kinematics of a former oceanic plate of the neotethys revealed by deformation in the ulukisla basin turkey kinematic reconstruction of modern ocean basins shows that since pangea breakup a vast area in the neotethyan realm was lost to subduction here we develop a first order methodology to reconstruct the kinematic history of the lost plates of the neotethys using records of subducted plates accreted to former overriding plates combined with the kinematic analysis of overriding plate extension and shortening in cretaceous paleogene times most of anatolia formed a separate tectonic plate here termed anadolu plate that floored part of the neotethyan oceanic realm separated from eurasia and africa by subduction zones we study the sedimentary and structural history of the ulukisla basin turkey overlying relics of this plate to reconstruct the tectonic history of the oceanic plate and its surrounding trenches relative to africa and eurasia our results show that upper cretaceous oligocene sediments were deposited on the newly dated suprasubduction zone ophiolites 92 ma which are underlain by melanges metamorphosed and nonmetamorphosed oceanic and continental rocks derived from the african plate the ulukisla basin underwent latest cretaceous paleocene n s and e w extension until 56 ma following a short period of tectonic quiescence eo oligocene n s contraction formed the folded structure of the bolkar mountains as well as subordinate contractional structures within the basin we conceptually explain the transition from extension to quiescence to shortening as slowdown of the anadolu plate relative to the northward advancing africa anadolu trench resulting from collision of continental rocks accreted to anadolu with eurasia until the gradual demise of the anadolu eurasia subduction zone

late cretaceous to late eocene hekimhan basin central eastern turkey as a supra ophiolite sedimentary magmatic basin related to the later stages of closure of neotethys abstract the hekimhan basin is here put forward as a type example of a globally important class of basin known as a supra ophiolite basin such basins form after the emplacement of ophiolitic i e oceanic rocks onto a passive continental margin but long prior to continental collision the hekimhan basin developed as part of the northern margin of the tauride microcontinent during the collision and suturing of two neotethyan oceans to the north namely the inner tauride ocean and the izmir ankara erzincan ocean the basin records two main stages of tectonic development during latest cretaceous to late eocene time the first phase of basin development during the late cretaceous maastrichtian began with the erosion of emplaced ophiolitic rocks resulting in non marine clastic sedimentation subsequently the basin rapidly subsided in response to inferred regional crustal extension resulting in the deposition of hemipelagic marls and local sapropelic mudstones the axial parts of the basin experienced alkaline within plate type basaltic volcanism the late maastrichtian culminated in deposition of shallow marine carbonates overlying paleocene sediments are restricted to thin localised marine evaporates associated with a low angle unconformity the second stage of basin development began during the early eocene with deposition of shallow marine carbonates coupled with localised basaltic volcanism again of extensional type the basin emerged during the mid late eocene in a late stage collisional to post collisional setting compressional deformation largely reflects post suture tightening a short lived marine transgression occurred during the mid miocene the basin was later deformed by both left lateral and right lateral strike slip several different tectonic models are considered notably extension related to the northward pull of a still subducting oceanic slab and back arc extension related to northward subduction of neotethys to the south the first alternative is consistent with the development of adjacent supra ophiolite basins e g ulukisla and darende basins and also with supra ophiolite basins elsewhere e g se turkey balkans oman

an example of an accretionary forearc basin from northern central anatolia and its implications for the history of subduction of neo tethys in turkey deformed sedimentary sequences of late cretaceous middle eocene age located between the sakarya continent and the anatolian complex have been interpreted as the fill of a forearc basin the history and structure of this basin are critical for understanding the evolution of the neo tethyan subduction in the middle east i test and elaborate upon this interpretation on the basis of three basic outcrop areas of upper cretaceous lower tertiary sedimentary sequences confined to a northeast southwest trending belt in north west ankara these are the alci kinik and orhaniye areas they expose two different sedimentary sequences called alci and orhaniye in the alci area the sequence starts at the base with the continental red clastic rocks on the erosional surface of an underlying ophiolitic melange and continues upward into the shallow marine reefal buildup of the late maastrichtian age the upper half of the alci sequence is separated from its lower half by a local disconformity and dominated by the continental debris flow deposits composed mostly of volcanic material by contrast both the kinik and orhaniye areas are characterized by a thick continuous and coarsening upward sequence overlying conformably the underlying ophiolitic melange the lower half of the orhaniye sequence is dominated by a deep marine flysch its middle part by continental clastic material and the topmost part by the shallow marine reefal buildup lower contact relationships lithologic composition facies distribution internal structures and the regional tectonic settings of both sequences strongly suggest that the above mentioned three outcrops preserve the remnants of a peripheral accretionary forearc basin forming the north northwestern margin of the haymana polath accretionary forearc basin during middle campanian middle eocene time this peripheral basin is here named orhaniye accretionary forearc basin

