Türkiye Jeoloji Bülteni

Abstract: The Umm-Qais plateau is situated in north Jordan, south of the Yarmouk River. It consists of elevenbasalt flows (about 190 m. thickness). The basalt flows belong to the Arabian Harrat volcanism. Petrographical,mineralogical and geochemical analysis of 11 rock samples indicated that the rocks are products of a continentalintra-plate magmatism, mostly as coarse-grained silica-undersaturated olivine-rich alkali basalt (AOB).Nepheline and Fo-olivine are among the normative minerals.The age of the basalt flows can be correlated with the basalt of the northern extension of the Umm-Qaisplateau north the Yarmouk River (Zamlat Bkhila plateau basalt) in the Golan Heights which was found to be3.7±0.36-3.11±0.16 Ma. Flow eruptions are contemporaneous with the second spreading stage of the Red Seaduring the Cainozoic over the past 5 Ma.Analysis of fractures showed mainly four dominant directions, namely ENE/WSW, NW/SE, NNE/SSWand NE/SW. They coincide with the trends of the Red Sea, Dead Sea transform fault, and some other distinct tectonic features.

Abstract: The investigated area is situated to the north of the Eastern Taurus and in the south of the Sivas basin,among Divriği-Sincan and Kangal towns. In this study, it has been aimed to define structural evolution of theregion in the light of main geological characteristics.The basement of the area is represented by a mosaic that is made up of Lower Paleozoic clastic rocks,Upper P ale ozoic-Mesozoic platform type carbonates of the Taurus Relative autochton, allocthons units of UpperCretaceous ophiolitic melange and Jurassic Ophiolitic Suite. The Maastrichtian-Quaternary cover overlies themosaic uncomfortably. The lowermost of the cover starts with a poligenic conglomerate of the Maastrichtian volcano-sedimentary sequence.In the Paleocene, Divriği Granitoides intruded the basement tectonic units and also the Maastrichtianvolcano-sedimentary sequence, as well. In the following, from lower to upper levels, Eocene shallow marinedeposits, Upper Oligocene-Lower/Middle Miocene lacustrine to fluvial rocks, Upper Miocene-Lower Pliocenefluvial to lacustrine deposits, Upper Pliocene-Quternary fluvial elastics to volcanics, alluvium and terracedeposits overlie unconformably the older rock units, respectivelyIn the studied area, Pre-Maastrichtian paleotectonic structures are mainly represented by the overthrustsplunging to the north. Along these overthrusts, allocthonous units obducted the Taurus Relative Autochton.Maastrichtian-Lower Pliocene transitional tectonic structures are represented by the folded systems in the NNWSSE trending to the north, in the NE-SW trending to the south of the region. On the basis of this setting, NEESSW compression is dominant to the north, NW-SE compression is dominant to the south of NE-SW trending riseof the basement rocks, which is made up of paleotectonic units. Upper Pliocene-Quternary Neotectonics structures are represented by conjugate NE-SW and NW-SE trending faults and N-S trending normal faults whose lateral slips is not more than 1 km.On the basis of main geological data presented above, it is suggested that ophiolites and ophioliticmelange of the region moved from north to south, and obducted over the Taurus Relative Autochton. The emplacement of the allocthonous units had been completed before Maastrictian time, and the granitoides had been intruded the region after paleotectonic period.Maastrichtian-Lower Pliocene cover has been folded under the control of the compression in differenttrending processes. In the end of transitional tectonic period, paleotectonic units outcroped along NE-SWtrending rise of the basement rocks in the middle of the study area.Upper Pliocene-Quaternary units of the Neotectonic period have not been folded and NW-SE trendingright lateral and NE-SW trending left lateral conjugate faults and N-S trending normal faults occurred under thecontrol of N-S directing compression. These structures have formed in accordance with the neotectonic processes representing North Anatolian Fault (NAF) and East Anatolian Fault (EAF) systems. 

Abstract: Karacaali magmatic complex, located at 10 km northeast of Kırıkkale town center, within the Kırşehir İ31-altopographic quadrangle of Turkey of 1/25.000 scale, mainly contains iron, copper-molybdenum and lead mineralisations. Karacaali magmatic complex is mainly composed of granitoid, rhyolite/rhyodacite and basaltic rocks Iron mineralisation mainly related to basaltic rocks in Karacaali magmatic complex, copper-molybdenum and lead-zinc mineralisations in granitic rocks are developed related to vertical or nearly vertical quartz,carbonate and turmaline with quartz veins. The main ore minerals are magnetite, hematite, ilmenite, pyrite, chalcopyrite, molybdenite, galena and sphalerite. The iron grade is within the range of 15%-60% FeO and the copper, molybdenum, lead, zinc grades are < 1,4 %, < 0,4%, < 0,1% and < 0,2%.Alteration types related to mineralisation are; tourmalinization, actinolitization, epidotization, chloritization and K-feldspar alteration in granitic and basaltic rocks, and argillation, silicification, alunitization in rhyolite/rhyodacites.Depending on the contact relations together with the structural-textural characteristics and the wall rockalterations, it can be concluded that the iron, copper-molybdenum and lead-zinc enrichments observed inKaracaali magmatic complex are the products of a single magmatic process. It is suggested that these mineralisations are associated with the interaction, assortment, mixing and differentiation processes taking place betweena granitic magma and a basaltic magma.

Abstract: Kumartaş formation, which outcrops in the northwest of Çankırı basin, laterallyand vertically grades in the overlaying Hançili formation. Syn-sedimentary structuresmostly normal faults observed within these units indicate existence of extensional tectonicsin Early - Middle Miocene in the Çankırı basin. These sedimentary units are laterfragmented by an east vergent tectonic sliver after early Pliocene.