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Research about Turkey

Source-linked reports with geographic coverage including Turkey.

At least 55 records · Page 3Linked to original sources
USGS1976

Bulk chemical analyses of petrographic thin sections of rocks of the Samli area, western Turkey

Petrographic thin sections have been analyzed for their major-element composition using a fusion-dilution technique and measuring the intensity of X-rays by means of the electron microprobe. The balsam-mounted thin sections were removed from the glass slides by soaking them in methylene chloride. The freed sections were mixed with twice their weight of Li 2 B 4 O 7 , and fused at 1100° C. A fragment of the resulting glasslike bead was mounted for probe analysis. Both wavelength and energy-dispersive detector systems were used for quantitative determinations of elements sodium through iron. Because the samples and standards are diluted and fused, powdered rock standards may be used as reference materials. The calibration curves obtained by plotting X-ray intensity versus concentration of the analyte are linear over the concentration ranges used in this work and have an overall range of error of 2 to 8 percent. Although some of the analytical values show excessive scatter for petrographically similar rocks, in general the analyses are acceptable given the sample size and analytical uncertainties. Bulk chemical analyses were made of 18 thin sections, including altered diabase, amphibolite, and calc-silicate hornfels produced by progressive contact metamorphism and associated with metasomatic magnetite deposits in the Samli area, western Turkey. Normative plots indicate that (1) diabase and amphibolite are compositionally related and are similar to average compositions of basalts and orthoamphibolites, and (2) calc-silicate hornfels appears to have been derived in part from amphibolite and in part from crystalline limestone that underlies much of the region.

Journal of Research of the U.S. Geological Survey↗
USGS1974

Geologic framework of the Kuluncak-Sofular Area, East-Central Turkey, and K-Ar ages of igneous rocks

The Kuluncak-Sofular area, located about midway between Sivas and Malatya in east-central Turkey is underlain by a variety of sedimentary, volcanic, and intrusive rocks. The sedimentary rocks have been deposited on a pre-Campanian serpentinite basement and include Cretaceous conglomerate, graywacke, tuff, and limestone; Eocene arkosic sandstone, conglomerate, and limestone; and Miocene limestone and dolomite. K-Ar ages determined for volcanic and intrusive rocks from the same area are 75.5 m.y. for alkalic diabase that intrudes the Upper Cretaceous sedimentary rocks; 74.3 and 71.1 m.y. for trachyte that partly overlies and partly intrudes the same Upper Cretaceous sequence; 65.2 m.y. for alkalic syenite that intrudes Upper Cretaceous limestone; 18.7 to 16.8 m.y. for andesite and basalt that overlie middle to late Eocene sedimentary rocks; and 14.1 m.y. for a dacite plug that cuts Miocene limestone. © 1974 Geological Society of America.