tertiary evolution of the sivas basin central turkey abstract the sivas basin is one of several basins in turkey formed during closure of the northern branch of neotethys in early tertiary times cretaceous ophiolitic fragments and eocene platform carbonates and volcaniclastics transported northwards into the basin as olistoliths and grain flow aprons were incorporated into autochthonous eocene turbidites and bioclastic limestones the sequence as a whole was thrust northwards in late eocene times a southward sloping terrestial foreland basin related to northward directed thrusting developed during oligocene times a piggy back basin developed on top of this thrust system during the late oligocene the eocene thrusts were reactivated probably resulting in northward propagation of thrusts in the subsurface in early and mid miocene times the basin was floored by a thrust sheet which had been cut by n s trending tear faults or oblique culminations as a result of non uniform thrust advance in pre miocene times these n s faults were subsequently reactivated as extensional faults radial to the thrust front during early to mid miocene alluvial and shallow marine sedimentation later strike slip displacement along the n s faults was associated with the development of the northern boundary fault of the sivas basin in late miocene times which is regarded as a left lateral transpressive fault related to the north anatolian fault zone

investigation of the deep structure of the sivas basin innereast anatolia turkey with geophysical methods abstract sivas basin is the easternmost and third largest basin of the central anatolian basins in this study gravity aeromagnetic and seismic data are used to investigate the deep structure of the sivas basin together with the well seismic velocity data geological observations from the surface and the borehole data of the celalli 1 well basement depth is modeled three dimensionally 3d using the gravity anomalies and 2d gravity and magnetic models were constructed along with a n s trending profile densities of the rock samples were obtained from the distinct parts of the basin surface and in situ susceptibilities were also measured and evaluated in comparison with the other geophysical and geological data additionally seismic sections in spite of their low resolution were used to define the velocity variation in the basin in order to compare depth values and geological cross section obtained from the modeling studies deepest parts of the basin 12 13 km determined from the 3d model are located below the settlement of hafik and to the south of zara towns geometry extension and wideness of the basin together with the thickness and lithologies of the sedimentary units are reasonably appropriate for further hydrocarbon exploration in the sivas basin that is still an unexplored area with the limited number of seismic lines and only one borehole

signature of slab fragmentation beneath anatolia from full waveform tomography when oceanic basins close after a long period of convergence and subduction continental collision and mountain building is a common consequence slab segmentation is expected to have been relatively common just prior to closure of other oceans in the geological past and may explain some of the complexity that geologists have documented in the tibetan plateau also we focus on the eastern mediterranean basin which is the last remainder of a once hemispherical neo tethys ocean that has nearly disappeared due to convergence of the india and africa arabia plates with the eurasia plate we present new results of full waveform tomography that allow us to image both the crust and upper mantle in great detail we show that a major discontinuity exists between western anatolia lithosphere and the region to the east of it also the correlation of geological features and the crustal velocities is substantially stronger in the west than in the east we interpret these observations as the imprint in the overriding plate of fragmentation of the neo tethys slab below it this north dipping slab may have fragmented following the eocene about 35 million years ago arrival of a continental promontory central anatolian core complex at the subduction contact from the eocene through the miocene slab roll back ensued in the aegean and west anatolia while the cyprus bitlis slab subducted horizontally beneath central and east anatolia following collision of arabia about 16 million years ago the cyprus bitlis slab steepened exposing the crust of central and east anatolia to high temperature and resulting in the velocity structure that we image today slab fragmentation thus was a major driver of the evolution of the overriding plate as collision unfolded

