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Open Journal of Geology 2018年第9期8卷 925-937页

作者： Peter Sunday Ola Federal University of Technology Akure Nigeria

Forty four (44) different forms of nannofossils recovered from the middle-Miocene to late-Miocene sediments of a section ((8900 - 11,000) ft (2713 - 3353 m)) of a well in the prolific oil producing Niger delta, Nigeria were described and grouped into twelve, though not on phylogenetic relationship, for documentation purpose. The standard strewn-slide technique was used to recover the fossils. The aim is to present the distinguishing morphological features of each of the nannofossils group. Of the recovered forms Genus, Discoaster, was found prominent and divisible into six sub-groups: 6-rayed discoaster with bifurcations, 6-rayed discoasters without bifurcation, 5-rayed discoasters, 5-rayed discoaster with acute bifurcations, 5-rayed nannolith and the indeterminate forms. Genus Sphenolithus recovered is also divisible into two: species without prominent apical spines and species with prominent, monocrystalline apical spines. Other genera found and described are Catinaster, Cyclicargolithus, Coccolithu, Minylitha, Syracosphaera, Helicosphaera, Pontosphaera, Calcidiscus and Reticulofenestra. All the nannofossils fall within NN11, NN10, NN9, NN8 and NN5 zones belonging to the Middle-Late Miocene age.

关键词： nannofossils Morphology Niger Delta Discoaster Sphenolithus Miocene

Miocene to Pliocene Paleoceanography of the Western Equatorial Pacific Ocean Based on Calcareous nannofossils, ODP Hole 805B

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Open Journal of Geology 2012年第2期2卷 72-79页

作者： Meutia Farida Ryo Imai Tokiyuki Sato Institute of Applied Earth Sciences Faculty of Engineering and Resource Science Akita University Akita Japan

We describe in detail the Miocene to Quaternary paleoceanography of the western equatorial Pacific Ocean based on calcareous nannofossils of Hole 805B. The relative abundance of Discoaster which lived in the lower photic zone under the stable sea with nutricline and thermocline, decreased step by step at NN5/NN6 and NN10/NN11 boundaries. Al- though the size of Reticulofenestra which is strongly influenced by nutrient, increased five times throughout the section, it drastically decreased in NN4-5 zone, NN10, NN12, and in NN15/NN16 boundary. On the basis of the relationship between Discoaster abundance and Reticulofenestra size change, collapse of the stability of the sea surface in the west- ern equatorial Pacific Ocean progressed step by step throughout the Miocene to Quaternary.

关键词： Paleoceanography Calcareous nannofossils Discoaster Reticulofenestra Nutricline Thermocline

Investigation of the Boundary between Abderaz and Kalat Formations Based on Calcareous nannofossils in West Kopet-Dagh (NE IRAN)

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Open Journal of Geology 2013年第3期3卷 178-186页

作者： Mohammad Anvar Moheghy Fatemeh Hadavi Behname Rahimi Department of Geology Faculty of Science Ferdowsi University of Mashhad Mashhad Iran

The biostratigraphy of calcareous nannofossils of the Cretaceous is investigated in the boundary between Abderaz and Kalat Formations through the record of species richness, diversity and distribution patterns in the west Kopet-Dagh region. The Kalat Formation comprising of coarse-grained detritus limestone with subordinate sandstone intercalations and the Abderaz Formation mainly consists of limestone, Shale and Limy marl. nannofossils of this boundary in each of studied sections are listed and figured. 21 species in?Ghalehzoo section, 29 species in Sheikh section and 19 species in Jozak section have been determined. Boistratigraphy based on calcareous nannofossil allow the identification of nannofossil standard zones CC21 and CC26 in all of sections, According to these zones in all of sections, the age of the studied thickness is Early Late Campanian-Late Late Maastrichtian in these sections.

关键词： nannofossils Biostratigraphy Abderaz Kalat Iran Kopet Dagh

Multi-Elemental Chemostratigraphy,Sequence Development,Depositional History,and Environmental Importance of Early Eocene Red Beds(Kuldana Formation)in NW Himalayas,Pakistan

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Journal of Earth Science 2024年第2期35卷 349-375页

作者： Amir Shahzad George Kontakiotis Thierry Adatte Khawaja Shoaib Ahmed Muhammad Tayyib Riaz Hammad Tariq Janjuhah Evangelia Besiou Institute of Geology University of Azad Jammu and KashmirMuzaffarabad13100Pakistan Department of Historical Geology-Paleontology Faculty of Geology and GeoenvironmentSchool of Earth SciencesNational and Kapodistrian University of AthensPanepistimiopolisZografou15784Greece Institute of Earth Sciences(ISTE) University of LausanneLausanneCH-1015Switzerland Department of Geology Shaheed Benazir Bhutto UniversitySheringalPeshawar18050Pakistan

