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Full-Text Articles in Physical Sciences and Mathematics

Post-Collisional Magmatism On The Northern Margin Of The Taurides And Its Geological Implications: Geology And Petrology Of The Yahyalı-Karamadazı Granitoid, Gonca Gençali̇oğlu Kuşcu, M. Cemal Göncüoğlu, İlkay Kuşcu Jan 2001

Post-Collisional Magmatism On The Northern Margin Of The Taurides And Its Geological Implications: Geology And Petrology Of The Yahyalı-Karamadazı Granitoid, Gonca Gençali̇oğlu Kuşcu, M. Cemal Göncüoğlu, İlkay Kuşcu

Turkish Journal of Earth Sciences

The Karamadazı Granitoid (Yahyalı-Kayseri) is a typical example of bimodal magmatism on the northern margin of the Eastern Tauride belt. The Karamadazı Granitoid intrudes the Palaeozoic-Mesozoic Yahyalı metamorphic rocks and is unconformably overlain by Upper Maastrichtian clastics. It consists of granodiorite-quartz diorite as the main intrusive phase, and includes leucogranites and aplitic dykes in its marginal parts. Samples from the Karamadazı Granitoid are calc-alkaline and calcic in character. The granodiorites are mainly metaluminous, whereas leucogranites and aplites are weakly peraluminous in nature. Plots of major-element oxides against SiO2 indicate a poor fractionation trend for the granodiorites. The leucogranites represent highly …


Metamorphic And Tectonic Evolution Of The Hırkadağ Block, Central Anatolian Crystalline Complex, Donna L. Whitney, Yildirim Di̇lek Jan 2001

Metamorphic And Tectonic Evolution Of The Hırkadağ Block, Central Anatolian Crystalline Complex, Donna L. Whitney, Yildirim Di̇lek

Turkish Journal of Earth Sciences

The Hırkadağ metamorphic block is a NE-SW-trending horst structure that is part of the Kırşehir Massif in the Central Anatolian Crystalline Complex (CACC). Along its southwestern margin, the block contains upper amphibolite facies metapelitic rocks that record peak metamorphic conditions of 670-710 °C, ~ 7 kbar, as determined by garnet-biotite geothermometry and garnet-sillimanite-plagioclase-quartz, garnet-rutile-sillimanite-ilmenite-quartz, and garnet-rutile-ilmenite-plagioclase-quartz geobarometry. A clockwise pressure-temperature path is inferred from thermobarometric results and analysis of reaction textures among aluminous phases. Following this medium-pressure metamorphism, low-pressure - high-temperature metamorphism resulted in widespread replacement of garnet by cordierite + spinel + sillimanite, partial replacement of spinel by corundum, …


Repetitive Subtidal-To-Coastal Sabkha Cycles From A Lower-Middle Miocene Marine Sequence, Eastern Sivas Basin, Faruk Ocakoğlu Jan 2001

Repetitive Subtidal-To-Coastal Sabkha Cycles From A Lower-Middle Miocene Marine Sequence, Eastern Sivas Basin, Faruk Ocakoğlu

Turkish Journal of Earth Sciences

In the study area, southeast of Zara in the Sivas Basin, the Lower-Middle Miocene marine Karacaören Formation consists of a succession of marine sedimentary rocks deposited within two trangressive-regressive cycles. The present study focuses on the facies characteristics, cyclic nature, and significance of the basin-wide distribution of a 100-m-thick gypsiferous sedimentary package overlying an otherwise transgressive segment of the lower sequence, within a marine setting. The typical lithologic expression of the studied sedimentary interval comprises generally fossiliferous mudstones, rare algal limestones and nodular gypsum. Detailed sedimentological observations, combined with palaeontological evidence, indicate that the mudstone intervals were deposited in a …


Stratigraphy, Geochemistry And Depositional Environment Of The Celestine-Bearing Gypsiferous Formations Of The Tertiary Ulaş-Sivas Basin, East-Central Anatolia (Turkey), Erdoğan Teki̇n Jan 2001

Stratigraphy, Geochemistry And Depositional Environment Of The Celestine-Bearing Gypsiferous Formations Of The Tertiary Ulaş-Sivas Basin, East-Central Anatolia (Turkey), Erdoğan Teki̇n