new kinematic and geochronologic evidence for the quaternary evolution of the central anatolian fault zone cafz as the kinematics of active faults that bound the anatolian plate are well studied it is now essential to improve our understanding of the style and rates of intraplate deformation to constrain regional strain partitioning and improve seismic risk assessments one of these internal structures the central anatolian fault zone cafz was originally defined as a regionally significant left lateral tectonic escape structure stretching for 700 km in a ne direction across the anatolian plate we provide new structural geomorphic and geochronologic data for several key segments within the central part of the cafz that suggest that the sinistral motion has been overstated the ecemis fault the southernmost part of the cafz has a late quaternary minimum slip rate of 1 1 0 4 mm a 1 slower than originally proposed farther north the erciyes fault has fed a linear array of monogenetic vents of the erciyes stratovolcano and 40ar 39ar dating shows a syneruptive stress field of ese wnw extension from 580 130 ka to 210 180 ka in the erciyes basin and central part of the cafz we mapped and recharacterized the erkilet and gesi faults as predominantly extensional these long term geological rates support recent gps observations that reveal ese wnw extension which we propose as the driver of faulting since 2 73 0 08 ma the slip rates and kinematics derived in this study are not typical of an escape tectonic structure the cafz is a transtensional fault system that reactivates paleotectonic structures and accommodates e w extension associated with the westward movement of anatolia

two stage development of the late cretaceous to late eocene darende basin implications for closure of neotethys in central eastern anatolia turkey

a new intracontinental transcurrent structure the central anatolian fault zone turkey abstract recent neotectonic studies including remote sensing aerial photographs geological field mapping on various scales and measured stratigraphic section substantiate the existence of a large sinistral intracontinental transcurrent structure which we call the central anatolian fault zone cafz this is an approximately 730 km long 2 km to 80 km wide ne trending active sinistral strike slip fault zone that cuts across the anatolian plateau between duzyayla in the northeast and anamur county in the southwest it continues onward beneath the eastern mediterranean sea and determines the boundary of the antalya and adana basins as far as to the west of cyprus the cafz is a very young neotectonic structure it resulted from the reactivation and propagation of an older paleotectonic structure the so called ecemi s corridor in both nne and sw directions across the inner tauride suture in the plio quaternary times based on geometric discontinuities the cafz is divided into 24 segments each of them is characterized by a number of strike slip morphotectonic features reflecting recent motions the easternmost part of the anatolian platelet is being deformed internally by several dextral to sinistral intraplate strike slip faults these are the lake salt fault zone lsfz the salanda fault sf the cafz the goksu yazyurdu fault zone gyfz and the malatya ovacik fault zone mofz they take up lesser motion and are younger than boundary faults of the anatolian platelet the gyfz and mofz splay from the natf cut across the anatolian platelet and then meet to the eatf whereas other faults are confined into the anatolian platelet and seem to be independent structures however present day structural pattern of all these intraplate faults and boundary faults of the anatolian platelet indicates a regional strain pattern of nnw sse directed shortening and ene wsw directed extension and they seem to have developed to accommodate northward motion of the arabian plate since late early pliocene times

environmental hazard analysis of a gypsum karst depression area with geophysical methods a case study in sivas turkey in the study area the geophysical properties of gypsum and filling materials karst structures that developed in gypsum and groundwater level were investigated according to the results of geophysical studies it was thought that the depression and dissolution weathering areas in the karst could be completely or partially filled with water air gypsum particles and one several or all of the alluvial units it was determined that resistivity and s wave velocity average 10 263 14 412 m average 655 m s and resistivity and s wave velocity of lsvz in the gypsum surfaced far from the source were lower 91 3 m 585 m s compared to the gypsum bedrock therefore it was observed that the resistivities and seismic velocities of the gypsum in the surfaced area were higher compared to the depression area the results were associated with karst as the main reason for dissolutions and depressions because the water draining leaking spreading from the water source progressed by creating low resistivity areas in the permeable filling material and the groundwater was near the surface therefore karst structures will probably continue to develop in this area and natural hazards may occur in the future

oligocene deposits of the zara hafik region sivas central turkey evolution from storm influenced shelf to evaporitic basin new stratigraphical and micropalaeontological data supplemented by detailed sedimentological and petrographical observations have been obtained from an almost completely exposed oligocene miocene succession near celalli in the zara hafik basin which forms part of a long lived zone of subsidence associated with the north anatolian fault system four laterally extensive lithostratigraphical units have been distinguished and ostracod microfaunas indicate that the lower two units are of middle oligocene age while bivalve brachiopod faunas from the third unit are also oligocene the status of the uppermost unit of redbeds remains equivocal but microfaunas from the capping marls are of lowermost miocene age