The Eocene Kuldana Formation(KF)in the Yadgar area of Pakistan,comprises a diverse range of sedimentary facies,including variegated red beds of shales,mudstones,and sandstones,as well as interbedded limestone and *** this study,we conducted an integrated micropaleontological,sedimentological,mineralogical,and geochemical investigation to determine the depositional setting,biochronology,provenance,and paleoclimate of the *** study identified six lithofacies and six microfacies,which indicate a variety of environments ranging from floodplains and channels to the margins and shallow marine *** nannofossil biostratigraphy places the KF in the Early Eocene,more precisely the NP10 zone(Ypresian),and the fossil zone of benthic foraminifera classifies the study section as the Shallow Benthic Zone SBZ-8(Middle Ilerdian 2).In terms of petrography,the KF sandstone was classified as litharenite and feldspathic litharenite,while the QtFL diagram suggests a recycled *** proxies indicate an oxidizing environment,a high-to-low regular sedimentation rate,moderate-to-intense chemical weathering in the source region,and a warm-humid to dry climate during the deposition of ***,the findings suggest that the deposition of KF marks the end of Neo-Tethys due to the Early Eocene Indian–Kohistan collision and that the uplifting of the Himalayas provided the source for the deposition of KF in the foreland *** study provides new insights into the depositional environment,biochronology,provenance,and paleoclimate of KF,and highlights the potential for red beds as reliable indicators of oxygenation levels in proximity to mineral deposits.

关键词： sedimentary microfacies Paleocene–Eocene thermal maximum stratigraphic correlations paleoenvironmental reconstruction nannofossils paleontology

Oldest Asian Record of Snapping Shrimps(Malacostraca:Alpheidae)from the Kutch Basin,Western India and Associated Biota:Biostratigraphic,Paleoenvironmental and Paleoecological Significance

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Acta Geologica Sinica(English Edition) 2022年第6期96卷 1867-1883页

作者： Vivesh V.KAPUR Kamlesh KUMAR Pranav J.PANDYA Amit KGHOSH Arindam CHAKRABORTY Anupam SHARMA Gaurav CHAUHAN M.G.THAKKAR Birbal Sahni Institute of Palaeosciences 53University RoadLucknow 226007India Department of Biology Shri R.R.Lalan CollegeBhujKachchh DistrictGujaratIndia Institute of Earth Sciences Academia SinicaTaipeiTaiwan 11529China Department of Earth and Environmental Science K.S.K.V.Kachchh UniversityBhujKachchh DistrictGujaratIndia

The oldest Asian record of alpheid shrimps,assigned to genus Alpheus,based on snapping claw fingertips from the Miocene Khari Nadi Formation in the Kutch Basin,western India reported herein,extends the fossil record of the family Alpheidae from Asia by~22 million *** early Miocene(Aquitanian)age is estimated based on the associated assemblage of calcareous nannofossils,Sphenolithus disbelemnos,Cyclicargolithus floridanus,and Reticulofenestra *** co-occurring microbiota includes bony fish otolith remains,identified as“genus Gobiidarum”,isolated teeth of Dasyatis rays,Sphyrna sharks,and teleosts,ctenoid and placoid scales,ostracods,belonging to the genera Paractinocythereis,Alocopocythere,Ruggieria,Aglaiocypris,Bairdoppilata,and echinoid *** together,the microfossil assemblage and data from chemical analyses using Energy Dispersive Spectroscopy,X-Ray Diffraction and Wavelength Dispersive X-Ray Fluorescence of host and associated lithologies suggests prevalence of a shallow(neritic)to coastal marine(intertidal)depositional *** present investigation also provides the oldest fossil evidence on the co-occurrence of Alpheus and gobiids(based on otoliths)that strongly advocates that the mutualistic association between these animal groups had developed by the Aquitanian.

