the oligo miocene qom formation iran evidence for an early burdigalian restriction of the tethyan seaway and closure of its iranian gateways in the central iranian esfahan sirjan and qom basins sedimentation of the oligo miocene qom formation took place on extensive mixed carbonate siliciclastic ramps during this time both basins were positioned at the eurasian margin of the tethyan seaway which connected the western and eastern regions of the tethys ocean at least until the late burdigalian during the so called terminal tethyan event the tethyan seaway was then closed due to the collision of the african arabian and iranian eurasian plates facies analysis of the sedimentary record of both basins indicates paleoenvironments ranging from terrestrial to open marine settings including mangrove restricted inner shelf lagoon seagrass meadow reefal and deeper offshore environments recognition of eight depositional sequences and elaboration of an integrated biostratigraphic framework calcareous nannoplankton planktic and larger benthic foraminifers gastropods and pectinids allow us to construct a basin spanning stratigraphy the assignment of the recognized sea level lowstands to the ru 3 to bur 3 lowstands of the global sea level curve enables a comparison with time equivalent sections from the zagros basin which was part of the african arabian plate on the opposing southern margin of the tethyan seaway the so calibrated sections display restrictions of the tethyan seaway and interruption of the south iranian gateways between the qom basin and the proto indopacific in relation to ongoing plate collision during the early burdigalian

a middle miocene carbonate platform under silici volcaniclastic sedimentation stress leitha limestone styrian basin austria depositional environments sedimentary evolution and palaeoecology abstract siliciclastic influx is a major control for neritic carbonates herein we present a shallow marine mixed silici volcaniclastic carbonate system from the middle miocene coralline algal dominated leitha limestone in the styrian basin austria the analyses of facies and stratal geometries reveal a succession of four depositional units and six facies types reef facies inter reef facies coralline algal debris facies rhodolith porites facies quartz sand planostegina facies coral carpet facies depositional unit 1 comprises patch reefs reef facies and surrounding carbonate sands inter reef facies which show a characteristic lateral succession of biotic associations reef corals rhodoliths nodular celleporiform bryozoans planostegina a similar modern analogue occurs in the red sea at the transition from patch reefs to seagrass meadows in contrast the coralline algal debris facies of depositional unit 2 represents a high energetic submarine dune environment a deepening shallowing trend is suggested by the gradual shift from the muddy rhodolith porites facies to the detritic quartz sand planostegina facies in depositional unit 3 while the vertical transition of coral carpet facies to rhodolith porites facies in depositional unit 4 suggests again a deepening despite an isolated inner basin setting on the middle styrian high the coralline algal and coral dominated benthic carbonate communities in all depositional units and facies were strongly influenced by terrigenous sedimentation coarser siliciclastic sedimentation was linked to low stands of relative sea level while fine clay fraction was deposited at any time due to the submarine alteration and reworking of volcanic ashes despite a high sedimentation stress the variety of coral communities patch reefs coral carpets non framework coral communities and coral diversity is unique for the entire central paratethys leptoseris and two not identified coral species one with thin platy plocoid the other with phaceloid branching growth form are new coral records for the central paratethys this is of particular importance for paleobiogeographic reconstructions since the styrian basin was located close to the northern margin of the global coral reef belt it is assumed that the relatively high total coral diversity reflects dynamic habitat and population structures in an unstable coral ecosystem at the edge of coral reef distribution which was highly vulnerable to tectonically controlled changes affecting nature and distribution of clastic sediments in general increasing siltation stress reduced coral diversity coral cover and colony sizes and led to the replacement of massive by platy growth forms and of suprastratal by constratal growth fabrics

