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Stage Boundaries In The Mississipian Of Taurides Based On Conodont Data: Statistical Analysis Taxonomy And BiostratigraphyOzdemir, Ayse 01 November 2012 (has links) (PDF)
Conodonts are important biostratigraphic tools for the delineation and calibration of the geochronological boundaries within the Carboniferous and used generally as stage-boundary markers for the Lower Carboniferous (Mississippian). The studied successions in the Central and Eastern Taurides were mainly deposited in a shallow marine environment during the Carboniferous time and they comprise less abundant and diversified conodont fauna. The conodont fauna represented by twenty-four species belonging to ten genera have been described from the studied sections (AS / AAO / BSE and HB) in the Taurides (Turkey). Regarding the first occurrences and last occurrences of biostratigraphically significant species within these sections, the following zones have been established across the Lower Carboniferous successions: (1) Polygnathus inornatus Zone (Hastarian-Lower Tournaisian) / (2) Gnathodus cuneiformis &ndash / Polygnathus communis communis Zone (Ivorian-Upper Tournaisian) / (3) Polygnathus mehli mehli Zone (Ivorian-Upper Tournaisian) / (4) Gnathodus girtyi girtyi Zone (Brigantian-Upper Visean) / (5) Gnathodus girtyi simplex Zone (Pendelian-Lower Serpukhovian) / (6) Rhachistognathus muricatus Zone (Zapaltyubinsky-Upper Serpukhovian) and (7) Declinognathodus inaequalis - Declinognathodus noduliferus Zone (Bogdanovsky-Lower Bashkirian). Based on the recovered conodont assemblages, Visean - Serpukhovian boundary has been recognized by the first occurrence of Gnathodus girtyi simplex and the Mid-Carboniferous boundary is delineated by the first occurrence of Declinognathodus inaequalis, which is an index taxon for the basal part of the Bashkirian. Based on the microfacies studies it can be concluded that conodont elements essentially obtained from the crinoidal bioclastic packstone-grainstone, crinoidal packstone-grainstone, coated bioclastic grainstone, intraclastic grainstone and spiculite packstone facies in the studied sections. It can be concluded that that the occurrence of abundant crinoids are indicative criteria for the presence of conodonts. Additionally, geometric morphometric analyses of biostratigraphically important genus, Gnathodus, on the basis of data available in the literature emphasize the importance of numerical taxonomy and reveal that taxonomic revision of this genus is needed.
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Taxonomy And Distribution Of The Benthic Foraminifera In The Gulf Of Iskenderun, Eastern MediterraneanOflaz, Sabire Asli 01 August 2006 (has links) (PDF)
The present study aims to investigate the foraminiferal assemblages of the recent
samples in terms of abundance and diversity, to determine the bathymetrical and
the geographical distributions of the foraminiferal assemblages. This study
further intends to put forward the responses of foraminifers to environmental
factors (e.g. bathymetry, salinity, substrate, pollution, water currents, etc.) on the
distribution of foraminifers.
In this manner, foraminiferal fauna has been taxonomically identified and
quantitatively analyzed in the 34 grab samples distributed at depths from 18 m. to
190 m. collected from the Gulf of iskenderun. Counting 300 individuals from
each sample, the relative abundances of 151 benthic foraminiferal species
belonging to suborders of Rotaliina, Miliolina, Textulariina, Spirillinina and
Lagenina have been determined.
The relative abundances of samples are dominated by Ammonia tepida / Adelosina
cliarensis, Nonion sp.A, Textularia bocki, Reussella spinulosa, Cribroelphidium
poeyanum, Adelosina pulchella, Buccella granulata, Elphidium advenum and
Nonion depressulum that are also common in the western Mediterranean.
Furthermore, the Lessepsian migrants / Peneroplis pertusus, Septoloculina
angulata, Septloculina rotunda, Septoloculina tortuosa, Vertebralina striata and
Amphistegina lobifera are abundant in only southeastern part of the gulf.
Because of complex distribution scheme of benthic foraminifers, some statistical
analysis (Cluster Analysis, DCA and CCA) have been applied to relative
abundance (percentage) of the most abundant, ecologically important taxa in
order to visualize assemblages and their representative species. Two main
clusters, mainly controlled by CaCO3 and substrate, have been obtained. It is
recognized that the distribution of benthic foraminiferal assemblages are not
strongly depend on depth as it expected.