giant magmatic water reservoirs at mid crustal depth inferred from electrical conductivity and the growth of the continental crust the formation of the continental crust at subduction zones involves the differentiation of hydrous mantle derived magmas through a combination of crystallization and crustal melting however understanding the mechanisms by which differentiation occurs at depth is hampered by the inaccessibility of the deep crust in active continental arcs here we report new high pressure electrical conductivity and petrological experiments on hydrated andesitic melt from uturuncu volcano on the bolivian altiplano by applying our results to regional magnetotelluric data we show that giant conductive anomalies at mid crustal levels in several arcs are characterized by relatively low amounts of intergranular andesitic partial melts with unusually high dissolved water contents 8 wt h2o below uturuncu the altiplano puna magma body apmb displays an electrical conductivity that requires high water content up to 10 wt dissolved in the melt based on crystal liquid equilibria and melt h2o solubility experiments such a super hydrous andesitic melt must constitute about 10 of the apmb the remaining 90 being a combination of magmatic cumulates and older crustal rocks the crustal ponding level of these andesites at around 6 kbar pressure implies that on ascent through the crust hydrous magmas reach their water saturation pressure in the mid crust resulting in decompression induced crystallization that increases magma viscosity and in turn leads to preferential stalling and differentiation similar high conductivity features are observed beneath the cascades volcanic arc and taupo volcanic zone this suggests that large amounts of water in super hydrous andesitic magmas could be a common feature of active continental arcs and may illustrate a key step in the structure and growth of the continental crust one sentence summary geophysical laboratory conductivity and petrological experiments reveal that deep electrical conductivity anomalies beneath the central andes cascades and taupo volcanic zone image the ponding of super hydrous andesitic melts which contributes to the growth of continental crust

paleocene carbonate turbidites of the şarkisla region turkey their significance in an orogenic basin abstract a paleocene carbonate sequence occurs in the southwestern part of the sivas refahiye basin arkisla province sivas turkey and is located in the northeast of central anatolia conclusions concerning the late mesozoic to early cenozoic sedimentary evolution have been derived mainly from the carbonate turbidites the vertical and lateral relationships of these rocks suggest deposition in a submarine fan complex three major megacycles characterized by a thickening and coarsening upward trend are seen in the upper cretaceous lower paleocene succession they are considered to represent basin facies in the lower levels passing upward into sediment attributed to distal fan facies on the basis of bed thickness distributions and bioclastic hemipelagic ratios agglomerates occur as laterally discontinuous mass flow deposits which formed on the slopes of local volcanoes located in the deeper part of the basin thin lava sheets are the products of stratovolcanoes which result from regional tectonic subsidence olistoliths occurring at several stratigraphic levels probably are the result of seismic events related to contemporaneous volcano tectonic activity two major turbiditic megacycles occur also in the middle and upper parts of the succession middle and upper paleocene the lower megacycle of this sequence conforms to the distal division of a suprafan lobe while the upper part is marked by a conspicuous thickening and coarsening upward character indicating a suprafan lobe environment this evidence is consistent with an overall progradation of the fan complex during the paleocene paleocurrent features and slump structures indicate that the marginal slopes of the basin extended in a northeast southwest direction and were inclined to the north sedimentologic stratigraphic tectonic and volcanic data from this sequence suggest that during the paleocene this area formed as an arc related basin

structure and kinematics of the central sivas basin turkey salt deposition and tectonics in an evolving fold and thrust belt this work has been made possible by funding from total s a in the framework of the structural geology chair at e2s university of pau pays adour held by jean paul callot

fluvial evaporitic and shallow marine facies architecture depositional evolution and cyclicity in the sivas basin lower to middle miocene central turkey abstract lower to middle miocene rocks in the karayun region of the sivas basin are represented by the agilkaya and egribucak formations forming a 4 km thick continuous section each formation is subdivided into three members representing similar lithofacies the lower members are made up of fluvial sheet sandstone and red mudstone that migrated laterally on a flood basin within a semi arid fan system the middle members are composed of bedded to massive gypsum and red green mudstone of a coastal and or continental sabkha environment they are intercalated with lagoonal dolomitic limestone and bituminous shale in the agilkaya formation and fluvial red pink sandstone red mudstone in the egribucak formation the upper members are made up of shallow marine fossiliferous mudstone and sandy limestone rapid vertical and horizontal facies changes in both formations reflect the locally subsiding nature of this molassic basin the overall section can be also subdivided into three orders of fining upward cycles type i cycles correspond to the agilkaya and egribucak formations each around 2 km thick and indicate two long term transgressive phases controlled by tectono eustatic factors type ii cycles 140 m thick on average are formed by alternations of fluvial sheet sandstone and red mudstone capped by up to 50 m thick red flood basin mudstone a 400 ka period milankovitch cyclicity related to astronomical climatic fluctuations is suggested as a governing mechanism although subsidence cannot be excluded the existence of laterally persistent fluvial sheet sandstone overlain by red mudstone that forms fining upward type iii cycles 10 m thick on average is attributed to changes in subsidence rate rhythmic alternations between gypsum beds and red green mudstone and or dolomitic limestone and bituminous shale observed in the middle members might be related to minor periodical climatic changes rather than to tectonics

