İzmir‐Ankara suture as a Triassic to Cretaceous plate boundary – data from central Anatolia

The İzmir‐Ankara suture represents part of the boundary between Laurasia and Gondwana along which a wide Tethyan ocean was subducted. In northwest Turkey, it is associated with distinct oceanic subduction‐accretion complexes of Late Triassic, Jurassic and Late Cretaceous ages. The Late Triassic and Jurassic accretion complexes consist predominantly of basalt with lesser amounts of shale, limestone, chert, Permian (274 Ma zircon U‐Pb age) metagabbro and serpentinite, which have undergone greenschist facies metamorphism. Ar‐Ar muscovite ages from the phyllites range from 210 Ma down to 145 Ma with a broad southward younging. The Late Cretaceous subduction‐accretion complex, the ophiolitic mélange, consists of basalt, radiolarian chert, shale and minor amounts of recrystallized limestone, serpentinite and greywacke, showing various degrees of blueschist facies metamorphism and penetrative deformation. Ar‐Ar phengite ages from two blueschist metabasites are ca. 80 Ma (Campanian). The ophiolitic mélange includes large Jurassic peridotite‐gabbro bodies with plagiogranites with ca. 180 Ma U‐Pb zircon ages. Geochronological and geological data show that Permian to Cretaceous oceanic lithosphere was subducted north under the Pontides from the Late Triassic to the Late Cretaceous. This period was characterized generally by subduction‐accretion, except in the Early Cretaceous, when subduction‐erosion took place. In the Sakarya segment all the subduction accretion complexes, as well as the adjacent continental sequences, are unconformably overlain by Lower Eocene red beds. This, along with the stratigraphy of the Sakarya Zone indicate that the hard collision between the Sakarya Zone and the Anatolide‐Tauride Block took place in Paleocene

Foraminiferal biostratigraphy and sequence stratigraphy of peritidal carbonates at the Triassic-Jurassic boundary (Karaburun Peninsula, Western Turkey)

Continuous shallow marine carbonates spanning the Triassic-Jurassic boundary are exposed in the Karaburun Peninsula, Western Turkey. The studied section (Tahtaiskele section) consists of Upper Triassic cyclic shallow marine carbonates intercalated with clastics overlain by Lower Liassic carbonates. Based on the microfacies stacking patterns, three main types of shallowing-upward cycles have been recognized. Cycles are mostly composed of subtidal facies at the bottom, intertidal/supratidal facies and/or subaerial exposure structures at the top. The duration of the cycles suggests that cycles were driven by the precessional Milankovitch rhytmicity. In the sequence stratigraphic frame of the Tahtaiskele section 4 sequence boundaries were detected and globally correlated. The first sequence boundary is located at the Alaunian-Sevatian boundary nearly coinciding with the first appearance of Triasina hantkeni. The second falls in the Rhaetian corresponding to a major sea level fall which led to the invasion of forced regressive siliciclastic deposits over the peritidal carbonates. The third occurs close to the T/J boundary and the fourth lies slightly above the base of the Jurassic. In the studied section, extinction, survival and recovery intervals have been recognized based on the stratigraphic occurrence patterns of benthic foraminifera and algae. Foraminifers became nearly totally extinct in the inner carbonate shelves at the Triassic-Jurassic boundary and an interval of approximately 0.5 my passed before the begining of the recovery of Jurassic foraminifera

End-Permian mass extinction of lagenide foraminifers in the Southern Alps (Northern Italy)