Geological Society of America Bulletin↗
USGS1972

Massive sulfide copper deposits of the Ergani-Maden area, Southeastern Turkey

The copper deposits of the Ergani-Maden area, in the Taurus Mountains of southeastern Turkey, have been a major source of copper for more than 4,000 years. The area is underlain by gently dipping mudstones interlayered with mafic volcanic rocks and lenticular beds of limestone, mainly of Eocene age. The layered rocks were intruded and slightly metamorphosed by large masses of gabbro and related mafic rocks that are now largely serpentinized. The copper deposits are in an east-trending belt about 20 km long, near the center of which is the town of Maden. A broad geochemical anomaly extends north-northwest and south-southeast from this belt, its axis passing near Maden. Near the mines the main igneous mass has a gently dipping roof and steep sides. Around and south of Maden, where the mass has barely been unroofed, are many roof pendants and remnants of sedimentary and volcanic material. One of these contains the largest mine in the area--the Ana Yatak. The largest deposit, the Aria Yatak ore body, occurs in a canoe-shaped pendant of mudstone that occupies atrough about 1 km long and 1/2 km wide in the top of the intrusive. The present vertical extent is about 170 meters. In the central and western parts of the trough the mudstone is chloritized and partly replaced by ore minerals. The main ore body is about 550 X 300 X 50 m in maximum dimensions. It consists mainly of pyrite and chalcopyrite, and locally it contains abundant magnetite or pyrrhotite. The gangue consists predominantly of chlorite, smaller amounts of quartz, and very minor amounts of calcite and barite. The massive sulfide ore body is underlain by "impregnation ore" in which veinlets and irregular small masses of sulfides are embedded in chloritized mudstone. A zone rich in supergene chalcocite, corellite, and bornite lies between the sulfide mass and the well-developed gossan in many places, and this was extensively mined in ancient times. The Mihrap Dagi mine, about 1 km northwest of the Aria Yatak deposit, is also near a contact between the intrusive and the sedimentary rock. It too contains a massive sulfide ore body accompanied by chloritized rock, but it contains little "impregnation ore." In the Ergani-Maden area, ore deposition followed a long history of sedimentation, lithification, faulting, intrusion of mafic igneous rocks, serpentinization, and further faulting, and was part of a broad-scale introduction of metal into the sedimentary, extrusive, and intrusive rocks. Thus it is epigenetic. The major ore bodies are fracturecontrolled replacement masses. Adularia which occurs in veins a few hundred meters south of the main sulfide ore bodies is inferred to have formed contemporaneously with the sulfide and shows a potassium-argon age of 31.5 +/- 0.8 m.y. If this inference is correcthe deposits formed during middle Oligocene or slightly later.

Ergani-Maden↗
USGS1972

Exploration for iron in the Sakarkaya-Cavdar area, Mugla district, Turkey

Between March 15 and May 10, 1969, previously known iron deposits were studied and new deposits sought in the Sakarkaya-cavdar area, Mugla District, Turkey. The objectives of the geological survey were: 1) to determine the nature, thickness, distribution, and geologic environment of the known deposits near Sakarkaya and cavdar; 2) to determine whether these deposits are in the same zone and if other deposits are present on exten-sions of the zone or zones containing the known deposits; 3) to determine whether two previously known deposits at Sakarkaya, about 600 meters apart,are continuous with one another; and 4) to train three MTA geologists in geological and geophysical methods, and in the evaluation of mineral deposits.

Mugla district↗
USGS1972

Geology of the Karakuz iron mine and vicinity, Hekimhan district, Turkey

The Karakuz mine area located 17 km northwest of the town of Hekimhan in central Turkey was investigated as part of the MTA-USGS Mineral Exploration and Training Project. The fieldwork consisted of geologic mapping supplemented by a magnetometer survey and trenching. The Karakuz mine has been in operation for the past ten years and produced 170,000 tons of iron ore in 1968. The rocks of the area are mafic and ultramafic rocks, limestone, and trachyte intruded by syenite (Cretaceous?), and an Eocene post-intrusive(?) sedimentary sequence. The mafic rocks and the trachyte were altered and mineralized as a result of the syenite(?) intrusion. The mafic rocks were metasomatically altered and the trachyte was partly silicified. Iron oxide minerals are present in the trachyte as irregular replacement bodies and veins and in the metasomatized mafic rocks as veins. A major structure which channeled the intrusion and iron oxide minerals is believed to underlie the area. Steeply dipping fractures trending about N. 80 ° E. and N. 10 ° W. acted as controls on the mineralization. A series of recent post-mineral faults, erosion, and weathering have produced the present landscape. The principal iron deposit is at the Karakuz mine where a central high-grade core is surrounded by low-grade material. The changes in grade reflect changes in the degree of replacement of the trachyte by iron oxides. The minerals are dominantly hematite, but magnetite and limonite are also present. East and west of the mine there are a series of low-grade replacement bodies and veins as well as iron boulder fields. A series of magnetic anomalies are present along the entire 4 km length of the area. The anomalies are interpreted to be caused principally by magnetite-bearing surface boulders and near-surface veins. Only a small part of some of the anomalies may be due to buried deposits of magnetite. The Karakuz mine has a remaining productive life of about 3 years unless low-grade material is mined. This may be feasible if the low-grade is concentrated at the mine. 'Additional exploration of the area is recommended with emphasis on a gravity survey and diamond drilling. Also, an investigation to determine the technical and economic feasibility of utilizing the low-grade material is recommended.

