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1.
The Miocene Kahramanmara? Peripheral Foreland Basin (KPFB) resemble to classic foreland basin model, with small differences. In the classic model, both the accretionary wedge and foredeep extend lengthways parallel to the plate margin. In addition, accretionary wedge includes wedge top basin or piggy back basin that extends parallel to foredeep. However, the accretionary wedge of the KPFB contains small half-graben type basins that obliquely intersect the plate margin between the Arabian Plate and the Anatolide–Taurides Platform (due to the irregular shape of the plate boundary). Tectonic lineaments controlled the shape and orientation of these basins and larger main depocentre of the KFPB, which were predominantly filled with deep-sea sediments. This paper focuses on the provenance of features of the KFPB, predominantly was fed from the northern basin margin, while also aiming to resolve the complex basin evolution that occurred during the Miocene.Clasts of Palaeozoic and Mesozoic limestone and ophiolites are common components of the confined deep-water clastic systems, which evolved as elongated trenches in the north-western sector of the KPFB during the Early-Middle Miocene. During the Middle Miocene, continuous thrusting of the northern basin margin to south caused depocentre migration to south-east, through the basin interior. At that time, the north-east and central depocentres of the KPFB were filled primarily by clasts of ophiolite and metamorphic units. The tectonic control on basin fill architecture can be observed anywhere in the KFPB. The principal tectonic features controlled the geometry and orientation of the canyon, the channel geometry of the deep-water slope on the northern basin margin, the frequency and distribution of slump-slide-debris flows and the overall pattern of sedimentation cycles in the stratigraphy of the slope and the central basin floor. Some basin sectors have continuously reactivated and as a result, different sediment entry points with substantial local accumulation of sediment and deformation have evolved on the slope and basin floor. Three scales of provenance were used to investigate the source rock: (a) field-based observation and analysis of conglomerate clasts, (b) modal analysis of sandstone facies and (c) geochemical analysis, all of which were in agreement.  相似文献   

2.
The Karalar galena-barite deposits are typical examples of the carbonate-hosted barite-galena deposits widely occurring in the Central Tauride Belt. These deposits are located in Permian limestones as ore veins along fault zones that are discordant to the bedding planes and as thin veinlets within hardly brecciated bottom zones of Permian limestones. The ore deposits contain mainly barite and galena and small amounts of sphalerite, pyrite, fahlore, limonite, quartz, and calcite. Barites occur during the earlier episode of mineralization and were mylonitized before the formation of galena. Galena and other minerals occur epigenetically with barite along porous zones between brecciated barite crystals and are especially abundant in the hardly mylonitized zones. Fluid inclusion studies indicate that the ore deposits of the area were developed by hydrothermal fluids with following characteristics: they contained NaCl, CaCl2, and MgCl2; the salinity of the fluids was relatively high and their temperature was low during the crystallization of barites in the earlier episode of mineralization; and the salinity of the fluids decreased and their temperature increased during the crystallization of sulfide minerals through the later episode of mineralization. δ18O and the δD results indicate that the water in the mineralizing fluid was of meteoric origin. The deposits were formed by deep meteoric water circulating through marine sediments. Shallow circulating and slightly warmed fluids dissolved Ba and sulfate from marine sediments of the basement and transported them to the mineralization environment during the early episode, while deep circulating and more heated fluids dissolved Pb, Zn, and other elements from the basement and reached the environment during the later episode of mineralization. The text was submitted by the authors in English.  相似文献   

3.
In the vicinity of Konya (Turkey),mafic,micro-porphyritic sub-volcanic rocks intrude into the Mesozoic units,which represents the only example of such a rock type in the region.40Ar/39Ar dating of two whole rock samples from the sub-volcanics gave ages of 13.72±0.13 and 12.40±0.11 Ma,suggesting temporal association to the Late Miocene-Pliocene high-K calc-alkaline volcanism in the region.The mineral chemistry and geochemical data permit us to classify the rocks as "minette" lamprophyres.They include diopside and phlogopite phenocrysts in a microcrystalline groundmass composed of sanidine,phlogopite,diopside and titano-magnetite.Segregation and ocelli-like globular structures occur commonly in the samples.In terms of major elements,the lamprophyres are calcalkaline,and potassic to ultrapotassic rocks.All the lamprophyres display strong enrichments in LILE (Rb,Ba,K,Sr),radiogenic elements (Th,U) and LREE (La,Ce) and prominent negative Nb,Ta,and Ti anomalies on primordial mantle-normalized trace element diagrams.Geochemical data suggest that the lamprophyres and high-K calc-alkaline rocks in the region derived from a subduction-modified lithospheric mantle source affected by different metasomatic events.Lamprophyric magmatism sourced phlogopite-bearing veins generated by sediment-related metasomatism via subduction,but high-K calc-alkaline magmas are possibly derived from a mantle source affected by fluid-rich metasomatism.  相似文献   

