Cankiri-Corum Basin Research Articles

Characteristic Mollusc, Larger Foraminifera Findings and Environmental Interpretations of the Middle Eocene Kocaçay Formation Deposits Around Ayvalıca (Bayat, Çorum)

Although the Cankiri-Corum Basin was studied for various purposes such as geological, stratigraphical, tectonic, coal and oil exploration, studies on fossils are limited. Especially there have not been detailed studies on molluscs and larger foraminifera. The research area is located at the vicinity of Ayvalica (north of Cankiri-Corum basin). The Middle Eocene Kocacay formation, which outcrops in the Cankiri-Corum Basin, is widespread around Bayat Corum in the north of the basin, Sulakyurt Kirikkale in the west, Cicekdagi Kirsehir in the south and Sungurlu Corum in the middle of the basin. The formation is composed of conglomerate, carbonated sandstone, limestone and sandy marls and also includes rich larger foraminifera and molluscs. This study mainly focuses on taxonomy and environmental interpretations of Ostrea roncaensis (Partsch in coll. Bayan, 1870) de Gregorio, 1884, Velates perversus (Gmelin, 1791) species from Mollusca and Nummulites beaumonti d’Archiac and Haime, 1853, N. aturicus Joly and Leymerie,1848, N. perforatus (de Montfort, 1808) and Assilina exponens (Sowerby, 1840) species from larger Foraminifera. In addition, considering faunal features from bottom to top Ostrea roncaensis, Velates perversus, Nummulites aturicus and Assilina exponens Abundance Biozones were identified. The age range of the Kocacay Formation is determined as Lutetian-Bartonian. Lithological and faunal contents indicate that sediments of the Kocacay formation were deposited within lagoon to nummulitic sets in a shallow marine environment.

Resource estimation for Alpagut - Dodurga coal field and determination of spatial distribution of coal quality parameters

In this study, coal seams of the Alpagut-Dodurga coal field, located in one of Anatolia's most important Tertiary-aged basins of the Cankiri-Corum Basin, were modeled in 3 dimensions by using Netpro/Mine software and geostatistical methods for the estimation of resource amount. Additionally, the spatial distributions of coal quality parameters (lower calorific value, ash content, and moisture content) were determined using the same software and mapped thematically. Mining activities with inaccurate methods and planning lead to unacceptable reserve losses. The selection and planning of effective and economic production methods could be possible with three-dimensional modeling, accurate determination of spatial distributions of quality parameters, and resource estimation. As a result of this study, the present resources estimated from the geologic solid model using Netpro/Mine software was found to be 19.5 × 106 m3. Modeling and 3-dimensional visualizations of resources in a scientific and rational manner with software provides mine planners with realistic production design and planning. These models have great importance in terms of providing quick and more reliable data to mine planners and managers during decision-making processes.

Palaeovegetational evolution of the Çankırı-Çorum Basin during the Mio-Pliocene (Central Anatolia) based on the IPR analysis method

Reconstruction of past vegetation and climates in the Cankiri-Corum Basin, one of the largest basins of Central Anatolia, is important for understanding the regional palaeovegetation. In this study, the palaeovegetational and palaeoclimatic proxies of the basin within the late middle Miocene and early Pleistocene interval are presented using the Integrated Plant Record (IPR) vegetation analysis and the coexistence approach (CA). The IPR analysis allows the reconstruction of six types of zonal vegetation: broad-leaved deciduous forests (BLDF), mixed mesophytic forests (MMF), broad-leaved evergreen forests (BLEF), xeric open woodlands and xeric grasslands or steppes, all identified from the microfloras of Cankiri-Corum Basin. During the late middle Miocene, warm temperate and humid climatic conditions prevailed and the palaeovegetation in the Cankiri-Corum Basin was represented by BLEF and an ecotone between MMF and BLEF. The cooling from the late middle Miocene to early late Miocene had begun as well, as low precipitation periods in the climatic conditions during the same time interval were recorded in the basin. Presumably, the proportion of broad-leaved deciduous elements remained balanced because the palaeotopography did not change significantly during the late Miocene in the Cankiri-Corum Basin. The recorded cooling could be related to a global climatic change from the middle to late Miocene. During the Tortonian to Messinian transition, the palaeovegetation type was represented by BLDF and suggests a continuous cooling trend in the basin. The palaeovegetation types of the late late Miocene comprise MMF in the northern part of the Cankiri-Corum Basin and xeric grassland or steppe in the southern part of the basin. Warm and dry climatic conditions were recorded from the Tortonian to the Messinian; these warm conditions during the Messinian could be correlated to the Messinian salinity crisis. According to the IPR analysis results, the northern part of the Cankiri-Corum Basin palaeotopography seems to be higher in altitude than the southern part. Palaeovegetation types in the latest late Miocene and early Pliocene were characterised by MMF and an ecotone between BLDF and MMF in the northern part of the Cankiri-Corum Basin and open woodland vegetation in the southern part of the basin. The percentage of the broad-leaved deciduous component from the latest late Miocene and early Pliocene decreases in the Cankiri-Corum Basin, which could be related to beginning uplift starting changes in the palaeotopography. In the early Pliocene, this uplift was continued in the basin.

