoic Gaoyuzhuang Formation is developed in the Yanshan area of North China,in which lots of grotesque matground structures (wrinkle structures and palimpsest ripples) are developed in beds of leiolite limestone at the Qiangou Section and lots of molar-tooth structures are developed in beds of leiolite limestone at the Jixian Section. The time scale of the Gaoyuzhuang Formation is deduced as 200 Ma (from 1 600 Ma to 1 400 Ma). The duration of an obvious hiatus between the Gaoyuzhuang Formation and the underlying Dahongyu (大红峪) Formation is deduced as 50 Ma to 100 Ma,thus the forming duration of the GaoyuzhuangFormation is thought as 100 Ma (1 500 Ma to 1 400 Ma). Furthermore,the age of the subface of the third member of the Gaoyuzhuang Formation that is just in the mid position of the Gaoyuzhuang Formation can be deduced as about 1 450 Ma,which is the basis to infer a stromatolite decline of the Mesoproterozoic occurring at ca. 1 450 Ma. Importantly,several features of both the molar-tooth structure and the stromatolite,such as the particular forming environment,the important facies-indicative meaning,and the episodic distribution in the earth history,might express the evolutionary periodicity of the surface environment of the earth and can provide meaningful clues for the understanding of the Precambrian world,although their origin and forming mechanism is highly contentious. Therefore,like other three stromatolitic declines,respectively,occurring at ca. 675 Ma,ca. 1 000 Ma,and ca. 2 000 Ma,the identification of the stromatolite decline occurring at ca. 1 450 Ma during the Golden Age of stromatolites (2 800 Ma to 1 000 Ma) has important meaning for the further understanding of the evolving carbonate world of the Precambrian. 相似文献
19.
笔者对腮林忽洞组的岩石地层特征、层序地层、生物(叠层石)地层进行了深入研究。将腮林忽洞组划分为4个岩性段、7个三级层序;根据叠层石组合特征,建立了3个叠层石组合;结合前人获得的两件同位素年龄(207Pb/204Pb)数据,认为腮林忽洞组的时代应归属中元古代长城纪—蓟县纪。 相似文献
20.
天津蓟县中元古界雾迷山组是一套厚度超过3 000 m的叠层石碳酸盐岩沉积序列,在该序列中潮下相叠层石生物层、凝块石生物丘与潮坪相泥晶白云岩、泻湖相白云质泥页岩一起构成若干个环潮坪型米级旋回--“雾迷山旋回层”。在雾迷山组下部发育微指状叠层石,并被古生物学家定义为“Pseudogymnosolen mopanyuensis-Scuphus-Yangzhuang columnaris”组合,即假裸枝叠层石科叠层石,沉积学家将其解释为元古代文石（灰华）海底沉淀物所构成的叠层石,代表从太古代海底结壳状文石沉淀物叠层石到新元古代碎屑结构相、富泥碳酸盐叠层石过渡时期的特殊产物。因此,雾迷山组巨厚的叠层石碳酸盐岩沉积序列,记录了元古代文石灰华海底沉淀物所构成的特殊的叠层石大规模消亡的层位,为研究前寒武纪以叠层石为代表的微生物碳酸盐岩所经历的漫长而复杂的地质历史演变提供了宝贵的材料。 相似文献