Ultimate morphological changes before the end-permian extinction: Changhsingian smaller foraminifera from the southern biofacies belt in Turkey

The Changhsingian of the Southern Biofacies Belt in Turkey is widely distributed in the Arabian Platform and in the Geyik Dagi and Aladag tectonic units and the Antalya Nappes of the Anatolide-Tauride Block. From non-fusulinoidean Fusulinata two distinct evolutionary trends, both belonging to the family Globivalvulinidae, occur in the Changhsingian. In the globivalvulinin trend, Paraglobivalvulina originated from Globivalvulina vonderschmitti close to the Capitanian-Wuchiapingian boundary commonly occurs in the latest Permian. Among the other descendants in this stock, Charliella, seems to have gone extinct at the Wuchiapingian-Changhsingian boundary and Urushtenella derived from Paraglobivalvulina occurs rarely in the Changhsingian. From the Septoglobivalvulina-Paraglobivalvulinoides lineage Paraglobivalvulinoides is rather rare and sporadic. One of the most remarkable evolutionary trends in the Southern Biofacies Belt is in the dagmaritin-type globivalvulinids. Paradagmarita, derived from Crescentia very close to the Wuchiapingian-Changhsingian boundary, comprises three distinct species (P. monodi, P. flabelliformis, P. planispiralis) in the Changhsingian. A new genus originated from Paradagmarita in the younger levels of the Changhsingian is characterized by a hook-shaped apertural flap protecting partly the apertural system. In addition, Paradagmacrusta derived from Paradagmarita close to the Wuchiapingian-Changhsingian boundary and Louisettita originated from Dagmarita in the late Wuchiapingian commonly occur in the Changhsingian.In the Southern Biofacies Belt, although Nodosariata occurs abundantly, colaniellids are totally absent. Syzraniidae, Protonodosariidae, Geinitzinidae, Robuloididae, Frondinidae and Pachyphloiidae frequently occur. From robuloidids, the genus Robuloides is frequent and displays distinct morphological variations close to the Permian-Triassic boundary.Several genera belonging to Miliolata, such as Agathammina, Hemigordius, Midiella, Neodiscus, Multidiscus, Neodiscopsis and Glomomidiellopsis occur rarely to commonly in the Changhsingian of the Southern Biofacies Belt. Among these taxa, distinct evolutionary changes occurred in the populations of Glomomidiellopsis (G. uenoi, G. lysitiformis). The genus Kamurana s.s. was probably derived from Glomomidiellopsis in the late Changhsingian

Late Cretaceous-Eocene Geological Evolution of the Pontides Based on New Stratigraphic and Palaeontologic Data Between the Black Sea Coast and Bursa (NW Turkey)

The Late Cretaceous-Eocene geological evolution of northwest Turkey between the Black Sea and Bursa was studied through detailed biostratigraphic characterization of eleven stratigraphic sections. The Upper Cretaceous sequence in the region starts with a major marine transgression and lies unconformably on a basement of Palaeozoic and Triassic rocks in the north (Istanbul-type basement) and on metamorphic rocks and Jurassic sedimentary rocks in the south (Sakarya-type basement). Four megasequences have been differentiated in the Late Cretaceous-Eocene interval. The first one, of Turonian to Late Campanian age, is represented by volcanic and volcanoclastic rocks in the north along the Black Sea coast, and by siliciclastic turbidites and intercalated calcarenites in the south, corresponding to magmatic arc basin and fore-arc basin, respectively. A major ridge along the present southern margin of the Kocaeli Peninsula separated these two realms. In the Late Campanian, volcanism and clastic sedimentation gave way to the widespread deposition of the pelagic limestone and marl of the Akveren Formation; only in the extreme south near Bursa are the pelagic micrites of the Akveren Formation replaced by calciturbidites and siliciclastic turbidites. The age of the Akveren Formation ranges from Late Campanian to Late Palaeocene. The third megasequence is a thick flysch wedge of Early Eocene age, which extends from north of Bursa to the Black Sea coast. The base of the Lower Eocene flysch is marked by a major unconformity. The flysch wedge marks the collision between the Pontides and the Anatolide-Tauride Block. The fourth megasequence is a thick volcanic and volcaniclastic series of late Early to Middle Eocene age, which extends from north of Bursa to the northern margin of the Armutlu Peninsula. The coherent Upper Cretaceous-Eocene stratigraphy, the laterally traceable facies belts, absence of ophiolitic slices and high pressure metamorphic rocks in the Upper Cretaceous-Tertiary series in the region between the Black Sea and Bursa indicate pre-Santonian juxtaposition of the Istanbul and Sakarya zones