4.
The Kozakli–Nev?ehir geothermal field extends a long a NW–SE direction at SE of the Centrum of Kozakli. The area is not rugged and average elevation is 1,000 m. The Kozanözü Creek flows towards north of the area. In the Kozakli thermal Spa area, thermal waters are manifested along a valley with a length of 1.5 km and 200 m width. In this resort some hot waters are discharged with no use. The thermal water used in the area comes from wells drilled by MTA. In addition, these waters from wells are also utilized by hotels, baths and motels belonging to City Private Management, Municipality and private sector. The measured temperature of Kozakli waters ranges from 43–51°C in springs and 80–96°C in wells. Waters are issued in a wide swampy area as a small group of springs through buried faults. Electrical conductivity values of thermal spring and well waters are 1,650–3,595 μS/cm and pH values are 6.72–7.36. Kozakli cold water has an electrical conductivity value of 450 μS/cm and pH of 7.56. All thermal waters are dominated by Na+ and Cl–SO4 while cold waters are dominated by Ca+2 and HCO3 ?. The aim of this study was to investigate the environmental problems around the Kozakli geothermal field and explain the mechanisms of karstic depression which was formed by uncontrolled use of thermal waters in this area and bring up its possible environmental threats. At the Kozakli geothermal field a sinkhole with 30 m diameter and 15 m depth occurred in January, 17th 2007 at the recreation area located 20 m west of the geothermal well which belongs to the government of Nev?ehir province. The management of the geothermal wells should be controlled by a single official institution in order to avoid the creation of such karstic structures affecting the environment at the source area.  相似文献   

5.
Mainly high-K, calc-alkaline, Late Miocene to Pliocene volcanic rocks cropped out of the Konya area in Central Anatolia, Turkey. The volcanic rocks are predominantly andesitic to dacitic in composition and rarely basalt, basaltic andesite, basaltic trachyandesite and pyroclastics. Kaolinite, illite, Ca-montmorillonite, alunite, jarosite, minamiite and silica polymorphs were formed by widespread and intense hydrothermal alteration in or around the volcanic products. To investigate the effects of hydrothermal alteration on the chemistry of volcanic rocks, the whole rock chemical composition (major and trace elements, including rare-earth elements (REE) was analysed. The results of the study demonstrate notable differences in the REE behaviour in the different sample groups. REE trends of fresh parent rocks to weakly-, moderately-altered, kaolinitic and alunitic rocks are characterised by strong LREE enrichment ((La/Lu)cn = 14.57, 11,8 to 15.20, 4.54 to 13.30, 12.5 to 24.2 and 34.6 to 47.26, respectively). Most of the samples have pronounced negative and/or weakly-negative Eu anomalies ranging from 0.75 to 0.98 while three samples have weakly-positive Eu anomalies. LRE element contents are higher than those of HREE in the samples. The LRE elements were strongly enriched in the kaolinitic and alunitic alteration; in weakly- and moderately-altered rocks. LREE are nearly immobile whereas HRE elements show different behaviour in different rock groups. The HFS and TRT elements are slightly mobilised in weakly-altered rocks, but enriched in other alteration types. Elements commonly assumed to be immobile (e.g. Y, Zr, Nb, Hf, TiO2, Al2O3, REE) show variation in mass calculation. LIL elements showed enrichment over LREE and MREE, and similar behaviour, in contrast with HFSE. A clear increment of trans-transition elements (TRTE) was found mainly in alunitic and partly in kaolinitic samples.  相似文献   

