On the geodynamics of the Alpine collisional granitoids from Central Anatolia: petrology,age and isotopic characteristics of the granitoids of the Ekecikdağ Igneous Association (Aksaray/Turkey)

Granitoids of the Ekecikda? Igneous Association (Central Anatolia/Turkey) are products of collisional–post-collisional magmatism in the Ekecikda? area. These granitoids are granodiorite, microgranite and leucogranite. Field relations of granodiorites with microgranites is obscured, but leucogranites intrude both rock types. Mean zircon laser ablation (LA)-ICP-MS ²⁰⁶Pb-²³⁸U ages of granodiorites and microgranites are 84.52 ± 0.93 Ma and 80.7 ± 1.6 Ma, respectively, and age of leucogranites is suggested as 80 Ma, based on field relations combined with ²⁰⁶Pb/²³⁸U and Rb-Sr ages. Crystallisation temperatures of granodiorites, microgranites and leucogranites are 728°C-848°C, 797°C-880°C, 704°C-809°C, respectively.

Geochemical characteristics including Sr-Nd isotopic evidences infer a non-cogenetic character, as there is a high crustal contribution in I-type granodiorite sources, a crustal source with insignificant and significant mantle inputs in S-type microgranites and leucogranites, respectively. LA-ICP-MS Lu-Hf isotope data from zircons reveal their crustal nature (εHf_(t): ?1.3 ± 0.5 to ?8.8 ± 0.5). Crustal melting linked to the Alpine thickening during the Late Cretaceous led to formation of heterogeneous sourced granitoids with crustal dominated sources in the Ekecikda? area. Understanding of the nature and evolution of collisional Ekecikda? granitoids is not only important to put contribution in the geodynamic evolution of Central Anatolia and surrounding Alpine area, but also to better understand systematics of collisional magmatic systems.     

Erratum to: Review of post-collisional volcanism in the Central Anatolian Volcanic Province (Turkey), with special reference to the Tepekoy Volcanic Complex

Neogene-Quaternary post-collisional volcanism in Central Anatolian Volcanic Province (CAVP) is mainly characterized by calc-alkaline andesites-dacites, with subordinate tholeiitic-transitional-mildly alkaline basaltic volcanism of the monogenetic cones. Tepekoy Volcanic Complex (TVC) in Nigde area consists of base surge deposits, and medium to high-K andesitic-dacitic lava flows and basaltic andesitic flows associated with monogenetic cones. Tepekoy lava flows petrographically exhibit disequilibrium textures indicative of magma mixing/mingling and a geochemisty characterized by high LILE and low HFSE abundances, negative Nb–Ta, Ba, P and Ti anomalies in mantle-normalized patterns. In this respect, they are similar to the other calc-alkaline volcanics of the CAVP. However, TVC lava flows have higher and variable Ba/Ta, Ba/Nb, Nb/Zr, Ba/TiO₂ ratios, indicating a heterogeneous, variably fluid-rich source. All the geochemical features of the TVC are comparable to orogenic andesites elsewhere and point to a sub-continental lithospheric mantle source enriched in incompatible elements due to previous subduction processes. Basaltic monogenetic volcanoes of CAVP display similar patterns, and HFS anomalies on mantle-normalized diagrams, and have incompatible element ratios intermediate between orogenic andesites and within-plate basalts (e.g. OIB). Accordingly, the calc-alkaline and transitional-mildly alkaline basaltic magmas may have a common source region. Variable degrees of partial melting of a heterogeneous source, enriched in incompatible elements due to previous subduction processes followed by fractionation, crustal contamination, and magma mixing in shallow magma chambers produced the calc-alkaline volcanism in the CAVP. Magma generation in the TVC, and CAVP in general is via decompression melting facilitated by a transtensional tectonic regime. Acceleration of the extensional regime, and transcurrent fault systems extending deep into the lithosphere favoured asthenospheric upwelling at the base of the lithosphere, and as a consequence, an increase in temperature. This created fluid-present melting of a fluid-enriched upper lithospheric mantle or lower crustal source, but also mixing with asthenosphere-derived melts. These magmas with hybrid source characteristics produced the tholeiitic-transitional-mildly alkaline basalts depending on the residence times within the crust. Hybrid magmas transported to the surface rapidly, favored by extensional post-collision regime, and produced mildly alkaline monogenetic volcanoes. Hybrid magmas interacted with the calc-alkaline magma chambers during the ascent to the surface suffered slight fractionation and crustal contamination due to relatively longer residence time compared to rapidly rising magmas. In this way they produced the mildly alkaline, transitional, and tholeiitic basaltic magmas. This model can explain the coexistence of a complete spectrum of q-normative, ol-hy-normative, and ne-normative monogenetic basalts with both subduction and within-plate signatures in the CAVP.     