the messinian salinity crisis past and future of a great challenge for marine sciences forty years after the image of the mediterranean transformed into a giant salty lake was first conceived the fascinating history of the messinian salinity crisis msc still arouses great interest across a large and diverse scientific community early outcrop studies which identified severe palaeoenvironmental changes affecting the circum mediterranean at the end of the miocene were followed by investigations of the marine geology during the 1950s to 1970s these were fundamental to understanding the true scale and importance of the messinian event now after a long period of debate over several entrenched but largely untested hypotheses a unifying stratigraphic framework of msc events has been constructed this scenario is derived mainly from onshore data and observations but incorporates different perspectives for the offshore and provides hypotheses that can be tested by drilling the deep mediterranean basins the msc was an ecological crisis induced by a powerful combination of geodynamic and climatic drivers which had a great impact on the subsequent geological history of the mediterranean area and on the salinity of the global oceans these changed the mediterranean s connections with both the atlantic ocean and the freshwater paratethyan basins causing high amplitude fluctuations in the hydrology of the mediterranean the msc developed in three main stages each of them characterized by different palaeoenvironmental conditions during the first stage evaporites precipitated in shallow sub basins the msc peaked in the second stage when evaporite precipitation shifted to the deepest depocentres and the third stage was characterized by large scale environmental fluctuations in a mediterranean transformed into a brackish water lake the very high resolution timescale available for some late miocene intervals in the mediterranean makes it possible to consider environmental variability on extremely short time scales including in some places annual changes despite this fundamental questions remain some of which could be answered through new cores from the deepest mediterranean basins improvements in seismic imaging and drilling techniques over the last few decades make it possible to plan to core the entire basinal messinian succession for the first time the resulting data would allow us to decipher the causes of this extreme environmental change and its global scale consequences

carbonate mounds from paradox to world heritage the recent marine carbonate world comprises two major compartments 1 the surface domain of the photozoan carbonates confined in space by water depth and by the penetration of light and 2 a deep domain where heterozoan mound builder guilds directly forage on fluxes of nutrients which primarily percolate from the photic zone and or are generated by in situ benthic processes locally giant cold water coral mounds tower up to heights of 150 to 250 m above the sea floor in general between 500 and 1300 m water depth and within sharply delineated provinces some 15 years of research on these giant mound provinces conveys a picture of their distribution in space and possibly sheds light on controls acting in concert globally there is no counterpart for the prolific north atlantic mound basin namb a chemical control is seen by an overlay of the mound provinces on a map of the aragonite saturation horizon ash an external physical control is inferred fromthe position of themound provinces girdling a vigorous north atlantic subtropical gyre systemand clustering close to the roof of the intermediate to deep water masses of a dynamically stratified ocean on the eastern boundary of the namb nutrient fluxes are enhanced by mixing processes driven either by internal waves between galicia and the shetlands or by the vast and heterogeneous eastern boundary upwelling system along the iberian african margins down to 10 n early diagenesis by carbonate dissolution and re precipitation driven by convecting or advecting internal fluids can contribute to stabilize such constructions facilitating an exuberant vertical accretion it is speculated that in thenorth atlantic ocean the deep water carbonate factory outclasses in size the shallow water coral reefs giant mound formation is a recurrent play of life since the dawn of the metazoans nama group upper neoproterozoic however with actors and plots varying from act to act remarkably literature reports only three occurrences of deep water mounds in the phanerozoic the modern ocean possibly the danian and the carboniferous some striking parallelisms in the development of the atlantic and the paleo tethys oceans combined with the developing insights in the controls on deep watermounds in the present ocean invite for a comparative study this has the potential to eventually shed light on the full circulation pattern of the paleo tethys ocean surface and deep comparative studies will build upon 1 modeling of ocean circulation constrained by the record of deep water carbonate systems and supported by advances in tracer and proxy tools and 2 field studies on representative and accessible continental locations the mound route that develops in morocco under the auspices of ioc unesco will provide tomulti disciplinary teams with marine and continental experience opportunities for confronting observations from the modern ocean and on key records of past oceanic basins it has the potential to eventually qualify for a unesco recognition as world heritage