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Micropalentological Analysis And Sequence Stratigraphy Through Upper Tournaisian Substage In Aladag Unit (central Taurides, Turkey)Dinc, Aksel Tugba 01 December 2009 (has links) (PDF)
The purpose of this study is to investigate the Upper Tournaisian substage within the Carboniferous carbonate deposits of the Aladag Unit in the Hadim region (Central Taurides) based on foraminiferal diversity and to study the meter scale
cyclicity in order to explain the sequence stratigraphic evolution of the carbonate
succession.
In this study, a 27.01 m thick stratigraphic section consisting of limestones and
shales was measured and 89 samples, collected along this section, were analyzed.
Micropaleontological analyses are based on benthic foraminifera. According to
the benthic foraminiferal assemblages, two biozones were identified as Zone Ut1
and Zone Ut2 within the Upper Tournaisian. Zone Ut1 is characterized by a poor
foraminiferal assemblage while the Zone Ut2 consists of a diverse Upper
Tournaisian foraminiferal fauna.
In order to construct a sequence stratigraphic framework and appreciate
depositional environmental changes, microfacies studies were carried out. Seven
microfacies types were recognized and depending on the stacking patterns of these
microfacies types, two fundamental types of cycles, A and B, were identified.
Through the measured section, twenty-five shallowing-upward meter scale cycles and two sequence boundaries were determined. Quantitative analysis of benthic
foraminifera was used to demonstrate the biological response to cyclicity. Since
foraminifers are very sensitive to sea level changes, the abundance of benthic
foraminifera displays a good response to sedimentary cyclicity.
In order to apply a worldwide sequence stratigraphic correlation, the sequence
boundaries and the meter scale cycles of this study were compared with those
described in South China and Western European platform and the Moscow
Syneclise. An Early Tournaisian transgression was followed by a major fall in
relative sea level during the Late Tournaisian. Two sequence boundaries
recognized in the measured section correspond to global sea level falls in the Late
Tournaisian.
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Foraminiferal Paleontology, Biostratigraphy And Sequence Stratigraphy Of The Permian-triassic Boundary Beds Of The Bolkar Dagi Unit (central Taurides, Turkey)Esatoglu, Aysel Hande 01 June 2011 (has links) (PDF)
The aim of this study is to designate paleontologic, biostratigraphic and
sequence stratigraphic characteristics of the Permian-Triassic Boundary beds of the
Bolkar Dagi Unit in the Hadim region (Central Taurides).
For this purpose a 48,06m thick stratigraphic section, composed of limestone,
siltstone and sandstone, was measured and 116 samples were analyzed through the
Permian Ta
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Palynostratigraphic And Palynofacies Investigation Of The Oligocene-miocene Units In The Kars-erzurum-mus Sub-basins (eastern Anatolia)Sancay, Recep Hayrettin 01 August 2005 (has links) (PDF)
Eleven dinoflagellates, acritarchs, and pollen biozones have been identified in Upper Eocene to Pliocene sediments combined from MuS, Tekman, Tercan-ASkale, Pasinler-Horasan basins and the Bayburt-Kars Plateau in this study. FAD& / #8217 / s of Compositae (tubuliflorae type), Slowakipollenites hipophä / eoides, Mediocolpopollis compactus, Monoporopollenites gramineoides and Umbelliferae at the base of Rupelian, FAD of Wetzeliella gochtii in the middle Rupelian, LAD of Ascostomocystis potane in the late Rupelian, LAD of Wetzeliella gochtii in the latest Rupelian, LAD of Deflandrea spp. in the latest Chattian, peak occurrences of Chriptoredium spp. in the early and late Aquitanian, FAD of Hystrichosphaeropsis obscura, followed by FAD of Membranilarnacea ?picena in the late Aquitanian should have particular emphasis for palynostratigraphic divisions in regional correlations and indicate that a continuous deposition took place in Eastern Anatolia from Late Eocene to the end of the Early Miocene. A relatively deeper marine deposition prevailed during the Late Eocene, which was followed by a shallowing-upward deposition during the Oligocene in MuS, Tekman, Tercan-ASkale, and Pasinler-Horasan basins. These basins were also characterized by an Early Miocene regional transgression, and terrestrial (lacustrine and fluvial) deposition during the Late Miocene-Pliocene whereas terrestrial conditions have been predominating since Late Eocene in the Bayburt-Kars Plateau. Paleoclimatological reconstructions of Eastern Anatolian Oligocene-Miocene sediments suggest temperate to subtropical climates in which mean annual temperatures vary between 15,6 to 21,3 ° / C, mean temperatures of the coldest and the warmest month are 5.0 to 13.3 ° / C and 24.7 to 28.1 ° / C, respectively, and mean annual precipitation is 1122.0 to 1522.0 mm.
