共查询到20条相似文献，搜索用时 281 毫秒
1.
《Sedimentary Geology》2005,173(1-4):345-371
Facies and environmental setting of the Miocene coral reefs in the Late Cenozoic Antalya Basin are studied to contribute towards a better understanding of the time and space relationships of the reef development and the associated basin fill evolution in a tectonically active basin. The Antalya Basin is an extention–compression-related late post-orogenic basin that developed unconformably on a basement comprising a Mesozoic para-authocthonous carbonate platform overthrust by the Antalya Nappes and Alanya Massif metamorphics within the Isparta angle. The Late Cenozoic basin fill consists of thick Miocene to Recent clastic-dominated terrestrial and marine deposits with subordinate marine carbonates and extensive travertines. Late Miocene compressional deformation has resulted into three parts, referred as Aksu, Köprüçay and Manavgat sub-basins, bounded by north–south extending dextral Kırkkavak fault and the westward-verging Aksu thrust.Coralgal reefs are common within the Miocene sequences and are represented by coral assemblages closely similar to that of the circum-Mediterranean fauna. They occur as massive, small, isolated, patch reefs that developed in two contrasting depositional systems (progradational coastal alluvial fan and/or fan-delta conglomerates and transgressive shelf carbonates) during Early–Middle Miocene and Late Miocene. The Early–Middle Miocene reefs are represented by rich and high-diversity hermatypic corals, mainly comprising Tarbellastraea, Heliastraea, Favites, Favia, Acanthastraea, Porites, Caulastraea and Stylophora with occasional presence of solitary (ahermatypic) corals, Lithophyllia, Mussismilia and Leptomusso, locally reflecting relative changes in the bathymetry. Densely packed, massive, domal and hemispherical growth forms bounded by coralline algae and encrusting foraminifera Acervulina construct the reef framework. They occur in the fan-deltas and the transgressive open marine shelf carbonates of the Manavgat and the Köprüçay sub-basins. The Late Miocene reefs occur only in the Aksu sub-basin and are characterized by low-diversity hermatypic corals exclusively dominated by Porites and Tarbelastraea with minor Siderastraea, Favites and Platygyra. They developed on alluvial fan/fan-delta complexes and shallow marine shelf carbonates.The Miocene coral reef growth and development in the Antalya Basin are characterized by large- to small-scale, transgressive–regressive reefal cycles which are closely related to the complex interaction of sporadic influxes of coarse terrigeneous clastics derived from the tectonically active basin margins and the related sea-level fluctuations. 相似文献
2.
Oligocene and Early Miocene coral assemblages from three sections of central Iran are investigated with respect to their
palaeoecological and palaeobiogeographic implications. These corals are compared with faunas from the Mediterranean Tethys
and the Indopacific. Associated larger foraminifers are used for biostratigraphy and to support the palaeoecological interpretation.
The studied sections are situated in the foreland basins of the Iranian Plate which is structured into a fore-arc and a back-arc
basin separated by a volcanic arc. The coral assemblages from Abadeh indicate a shallowing-upward trend. Infrequently distributed
solitary corals at the base of the section indicate a turbid environment. Above, a distinct horizon characterised by a Leptoseris-Stylophora assemblage associated with lepidocyclinids and planktonic foraminifers is interpreted as maximum flooding surface. Small
patch reefs with a Porites-Faviidae assemblage are a common feature of Late Oligocene to Early Miocene coral occurrences and indicate water depths of
less than 20 m. The diversity of the coral faunas shows marked differences. Oligocene corals from the Esfahan-Sirjan fore-arc
basin comprise more than 45 species of 32 genera and occur in a wide range of environments. Early Miocene corals from the
Qom back-arc basin are less frequent, show a lower diversity (13 genera with 15 species) and occur in single horizons or small
patch reefs.
Received: 4 December 1998 / Accepted: 3 June 1999 相似文献
3.
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
4.