geochronology and stable isotope signature of alteration related to hydrothermal magnetite ores in central anatolia turkey hydrothermal iron ores at divrigi east central anatolia are contained in two orebodies the magnetite rich a kafa and the limonitic b kafa resources of 133 8 mt with 56 fe and 0 5 cu the magnetite ores are hosted in serpentinites of the divrigi ophiolite at the contact with plutons of the murmano complex hydrothermal biotite from the divrigi a kafa yield identical weighted mean plateau ages of 73 75 0 62 and 74 34 0 83 ma 2 this biotite represents a late alteration phase and its age is a minimum age for the magnetite ore similar magnetite ores occur at hasancelebi and karakuz south of divrigi there the iron ores are hosted in volcanic or subvolcanic rocks respectively and are associated with a voluminous scapolite amphibole biotite alteration at hasancelebi biotite is intergrown with parts of the magnetite and both minerals formed coevally the weighted mean plateau ages of hydrothermal biotite of 73 43 0 41 and 74 92 0 39 ma 2 therefore represent mineralization ages hydrothermal biotite from a vein cutting the scapolitized host rocks south of the hasancelebi prospect has a weighted mean plateau age of 73 12 0 75 ma 2 this age together with the two biotite ages from the hasancelebi ores constrains the minimum age of the volcanic host rocks syenitic porphyry dikes therein and the scapolite alteration affecting both rock types pyrite and calcite also represent late hydrothermal stages in all of these magnetite deposits the sulfur isotope composition of pyrite between 11 5 and 17 4 34s vcdt points towards a non magmatic sulfur source of probably evaporitic origin calcite from the divrigi deposit has 18o vsmov values between 15 1 and 26 5 and 13c vpdb values between 2 5 and 2 0 which are compatible with an involvement of modified marine evaporitic fluids during the late hydrothermal stages assuming calcite formation temperatures of about 300 c the presence of evaporite derived brines also during the early stages is corroborated by the pre magnetite scapolite alteration at divrigi and hasancelebi karakuz and with paleogeographic and paleoclimatic reconstructions the data are compatible with a previously proposed genetic model for the divrigi deposit in which hydrothermal fluids leach and redistribute iron from ophiolitic rocks concomitant with the cooling of the nearby plutons

assessment of naturally occurring arsenic contamination in the groundwater of sarkisla plain sivas turkey high arsenic levels in groundwater of the aquifers belonging to the pliocene terrestrial layers and quaternary alluvial sediments have become a significant problem for the inhabitants living in sarkisla turkey the main objective of this study was to determine the origin and arsenic contamination mechanisms of the sarkisla drinking water aquifer systems the highest arsenic concentrations were found in pliocene layers and alluvial sediments with concentrations ranging from 2 1 to 155 mg kg these rocks are the main aquifers in the study area and most of the drinking groundwater demand is met by these aquifers groundwater from the pliocene aquifer is mainly ca hco3 and ca so4 water type with high ec values reaching up to 3 270 s cm which is due to the sulfate dissolution in some parts of the alluvial aquifer stable isotope values showed that the groundwater was of meteoric origin tritium values for the groundwater were between 8 31 and 14 06 tu representing a fast circulation in the aquifer arsenic concentrations in the aquifers were between 0 5 and 345 g l the highest arsenic concentrations detected in the pliocene aquifer system reached up to 345 g l with an average value of 60 38 g l the arsenic concentrations of the wells were high while the springs had lower arsenic concentrations these springs are located in the upper parts of the study area where the rocks are less weathered the hydrogeochemical properties demonstrated that the water rock interaction processes in sulfide bearing rocks were responsible for the remarkably high groundwater arsenic contamination in the study area in the study area the arsenic levels determined in groundwater exceeded the levels recommended by the who therefore it is suggested that this water should not be used for drinking purposes and new water sources should be investigated