6.
The study area is situated within the complex structure and karst system of the western Taurids. Basinwide interpretation of the structural features, each of which has great importance, will enlighten many complicated hydrogeologic problems encountered in the area. Thus, considering the previous views on the structural geology of the area, an interpretation of the structural and tectonic features of the study area by means of satellite images was undertaken, and based on the data gained, new approaches were suggested to solve the hydrogeological problems. In particular, determination of the recharge-discharge mechanisms of the Olukköprü and Dumanli karst springs, which are the most important karst groundwater discharge points in the region, has been attempted. Within the framework of this study, a tectonic-lineament map of a large area covering Eirdir, Beyehir, and Sula lakes at the north and the basins to the south of these lakes was prepared.  相似文献   

7.
Numerical modelling techniques enable forcing function at the point of contact in a hail impact to be predicted, but many models available in commercial software have not been verified by experiments. A recently developed deterministic model is only able to simulate the impact action of an idealised spherical hailstone. Results recorded from the impact testing of non-spherical simulated hail ice specimens show wide scatters and are different to spherical specimens. A stochastic model has been developed in this study to incorporate the variability of the modelling parameters representing the behaviour of non-spherical ice specimens and to generate time histories of contact force for given impact scenarios. A probabilistic model which was developed previously to provide predictions of the distribution of the size of hailstones in a severe category hailstorm has also been further developed to provide predictions of the maximum contact force values in probabilistic terms. For any given pre-defined forcing function denting into the surface of a steel plate can be estimated by finite element analysis or experimentally on a test machine. The new knowledge base introduced in this paper can be used by manufacturers and designers to re-assess existing products and in making improvements to future installations taking into account cost–benefit considerations.  相似文献   

8.
This paper describes the occurrence of dolomite and the mechanism of dolomitization of the Upper Triassic-Lower Jurassic K?z?loren Formation in the autochthonous Bolkardag? unit of the middle Taurus Mountains in south western Turkey. Dolomites were analyzed for geochemical, isotopic and crystallographic variation. Dolomites occur as a replacement of precursor carbonate and cement. The dolomite crystals range from <10 to ~1000 μm existing as both replacements and cements. Sr concentrations range between 84 and 156 ppm, and the molar Sr/Ca ratios of dolomitizing fluids are estimated to range between 0.0066 to 0.013 ratios. Dolomites are Ca-rich (with average CaCO3 and MgCO3 equal to 56.43 and 43.57 mol%, respectively) and they are non-stoichiometric, with an average Sr=116 ppm, Na=286 ppm, Mn=81 ppm, Fe=1329 ppm, and δ18O and δ13C ranges from –0.6‰ to –6.1‰ Pee Dee Belemnite [PDB], and +1.2 to +3.9‰ PDB. The North American Shale Composition [NASC]-normalized rare earth element (REE) values of the both limestone and dolomite sample groups show very similar REE patterns characterized by small positive Eu (mean=1.32 and mean=1.42, respectively) and slightly or considerably negative Ce (mean=0.61 and mean=0.72, respectively) anomalies and a clear depletion in all REE species. The K?z?loren Formation dolomites have been formed as early diagenetic from mixing zone fluids at the tidal-subtidal environment and at the late diagenetic from basinal brines at the shallow-deep burial depths.  相似文献   

9.
Landslides cause heavy damage to property and infrastructure, in addition to being responsible for the loss of human lives in many parts of the Turkey. The paper presents GIS-based spatial data analysis for landslide susceptibility mapping in the regions of the Sultan Mountains, West of Akşehir, and central part of Turkey. Landslides occur frequently in the area and seriously affect local living conditions. Therefore, spatial analysis of landslide susceptibility in the Sultan Mountains is important. The relationships between landslide distributions with the 19 landslide affecting parameters were analysed using a Bayesian model. In the study area, 90 landslides were observed. The landslides were randomly subdivided into 80 training landslides and 10 test landslides. A landslide susceptibility map was produced by using the training landslides. The test landslides were used in the accuracy control of the produced landslide susceptibility map. Approximately 9% of the study area was classified as high susceptibility zone. Medium, low and very low susceptibility zones covered 8, 23 and 60% of the study area, respectively. Most of the locations of the observed landslides actually fall into moderate (17.78%) and high (77.78. %) susceptibility zones of the produced landslide susceptibility map. This validates the applicability of proposed methods, approaches and the classification scheme. The high susceptibility zone is along both sides of the Akşehir Fault and at the north-eastern slope of the Sultan Mountains. It was determined that the surface area of the Harlak and Deresenek formations, which have attained lithological characteristics of clayey limestone with a broken and separated base, and where area landslides occur, possesses an elevation of 1,100–1,600 m, a slope gradient of 25°–35° and a slope aspect of 22.5°–157.5° facing slopes.  相似文献   