Turkish Journal of Earth Sciences

Celestine-bearing evaporite mineralization is widespread in the Tertiary evaporitic units of the Ulaş-Sivas Basin, east-central Anatolia. The oldest deposition of gypsum, which is of laminated character, occurred in a shallow inner-lagoonal environment or in depressions during Late Eocene regression. Thick gypsum and overlying beds composed of alternating bedded, nodular gypsum and sandstone developed in coastal sabkhas and abandoned channels within a meander-river complex during Oligocene time. The last occurrence of evaporitic units, namely massive and bedded gypsum alternating with sandstones and fossiliferous limestones, resulted from limited marine transgression of an Early Miocene sea along the southern margin of the Sivas …


Extensional Tectonics And The Geometry Of Related Macroscopic Structures: Field Evidence From The Gediz Detachment, Western Turkey, Hasan Sözbi̇li̇r Jan 2001

Extensional Tectonics And The Geometry Of Related Macroscopic Structures: Field Evidence From The Gediz Detachment, Western Turkey, Hasan Sözbi̇li̇r

Turkish Journal of Earth Sciences

The large-scale, low-angle Gediz detachment fault that constitutes the southern margin of the Gediz graben (also known as the Alaşehir graben) has macroscopic structures of extensional origin, such as folds and back-tilted strata. The folds were formed as antiformal and synformal structures with axes both parallel and perpendicular to the extensional direction in their footwalls and hanging-walls, respectively. An extension-parallel antiform-synform pair in the footwall of the Gediz detachment, namely the Oyukkıran antiform and the Keserler synform, are recognized south of Dereköy village (Salihli) on the southern margin of the Gediz graben. These are NE-trending domal and basinal structures with …


The June 6, 2000, Orta (Çankırı, Turkey) Earthquake: Sourced From A New Antithetic Sinistral Strike-Slip Structure Of The North Anatolian Fault System, The Dodurga Fault Zone, Ali̇ Koçyi̇ği̇t, Bora Rojay, Mustafa Ci̇han, Arda Özacar Jan 2001

The June 6, 2000, Orta (Çankırı, Turkey) Earthquake: Sourced From A New Antithetic Sinistral Strike-Slip Structure Of The North Anatolian Fault System, The Dodurga Fault Zone, Ali̇ Koçyi̇ği̇t, Bora Rojay, Mustafa Ci̇han, Arda Özacar

Turkish Journal of Earth Sciences

The İsmetpaşa-Kargı section of the North Anatolian Fault System (NAFS) consists of six subfault zones, namely the Eskipazar, the Ulusu, the Tosya, the Çerkeş-Kurşunlu, the Devrez and the newly detected Dodurga fault zone (DFZ). Together these fault zones form a well-developed dextral strike-slip-faulting pattern, in which the DFZ is an antithetic secondary strike-slip component, indicated by focal-mechanism solutions of moderate and large earthquakes that have occurred in the İsmetpaşa-Kargı section of the NAFS. The DFZ is a ~36-km-long, ~N-S-trending strike-slip structure located in the area between Saçak village in the north and Kösrelik village in the south. Pre-Upper Pliocene rocks …


Characteristics Of The Weathering Zones Developed Within The Tuffs Of The Midas Monument, Tamer Topal, Burak Sözmen Jan 2001

Characteristics Of The Weathering Zones Developed Within The Tuffs Of The Midas Monument, Tamer Topal, Burak Sözmen

Turkish Journal of Earth Sciences

The Midas monument, an impressive cult facade located in the southern part of the Eskişehir province in central Anatolia, Turkey, was made within tuffs (white and pink), which now have deterioration problems. In this study, the depth and characteristics of the weathering zones that have developed in the white and pink tuffs have been investigated through thin-section studies, X-ray powder diffractometry, methylene blue adsorption tests, major-element analyses, and some index parameters. It has been determined that the feldspar minerals are mechanically fractured due to weathering. The tuffs contain small amounts of clay minerals. An approximately 1-cm-thick silica-rich zone has developed …


Tectonic Implications Of Some Cretaceous Pillow Basalts From The North Anatolian Ophiolitic Mélange(Central Anatolia-Turkey) To The Evolution Of Neotethys, Bora Rojay, Kenan M. Yaliniz, Demi̇r Altiner Jan 2001

