Türkiye Jeoloji Bülteni

Abstract: Zunächst werden kurz die Untersuchungsmethoden erwähnt unddann die physikalisch-chemischen Entstehungsbedingungender untersuchten natürlichen Vorkommen nach petrologischenGesichtspunkten festgestellt. Nach der begleitenden Diopsid-Wollastonit-Andradifazies ist anzunehmen, dass das kontakt - metasomatische Zinkblendevor- kommen von Bağırkaç(im Eybek Granodioritmassiv) bei 500 bis 1000 Bar Druck und400° bis 500°C Temperatur entstanden ist. Dagegen rechtfertigen die spektroskopischen Analysen des Karakoca - Vorkommens (im Eğrigöz - Karakoca Granit- massiv) einen hydrothermalen Entstehungsbereich bei 100 bis 200 Bar Druck und 200°bis 300°C Temperatur.Weiter wurden die Pyrrhotingehalte und die Gitterkonstanten derZinkblendemischkristalle auf die Apsis - und Ordinatenachseneines Koordinatensystems aufgetragen und die Zusammenhänge diskutiert. Es konnte gezeigt werden, dass in den natürlichenZinkblendemischkristallen das VEGARD - Gesetz bis 10 % FeSGehalt gilt.Schliesslich wurden die analytischen Daten in die, aus den Literatür übernommenen Synthesediagramme eintgetragen undVergleiche gezogen. Es wurde gezeigt, dass die Ablesung derBildungstemperatur allein aus dem FeS - Gehalt der Zinkblende nicht möglich ist. İn übereinstimmenden Fällen kann dieserals Wegweiser dienen. Wie auch aus den Ietzten Synthesediagrammen hervortritt, nimmt der FeS-Gehalt derZink-blende mit abnehmender Temperatur zu. DieseFeststellung steht mit den älteren Anschauungen imW i d e rspruch.

Abstract: Dans des certaines parties de la région de Samandağı - Hatay, la qualité de l`eau est salée; il n`est guère possible de résoudrele problème de l`extesion de salinité par les méthodes géochmiques et tes sondages que l`on a déjà forés.II est donc bien connu que les méthodes géoélectriques s`appliquent couramment à la résolution de ces genres problèmes.Les paramètres électriques peuvent être calculés en utilisant desméthodes ée resistivité à partir de la surface.II est fort possible de résoudre les problèmes concernant les qualités des eaux, en déterminant ces paramètres qui correspondentaux propriétés électroniques et éléctrolitiques des roches, dansdes zones noncimentées et saturées 100 % par l`eau.Nous tenterons ici d`expliquer la résolution de l`interférence del`eau salée - nonsalée et les résultats que nous avons obtenus;selon lesquels nous voulons également montrer la coincidenceentre les forages proposés et effectués. 