The Permian-Triassic boundary, examined at two sections in the Southern Alps, occurs similar to 1.0 to 1.5 m above the base of the Tesero Oolite Member of the Werfen Formation in a depositionally continuous sequence of inner neritic carbonates. Lagenide foraminifers from the boundary interval comprise 27 species in 15 genera plus additional unidentified taxa, most of which became extinct during the end-Permian crisis. The only survivors were "Nodosaria" elabugae and unidentified species in Geillitzina and Nodosinelloides, with representatives of the latter two genera being short-term holdovers. The end-Permian lagenide extinction level occurs a few decimeters below the biostratigraphically defined erathem boundary, just above the contact between the Bulla Member of the Bellerophon Formation and the overlying Tesero Oolite Member. Confidence intervals (> 96%) for the lagenide extinction at the two sections are 0.03 and 0.04 to thick. Plots of species' stratigraphic abundance versus their last observed occurrences below the estimated extinction intervals at both localities are consistent with abrupt extinction or gradual extinction lasting no more than the time required for 1 m of rock to accumulate. Blooms of the foraminiferal disaster taxa Rectocornuspira kalhori and Earlandia sp. occur in the extinction interval and continue well into the Dienerian part of the Mazzin Member of the Werfen Formation, consistent with a protracted survival phase. A detailed carbon isotope record has been obtained from rocks bracketing the extinction at the well-known Tesero section. The combined microfossil and carbon isotope data indicate that the extinction occurred during an initial negative shift in delta C-13. Therefore, the negative excursion is likely to be related to the cause of extinction and unlikely to be merely a consequence of extinction

Modeling and optimization of bioactive compounds from jujube (Ziziphus jujuba Mill.) vinegar using response surface methodology and artificial neural network: Comparison of ultrasound processing and thermal pasteurization

In recent years, vinegar varieties have been preferred by consumers because of their beneficial effects on human health. Vinegar contains different bioactive components and antioxidants according to the fruit or vegetable used as raw materials. In this study, three different samples of jujube vinegar-traditional jujube vinegar (TJV), pasteurized jujube vinegar (PJV), and ultrasound-treated jujube vinegar (UJV)-were studied. Ultrasound parameters were determined as 6.2 min and 60.6% amplitude. Response surface methodology (RSM) and artificial neural network (ANN) showed a high correlation. After ultrasound treatment, the bioactive components in the UJV samples increased compared with the TJV samples. Caffeic and ferulic acids were identified as the dominant phenolic components in jujube vinegar samples. Jujube vinegar samples contained 22-27 volatile compounds. As a result of the study, ultrasound treatment applied to jujube vinegar positively affected phenolic components, organic acids, volatile components, and mineral content, allowing for the development of a new healthy product. Practical Applications The effects of ultrasound processing on jujube vinegar were investigated in this study. The bioactive qualities of jujube vinegar were enriched by ultrasound. ANN outperformed RSM in terms of correlation.. Mineral and phenolic compounds were affected by ultrasound treatment. Caffeic and ferulic acids are major phenolics in jujube vinegar. The application of ultrasound to jujube vinegar was found to be effective

Triassic Foraminifera From the Great Bank of Guizhou, Nanpanjiang Basin, South China: Taxonomic Account, Biostratigraphy, and Implications for Recovery From End-Permian Mass Extinction

Foraminifera are important components of tropical marine benthic ecosystems and their recovery pattern from the end-Permian mass extinction can yield insights into the Mesozoic history of this group. Here we report the calcareous and agglutinated foraminifera recovered from five measured stratigraphic sections on the Great Bank of Guizhou, an uppermost Permian to Upper Triassic isolated carbonate platform in the Nanpanjiang Basin, south China. The material contains \u3e100 Triassic species, including three that are newly described (Arenovidalina weii n. sp., Meandrospira? enosi n. sp., and Spinoendotebanella lehrmanni n. gen., n. sp.), ranging from Griesbachian (Induan) to Cordevolian (Carnian) age. The species belong to the classes Miliolata, Textulariata, Fusulinata, Nodosariata, and to an unknown class housing all aragonitic forms of the orders Involutinida and Robertinida. Based on previously established conodont zones and carbon isotope chemostratigraphy, the Griesbachian (early Induan) through Illyrian (late Anisian) interval has been subdivided into 12 foraminiferal zones and two unnamed intervals devoid of foraminifera. Following the extinction at the Permian-Triassic boundary, habitable ecological niches of Griesbachian age were invaded by disaster taxa that subsequently became extinct during the Dienerian (late Induan) and left no younger descendants. The disaster taxa were replaced by Lazarus taxa with Permian origins, which were then decimated by the Smithian-Spathian (mid-Olenekian) boundary crisis. The tempo of recovery appears to have been modulated by environmental changes during the Griesbachian through Smithian that involved both climate change and expansion of anoxic ocean bottom waters. Uninterrupted and lasting recovery of benthic foraminifera did not begin until the Spathian