Recent bloedite from İshaklı Lake, Çankırı-Çorum Basin, Turkey: a mineralogical and hydrogeochemical investigation

Bloedite (Na2Mg(SO4)2·4H2O), which is a sodium-magnesium sulfate mineral, has been determined for the first time in Turkey, in the Ishakli Lake within the Cankiri-Corum Basin. The Ishakli Lake is a seasonal playa lake which is an east–west extending lake with an area of 0.22 km2. Geochemical analyses (XRD, XRF, SEM) of the mineral crust samples indicate that they are composed chiefly of bloedite and thenardite (Na2SO4) minerals and lesser amounts of halite (NaCl) and gypsum (CaSO4·2H2O). In the blodite-thenardite association, thenardite mineral grows on bloedite crystals and it is crystallized after bloedite. The well and the spring (and fountain) waters in the vicinity of the lake are saturated with respect to calcite, dolomite, aragonite and talc minerals. In the waters of the Ishakli Lake, however, the degree of saturation of these minerals gradually increases and they become saturated with respect to anhydrite and gypsum as well. Lake waters represent a hydrochemical facies of Na–Mg–SO4–Cl (type I). Tritium data (3H) indicate that lake waters have higher tritium content (7.55 TU) than the springs and fountains (5.45–6.15 TU), and although there is a thick rock-salt drilled at the bottom of lake (to a depth of 220 m), no recent halite precipitation is observed in the lake bottom. This is attributed to recent recharge and the absence of deep groundwater circulation. The δ18O–δ2H data show that spring and fountain waters are in shallow circulation and have undergone a slight evaporation while waters of Ishakli Lake experienced an intense evaporation. According to Mineral Formation Model proposed herein, a portion of the rainfall reaches directly the lake. Additionally, there is recharge from springs, which travel through the Bozkir Formation and reach the lake. During hot periods, evaporation process begins with carbonate and gypsum precipitation as a white-colored crust on the mud flat along the shore of the lake. Therefore, calcium deficit occurs in the lake water. Further evaporation and possible cation exchange process in clay and muds at the lake bottom might be responsible for the formation of Na-sulfate (bloedite + thenardite) mineralization.

Small hyotheriine suids (Mammalia, Artiodactyla) from the late early Miocene of Turkey and a short overview of early Miocene small suoids in the Old World

Suoids are conspicuous components of late early Miocene faunas in Europe, Asia, and Africa. Strikingly, despite a rich fossil record at the Old World scale, no early Miocene suoid remains were known thus far from Anatolia, a region located at the crossroads between Africa, Arabia, Asia, and Europe. Here we describe a fragmentary cranium, mostly preserving the palate, and a dp4 of small suids from the Semsettin locality in the Cankiri-Corum Basin, north Central Anatolia. These remains document the first suoids ever recorded in the Early Miocene of Turkey. Both remains are attributed to the subfamily Hyotheriinae. The fragmentary cranium presents an original combination of characters and is attributed to Nguruwe ? galaticum sp. nov. The isolated dp4, of much smaller size, is here attributed to another hyotheriine taxon of indeterminate genus and species. Nguruwe ? galaticum sp. nov. shows equal affinity with both Asiatic and African Hyotheriinae.