Miocene coral-bearing limestones, distributed in the western Makran Basin, are attributed to Aquitanian and Burdigalian. This investigation is focused on three Early Miocene coral-bearing limestone sections in western Makran. Remarkably, well-preserved scleractinian corals and other components could be very definitive to reconstruct paleoenvironmental conditions. Lithologically, there are some differences between the studied sections. Furthermore, zooxanthellate corals are diverse and abundant in all sections. Based on different components and richness of zooxanthellate corals, it seems that the studied carbonate corals are precipitated in a subtropical condition, between 19 and 20 °C in all sections. In light of the dominancy of corals, the presence of symbiont-bearing larger benthic foraminifera (LBF), lithological features, bioeroding features, and encrusting organisms, the oligotrophic to slightly mesotrophic conditions are considered for Tejek section and the mesotrophic condition had been prevailed in Kermestan and Irer sections. According to light intensity in water column and coral morphotypes, Tejek section is considered to precipitate under euphotic to slightly mesophotic condition, while Kermestan and Irer sections were deposited under mesophotic to euphotic light conditions. In transparent water, photic zones continue to deeper depths, while in less transparent water, these zones are limited to shallower parts. A defined depth in the photic zone may represent euphotic, mesophotic, or oligophotic zone. Based on the water transparency, a taxon in a defined photic zone can occur in various depths. On the basis of trophic-light intensity-depth chart, the estimated depth ranges are 12–85 m for Tejek section and 5–62 m for Kermestan and Irer sections. Water energy as another important factor in environmental condition is acquired from coral morphotypes. Accordingly, Tejek section is precipitated under moderate-high energy and Kermestan and Irer sections are deposited in low to moderate-high energy. The presence of encrusting coralline algae, corals, and other constituents is indicative of different substrates in the studied areas. Corals favorably develop in normal salinity waters. The existence of colonial corals and occurrence of benthic foraminifera with hyaline wall indicate normal seawater conditions. 相似文献
5.
MICHELE MORSILLI FRANCESCA R. BOSELLINI LUIS POMAR PAMELA HALLOCK MARC AURELL CESARE A. PAPAZZONI 《Sedimentology》2012,59(3):766-794
Lower Priabonian coral bioherms and biostromes, encased in prodelta marls/clays, occur in the Aínsa‐Jaca piggyback basin, in the South Central Pyrenean zone. Detailed mapping of lithofacies and bounding surfaces onto photomosaics reveals the architecture of coral buildups. Coral lithosomes occur either isolated or amalgamated in larger buildups. Isolated lithosomes are 1 to 8 m thick and a few hundred metres wide; clay content within coral colonies is significant. Stacked bioherms form low‐relief buildups, commonly 20 to 30 m thick, locally up to 50 m. These bioherms are progressively younger to the west, following progradation of the deltaic complex. The lowermost skeletal‐rich beds consist of bryozoan floatstone with wackestone to packstone matrix, in which planktonic foraminifera are abundant and light‐related organisms absent. Basal coral biostromes, and the base of many bioherms, consist of platy‐coral colonies ‘floating’ in a fine‐grained matrix rich in branches of red algae. Corals with domal or massive shape, locally mixed with branching corals and phaceloid coral colonies, dominate buildup cores. These corals are surrounded by matrix and lack organic framework. The matrix consists of wackestone to packstone, locally floatstone, with conspicuous red algal and coral fragments, along with bryozoans, planktonic and benthonic foraminifera and locally sponges. Coral rudstone and skeletal packstone, with wackestone to packstone matrix, also occur as wedges abutting the buildup margins. Integrative analysis of rock textures, skeletal components, buildup anatomy and facies architecture clearly reveal that these coral buildups developed in a prodelta setting where shifting of delta lobes or rainfall cycles episodically resulted in water transparency that allowed zooxanthellate coral growth. The bathymetric position of the buildups has been constrained from the light‐dependent communities and lithofacies distribution within the buildups. The process‐product analysis used here reinforces the hypothesis that zooxanthellate corals thrived in mesophotic conditions at least during the Late Eocene and until the Late Miocene. Comparative analysis with some selected Upper Eocene coral buildups of the north Mediterranean area show similarities in facies, components and textures, and suggest that they also grew in relatively low light (mesophotic) and low hydrodynamic conditions. 相似文献
6.
The concentrations of six heavy metals (Fe, Mn, Ni, Cu, Pb and Zn) were studied in 11 hard and 4 soft common coral species
collected from Hurghada, Wadi Al-Gemal and Gola’an along the Red Sea coast to assess the differential abilities of corals
to concentrate and assimilate the heavy metals inside soft coral tissues and hard coral skeletons. These results reveal the
order of Fe > Zn > Ni > Pb ≥ Mn > Cu. Fe recorded significant high concentrations in mushroom (funnel) forms of the soft corals
at the different sites; 125.19, 101.71 and 90.44 ppm at Gola’an, Hurghada and Wadi Al-Gemal, respectively. The soft coral
species recorded the highest average concentration of Mn, Ni, Cu and Zn than the hard corals, which were 13.22, 16.05, 13.08
and 148.17 ppm, respectively. Generally, soft corals show higher metal concentrations than the hard ones; moreover, Hurghada
recorded a higher trend of metal concentrations in soft and hard corals than the other sites. The study concluded that many
biological and local environmental factors influenced the metal occurrences and uptakes in both coral forms such as, the exposed
surface area for metal uptake, turbidity, overlying mucus thickness and the ability of metals to substitute inside the crystal
lattice of the hard corals. 相似文献
7.