The influence of seawater carbonate chemistry, mineralogy, and diagenesis on calcium isotope variations in Lower-Middle Triassic carbonate rocks

The geological calcium cycle is linked to the geological carbon cycle through the weathering and burial of carbonate rocks. As a result, calcium (Ca) isotope ratios (44Ca/40Ca, expressed as δ44/40Ca) can help to constrain ancient carbon cycle dynamics if Ca cycle behavior can be reconstructed. However, the δ44/40Ca of carbonate rocks is influenced not only by the δ44/40Ca of seawater but also by diagenetic processes and fractionation associated with carbonate precipitation. In this study, we investigate the dominant controls on carbonate δ44/40Ca in Upper Permian to Middle Triassic limestones (ca. 253 to 244 Ma) from south China and Turkey. This time interval is ideal for assessing controls on Ca isotope ratios in carbonate rocks because fluctuations in seawater δ44/40Ca may be expected based on several large carbon isotope (δ13C) excursions ranging from − 2 to + 8‰. Parallel negative δ13C and δ44/40Ca excursions were previously identified across the end-Permian extinction horizon. Here, we find a second negative excursion in δ44/40Ca of ~ 0.2‰ within Lower Triassic strata in both south China and Turkey; however, this excursion is not synchronous between regions and thus cannot be interpreted to reflect secular change in the δ44/40Ca of global seawater. Additionally, δ44/40Ca values from Turkey are consistently 0.3‰ lower than contemporaneous samples from south China, providing further support for local or regional influences. By measuring δ44/40Ca and Sr concentrations ([Sr]) in two stratigraphic sections located at opposite margins of the Paleo-Tethys Ocean, we can determine whether the data represent global conditions (e.g., secular variations in the δ44/40Ca of seawater) versus local controls (e.g., original mineralogy or diagenetic alteration). The [Sr] and δ44/40Ca data from this study are best described statistically by a log-linear correlation that also exists in many previously published datasets of various geological ages. Using a model of early marine diagenetic water-rock interaction, we illustrate that this general correlation can be explained by the chemical evolution of bulk carbonate sediment samples with different initial mineralogical compositions that subsequently underwent recrystallization. Although early diagenetic resetting and carbonate mineralogy strongly influence the carbonate δ44/40Ca values, the relationship between [Sr] and δ44/40Ca holds potential for reconstructing first-order secular changes in seawater δ44/40Ca composition

Microencrusters from the Upper Jurassic–Lower Cretaceous İnaltı Formation (Central Pontides, Turkey): remarks on the development of reefal/peri-reefal facies

A detailed taxonomical study was carried out for the identification of encrusting micro- organisms. Among these microencrusters, Perturbatacrusta leini, Iberopora bodeuri, Calcistella jachenhausenensis, and Pseudorothpletzella schmidi have been taxonomically revealed for the first time in Turkey. Within the biostratigraphic frame of the I. nalti Formation consisting of Mesoendothyra izjumiana zone ( Kimmeridgian), Calcistella jachenhausenensis zone ( Lower Tithonian- Upper Tithonian) and Protopeneroplis ultragranulata zone ( Upper Tithonian- Berriasian), carbonate sedimentation occurred in five depositional environments comprising slope, fore- reef, reef, back- reef and lagoonal environments. The majority of the reefal deposits of the I. nalti carbonates can be classified as coral- microbial- microencruster boundstones, which frequently occur in association with back- reef and fore- reef deposits within the Kimmeridgian- Berriasian interval. A shallowing and a subsequent deepening of water depth in the Berriasian have been revealed by the examination of stacking patterns and vertical evolution of the microfacies. Based on the observed microfacies and general features of micro- encrusting organisms, it is concluded that I. nalti carbonates share many similarities with the reefal carbonate deposits of Intra- Tethyan domain in terms of microfacies types and microencruster content