GLAUBERITE-HALITE ASSOCIATION IN BOZKIR FORMATION (PLİOCENE, ÇANKIRI-ÇORUM BASİN, CENTRAL ANATOLİA, TURKEY)

Tersiyer yasli Cankiri-Corum Havzasi, Orta Anadolu’da evaporitik formasyonlar iceren en buyuk havzalardan biridir. Havzada Pliyosen yasli evaporitleri iceren Bozkir formasyonunda yapilan karotlu sondaj calismalarinda sedimantasyon ile es yasli globerit (Na2Ca(SO4)2) ara duzeyleri (sabkha) iceren kalin kayatuzu (halit, NaCI), yataklanmasi tespit edilmistir. Mevsimsel degisimlerin etkin oldugu playa gol - sabkha ortaminda cokelmis olan Bozkir formasyonundaki kayatuzu iceren duzeyler; tuz uyesi olarak ilk defa bu calismada tanimlanmistir. Sabkha-playa gol gecis ortaminda yapilan sondaj calismalarinda, Bozkir formasyonu uc litolojik zona ayrilmistir. Bunlar alttan uste dogru kiltasi-az anhidrit zonu, kayatuzu-kiltasi-anhidrit-globerit zonu (tuz uyesi) ve kiltasi-jipsaz anhidrit zonudur. Tuz uyesi icerisinde kayatuzu 115 m. ye varan kalinliklarda kesilmistir. Cogunlukla tabakali, beyaz, acik/koyu gri, renklerde gozlenen kayatuzu (playa gol), sedimantasyona uyumlu ve dusuk egimlidir. Tuz uyesi icerisindeki globerit cokeliminin en kalin olarak gozlendigi duzey globerit-camurtasi zonu olarak tanimlanmistir. Camurtasi egemen bir matriks iceresinde disk ve rozet sekilli bireysel formlar olarak gozlenen globerit minerali, tuzlu camur duzlugu ortaminda (sabkha), diyajenetik bir mineral olarak olusmustur. Yapilan jeokimyasal analizlerde (XRD, XRF, SEM) sabkha ortaminda karmasik kristal formlari iceren bir matriks icerisinde, anhidrit mineralinden sonra globerit minerali kristallendigi, halit mineralinin de globerit minerali uzerinde buyudugu bazen de catlak ve kirik dolgusu seklinde gozlendigi tespit edilmistir. Ekonomik bir kalinlik olusturmayan globerit minerali cokelimi, bilimsel olarak Cankiri- Corum Havzasinda fosil Na-sulfat cokeliminin varligini ortaya koymak acisindan buyuk onem tasimaktadir.

Geophysical investigation and hydrocarbon potential of Cankiri–Corum Basin, Turkey

The Cankiri–Corum Basin is one of the larger, onshore sedimentary basins in central Turkey. In this paper, the integration of geophysical data and geological findings in the Cankiri–Corum Basin was performed and they both present a complex basin structure. In the frame of geophysical study, two-dimensional (2D) models were constructed using gravity and magnetic anomalies. Seismic sections were interpreted and correlated with the 2D models using the borehole data as control. Basement depth, basin geometry and sources for magnetic anomalies along the 2D model profiles were determined in integration of seismic, gravity, aeromagnetic and borehole data. Seismic section CC-L-1 is correlated with the Topuzsaray-1 well. Tuffs and volcanic units penetrated in this well might be correlated across a reverse fault close to the borehole. Seismic sections, CC-L-2 and CC-L-3, are consistent with the gravity models at the deeper parts of the sections. On the other hand, there are inconsistencies in the shallow sections with the gravity models due to unexpected velocity variations in both the horizontal and vertical directions. The average depth of basement was found to be about 5 km by means of gravity modelling, which was correlated with the seismic sections. Magnetic anomalies are represented by intense values in the NW portion of the study area, but they indicate very low intensities in the middle of the map. A reverse magnetised body to the north of the study area was modelled in 2D along a profile and it was interpreted that this body might be an ophiolitic remnant. Polarities of many anomalies to the south and northeast of the region indicate remanent magnetisation. Alignment of the polarities extends in the northwest direction, indicating that the region rotated in the anticlockwise direction. Because there is around a 5 km sedimentary basin fill in the study area, it may exhibit hydrocarbon potential and the Yesilcat oil seep evidences this potential. Surface samples were collected to examine source rock potential and to correlate with the Yesilcat seep by analysing the organic geochemical properties. In this study, 72 samples were collected from different formations and it was found that the Yoncali Formation displays better source rock potential than the other formations studied.