Petrolgy of the volcanic/subvolcanic members of the volcanosedimentary Maden Complex in Eastern Turkey

Maden Complex exposed in Eastern Turkey, is a succession of volcano-sedimentary rocks and tectonically overlain by Bitlis Metamorphics and Cretaceous ophiolitic rocks. The succession includes shallow-water deposits and deep marine pelagic sediments intercalated with pillow lavas ranging from a few centimeters to ten meters in diameter. The planktonic foraminiferal assemblages from micritic limestones and zircon U-Pb ages from selected sedimentary rocks indicate the age of Late Ypresian - Early Lutetian. Plagioclase and clinopyroxenes are the main mineral phases, olivine rarely found as altered phenocrysts. Clinopyroxenes are augite and diopside, and their compositions are ranging between Wo44-51, En27-43, Fe10-21. The anorthite contents of plagioclases are between 32- 67 % in unaltered grains. The crystallization temperatures and pressures obtained from clinopyroxene chemistry are ranging from 1126 to 1250oC and 3 to 8 Kbar, respectively. The majority of the volcanic/subvolcanic rocks are subalkaline-tholeiitic basalts however; a few andesitic and rhyolitic derivatives are also present. The whole – rock and Sr-Nd-Pb isotope compositions reveal that the basaltic rocks are originated from E-MORB like asthenospheric mantle source without a subduction component

Geological and Geochemical Evolution Of Eocene Maden Volcanism (Eastern Anatolia)

Maden Kompleksi Kahramanmaraş’ın kuzeyinden başlayıp Van’ın güneyine kadar devamlılığı takip edilebilen volkanosedimanter bir kayaç topluluğudur. Bu çalışma Maden Kompleksi’nin Çatak (Van)- Kozluk (Batman) arasında yüzeylenen volkanitlerinin jeolojik ve petrolojik özelliklerini konu almaktadır. Güneydoğu Anadolu Orojenik Kuşağı’nın nap zonunda yer alan kompleks, çalışma alanı içerisinde Bitlis Metamorfitleri ve Kretase yaşlı ofiyolitik birimler tarafından tektonik olarak üzerlenmektedir. Maden Kompleksi konglomeratik bir istif olan Ceffan Formasyonu, numulitlialveolinli kireçtaşından oluşan Arbo Formasyonu, pembe-kırmızı renkli ve yer yer kumtaşı şeyl ardalanmaları içeren Melefan Formasyonu, çoğunlukla bazaltik volkanik kayaçlardan oluşan Karadere Formasyonu, Bitlis Masifi’ni kesen subvolkanik dayklar ve kumtaşı şeyl ardalanmasından oluşan Narlıdere Formasyonu ile karakterize edilmektedir. Denizel sedimanların planktonik foraminifer yaşları Erken-Orta Eosen’e, sedimanter birimlerden elde edilen en genç detritik zirkon yaşları Üst Eosen’e, mağmatik birimlerin tüm kayaç 40Ar/39Ar plato yaşları ise Erken-Üst Eosen’e işaret etmekte olup havzada çökelimin ve mağmatizmanın Erken Eosen’den-Üst Eosen’e kadar devam ettiğine işaret etmektedir. Başlıca plajiyoklas + klinopiroksen ± olivin ± amfibol fenokristallerinden oluşan volkanik/subvolkanik kayaçlar çoğunlukla subalkali-toleyitik bazaltlardan oluşmaktadır ve nadiren andezitik ve riyolitik türevleri de bulunmaktadır. Klinopiroksen kimyası kullanılarak hesaplanan sıcaklık ve basınçlar volkanitler ve dayklar için benzer kristallenme koşullarına işaret etmektedir. Elde edilen değerler volkanitler için sırasıyla 1125-1260℃ ve 1,6-10,8 Kbar arasında, dayklar için 1076- 1215°C ve 1,2-9,4 Kbar arasında değişmektedir. AFC modellemeleri volkanik/subvolkanik kayaçların, kabuksal litolojilerden kontaminasyona uğradığını göstermektedir. Elde edilen veriler Maden Havzası’nın Bitlis-Pütürge Masifi üzerinde açılan bir havza olduğuna işaret etmektedir. Kuzeye doğru Bitlis-Pütürge Masifi’nin altına dalan Arap levhasının okyanusal litosferinin Erken Eosen döneminde kopması, Erken-Geç Eosen aralığında yitim bileşeninden bağımsız astenosferik mantoyu karakterize eden lavların havzanın güneyine, yitim bileşeni içeren ergiyiklerin ise havzanın kuzeyine yerleşmelerine sebep olmuştur