Abstract: The Carboniferous stratigraphy of İstanbul is describedwith special reference to the western part of Bosporus (Thracianarea). On the basis of particular stratigraphic successions ,andstructural features the Thracian area is subdividied in subareas of Istinye, Kâğıthane, Cebeciköy ,and Zekeriyaköy.The upper part of a predominantly nodular limestone unit(Büyükada fm.) is subdivided in two members, in ancendingorder: Ayineburnu ,and Küçükyalı. The Ayineburnu member iscomposed of thin-to medium - bedded nodular limestone ,andlaminated calcareous shales ,and ranges from Late Devonian toEarly Tournaisian in age. İt conformably overlaps the older Devonian strata on Ordovician rocks. The Küçükyalı member isrepresented by channel-filled turbidite graywacke ,and shale. TheBaltalimanı formation is mainly composed of lydites ,and subordinate siliceous shales. İt is Early / Middle Tournisian, / both,in age. The Trakya formation is characterized by thick shales,graywackes ,and lithic - conglomerates which are highly variableboth lateraly ,and vertically. The flysch facies, anyway interrupted, is predominant. On the basis of fine- ,and coarse-clastics ,anddistribution of carbonates the Trakya formation is subdividedin three members, in ascending order: Acıbadem, Küçükköy ,and Çamurluhan. The formation ranges from Late Tour-naisian to nearly Late Middle Visean in age. The Acıbadem memberconsists of shale ,and claystone with limestones intercalated.The Küçükköy member is composed of shales, thick-beddedgraywackes, lithic-conglomerates ,and subordinate limestones.The Çamurluhan member is mainly made up of shales with graywckes, lithic-and quartz - conglomerates, ,and limestones. Theshales become sandier ,and pebbly toward the north. The thickness, the biofacies, likewise change in the same direction. Atthe north, the shales are the time equivalent of the lower part ofthe overlying Cebeciköy limestone. The Cebeciköy limestone İscomposed of bioclastic limestone, subordinate shales, secondary dolomite ,and chert. The unit is of shelf-edge carbonate type ,and is Late Middle to Middle Late Visean in age. The Gümüşdere formation consists of graywacke, feldispathic garywacke,feldispathic conglomerate, shale ,and Iydite. The basal siliceousshale ,and Iydite designated the Kartaltepe member. İn the souththe siliceous shales predominate which gradationally overlie theCebeciköy limestone. İn the north, the lydites discordantly reston the lower sections of the Çamurluhan member. The flora ofthe member is in favor of a Late Visean- Namurian age. The maingraywacke section of the formation is of flysch facies. Minorcoal seams are present in the uppermost part of the formation.The Çiftalan formation consists of medium-to thick - bedded,subgraywackes. İt strikes parallel with the Gümüşdere formation ,and bears some compositional similarity to it. The Değirmendere formation consists of aphanitic limestone, clayey limestone ,and intraformational limestone - breccia. Secondary dolomitization is widespread. The poor microfauna bears the commonelements for Carboniferous ,and Permian. The Uskumruköy formation is composed of reddish shales, at its base ,and pebblygraywackes, on its higher section. The contact to the underlying limestone is obscured. Some coalified plant remnants occursparodically in the sandstones.İn the Thracian area the late Laramide phases appear to havebeen responsible for a large part of the deformation. Three Alpine stages are differentiated, in relative age : (a) overturnedfolds, steep thrust faults which are arranged along a WNW linemay be virtually connected with the thrusting towards the north- Zekeriyaköy overthrust-, (b) mosaic-fault system, resulted inby the release tectonic, (c) sinistral strike-slip faults with the NEtrend. The N trends, more / less separated from the Alpine features, can be attributed to the Varistic.

Abstract: Vanadinite ,and desclozite of secondary lead mineralsoccur in a cave between the ovelying dolomite marble ,and the sericitecale schist at the bottom of the Keban metamorphic massive, Elazığ county East Turkey.The minerals having different mineralogical properties show distinct zoning marking changes in composition during the formation.These supergene products of the lead ,and zinc deposit are believed to take their lead, zinc ,and copper content from the primary sulphides. The secondary deposit is lithogene in origin beingformed by lateral secretion.It is most unlikely that the occurrence indicates that additionallead-zinc ore bodies can be found further away from the knownare bodies. 

Abstract: Harhor formation (Late Middle Eocene) outcrops in asmall syncline, situated to the north of the Haymana Anticline.The formation overlies the Çayraz formation (with abundant nummilites ,and assylinas) with a thin conglomerate ,and consists ofalternations of thick (50-200 cm.) sandstones ,and thin mudstone bands. Total visible thickness of the formation is 255 m. Theupper part, forming the centre of the syncline, is eroded. Thesecalcareous sandstones contain approximately 20 % muddy matrix ,and consist of volcanic rock fragments (more than 50 % byvolume), metamorphic schist, granite, limestone ,and chert fragments, as well as angular quartz, orthoclase ,and abundant calcicpiagioclase. Thus, the rock may be named as a litharenite, / evena volcanic - arenite. Heavy minerals consist of mainly glaucophane, garnet, apatite, zircon ,and tourmaline, in addition to abundantopaque iron minerals ,and a few others. The first three mineralsshow a good correlation in their «abundance» (Norman, 1969) within the rocks.Sediments of Harhor formation are probably derived from variouscomplex sources : basic volcanic, metamorphic, sedimentary ,andacid intrusive areas. In technically active geologic conditions, theywere first accumulated in relatively shallow marine waters (neritic environment) where from time to time, they formed submarineslumps, turning in turbidity currents. These currents resedimented the materials as turbidites in the deeper parts of the basins.The increase / decrease of abundance of various heavy mineralgroups at different stratigraphic levels may be explained by differential uplift in the source areas ,and widespread climatic changes which affected the rate of erosion.