investigation into the regional wrench tectonics of inner east anatolia turkey using potential field data abstract the residual aeromagnetic and gravity anomalies of inner east anatolia surveyed by the mineral research and exploration mta of turkey display complexities some faults which are known and new lineaments are drawn from maxspot map derived from the location of the horizontal gradient of gravity anomalies tectonic lineaments of inner east anatolia exhibit similarities to the direction of east anatolian fault zone anticlockwise rotation approximately 30 defined from disorientations of aeromagnetic anomalies the lineaments obtained from maxspots map produced from the gravity anomalies and disoriented aeromagnetic anomalies are in line with the mobilistic system revealed by the palaeomagnetic data these alpine age continental rotations caused westward wrenching of the global lithosphere and led to significant tectonic reactivation and deformations gps measurements current tectonic knowledge and the results of the evaluation of potential field data were combined in a base map to demonstrate similarities

characteristic features and structural evolution of a post collisional basin the sivas basin central anatolia turkey abstract the ene ssw trending sivas basin is located at the easternmost wedge like tip of the central anatolian block and exhibits characteristics of two other basins one in west central anatolia and the other in eastern anatolia the sivas basin started to form within a collisional mosaic during maastrichtian time with the pre maastrichtian basement the latter composed of continental metamorphic rocks jurassic lower cretaceous platform carbonates of the tauride belt and ophiolites and ophiolitic melange derived from closure of the northern branch of neo tethys similar tertiary basins were developed on comparable collisional mosaics in other parts of anatolia the sivas basin is asymmetrical in both the longitudinal and transversal directions its infill is dominated by a thick maastrichtian tertiary shallow marine continental succession resting unconformably on pre maastrichtian basement rocks and dissected into several subbasins this infill consists of post collisional deposits which overlie paleotectonic units unconformably and each subbasin is bounded by northeast southwest trending oblique slip faults exhibiting dominant strike slip the subbasins are characterized by contrasting stratigraphic successions although all are composed of interstratified continental and shallow marine facies both the northern and southern margins of the subbasins include upper eocene olistostromes containing mega blocks of varied origin the latter are sourced in paleotectonic units and were reworked in a shallow marine depositional setting the fill of the middle subbasins exhibits strong vertical and lateral facies changes characterized by local and regional unconformities and includes continental to shallow marine volcanic rocks this basin was deformed under north south directed compression during late pliocene quaternary times during the neotectonic phase of deformation this deformation divided the basin into new small scale mainly pull apart subbasins including those at imranli ishani altinyayla and arkisla from stratigraphic and structural correlations a post collisional intra continental basin model for the sivas basin is preferred

facies partitioning and stratal pattern in salt controlled marine to continental mini basins examples from the late oligocene to early miocene of the sivas basin turkey the sivas basin turkey records a complex interaction between sedimentation salt tectonics and regional shortening leading to the formation of numerous mini basins the segmentation into mini basins was initiated during the oligocene by the deposition of the fluvio lacustrine karayun fm this continental succession is overlain abruptly by an oligo miocene shallow marine succession karacaoren fm which comprises two main sub environments i mixed deltaic and carbonate ramp ii coastal plain and lagoon the karacaoren fm forms a marine succession more than 1500 m thick that passes vertically upwards into a continental succession the fluvial dominated benlikaya fm these two formations are the focus of the present study during the period of marine sedimentation the competing accumulation of carbonates and clastics is related not only to the topography inherited from salt tectonics but also to relative sea level variations expressed by two large scale transgressive regressive cycles we analyse these complex facies and stratal relationships to illustrate the modifications induced by salt tectonics this study is based on extensive fieldwork and mapping making use of numerous measured stratigraphic sections and aerial photos over a large area comprising more than fifteen adjacent outcropping mini basins the aim of this study is to provide a detailed description of the stratigraphic relationships correlations and sedimentary systems distribution in mini basins during deposition of the oligo miocene shallow marine and continental successions we first clarify the vertical stratigraphic succession of the oligo miocene marine and continental deposits and establish correlations between the studied mini basins these correlations then allow us to characterize and assess the local effects of salt withdrawal in relation to the regional forcings associated with flexural subsidence tectonic shortening and relative sea level changes an improved understanding of the complex interactions of these variables provides a framework to distinguish the mechanisms that control facies distribution and stratal geometry in salt basins