10.
The study area is 35 km east of the city center of Mu, Turkey. The rock units in the area include Paleozoic Bitlis Metamorphites, Cenozoic flysch and Solhan Volcanities and Pliocene formations. A long-term discharge change was monitored in the Karasu spring. The amount of water discharged by the spring during June 3 and October 11, 2002 was 7.18×106 m3 while its storage capacity during May 26 and November 11, 2002 was 4.42×106 m3.NH4 – N, NO2 – N, NO3 – N, total PO4 – P, SO4 and total organic carbon (TOC) contamination were determined in the recharge area of the spring and other well and spring waters in the vicinity. NH4 – N, NO2 – N, NO3 – N, total PO4 – P, SO4 and total organic carbon contamination around the Budak, ivbai, Gölbai, Sazlikbai and Altinova villages are well above the drinking water standards of the Turkish Standard Institute (TSE) and World Health Organization (WHO) (1984). Similarly, water samples of K4, K5 and K6 branches of the Karasu spring and S1, S2, S3 and S4 points in the swamp area yielded concentrations much more than limit values.  相似文献   

11.
Lake Seyfe is located in a closed basin near K?r?ehir in the central Anatolian region, Turkey. The aim of this study is to evaluate the groundwater quality and effects of lithogenic contamination carried out in the Lake Seyfe basin, which is represented by various lithologies and groundwater types. Seyfe, Horla and Akp?nar springs are recharged through marbles at the western and southwestern of the basin are ultimately and discharged into the K?z?l?rmak Formation and Lake Seyfe. The waters of deep wells drilled into the marbles are of bicarbonate type (type I) in the Ca2+–Mg2+–HCO3 ? and Ca2+–HCO3 ? facies. Özlühüyük spring and waters from most of trenches and shallow wells, which are fed by the K?z?l?rmak Formation, have a mixed (type II) composition in the Ca2+–Mg2+–HCO3 ?–Cl? facies. Groundwater in the alluvium and K?z?l?rmak Formation along Lake Seyfe has a salty (type III) character in the Na+–Cl? facies. The main reasons of formation and change of the groundwater salinity and hydrochemical facies in the Seyfe basin are causing the various (a) lithogenic pollution and heterogeneity of the K?z?l?rmak Formation, (b) salinity of the upper soil zones, and (c) evaporation of the trench and channel waters open to the atmosphere. Considering parameters such as sodium hazard, specific conductivity, bicarbonate and carbonate hazards, waters in the study area are generally suitable for agricultural usage.  相似文献   

12.
The physical (turbidity, color, smell, taste, pH, and conductivity) and geochemical properties (Ca, Mg, Na, Fe, Mn, Al, K, Cl?, HCO3 ?, SO4 2?, Fe, Cu, Co, Ni, Zn, Cd, Pb, and Cr) of the drinking water in Gümü?hane city center were determined. This city center constitutes the study area. The pH levels of the water samples ranged from 6.3 to 8.2, and their conductivities ranged between 240 and 900 μS. These findings were concordant with the drinking water standards of the Turkey Standard Institute and the World Health Organization. The hardness of the water samples in the study area was between 18.1 and 115.1 °Fr. These samples were classified as extremely hard, hard, and quite hard. In addition, an assessment using the criteria for Inland Surface Water Classification indicated that considering certain parameters (pH levels, amount of Na, SO4 2?, Fe, Mn, Al, Co, Ni, Cu, and Cr), the samples belonged to class I (high quality) water. When Cl? amount and conductivity were considered, the samples belonged to the first and second classes (less polluted) of water. The water in the study area was generally classified as carbonated and sulfated (Ca + Mg > Na + K) water classes. This water contained more weak acids than strong acids (HCO3 ? + CO3 2? > Cl? + SO4 2?). The pH levels (6.3–8.2) of the water in the study area were unrelated to the varying concentrations of metals in the water. Elements such as Fe, Ni, Cd, Pb, Zn, and Cu increase in the water through the water–rock interaction in the area in which water rises or through the mixture of water with either mine or industrial wastes. In addition, several water samples belonged to an acceptable water class for drinking and usage.  相似文献   