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Micropaleontological Analysis And Facies Evolution Across The Tournaisian-visean Boundary In Aladag Unit (central Taurides, Turkey)Peynircioglu, Ahmet Ali 01 December 2005 (has links) (PDF)
This study aims to enlighten microfacies evolution and micropaleontological properties of the Tournaisian & / #8211 / Visean boundary in Aladag Unit (Central Taurides, Turkey). Two sections comprising dark shale and dark limestone alternations, including a fairly dolomitized part towards their top are measured. The microfacies analysis suggests a subtidal depositional environment.
Foraminiferal assemblages were distinguished at Section AP and biozonation was documented. The biozonation separates the measured section into three zones, described as A, B and C. Zone A is scarce foraminifera fauna, and mainly contains Earlandia sp. Zone B is defined by appearance of a diversified foraminifera fauna and the first appearance of Lugtonia monilis (Malakhova, 1955) with Eoparastaffella sp. (morphotype 1). Zone C is defined according to the first appearance of Eoparastaffella simplex (Vdovenko, 1964) (morphotype 2) and foraminifers Laxaendothyra ex. gr. laxa. Tournaisian & / #8211 / Visean boundary is defined at the 60th sample, due to appearance of Eoparastaffella simplex (Vdovenko, 1964) (morphotype 2).
Seven microfacies types in section AP, and six microfacies types in section PA are identified and, the intensely sampled part of the measured section AP is separated into 13 shallowing upward meter-scale cycles. These cycles, showing
subtidal character are detected by both repetitions of microfacies and changes in abundance of foraminifers.
A contrasting evaluation of the Tournaisian & / #8211 / Visean boundary of Taurides with Guangxi, South China and Dinant, Belgium is presented. The Chinese stratotype contains a diverse, more complete fauna of Tournaisian - Visean foraminifera, while the Belgium and Turkish sections are scarcer and most probably facies controlled.
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Foraminiferal Paleontology And Sequence Stratigraphy In The Upper ViseanDemirel, Seda 01 September 2012 (has links) (PDF)
The aim of this study is to investigate the Upper Visean substages, delineate the Visean - Serpukhovian boundary with calcareous foraminifera and interpret the foraminiferal evolution and sequence stratigraphical framework by using sedimentary cyclicity across the boundary section. For this purpose a 59,61 m thick stratigraphic section consisting of mainly limestone and partly sandstone and shale is measured in the Aziziye Gedigi and Oruç / oglu Formations in the Pinarbasi Region of Eastern Taurides.
A detailed micropaleontological study has revealed presence of important foraminiferal groups namely, parathuramminids, earlandiids, endothyroids, archaediscids, biseriamminids, fusulinids, loeblichids, tournayellids and paleotextularids and 145 species and three biozones. The biozones are, in ascending order, Eostaffella ikensis &ndash / Vissarionovella tujmasensis Zone (Mikhailovsky / Late Visean), Endothyranopsis cf. sphaerica &ndash / Biseriella parva Zone (Venevsky / Late Visean) and Eostaffella pseudostruvei &ndash / Archaediscids @ tenuis stage Zone (Taurssk / Early Serpukhovian).
A detailed microfacies analysis was carried out in order to understand the depositional history and sedimentary cyclicity and construct the sequence stratigraphic framework of the studied area. Three main depositional environments consisting of open marine, shoal or bank and tidal flat environments were interpreted based on the analysis of 12 major microfacies and 11 sub-microfacies types. Based on the vertical association of microfacies twenty-six cycles, two sequence boundaries and three sequences were recognized in the studied section and these two sequence boundaries, which correspond to the Mikhailovsky and Venevsky horizons, are the records of the global sea level changes during the Late Paleozoic Ice Age. Within this context Visean &ndash / Serpukhovian boundary falls in the transgressive system tract of the third sequence. The duration of cycles are calculated as 117 ky and interpreted as orbitally induced glacioeustatic cycles.