The Eurasian epicontinental sea was an important carbon sink during the Palaeocene-Eocene thermal maximum

The Palaeocene-Eocene Thermal Maximum (ca. 56 million years ago) offers a primary analogue for future global warming and carbon cycle recovery. Yet, where and how massive carbon emissions were mitigated during this climate warming event remains largely unknown. Here we show that organic carbon burial in the vast epicontinental seaways that extended over Eurasia provided a major carbon sink during the Palaeocene-Eocene Thermal Maximum. We coupled new and existing stratigraphic analyses to a detailed paleogeographic framework and using spatiotemporal interpolation calculated ca. 720–1300 Gt organic carbon excess burial, focused in the eastern parts of the Eurasian epicontinental seaways. A much larger amount (2160–3900 Gt C, and when accounting for the increase in inundated shelf area 7400–10300 Gt C) could have been sequestered in similar environments globally. With the disappearance of most epicontinental seas since the Oligocene-Miocene, an effective negative carbon cycle feedback also disappeared making the modern carbon cycle critically dependent on the slower silicate weathering feedback.</p

Baudiella stampflii n gen n sp and its position in the evolution of Late Permian ozawainellid fusulines

The name Baudiella is proposed for a new ozawainellid fusuline genus characterized by the presence of septal folds in the mature stage of spirally coiled test. Baudiella evolved directly from Reichelina in the early Changxiangian (Late Permian) and constitutes a different lineage within the evolution of the parareichelinin stock

Mudurnu-Göynük Havzası’nın (Orta Sakarya Bölgesi) Kretase-Paleojen Sınır Tabakalarında Planktonik Foraminifer Biyostratigrafisi, Türlerin Sayısal Analizleri ve Paleoortamsal sonuçlar

Özet:Jeoloji tarihinde kaydedilen en önemli toplu yok olma olaylarından biri Kretase-Paleojen sınırında (K-Pg) gerçekleşmiş ve Üst Kretase planktik foraminiferlerinin tümü (Guembelitria cretacea, Hedbergella holmdelensis ve Hedbergella monmouthensis türleri hariç) bu sınırda yok olmuştur. Bu katastrofik yokoluşun denizel ortamlarda en güçlü verileri planktik foraminiferlerden elde edilmekte ve K-Pg sınırı planktik foraminiferleri temel alarak birçok global ölçekteki araştırmaya konu olmaktadır. Türkiye’de ise bu sınırı içeren istifler genelde yüksek çözünürlülüğü olmayan biyostratigrafik amaçlı çalışmalarda ele alınmıştır. Bu proje kapsamında Mudurnu-Göynük Havzası Kretase-Paleojen sınır istifi planktonik foraminiferler kullanılarak ayrıntılı bir şekilde çalışılacaktır. Sık aralıklarla (2-5 cm aralıklarla) toplanan örneklerden elde edilecek olan planktonik foraminifer türleri ile Kretase-Paleojen sınır tabakalarında yüksek çözünürlüklü bir biyostratigrafik çatı kurulacaktır. Bu veriler ışığında Kretase-Paleojen sınırı ayrıntılı bir şekilde (2-5 cm lik bir aralıkta) belirlenecektir. Her örnekten toplanacak 300 planktonik foraminifer bireyi ile türlerin topluluk içindeki biyo-çeşitliliği ve bollukları belirlenecektir. Bu sayısal analizler planktonik foraminiferlerin K-Pg sınırındaki evrimleşme ve yok oluş modelleri yanında (ani veya dereceli olup olmadığı) yokoluştan sonraki evrimsel gelişimlerinin gözlemlenmesine de yardımcı olacaktır. Mikrofasiyes analizleri yapılac

Danielita gailloti n.gen., n. sp., within the Evolutionary Framework of Middle-Late Permian Dagmaritins

The name Danielita is proposed for a new dagmaritin genus characterized by a biserial arrangement of chambers with spine-like extensions at chamber corners and a perforated wall. Danielita differs from Dagmarita, from which it was derived, by a perforated wall and constitutes one of the peculiar evolutionary trends of the dagmaritin stock. Early dagmaritins evolved from Globivalvulina cyprica by the appearance of Sengoerina in the Capitanian and the frequently encountered association G. cyprica-Sengoerina-Dagmarita-Danielita in Turkey suggests that the evolutionary derivations of dagmaritin genera occurred very rapidly in the Capitanian