13.
This paper evaluates the effects of Torul dam on the stream Harşit water quality in terms of 13 physico-chemical parameters in the Gümüşhane Province, Eastern Black Sea Basin, Turkey. For this purpose, a study was fortnightly conducted during the four seasons between March 2009 and February 2010. In two monitoring stations selected in the upstream and downstream of the Torul dam, T, pH, DO and EC were determined in situ, and collected water samples were analyzed for TH, COD, NH4 +-N, NO2 -N, NO3 -N, TN, TKN, PO4 3−-P and MBAS. According to the Turkish Water Pollution Control Regulation (TWPCR), the stream Harşit was classified, and the obtained results were evaluated for the values proposed by Turkish Standard (TS) 266 and World Health Organization (WHO) guidelines. The results showed that the stream Harşit has high-quality water in terms of, T, pH, DO, COD, NH4 +-N and NO3 -N, but slightly polluted water in terms of NO2 -N, TKN and PO4 3−-P, and polluted for MBAS. It was concluded that Torul dam has a positive effect on the stream water quality in terms of decrease in the annual average concentration values. The percent decreases for TH, COD, NH4 +-N, NO2 -N, NO3 -N, TN, TKN, PO4 3−-P and MBAS were 17.1, 20.3, 56.2, 62.6, 11.7, 11.9, 11.4, 17.8 and 71.4, respectively. The reason for these decreases is probably due to the Torul dam reservoir where the water has a hydraulic residence time and the exposure to chemicals by aquatic organisms or populations that ingest the water. Also, statistical analysis shows that there are significant correlations among the studied parameters.  相似文献   

14.
This paper describes the occurrence of dolostone and the mechanism of dolomitization of the Upper Devonian Gölbo?az? Formation in the allochthonous Taurus Mountains Alada? unit in Turkey. The Upper Devonian Gölbo?az? Formation carbonates, with dominant ostracod-bearing mudstone and wackestone, formed tidal and subtidal environments, and some of these rocks were dolomitized from shallow to deep burial. On the basis of the field, the petrographic and geochemical features, four different replaceable and cement dolostone phases have been recognized. The replacive dolostones contain (1) very fine to fine crystalline planar-s dolostone (df1), (2) medium to coarse crystalline planar-s to planar-e dolostone (df2), (3) coarse to very coarse crystalline non-planar-a dolostone (df3), and (4) coarse to very coarse crystalline planar dolostone cement (df4). The replacive dolostones are disordered to moderate the ordered and calcium-rich. They are non-stoichiometric and have 46–59 mol% CaCO3 and 41–54 mol% MgCO3 total contents. The df1 dolostones have MgCO3 contents of 41–54 mol%, the df2 dolostones have 41–53 mol%, the df3 dolostones have 49 mol%, and the df4 dolostones have 49–50 mol%, respectively. The Gölbo?az? dolostones have δ18O values of ?9.44 to ?2.20‰ Vienna Pee Dee Belemnite (VPDB) and δ13C values of ?1.58 to +2.52 VPDB. Sr, Na, Mn, and Fe concentrations of replacive dolostones are 74–184, 148–593, below detection level (bdl)–619, and 1049–9233 ppm, respectively. The petrographic and geochemical data demonstrate that the replacive dolostones occurred prior to the chemical compaction at shallow to intermediate burial depths from Late Devonian seawater and/or seawater lightly modified by water–rock interaction process and later recrystallized by basinal brines at increasing burial depths and temperature. The North American Shale Composite-normalized rare earth element values of both limestone and dolostone show very similar rare earth element patterns characterized by slightly or considerably negative cerium (Ce) anomalies and a clear depletion in all rare earth element species. The dedolomitization observed in the Gölbo?az? Formation is thought to occur by the oxidizing effect of the meteoric water in the shallow burial environment during the telodiagenesis.  相似文献   