Properties of geothermal resources in Kebilli region, Southwestern Tunisia

The Kebilli region is located in the Southwestern part of Tunisia, and is characterized by the presence of deep and shallow geothermal systems (continental intercalary and complex terminal). Chemical and isotopic contents are used to classify the type and determine the origin of thermal water. An evaluation of reservoir temperature and a possible geothermal fluid mixing are also carried out. Both continental intercalary-deep aquifer and complex terminal-shallow aquifer are of Na–(Ca)–Cl–(SO₄) mixed water type. The use of different geothermometers and the computation of saturation indexes for different solid phases suggests that the thermal reservoir temperature of the continental intercalary is between 92 and 105 °C, while the fluid temperature from the shallow complex terminal aquifer ranges from 50 to 75 °C. Also, the isotopic data indicates the old origin of all groundwater of Southwestern Tunisia. Mixing effects characterizing the continental intercalary and the complex terminal aquifers were identified using δ²H and δ¹⁸O relationship. It appears that the upward movement of thermal water from the deep aquifer to shallow ones is probably due to the abundant fractures in the research area.     

Bivariational calculations for radiation transfer in an inhomogeneous participating medium

Equations for radiation transfer are obtained for dispersive media with space-dependent albedo. Bivariational bound principle is used to calculate the reflection and transmission coefficients for such media. Numerical results are given and compared.     

基于SAR的拉合尔地面沉降监测与沉降因素评价（英文）

合理开发和管理自然资源对于实现可持续发展至关重要,地面沉降作为目前影响城市可持续发展的最重要地质灾害,其与人类活动有着紧密的关系,如地下水开采,基础设施开发导致的施工超载等。巴基斯坦第二大城市拉合尔出现了显著的地面沉降现象,与此同时,拉合尔也正在经历城市化过程中的人口密度急剧增加、大规模城市建设和地下水开采,通过分析拉合尔地面沉降的不同空间模式与人类活动的对应关系,将有助于合理规划拉合尔城市的发展。本文利用永久散射体合成孔径雷达干涉测量(PSI)技术对拉合尔2018年8月-2019年8月的Sentinel-1数据进行In SAR处理,获取了该城市的地表形变速率为-114-15毫米/年,并结合拉合尔的土地覆盖图、交通网络和水道、土壤类型、人口密度和现场点数据,分析各种因素在地面抬升或沉降发生中的作用。结果显示,沉降与各种参数（如地下水抽取和地下水位降低、土壤类型变化、土地覆盖变化、地表水通道和人口密度）之间建立了很强的相关性,其中拉合尔中部人口密集,地下水开采严重,使其成为该地区沉降最为严重的区域,而在拉维河附近人口较少的农村地区,由于通过运河系统,地下水得到河流补给,观察到了地表抬升。     

Faulting, mass-wasting and deposition in an active dextral shear zone, the Gulf of Saros and the NE Aegean Sea, NW Turkey

Structural, mass-wasting and sedimentation processes along an active dextral shear zone beneath the Gulf of Saros and the NE Aegean Sea were investigated on the basis of new high-resolution swath bathymetric data and multi-channel seismics. A long history of dextral shearing operating since the Pliocene culminated in the formation of a NE-SW-trending, ca. 800-m-deep basin (the so-called inner basin) in this region, which is bordered by a broad shelf along its northern and eastern sides and a narrow shelf at the southern side. The western extension of the North Anatolian Fault Zone (the Ganos Fault) cuts the eastern shelf along a narrow deformation zone, and ends sharply at the toe of the slope, where the strain is taken up by two NE-SW-oriented fault zones. These two fault zones cut the basin floor along its central axis and generate a new, Riedel-type pull-apart basin (the so-called inner depression). According to the bathymetric and seismic data, these basin boundary fault zones are very recent features. The northern boundary of the inner depression is a through-going fault comprising several NE-SW- and E-W-oriented, overlapping fault segments. The southern boundary fault zone, on the other hand, consists of spectacular en-echelon fault systems aligned in NE–SW and WNW–ESE directions. These en-echelon faults accommodate both dextral and vertical motions, thereby generating block rotations along their horizontal axis. As the basin margins retreat, the basin widens continuously by mass-wasting of the slopes of the inner basin. The mass-wasting, triggered by active tectonics, occurs by intense landsliding and channel erosion. The eroded material is transported into the deep basin, where it is deposited in a series of deep-sea fans and slumps. The high sedimentation rate is reflected in an over 1,500-m-thick basin fill which has accumulated in Pliocene–Quaternary times.     