Tectonic Implications Of Some Cretaceous Pillow Basalts From The North Anatolian Ophiolitic Mélange(Central Anatolia-Turkey) To The Evolution Of Neotethys, Bora Rojay, Kenan M. Yaliniz, Demi̇r Altiner

Turkish Journal of Earth Sciences

The most widespread blocks within the North Anatolian ophiolitic mélange of central Anatolia (Turkey) are ophiolitic fragments, Jurassic-Cretaceous carbonate blocks and pillow basalts. The blocks of pillow basalts have an immobile trace-element geochemistry that is characteristic of ocean-island alkali basalts. An N-MORB-normalized spider diagram shows a distinctive enrichment of most incompatible trace elements and exhibits a far greater range of absolute abundances than N-MORB. Selected incompatible-element contents and ratios of basalts show high Ba/Nb (~8),low Zr/Nb(~5)and low La/Nb(~0.5)relative to N-MORB. The presence of thin-shelled \"Protoglobigerina\" and Cadosina associated with miliolids and epistominid foraminifers indicates that the age of the pink …


Geochemistry And Mineralogy Of The Skarns In The Çelebi District, Kırıkkale, Turkey, İlkay Kuşcu Jan 2001

Geochemistry And Mineralogy Of The Skarns In The Çelebi District, Kırıkkale, Turkey, İlkay Kuşcu

Turkish Journal of Earth Sciences

The Çelebi district is well known for its polymetallic Fe-W and Cu vein ores. These ores are hosted by calcic skarn zones, which are broadly classified as \"intrusive around skarn\" type. Both exoskarns (pyroxene-garnet) and endoskarns (epidote-pyroxene) occur in the district. The formation of endoskarns is manifested by complete replacement of plagioclase by epidote and pyroxene; the epidotized granitoids are regarded as incipient and/or early metasomatic products. The abundance of pyroxene in endoskarns tends to increase with plagioclase content and within the groundmass of the granitoids towards exoskarn zones. The increase in pyroxene is also coincident with the formation of …


Development Of A Basic Gis Database For The Yeşilırmak Watershed Provinces Using Satellite Images And Other Data, Hülya Yildirim, Erhan Alparslan, Mehmet Emi̇n Özel, Ci̇hangi̇r Aydöner, Samuray Eli̇taş, Nalan Jale Di̇van, Mehmet Dağci, Asli Süha Dönertaş Jan 2001

Development Of A Basic Gis Database For The Yeşilırmak Watershed Provinces Using Satellite Images And Other Data, Hülya Yildirim, Erhan Alparslan, Mehmet Emi̇n Özel, Ci̇hangi̇r Aydöner, Samuray Eli̇taş, Nalan Jale Di̇van, Mehmet Dağci, Asli Süha Dönertaş

Turkish Journal of Earth Sciences

Remote-sensing and geographic-information-systems (GIS) techniques were jointly used in this study to establish a GIS database system for the Yeşilırmak watershed provinces, which include Amasya, Tokat, Çorum, Yozgat and Samsun. Composite multicolour images (down to 6 m resolution) from the LANDSAT TM and Indian IRS C/D satellites, land-use/land-cover maps derived from these images, road networks, soil information, digital terrain model, slope and aspect information derived from digital elevation data and meteorological data at province level are the major constituents of this database. A 'project office' has been established with trained personnel at each province centre to effectively use the resultant …


A Proposal For A Method To Establish Natural-Hazard-Based Land-Use Planning: The Adapazarı Case Study, Alper Çabuk Jan 2001

A Proposal For A Method To Establish Natural-Hazard-Based Land-Use Planning: The Adapazarı Case Study, Alper Çabuk

Turkish Journal of Earth Sciences

As a result of recent disasters in northwest Turkey (Marmara earthquake August 17, 1999/Düzce earthquake November 12, 1999), many buildings collapsed and many people experienced physical and mental problems. We can suppose that the problems caused by these earthquakes will be solved in the future, but geological studies show that the problems will not disappear in that many scientists are predicting a new disaster that will affect the same region. A design of natural-hazard land-use planning for minimising the consequences of recent and possible earthquakes is presented herein. The Adapazarı case is used to demonstrate the fundamentals of this study. …


Obituary, Aral İ. Okay, M. Cemal Göncüoğlu Jan 2001

Obituary, Aral İ. Okay, M. Cemal Göncüoğlu

Turkish Journal of Earth Sciences

No abstract provided.