15.
The sinuosity factor (SF) is a critical value in karst systems in terms of estimating their hydrodynamic parameters including groundwater velocity, coefficient of dispersion, etc., through dye tracer experiments. SF has been used in a number of different dye tracer experiments in karstic systems to estimate a representative flow path. While knowing SF is crucially important in the estimation of hydrodynamic parameters, its calculation is associated with significant uncertainty due to the complexity of subsurface karstic features. And yet, only a few studies have discussed its uncertainties, which might lead some errors in estimation of hydrodynamic parameters from dye tracer experiment. In this study, dye tracer experiments were conducted in two consecutive years (2003 and 2004) representing low and high flow conditions in the Beyyayla sinkhole (Eski?ehir, Turkey) where the flow path is well known. Uranine was used in experiments as a tracer and QTRACER computer program was used to determine the hydrodynamic properties of the Beyyayla karst system as well as to gain insights into the effects of SF from dye tracer experiments on estimated parameters. The results showed that the breakthrough curve follows a unimodal and a bimodal distribution in low and high flow conditions, respectively. These different distributions stem from the water transport mechanisms, where velocities were calculated as 58.2 and 93.6 m h?1 during low and high flow conditions observed in a spring emerging from the south side of the studied system. The results also show that the coefficient of dispersion, Reynolds number, and Peclet number increased and longitudinal dispersivity decreased with the higher flow rate. Furthermore, the estimated parameters did not vary with either the flow conditions or the tracer transit time, but they have shown some variations with SF. When SF was increased by 50 %, a change in these parameters was obtained in the range of 50–125 %.  相似文献   

16.
The Mediterranean-type karst-bauxite deposit of Morta?, south Turkey, placed unconformably between Cenomanian and Senonian shallow marine limestones is built of massive (MB), oolithic (OB), breccia-bearing (BB) and earthy (EB) bauxite horizons, from top to bottom. The MB layer is enriched in Al and REE (except Ce) due to loss of Si, Na, K, Mg and P. REE are accumulated in the BB but depleted in the EB layers. The ferruginous OB lost LREE and gained in HREE probable due to scavenging by authigenic heavy minerals like rutile, anatase and titanite. Total REE contents in the bauxite profile display an increasing trend from bottom to top, while negative and maximum positive Ce anomalies characterize the upper and the lower parts of the profile, respectively. This unusual REE behavior is explicable by assuming mobilization of Ce(IV) either under reducing condition or chemical complexation under alkaline conditions in the top layer and scavenging of Ce by Al-Mg hydrosilicates and Ti-oxides and/or precipitation with authigenic REE minerals, especially of the bastnäsite group near the bedrock limestones. Similarity in chondrite normalized-REE patterns of the Seydi?ehir phyllites, bauxite and terra rossa samples and the presence of tridymite (?) in bauxites makes a felsic source rock most likely and reveal a close genetic relationship between the Seydi?ehir phyllites and the recent terra rossa occurrences. The REE patterns of the bauxites resemble those of the Katrangedi?i limestone despite variations in ΣREE. Field observations and geochemical data together with mass-balance calculations suggest that the Morta? deposit was derived from the Seydi?ehir phyllites and argillic phase within the Katrangedi?i limestone which in turn have Precambrian (?) felsic, probably granitic precursors.  相似文献   

17.
It is known that the increasing use of coal as an energy source led to the growing environmental and health problems. But comprehensive knowledge of coal quality parameters may help to reduce some of these problems. The ?anakkale-?an coalfield is located …  相似文献   