Turkey↗
USGS1972

Geology of the Karamadazi iron mine, Kayseri Province, Turkey

A one-week underground geologic mapping program was conducted at the Karamadazi iron mine in order to describe the mine geology and obtain data that might help in the understanding of other similar deposits in Turkey. The Karamadazi mine is in a contact-metasomatic magnetite deposit 65 km. south-southwest of Kayseri, Turkey. The mine currently produces as much as 60,000 tons of iron ore per year containing approximately 60 percent iron. The mine is at a contact between granite and Permian and Carboniferous limestones. The limestones have been metamorphosed to marble and skarn, and the granite has a syenitic contact phase. The skarn has been partly replaced by massive magnetite ore and by minor quartz, calcite, and pyrite gangue. The main magnetite deposits are in a skarn zone 350-meters long by 20 to 70 meters wide that contains an estimated 40 percent magnetite in very irregular, steeply dipping ore bodies. Additional ore may be present under alluvial cover east of the mine; a magnetic survey of this area is recommended.

Kayseri Province↗
USGS1972

Geologic reconnaissance of the Uzunpinar iron mine and vicinity, Kayseri Province, Turkey

The Uzunpinar iron mine consists of two pits. The lower, larger pit is situated at the edge of a valley and the smaller upper pit is 1.1 km to the southwest on a limestone ridge. The upper pit is near the northern end of a northeast-trending mineralized fault zone that consists of altered limestone, silicified rock, hematite, and some magnetite. The lower pit exposes a west-trending magnetite-hematite lens that is directly on line with the fault zone and probably is controlled by an extension of the fault zone.

Kayseri Province↗
USGS1972

Iron prospect near Kayalar, Balikesir Province, western Turkey

In July 1968 a brief reconnaissance was made of an area about 3 km northeast of Kayalar village, Balikesir Province (1:25,000 topographic sheet 119-a3), as part of the cooperative geologic program being undertaken by the Mineral Exploration and Research Institute of Turkey (MTA) and the U. S. Geological Survey (USGS) under the auspices of the Government of Turkey and the Agency for International Development,U. S. Department of State. The coordinates of Kayalar are approximately 39°50130"N, 27°40'30"E. This investigation was made to check a verbal report that the area contained significant iron mineralization, possibly in the form of a bedded iron deposit.

Balikesir Province, Kayalar↗
USGS1972

Geology of the Otlukilise iron mine, Sivas Province, Turkey

The Otlukilise iron mine consists of two large bodies (260 by 200 m and 240 by 140 m in diameter) and one small body of iron-bearing sedimentary rocks surrounded by massive recrystallized limestone. The iron-bearing strata are composed from the base upward of conglomerate, sandstone, silt-stone, and claystone containing clastic hematite and magnetite. The lime-stone adjacent to these sedimentary rocks contains fracture fillings and replacement deposits of hematite and limonite that apparently formed from iron leached from the sedimentary rocks. The sedimentary rocks form doubly plunging synclines bordered by ring fault complexes. The border faults have an inward dip, which flattens with depth, and appear to die out downward. The iron-bearing strata appear to be sinkhole fillings in which compaction and possible later lowering of the base of the sinkhole steepened the initial inward dips and caused the border faults. Both sedimentary and replacement deposits form ore, although most of the iron-bearing rock at the mine is below ore grade. The principal ore zone lies just below the contact between iron-bearing strata and limestone. Three-quarters of a million tons of ore have been shipped.