Wang Zhiping 《《地质学报》英文版》1989,63(2):103-114
China is rich in Middle and Carboniferous fossil corals. The coral faunas in different regions have varying characteristics and can be divided into distinct assemblages. The coral fauna in South China is dominated by the order Caninida and contains numerous endemic elements; that in North China has a lot of Middle Carboniferous corals which are monotonous in species, with Late Carboniferous solitary corals being predominant. The coral fauna in Junggar mainly contains large bi-zoned solitary caninids, while that in southern Khingan is similar to that in South China due to the presence of abundant tri-zoned compound corals. In northern Tibet the coral fauna is also similar to that in South China, but in southern Tibet it is of a cold-water type. Therefore, the Middle and Late Carboniferous coral geography of China can be divided into the Tethys, Boreal and Gondwana Realms. 相似文献
8.
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
9.
云南保山地区的下石炭统 总被引：4，自引：1，他引：4
<正> 云南保山地区下石炭统及其生物群曾引起许多学者的兴趣(Reed l927;王鸿桢,1945;段丽兰,1973,1985;宋学良,1982;金玉玕、方润森,1983;杨宗仁,1983;陈重泰,1984;陈根保,1984;金苏华,1992),其主要原因在于丰富而特殊的生物类群,悬而未决的地层问题以及独特的生物地理位置。本文以4条剖面(图1)为基础,依据多门类的生物化石对诸如本区杜内/维宪阶界线、Siphonophyllia-Keyserlingophyllum(Humboldtia)动物群的时代、冷水(凉水)珊瑚动物群、岩石地层单位等问题进行讨论。 相似文献
10.
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
11.
西藏北羌塘盆地索瓦组底界可对比为上侏罗统,关于该组上界能否达到下白垩统还需证实.半岛湖地区3个地点见隆起平缓且以珊瑚和层孔虫格架岩为主的层状礁,底栖群落结构显示以Pachythecopora pachytheca Deng,Actinostromaria motianlingensis Dong et Wang和Spongiomorpha robusta Yang et Wang为主体,其次还含有Latusastraea xigazeensis Liao et Xia,Preverastraea sp.,Ptychochaetes cf.globosus Koechlin和Spongiomorpha asiatica xainzaensis Deng.索瓦组上部孢粉组合中的Dicheiropollis etruscus为特提斯海周边地区早白垩世早期的特征分子;Senegalosporites和Steevesipollenites两属多见于早白垩世晚期乃至更晚的孢粉组合中,尚未见产于白垩纪以前地层的记录.珊瑚及孢粉组合指示索瓦组的主体部分为上侏罗统,而上部可对比为下白垩统. 相似文献
12.
Holocene reef development was investigated by coring on Britomart Reef, a mid-shelf reef, 23 km long and 8 km wide situated 120 km north of Townsville in the central Great Barrier Reef (GBR). Two holes were drilled, Britomart 1 on a lagoon patch reef, and Britomart 2 on the windward reef crest. The Holocene reef (25·5 m) is the thickest yet recorded in the GBR and overlies an uneven substrate of weathered Pleistocene limestone. Mineralogical and geochemical analyses show that magnesian calcite and aragonite were converted to low Mg-calcite below the Holocene-Pleistocene disconformity. Corals above the interface have 7500–8500 ppm Sr, but 1650–1500 ppm just below it, decreasing to 400–800 ppm downwards. The intermediate Sr values could be due to partial replacement of aragonite by calcite or higher original Sr content in the corals. Three units are recognized in the Holocene: (1) coral boundstone unit, (2) coral framestone unit, and (3) coral rudstone unit. The coral boundstone unit forms the top 5 m of both cores and is algal-bound coral rubble similar to the present reef top. The coral framestone unit is composed of massive head corals Diploastrea heliopora and Porites sp., and is currently forming in patch reefs situated in the lagoon and along the reef front. The coral rudstone unit comprises coral rudstone and floatstone with unabraded, and unbound, coral clasts in muddy matrix. This matrix may be up to 30% sponge chips. Radiocarbon dating indicates the reef grew more rapidly under the lagoon than under the reef front from 7000 to 5000 yr BP. The rate of reef growth matched existing estimates of sea-level rise, but lagged approximately 1000 years (5–10 m) behind it. Most of the reef mass accumulated between 8500 and 5000 yr BP as a mound of debris, perhaps stabilized by seagrasses or algae. Accretion of the reef top in a windward direction between 5000 and 3000 yr BP created the present, steep reef-front profile. 相似文献
13.
