Türkiye Jeoloji Bülteni

Abstract: Karalar barit e - galena deposits are the typical examples of the carbonate hosted barite - galena, deposits oc curedin the Central Tauride Belt Ore deposits (Büyük and Boy alık Mines) of the area occured in the limestones of thePermian Bıçkıcı Formation as ore veins along the fault zones which are discordant to the bedding planes.Microscopic and XRD studies show that the ore deposits mainly contain barite (80 - 85 %) and galena (10 - 15 %)and small amounts of sphalerite, pyrite, fahlerz, limonite, quartz and calcite. Barit e s were occurred during the earlierepisode of mineralization and mylonitized before than the galena formation. The measurements of TfM, T m ICE an(^ ^H during the fluid inclusion studies indicate that the ore deposits of thearea were developed by hydrothermal fluids with following characteristics; the presence of the salts of CaCl2 andMgCİ2 which indicate that the fluids are of sea water o rig ine or circulated in the marine sediments, the salinity of thefluids were relatively high and their temperature were low during the crystallization of barites (earlier episode ofmineralization), and the salinity of the fluids decreased while their temperatures increased during the crystallizationof sulfide m inerals {later episode of m ineralization).The disharmonies between the salinity and temperature of the fluids during the early and later episode ofmineralization may be explained as; the fluids were siuficial o rig ine (either meteoric or sea water) rather thanmag mat ic origine and the fluids which circulated in the shallow depth were sligtly warmed, dissolved the Ba andsulfate from the marinal sediments of the basement and transported to the mineralization environment during theearly episode, while the deeply circulated fluids were heated up to the higher temperatures, dissolved the Pb, Zn andother elements from the basement and reached to the environment during the later episode of mineralization.

Abstract: Divriği (Sivas) A-B kafa mineralizations show stratigraphic and tectonic relationships to Murmano plııton,Akdağ limestones and serpentinized ultramafic rocks in Güneş ophiolite. The magmatic-hydrothermal system thatcontrols the mineralizations is related to emplacement, crystallization and cooling of the Late Cretaceous Murmanopluton. The plutonic rocks have been experienced a pervasive alkaline metasomatism resulting in scapolitizationfollowed by a potassic alteration with a secondary K-feldspar formation. The mineralization is hosted by thesemetasomatic rocks, and as endoskarns. The exoskarn are not observed  are not of importance and limited to a fewveinlets within the serpentinized ultramafic rocks. The alterations and mineralizations were formed in threesuccessive stages in the region. The first prograde stage, dominates in region known as A-kafa, This phase is resultedin the formation of metasomatic zones starting from granitoids (central parts) to serpentinites as scapolite, scapolitegarnet zones. The retrograde stage consists of phlogopite-magnetite+K-feldspar (iscapolite ±gamet) zones. Theproducts of this stage is observed in the B-kafa region and also in the A-kqfa region as superimposing and replacing the prograde assemblages. The late-alteration stage, which is the last stage, is represented by hematite,limonite, goethite and sulfide mineralizations formed by hybrid hydrothermal systems in brecciated, sericitized andcarbonated rocks. The B-kqfa mineralizations that are regarded as the continuum of hydrothermal system forming theA-kafa mineralizations have a conical shape thinning downward. Therefore, it resembles to breccia pipes anddiatremes in Fe-oxide-Cu-Au systems. The contacts of brecciated rocks with recrystallized limestones are mainlysharp, while it is sheared and faulted with serpentinized rocks. The silicification and carbonization that increasedownward is accompanied by sulfide mineralization. However, martitized zones grade downward in massivemagnetite bearing zones. The sericities at shallower levels and barite-bearing limestones in contact with thesegranitoids represent the late and low temperature products of the hydrothermal system.

Abstract: Glacial andperiglacial features ofLate Quaternary age are observednear Geyikdağ (Centra! Taurus Mountains) inU-shaped valleys located at an altitude of more than 2000 in and surrounded by mountain ranges reaching 2850 in.The Namaras Valley and its tributary Susam Valley are characterized by coarse loose materialforming chaotic knoband-kettle topography covering more than 30 knT. Mounds, 1-10 m high and 10-30 hi wide, are separated by 5-30 mwide, few meters deep, irregular depressions. The uppersurfaces of the mounds are covered by angular to şubatıgularlimestone pebbles and blocks and internal sediments show a typical diamicton appearance with pebbles suspended ina muddy to sandy matrix. These chaotic structures are interpreted as hummocky disintegration morainesfrom form erglaciers. Several morainic ridges, up to 200 m high and more than 500 m long that limit the hummocky moraines areinterpreted as ice-marginal lateral, and terminal moraines. In the tributary Susam Valley, part of the coarse loosematerial forms a tongue-shaped structure with successive arcuate ridges and furrows al its down valley reach. Thisstructure, which is connected upward to a talus slope and perched cirque, ressembles the morphology of a periglacialrock glacier but is interpreted as the disintegration moraine controlled by small periodic retreat and readvance of thelast active, ice-front in this region. The distribution of valley glaciers and sedimentological aspects of the related moraines are poorly known inTurkey. The identification: of different types of moraines and their deposition®! conditions in Geyikdağ providehnportctnt information in the understanding of dynamics, magnitude and timing of Late Quaternary glaciations inTurkey. 

Abstract: Preseni day glaciers and Late Quaternary glacier related landforms and deposits in Turkey occur in 3 majorregions: J. The Taurus Mountain Range, 2. The Politic Mountain Range and 3. Volcanoes and independent mountainsscattered in the A natolian plateau.The Taurus Mountain Range (Mediterranean coast and SE Turkey); Two thirds of the present day glaciers areconcentrated in the SE pan. Among these, Mount Clio (4168 m) alone supports more than ten glaciers. Hem the actual snowline changes between 3400-3600 m and the Last Glacial snowline is estimated to have been at around2800. In the Central part, Aladağ (3756m) and Bolkardağ (3524 m) constitute two of the most important mountainswhere modern glaciers, although very small, are present. Even though there are signs of past glacial activity (LastGlacial snowline is estimated to be around 2200 m), no glaciers are present in the W Taurus Mountains today.The Pontic Mountain Range (Eastern Black Sea coast): The highest peak of the Pontic Range is Mount Koçkar(3932 m,) where five glaciers are developed. Several other mountains such as Verçenik (3710 m)} Bulut (3562 m),Altıparmak (3353 m), Karagöl (3107 m) and Karadağ (3331 m) also support various glaciers. The modern snowlineelevation is much lower on the north facing slopes (3100-3200 m) compared to that of south face (3550 m), becauseof the effect of more humid air masses. The Last Glacial snowline elevation was 2600 m on average.Volcanoes and independent mountains scattered in the Anatolian plateau: In the interior of the country, volcanoessuch as Mount Ararat (Ararat) (5165 m), with an ice cap of 10 km2; Mount Şüphem (4058 m) and Mount Erciyes(3917 m) show signs of glacial activity and active glaciers. On the other hand, Mount Uludağ (2543 m), MountMercan (3368 m) and Mount Mescid (3239 m) in Central A natolia also bear traces of past glacial activity.Asa whole, very limited data are available on Turkish glaciers, and recent observations indicate a glacier recessionat least since the beginning of the 20th century.