18.
Palaeo- and Neo-Tethyan-related magmatic and metamorphic units crop out in Konya region in the south central Anatolia. The Neotethyan assemblage is characterized by mélange and ophiolitic units of Late Cretaceous age. They tectonically overlie the Middle Triassic–Upper Cretaceous neritic to pelagic carbonates of the Tauride platform. The metamorphic sole rocks within the Konya mélange crop out as thin slices beneath the sheared serpentinites and harzburgites. The rock types in the metamorphic sole are amphibolite, epidote-amphibolite, garnet-amphibole schist, plagioclase-amphibole schist, plagioclase-epidote-amphibole schist and quartz-amphibole schist. The geochemistry of the metamorphic sole rocks suggests that they were derived from the alkaline (seamount) and tholeiitic (E-MORB, IAT and boninitic type) magmatic rocks from the upper part of the Neotethyan oceanic crust. Four samples from the amphibolitic rocks yielded 40Ar/39Ar isotopic ages, ranging from 87.04 ± .36 Ma to 84.66 ± .30 Ma. Comparison of geochemistry and geochronology for the amphibolitic rocks suggests that the alkaline amphibolite (seamount-type) cooled below 510 ± 25 °C at 87 Ma whereas the tholeiitic amphibolites at 85 Ma during intraoceanic thrusting/subduction. When all the evidence combined together, the intraoceanic subduction initiated in the vicinity of an off-axis plume or a plume-centered spreading ridge in the Inner Tauride Ocean at 87 Ma. During the later stage of the steady-state subduction, the E-MORB volcanics on the top of the down-going slab and the arc-type basalts (IAT/boninitic) detached from the leading edge of the overriding plate, entered the subduction zone after ~2 my and metamorphosed to amphibolite facies in the Inner Tauride Ocean. Duration of the intraoceanic detachment (~87 Ma) and ophiolite emplacement onto the Tauride-Anatolide Platform (Tav?anl? Zone), followed by subsequent HP/LT metamorphism (~82 Ma) spanned ~5 my in the western part of the Inner Tauride Ocean.  相似文献   

19.
This study examines the local geological conditions and soil structure as possible causes of the collapse of the Zümrüt Building 2 February 2004. This catastrophe resulted in 92 fatalities and 35 injuries. This study also examines other views which claim weak soil structure, elastic and consolidation settlement of soil and excessive groundwater extraction as well as subsidence resulting from the underground silt erosion as possible factors. Zümrüt Building was constructed on normally consolidated, low plasticity clay. The underground water table was 30 m in depth. The internal friction angle of soil was 8°–30°, its cohesion was between 34 and 127 kN/m2 and standard penetration test numbers varied between 11 and 50. The underground water level beneath Zümrüt Building had risen 4.5 m since its construction. Therefore the claim that subsidence resulting from the decrease of underground water level contributed to the collapse is incorrect. Secondly the settlement, resulting from the filling up of the pores created by the silt receding with the underground water, was 4.4 mm in total, and attributing this as the primary cause of the collapse is also incorrect. Soil properties, in situ and laboratory test results showed that the existing and/or expected settlement and the differential ground settlement in the Zümrüt building vicinity had the potential to cause structural damage. The tensile stresses caused by differential settlements recorded here are thought to be an indicator, but not the main cause contributing to the collapse of the building. The Zümrüt Building collapse was due to several compounding mistakes during the construction phase. These were geotechnical and other project faults and the use of low quality construction materials. The resulting catastrophe caused 92 fatalities, 35 injuries and a material loss of approximately US$7 million.  相似文献   

20.
Ammonitico Rosso type sediments (ARTS) form the bottom level of the ?enköy Formation in the Gümü?hane area. The formation accumulated in the rift-related basins triggered by extensional tectonic regimes in the Early Jurassic times. Six different sections were studied in this area in order to interpret the lithostratigraphy, facies, and deposition environments of the ARTS. Two basic lithofacies were distinguished, nodular-marly and nodular-calcareous. These facies provide useful information regarding depositional conditions in the area and environmental energy. These factors were mainly related to the relative sea-level that in turn was controlled by tectonic and eustasy conditions. In addition, seven different types of microfacies were recognized and described as a result of the detailed analysis of the sections. The results of the analysis show that these sediments in the Gümü?hane area were developed in transgressive phases/events. These sediments share characteristics with other peri-Mediterranean regions and sea-level curves, and show a similarity to the major transgressive pulse during the Pliensbachian stage. Deposition of ARTS was controlled by syn-depositional extensional movements, leading to their accumulation on top of tilted blocks, slopes and horsts in an open marine environment. The ARTS were developed during the rifting of the continental margins pointing up the phases of the Tethys opening. Neptunian dykes verifying this opening developed at different levels of the ARTS and were filled with overlying sediments. These results support the hypothesis that the ARTS were formed in tectonically active environments where extensional tectonic movements were continuously improved during the deposition of the ARTS.  相似文献   

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