关键词： biostratigraphy Crustacea Caridea Elasmobranchs Gobiidae invertebrate and vertebrate paleontology nannofossils Oligocene-Miocene Indian subcontinent

Biostratigraphy,Depositional and Diagenetic Processes in Carbonate Rocks from Southern Lebanon:Impact on Porosity and Permeability

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Acta Geologica Sinica(English Edition) 2021年第5期95卷 1668-1683页

作者： Hammad Tariq JANJUHAH Josep SANJUAN Mohammad ALQUDAH Mohamed K.SALAH Department of Geology American University of BeirutRiad El-SolhBeirut 11072020Lebanon Department of Geology Shaheed Benazir Bhutto UniversitySheringalDir Upper 18050Pakistan Department of Earth and Environmental Sciences Yarmouk UniversityIrbid 21163Jordan

Carbonate rocks contain prolific hydrocarbon reserves all over the world,particularly in the Middle *** exploration and production strategies,it is essential to understand carbonate reservoirs in terms of their internal characteristics,depositional environment,relative age,diagenetic processes and impact on petrophysical *** study has been performed on exposed Cretaceous,Paleocene and Miocene marine carbonate sedimentary sequences in two localities(Maghdoucheh and Qennarit)near the city of Sidon(Southern Lebanon).It represents the first comprehensive study that takes into consideration the carbonate reservoir facies,diagenetic history and reservoir quality in the *** at Maghdoucheh are mainly dominated by limestone beds showing sedimentary structures and erosive bases alternating with microfossil-rich silty marls,related to a shallowing upward sequence in a restricted marine platform *** of benthic foraminifera and mollusks dominate the fossil assemblage extracted from the studied *** microfossil and nannofossil assemblage detected in the Maghdoucheh sections indicates a middle Miocene *** at Qennarit are composed of mudstone/wackestone limestone beds rich in planktonic foraminifera and nannofossils related to open marine *** on the nannofossil content,rocks from Qennarit 1 and 2 are Paleocene and Cretaceous in age,*** main types of microfacies have been identified,i.e.(1)microbioclastic peloidal calcisiltite,(2)pelagic lime mudstone and wackestone with planktonic microfossils,(3)grainstone/packstone with abundant foraminifera and(4)fenestral bindstones,mudstones and packstones with porostromate *** porosity-permeability(poro-perm)analysis of representative samples reveals moderate to good porosity but very low *** is mainly due to the presence of large moldic pores that are isolated in *** diagenetic features are dominated by micritization and dissolut

关键词： lithofacies diagenesis microfossils nannofossils reservoir quality Middle East carbonates

Possible markers of the Jurassic/Cretaceous boundary in the Mediterranean Tethys:A review and state of art

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Geoscience Frontiers 2011年第4期2卷 475-490页

作者： Jozef Michalik Daniela Rehkov Slovakian Academy of Sciences Geological InstituteDubravska cesta 9P.O.Box 106840 05 BratislavaSlovak Republic Comenius University Faculty of Natural SciencesDepartment of Geology and PalaeontologyMlynska dolina G-1842 15 BratislavaSlovak Republic

During the last decades,several integrated studies of Tethyan Jurassic/Cretaceous boundary sections from different countries were published with the objective to indicate problems for the selection of biological,chemical or physical markers suitable for identification of the Jurassic/Cretaceous boundary-the only system boundary within the Phanerozoic still not fixed by *** the boundary between the Jurassic and Cretaceous systems is a matter of global scale *** problem of proposing possible J/K boundary stratotypes results from lack of a global index fossils, global sea level drop,paleogeographic changes causing development of isolated facies areas,as well as from the effect of Late Cimmerian *** contribution summarizes and comments data on J/K boundary interval obtained from several important Tethyan sections and shows still existing problems and discrepancies in its determination.

关键词： J/K boundary Interregional correlation Biostratigraphic proxies Calpionellids nannofossils

Late Maastrichtian Calcareous Nannofossil Biostratigraphy and Paleoecology of the Tamera Well, Siwa Area, Western Desert, Egypt

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International Journal of Geosciences 2013年第6期4卷 985-992页

作者： Esam Zahran Geology Department Faculty of Science Damanhour University Damanhour Egypt

The upper Cretaceous interval of the Khoman Formation in the Tamera well, Siwa area, Western Desert of Egypt was studied for the first time on the basis of calcareous nannofossils. Twenty-one nannofossil species were identified from this interval. The study interval includes the Micula murus Zone, which is precisely dated as Late Maastrichtian age. The Micula murus Zone includes besides the marker species: Micula decussata, Watznaueria barnesae, Arkhangelsktella cymbiformis and relatively rare occurrences of Eiffellithus turrisieffellii, Cribrosphaerella ehrenbergii, Thoracosphaera operculata and Braarudosphaera bigelowii. The latest Maastrichtian Micula prinsi Zone is missing, and an unconformity surface is detected in this well. The high abundance of Micula decussata is indicative of very low surface productivity and high-stress environmental conditions. Several nannofossil species are recognized as cool water indicators such as Micula decussata, and Arkhangelsktella cymbiformis.

关键词： Formation nannofossils Micula Prins Late Maastrichtian