Sivas Province↗
USGS1972

Bartin-Amasra earthquake, Turkey, September 3, 1968

A brief examination of the Bartin-were whether earthquake area was made on September 23 and September 24,1968, by the authors to determine whether or not geologic effects had been produced that were significant enough to warrant further detailed study by the Mineral Research and Exploration Institute of Turkey or by the National Center for Earthquake Research of the U.S. Geological Survey. In particular, the questions to be answered were whether this "natural experiment" had produced unique or unusual results that would cast light on means of controlling damage by geologic conditions, and whether or not surface faults or other tectonic deformation, h.ad developed which might help define the geologic control of earthquakes in northern Turkey. The brief field examination was made jointly by personnel of the U.S. Geological Survey and Mineral Research and Exploration Institute of Turkey, because of the interest of both agencies in the earthquake hazard problem. Both agencies had participated in the Conference on Earthquake Hazard Minimization sponsored by the Central Treaty Organization held in Ankara in July 1968. The brief examination was, in part, prompted by the recommendations of the Conference group to take advantage of each significant earthquake to learn "how to live with earthquakes in greater safety." No additional study of this earthquake by either organization seems warranted at this time, and our observations made during the brief investigation are reported here.

Amasra, Bartin↗
USGS1972

Benefaction studies on the Hasan Celebi magnetite deposit, Turkey

Bench-scale and semicontinuous tests were performed on surface, trench, and diamond drill core samples from the Hasan Celebi low-grade magnetite deposit to determine the optimum benefication procedures utilizing wet magnetic separation techniques. Composite core samples typically contain about 27 percent recoverable magnetite and require crushing and grinding through 1 mm in size to insure satisfactory separation of the gangue from the magnetite. Regrinding and cleaning the magnetite concentrate to 80 percent minus 150-mesh is necessary to obtain an optimum of 66 percent iron. Semicontinuous pilot-plant testing with the wet magnetic drum using the recycled middling technique indicates that as much as 83 percent of the acid-soluble iron can be recovered into a concentrate containing 66 percent iron, with minimum deleterious elements. This represents 27 weight percent of the original ore. Further tests will continue when the Maden Tetkik ve Arama Enstitusu (MTA) receives 24 tons of bulk sample from an exploratory drift and cross-cut now being driven through a section of the major reserve area.

Open-File Report↗
USGS1972

Interim results of geological investigations in the vicinity of the Ergani-Maden massive copper deposits near Maden, Elazig, Turkey

As a result of geologic studies and geochemical reconnaissance by Griffitts, Albers, and brier in 1969 in the Ergani-Maden district of eastern Turkey, seven areas were recommended for more detailed investigation. Two of these, here termed Areas 1 and 2, were mapped geologically and sampled geochemically in June and July 1970 by .4. E. Weissenborn, U. S. Geological Survey, and Omer Oner and Metin Sengun, Mineral Research and Exploration Institute (MTA), an agency of the Turkish Government. This study was part of a mineral exploration and training project conducted by the U. S. Geological Survey in cooperation with MTA under the auspices of the Agency for International Development, U. S. Department of State. Mapping and sampling of four of the other areas was completed in August and September by Oner and Sengun, but this report concerns only Areas 1 and 2. The geological environment in Areas 1 and 2 appears favorable for additional ore bodies of the Ergani-Maden type, which have been Turkey's most important producer of copper. Weak but distinct anomalies developed by the geochemical sampling in Area 1 adjacent to the Mihrap Dagi deposit suggest that other ore bodies maybe found along the northwesterly trend defined by the Mihrap Dagi, Arpa Meydan, Ana Yatak mines, and the Mizir Tepe prospect. Recommendations are made for 8 drill holes in Area 1 to test this possibility. Two additional holes are also recommended in Arc.: 1. Two less pronounced anomalies were developed in Area 2. Two drill holes are suggested to test them.

Elazig↗