Sedimentology of the Miocene evaporitic succession in the north of Çankiri-Çorum basin, central Anatolia, Turkey

The upper Miocene non-marine sediments of the Cankiri-Corum basin in central Anatolia, have both evaporitic and non-evaporitic successions. These sediments were deposited in an evaporitic lake which had temporary episodes of palustrine conditions in response to seasonal or climatic changes. The successions show different facies such as sulfates, carbonates and siliciclastics. The sulfates comprise primary, reworked and diagenetic gypsum. The primary deposits are predominantly laminated gypsum, bedded gypsum and selenite. The reworked (detrital) gypsum comprises gypsite, gypsarenite, gypsrudite and breccias. The diagenetic type comprises micro- and macrogypsum nodules. The carbonates mainly include clayey limestone, oolitic limestone and dolomite. The siliciclastics comprise red beds and both channel and non-channel, conglomerates and mudstones. Laminated gypsum, composed of alternating gypsum and dolomite, was a result of environmental schizohalinity. Bedded gypsum was precipitated in the deeper part of the lake during high evaporation periods. Chevron-type selenite crystals formed on saline mud flats during the times of aridity, whereas the discoidal-type seen in the organic-rich mudstones occurred in the gypsiferous marshes during the times of humidity. Reworked (detrital) gypsum dominates the lake margin. These formed during periodic wet episodes that caused reworking of primary gypsum. Gypsum nodules occurred as both early and late diagenetic products. Carbonates and siliciclastics were deposited during the freshening periods of the lake. Climatic or seasonal changes were the main causes of the depositional styles of the upper Miocene evaporitic and non-evaporitic lacustrine deposits in Cankiri-Corum basin. Additionally, the transition upward from alluvial to lake environment implies an important change in drainage patterns that likely occurred as a result of marginal fault activity.

Sedimentological and Petrographical Aspects of Upper Miocene Evaporites in the Beypazari and Çankiri-Çorum Basins, Central Anatolia, Turkey

Upper Miocene evaporites in the Beypazari and Cankiri-Corum basins were deposited in an inter-montane playa–lake complex environment and are intercalated with gypsiferous mudstones and clay-stones. In the Beypazari basin, these evaporites are part of the Kirmir Formation, and in the Çankiri-Çorum basin they occur in the Bozkir Formation. In these two basins, the evaporite minerals comprise mainly Ca-sulfate (gypsum and anhydrite) and Na-sulfate minerals (glauberite and thenardite). The Kirmir Formation consists of a cyclic alternation of gypsiferous claystone, carbonate mud-stone, gypsum-cemented sandstone, alabastrine gypsum rosettes after glauberite, and laminated-banded pseudomorphic alabastrine secondary gypsum after Na-sulfate minerals; at the top, a thick-bedded porphyroblastic secondary gypsum lithofacies is present. The Na-sulfate lithofacies in the Kirmir Formation is dominated by lens-shaped idiomorphic glauberite crystals, which are cemented and/or replaced by thenardite. In the weathering zone of the Na-sulfate deposit, glauberite minerals are transformed to the secondary gypsum that shows a very typical crystalline texture. The main crystalline textures of this secondary gypsum are reticulate, acicular, spindle-shaped acicular, and zigzag textures with acicular crystalline fabric in alabastrine and porphyroblastic secondary gypsum matrix. The Bozkir Formation in the Cankiri-Corum basin comprises, in ascending order, claystone, gypsum-cemented sandstone, laminated to thin-bedded limestone and claystone alternations, nodular alabastrine and porphyroblastic secondary gypsum after anhydrite, laminated secondary gypsum (after gypsarenite?), and thick-bedded alabastrine secondary gypsum after glauberite (at some localities) and claystone alternations, alabastrine micro-nodular secondary gypsum after anhydrite and claystone with displacively grown discoidal gypsum crystal alternation, partly primary and partly secondary gypsum with claystone, and, at the top, selenitic gypsum, a lithofacies of the gypsarenite-gypsiferous claystone alternation. The evaporite sequences of the Bozkir Formation can be divided simply into two parts—a lower part represented by predominantly secondary gypsum and an upper part consisting of mainly primary gypsum (selenites and gypsarenites). Geochemical study of the secondary gypsum after glauberite shows that this type of gypsum has less than 1% Na2O, which is attributed to weathering of the outcrop. Thus, typical secondary gypsum textures after glauberite may be used as a guide in Na sulfate exploration.

Strontium and cesium sorption of some Anatolian zeolites

Zeolite samples of Tertiary age obtained from different areas of Anatolia (Turkey) are classified as Clinoptilolite, Analcime or Heulandite and we have investigated their sorption capacity for Cs+ and Sr2+ ions from aqueous solutions. Quantitative analysis of the zeolite samples untreated and treated with chloride salts of Cs+ or Sr2+ in aqueous solutions, for Na, Mg, Al, Si, P, K, Ca, Ti, Mn and Fe were performed using EDXRF. Chemical analysis indicated that the Clinoptilolite type zeolite from the deposits of Cankiri-Corum Basin of Anatolia is the best sorber for Sr and Cs ions.