Amjad Ali Pirzada Jamal A. Siddiqui Kate Bromfield Athar Ali Khan Pervaiz Iqbal 《Arabian Journal of Geosciences》2017,10(23):520
Uplifted reefs due to being important palaeoclimate archives and a rich source of information on past physical and geochemical changes globally have become the centre of marine research. The uplifted fossil Quaternary coral communities of Jiwani and Gwadar are perfect places to study the palaeoclimatic and geological changes that have shaped the Balochistan coast. Studies on the palaeodiversity of corals along the Makran coast of Pakistan are lacking. In the present study, the samples collected using line intercept method from four uplifted sites (Balochistan coast: one at Gwadar and three at Jiwani) were analysed. The relative distribution and diversity of scleractinian fossil corals was determined, and the factors responsible for coral decline along Pakistan coast were compared with modern coral distribution and diversity. A total of 48 fossil coral species were recorded in nine families and 22 genera. High coral diversity was recorded in the uplifted landward sites of Jiwani and Gwadar headland. Terraces close to the shore at Jiwani had lower diversity. The corals seem to be Quaternary: most likely Pleistocene to Holocene. The modern fauna lacks many species recorded in the fossil community, thus suggesting a faunal turnover in diversity and redistribution of coral fauna which may be linked with past geological events and increasing anthropogenic pressure. 相似文献
14.
华南泥盆系－石炭系界线附近的珊瑚、有孔虫和牙形类及其地层意义 总被引：1，自引：1，他引：0
华南地区岩关阶依皱纹珊瑚可分为Ｃｅｒｉｐｈｙｌｌｕｍ－Ｃａｎｉｎｏｐｈｙｌｌｕｍｐａｔｕｌｕｍ（Ｇ－Ｃ）组合带、Ｃｙｓｔｏｐｈｙｒｅｎｔｉｓ（Ｃ）延限带和Ｐｓｅｕｄｏｕｒａｌｉｎｉａ（Ｐ）延限带及相应的有孔虫带和牙形类带（表１）。与法国一比利时盆地、英国和俄罗斯奥莫朗地区有关生物地层相比,Ｃ－Ｃ组合带与法一比盆地的ＲＣ１间隔带下部和英国的Ｋｍ－Ｋ１亚带大致相当;Ｃ延限带与ＲＣ１间隔带上部至ＲＣ２间隔带下部和英国的Ｋ２－Ｚ１亚带对比;Ｐ延限带与ＲＣ２间隔带上部至ＲＣ３奥佩尔带和英国的Ｚ方亚带至γ层对比。若以Ｐ延限带或所谓的＂Ｃ－Ｐ间隔带＂做为中国石炭系与泥盆系的分界标志,则石炭系的底界过于偏高。笔者认为Ｃ－Ｃ组合带或邵东组属于早石炭世地层。 相似文献
15.
Richet Rémy Chazottes Véronique Cabioch Guy Frank Norbert S. Burr George 《Quaternary Science Reviews》2011,30(19-20):2827-2838
Coral reef growth and development depend on several environmental factors, including tectonic and climatic parameters and local ecological drivers. Reef growth is especially sensitive to sea-level variations. Paleo-water depth reconstructions are essential tools used to determine reef growth patterns during different periods of reef growth. Assemblages of corals and/or coralline algae have been commonly used in such paleodepth reconstructions. This study shows that using microendolith ichnocoenoses can sometimes provide better accuracy than traditional coralgal analyses, particularly in the depth-range 0–10 m where coralgal assemblages usually show broad distribution ranges. Holocene and Pleistocene cores from two barrier reef sites on the west coast of Grande Terre in New Caledonia are examined here. Holocene reef development at these sites feature examples of microendolith ichnocoenoses that document rapid environmental changes and small sea-level variations of about 2–5 m in amplitude, and record these changes with more accuracy than coral and coralline algae assemblages which are highly dependant on the hydrodynamic energy of the setting. During the Pleistocene, which was less chronologically constrained, the microendolith ichnocoenoses also reflect paleo-water depths and reef-growth patterns at different periods of reef history. 相似文献
16.
Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been used to assess the impact of metal pollution on Porites skeletons taken from the Gulf of Thailand since the 1980s. The collection period coincided with a series of laws enacted by the Thai government to curb environmental pollution. The extent of metal pollution by riverine input, including aerosol deposits, was assessed by comparing the metal/Ca (Me/Ca) ratios in the Thai corals to the ratios of another colony of corals sampled from Rukan-sho, a relatively unpolluted coral reef located in Okinawa, Japan. In this comparison, high riverine inputs of Ba, V, Cd and Pb were observed in the Thai coral samples. Higher V/Ca ratios found in the Thai corals compared to the Rukan-sho coral suggest anthropogenic V inputs due to fuel oil pollution in the Gulf since the late 1990s. The levels of Cd in the coral suggest a gradual decrease in the Gulf in the late 1990s, with a drastic drop in concentration from the 1980s. The historical variation in Pb/Ca ratios recorded in the coral skeletons suggests that exposure to anthropogenic Pb was a result of discharge from urbanized areas from 1984 to 1998, which has been gradually reduced since Thailand prohibited the use of leaded gasoline in the late 1990s. 相似文献
17.
<正> 小茨山珊瑚礁剖面位于安徽含山县城南4km处的小茨山东坡,地层为和州组,礁体南北向延展100余米,地层倾向北西。下伏高骊山组为生物碎屑钙质泥岩,厚0.2m,棕 相似文献
18.
S. Aboglila K. Grice K. Trinajstic C. Snape K.H. Williford 《Applied Geochemistry》2011,26(9-10):1694-1705
The present paper involves a detailed evaluation of specific steroid biomarkers by gas chromatography–mass spectrometry (GC–MS) and GC-metastable reaction monitoring (MRM) analyses of several crude oils and source rocks from the East Sirte Basin. 24-Norcholestanes, dinosteranes, 4α-methyl-24-ethylcholestanes and triaromatic steroids have been identified in both source-rocks and crude oils of the East Sirte Basin. Diatoms, dinoflagellates (including those potentially associated with corals) and/or their direct ancestors are amongst the proposed sources of these biomarkers. These biomarker parameters have been used to establish a Mesozoic oil–source correlation of the East Sirte Basin. Hydropyrolysis of an extant coral extract revealed a similar distribution (although immature) of dinosteranes and 4α-methyl-24-ethylcholestanes also observed in the Sirte oils and source-rocks. This is consistent with the presence of dinoflagellates present during the deposition of the Mesozoic aged East Sirte Basin Formations.A good data correlation for the rock extracts revealed a similar distribution of 3,24-dimethyl triaromatic steroids, 3-methyl-24-ethylcholestanes, 4-methyl-24-ethylcholestanes and 2-methyl-24-ethylcholestanes observed in one of the oil families and associated source-rocks for the East Sirte Basin. 相似文献
19.
Saber Al-Rousan Rasheed Al-Shloul Fuad Al-Horani Ahmad Abu-Hilal 《Environmental Earth Sciences》2012,67(7):2003-2013
The concentrations of six heavy metals were studied in five living coral species and their fossil counterparts collected along the Jordanian Coast of the Gulf of Aqaba. The study aimed at investigating the validity of using coral skeletons as bioindicators for environmental pollution by heavy metals in the Gulf of Aqaba, Red Sea. The skeletal samples of the collected corals were acid digested and analyzed for Cd, Cu, Fe, Mn, Pb, and Zn content using flame atomic absorption spectrophotometer. The results obtained have shown that higher concentrations of heavy metals were found in coral skeletons from areas hosting intense developments and human activities. The massive Porites sp. coral tended to accumulate the highest metal concentrations among the other species (except for Mn). This was due to interspecific differences or selectivity of heavy metals between different coral species. It was noteworthy that fossil coral species recorded higher average metal concentrations than their living counterparts; this was attributed to surface contamination due to prolonged burial of the fossil corals in sediment over the years. The study concluded that corals (specially the massive Porites species) are vulnerable to the accumulation of high concentrations of heavy metals in their skeletons and therefore can serve as proxies to monitor environmental pollution. 相似文献
20.
新疆北部泥盆纪床板珊瑚组合特征兼论下、中泥盆统的划分 总被引：2，自引：0，他引：2
《地层学杂志》1986,(1)
<正> 新疆北部阿尔泰山、东、西准噶尔及北天山地区,下、中、上泥盆统皆有床板珊瑚,垂直变化明显,形成了自奥陶纪以来第三个繁盛期。本文将本区泥盆纪床板珊瑚分布规律及其组合特征介绍如下: 相似文献