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Campanian-maastrichtian Planktonic Foraminiferal Investigation And Biostratigraphy (kokaksu Section, Bartin, Nw Anatolia): Remarks On The Cretaceous Paleoceanography Based On Quantitative DataGuray, Alev 01 August 2006 (has links) (PDF)
The aim of this study is to delineate the Campanian-Maastrichtian boundary by using planktonic foraminifers. In this manner, Kokaksu Section (Bartin, NW Anatolia) was selected and the Akveren Formation, characterized by a calciturbiditic-clayey limestone and marl intercalation of Campanian-Maastrichtian age, was examined. 59 samples were emphasized for position of boundary.
Late Campanian-Maastrichtian planktonic foraminifers were studied in thin section and by washed samples. Two different biostratigraphical frameworks have been established. Globotruncanid zonation consists of Campanian Globotruncana aegyptiaca Zone, Upper Campanian-Middle Maastrichtian Gansserina gansseri Zone and Upper Maastrichtian Abathomphalus mayaroensis Zone, whereas heterohelicids biozonation includes Campanian Pseudotextularia elegans Zone, Lower Maastrichtian Planoglobulina acervuloinides Zone, Middle Maastrichtian Racemiguembelina fructicosa Zone and Upper Maastrichtian Pseudoguembelina hariensis Zone. Campanian-Maastrichtian boundary was determined as the boundary between Pseudotextularia elegans and Planoglobulina acervuloinides zones and Cretaceous-Tertiary boundary was designated by total disappearance of Late Cretaceous forms. Heterohelicid biozonation has been established in this study for the first time in Turkey.
Collecting 300 individuals from each sample, diversity and abundance of assemblages were analyzed in terms of genus and species. ir evaluation of are important in observation of evolutionary trends and ecological changes. Moreover, evolution of different morphotypes is important in this evaluation. Such a study is new in Turkey in terms of examination of responses of planktonic foraminifers to environmental changes.
Taxonomic framework has been constructed to define each species and differences of comparable forms have been discussed. Both scanning electron microscope (SEM) photographs and thin section photographs were used in order to show se distinctions.
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Evaluation Of A Cenozoic Lacustrine Basin-hancili Formation (kalecik-ankara) And Its Paleoenvironment And Paleoclimate Analysis Based On Mineral FaciesAker, Serdar 01 January 2013 (has links) (PDF)
The major purpose of this study is to evaluate the paleoenvironmental and
paleoclimatological conditions during the Middle Miocene-Early Pliocene in Kalecik-Ankara
by using mineralogical and geochemical proxies from Hanç / ili Formation.
To achieve a high-resolution paleoclimate data, 2 stratigraphic sectioning and 1 continous
core drilling were examined. Field studies were followed by analytical techniques on the
selected representative samples. The mineralogical compositions of the bulk samples and
the minerals of the clay fractions were determined by X-ray diffractometer. Scanning
electron microscopic analyses were also carried on the specific samples which have the
potential to define the important microstructural units. The major and trace elemental
compositions were determined by X-ray fluoresence spectrometer. Additionally, the stable
isotope compositions of the samples selected from the continous core drilling on Hanç / ili
formation were among the major proxies to gather a paleoenvironmental and
paleoclimatrological approach.
All the proxies employed for this study clearly indicate that mineralogical and geochemical
signatures are consistent with each other and can be used for paleoclimatic interpretations.
The stable isotope values point that C4 plants were dominant during the deposition of
Hanç / ili Formation, while evaporation caused the development of alkaline environment which
is seasonally dry with depositional temperature approximately between 25-30° / C. During
deposition, lava flowand tuff were deposited due to the volcanic activity in the vicinity of the
lake. Based on this volcanism, economical bentonite deposits were originated. The lake at
which the Hanç / ili formation was deposited, completed its development in a time to time
silicate rich and salty-alkaline anvironment.
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