tectonostratigraphic evolution of the upper cretaceous cenozoic central anatolian basins an integrated study of diachronous ocean basin closure and continental collision

unconformity bounded stratigraphic units ubsus in an italian alluvial plain area recognizing and dating abstract we studied the coastal zone of the tavoliere di puglia plain puglia region southern italy with the aim to recognize the main unconformities and therefore the unconformity bounded stratigraphic units ubsus salvador 1987 1994 forming its quaternary sedimentary fill recognizing unconformities is particularly problematic in an alluvial plain due to the difficulties in distinguishing the unconformities that bound the ubsus so far the recognition of ubsus in buried successions has been made mostly by using seismic profiles instead in our case the unavailability of the latter has prompted us to address the problem by developing a methodological protocol consisting of the following steps i geological survey in the field ii draft of a preliminary geological setting based on the field survey results iii dating of 102 samples coming from a large number of boreholes and some outcropping sections by means of the amino acid racemization aar method applied to ostracod shells and 14c dating filtering of the ages and the selection of valid ages iv correction of the preliminary geological setting in the light of the numerical ages definition of the final geological setting with ubsus identification of a hypothetical or attributed time range htr or atr for each ubsu the former very wide and subject to a subsequent modification the latter definitive v cross checking between the numerical ages and or other characteristics of the sedimentary bodies and or the sea level curves with their effects on the sedimentary processes in order to restrict also the hypothetical time ranges in the attributed time ranges the successful application of aar geochronology to ostracod shells relies on the fact that the ability of ostracods to colonize almost all environments constitutes a tool for correlation and also allow the inclusion in the same unit of coeval sediments that differ lithologically and paleoenvironmentally the treatment of the numerical ages obtained using the aar method required special attention the first filtering step was made by the laboratory rejection criteria a and b then the second filtering step was made by testing in the field the remaining ages among these in fact we never compared an age with a single preceding and or following age instead we identified homogeneous groups of numerical ages consistent with their reciprocal stratigraphic position this operation led to the rejection of further numerical ages that deviate erratically from a larger homogeneous age population which fits well with its stratigraphic position rejection criterion c after all of the filtering steps the valid ages that remained were used for the subdivision of the sedimentary sequences into ubsus together with the lithological and paleoenvironmental criteria the numerical ages allowed us in the first instance to recognize all of the age gaps between two consecutive samples next we identified the level in the sedimentary thickness that is between these two samples that may represent the most suitable ubsu boundary based on its lithology and or the paleoenvironment the recognized units are i coppa nevigata sands nea htr mis 20 14 atr mis 17 16 ii argille subappennine asp htr mis 15 11 atr mis 15 13 iii coppa nevigata synthem nvi htr mis 13 8 atr mis 12 11 iv sabbie di torre quarto stq htr mis 13 9 1 atr mis 11 v amendola subsynthem mlm1 htr mis 12 10 atr mis 11 vi undifferentiated continental unit uci htr mis 11 6 2 atr mis 9 3 7 1 vii foggia synthem tgf atr mis 6 viii masseria finamondo synthem tpf atr upper pleistocene ix carapelle and cervaro streams synthem rpl subdivided into ixa incoronata subsynthem rpl1 htr mis 6 3 atr mis 5 3 ixb marane la pidocchiosa castello subsynthem rpl3 atr holocene x masseria inacquata synthem naq atr holocene the possibility of recognizing and dating quaternary units in an alluvial plain to the scale of a marine isotope stage constitutes a clear step forward compared with similar studies regarding other alluvial plain areas where quaternary units were dated almost exclusively using their stratigraphic position as a result they were generically associated with a geological sub epoch instead our method allowed a higher detail in the timing of the sedimentary processes for example mis 11 and mis 5 5 deposits have been recognized and characterized for the first time in the study area highlighting their importance as phases of sedimentation

an aerial view of 80 years of climate related glacier fluctuations in southeast greenland both marine and land terminating glaciers in southeast greenland have experienced dramatic recent retreat an 80 year record of historical aerial photographs and satellite imagery shows that many land terminating glaciers in this region retreated more rapidly in the 1930s than today whereas marine terminating glaciers have retreated faster in the 2000s