Determining and Mapping Eco-Cultural Subregions Using GIS and Simos Procedure

Immovable cultural properties constituting cultural heritage centre upon regions that have the level of natural features required for basic human needs. Such regions constitute a space with characteristics of an eco-cultural subregion and they do not have any administrative or geographical boundaries. Aims of this study are to introduce the concept of eco-cultural subregion, which is the holistic expression of natural features together with cultural heritage, to the literature; to present a method in identifying geographical boundaries of subregions; and to formulate a classification system. The research was conducted in the Phrygian Valley, which is one of the most important centres of ancient Phrygians in Western Anatolia, using a method based on GIS-MCDM (Geographic Information System-Multiple Criteria Decision Making). The selected MCDM technique was Simos Procedure. Natural features and cultural heritage were considered together and the entire Phrygian Valley was approached as both an ecological and a cultural region. Ecological features were analysed using 7 main and 17 subfactors, while cultural heritage was analysed using 2 main factors and 15 subfactors. Simos Procedure was employed in the assignment of weight for main factors and subfactors. First 17 ecological subregions with similar characteristics under 4 levels were identified. Considering their cultural heritage values, a classification system was formulated and eco-cultural subregions were expressed in level/degree in this system. In consequence of this procedure boundaries of eco-cultural subregions were drawn and mapped. This classification also enabled to identify the concept of eco-cultural subregion which is not found in the literature. It is expected that eco-cultural subregions will provide to discuss ecological features and cultural heritage holistically in conservation and planning studies.     

Factors controlling the morphological evolution of the Çanakkale Strait (Dardanelles, Turkey)

Seismic profiling, bathymetric and physical oceanographic data collected from the Çanakkale Strait revealed that the morphological evolution of the strait has been controlled by tectonic activity, and sediment erosion and deposition. Sediments in the strait have been sourced mostly by rivers draining the Biga Peninsula during lowstand periods. In highstand periods, by contrast, deposits in the strait were reworked by currents. The seafloor morphology of the Çanakkale Strait is also controlled by a sequence of factors ranging from tectonics to current erosion and deposition. Channel deposits overlying the basement are being eroded at the narrower, meandering central section of the strait (the Nara Passage) due to high current velocities. The eroded sediments are deposited in the relatively linear and wider, northern and southern sectors of the strait exposed to low current velocities. As a result, the high-energy areas are more deeply incised due to the erosion, whereas deposition elevates the seafloor in the areas exposed to lower current energy. Three strike-slip faults, which possibly relate to the activity of the North Anatolian Fault Zone, are responsible for the irregular shape of the strait and this, in turn, controls the current velocity along the strait. The high-energy conditions probably commenced with the latest invasion of Mediterranean waters some 12 ka b.p., and have continued as a two-layered current system to the present day.     

Late Quaternary evolution of the Çanakkale Strait region (Dardanelles, NW Turkey): implications of a major erosional event for the postglacial Mediterranean-Marmara Sea connection

Seismic and bathymetric data from the Çanakkale Strait and its extensions onto the shelves of the Marmara and Aegean seas indicate that the strait was formed mainly by an erosional event. Four seismic units are observed on seismic profiles. The lower two of these (units 4 and 3) constitute the basement of a regionally widespread erosional unconformity (ravinement), which developed during marine isotope stage 2 (MIS 2). The two upper units (units 2 and 1), which overlie the ravinement surface, form a higher-order sequence. Sequence stratigraphic analysis indicates that units 2 and 1 deposited as lowstand and highstand systems tracts respectively, since the end of MIS 2. The transgressive systems tract is represented by a major erosional event which occurred throughout the Çanakkale sill area when the Mediterranean-Marmara Sea connection and, hence, the Çanakkale Strait was formed. The existence of the erosive ?arköy Canyon along the shelf edge of the southern Marmara Sea demonstrates that the flow direction causing the erosion was from south to north, thus proving that it was produced by Mediterranean water flowing over the sill into the Marmara Sea basin.