ecospace variability along a carbonate platform at the northern boundary of the miocene reef belt upper langhian austria the south western edge of the leitha mountains in the southern vienna basin austria exposes parts of an upper langhian middle badenian shallow water 30 m carbonate platform the study of its ecospace comprises sedimentological and palaeontological data of 4 up to 36 m thick carbonate sections of the mullendorf quarries which have been logged and subjected to detailed investigation and sampling the sedimentary record is dominated by coralline algal debris sands which represent 7 distinct lithofacies bioclastic coralline algal mollusc facies hyotissa facies isognomon facies coral facies rhodolith facies bryozoan facies all these facies are described in detail in respect to lithology and biota and are palaeoecologically interpreted striking features of these limestone successions are periodical intercalations of coral and mollusc rich horizons their formation had been triggered by water turbidity and low amplitude changes in relative sea level these relations are especially interesting as the platform carbonates formed at the northern edge of the langhian peri mediterranean reef belt water turbidity as ecological master factor and depth played the fundamental role in ecosystem and community expression within ecospace the lateral distribution and the ecological relations between the various facies types allow proposing an ecospace occupation model

the petrology and palaeoenvironment of the sortino group miocene of se sicily evidence for periodic emergence the sortino group of carbonates consists of three formations which developed on a shallow marine shelf during tortonian and lower messinian times the two lower formations contain three bioherms and are intercalated with thick volcaniclastic sequences the youngest formation is dominated by shoal water lagoonal and peri tidal carbonates early submarine lithification is well developed within the bioherms and consists of construction by both algae and invertebrates the development of peloidal micrites and isopachous fringe growth superimposed upon these are a series of both meteoric phreatic and vadose textures related to episodic emergence of the bioherms these features include bladed cements showing cathodoluminescence pendent cements brecciation alveolar texture and palaeosols the sicilian strata may be directly correlated with the maltese islands sequence and collectively exhibit the effects of fluctuating mediterranean sea levels at an early stage in the late miocene salinity crisis

sea level highstand and lowstand shedding related to shelf margin aggradation and emersion upper eocene oligocene of maiella carbonate platform italy abstract sequence stratigraphic analysis of the upper eocene lower oligocene of the maiella carbonate platform allows the timing of shelf aggradation and erosion to be linked to shedding onto the slope and relative sea level stands the shelf was eroded during lowstands and the lowstand slope sediments are thin channelized lithic breccias with clasts eroded from an emerged reef tract highstand shedding of skeletal sands from the inner shelf resulted in thick coarsening and thickening upward successions of turbidites

the dagpazari carbonate platform mut basin southern turkey facies and environmental reconstruction of a coral reef system during the middle miocene climatic optimum abstract plate tectonics and climate change have deeply influenced the evolution of coral reef systems of the mediterranean during the miocene most of this information is based on studies of coral reefs from the western and central sectors of the mediterranean this study reports facies analyses sr isotope stratigraphy and environmental reconstructions of the dagpazari coral reef system located within the mut basin in southern turkey stratigraphic correlations and sr isotope ratios on several oyster shells date the dagpazari reef to the early langhian ten different facies have been recognized and their arrangement has led to the identification of two main depositional units interpretation of the biotic associations indicates that the dagpazari depositional system developed constantly within the euphotic zone the reef framework was mainly built by massive faviid and poritid zooxanthellate corals whereas loose grain sediments were essentially produced by halimeda coralline red algae or influenced by the presence of seagrass colonizations this study highlights for the first time the great importance of halimeda as sediment producer in the eastern mediterranean coral reef systems this role is related to the common occurrence of halimeda plates within almost all the reef facies but especially to the presence of large in situ bioherms dominated by the algal segments dagpazari langhian halimeda bioherms also represent the oldest of these structures so far recorded in the fossil record the development of the dagpazari platform was mainly controlled by eustatic fluctuations of the sea level and by the morphology of the antecedent substrate in particular the occurrence of a pre existent topographic high promoted the constant presence of shallow water environments throughout the depositional history of the reef system with the production of euphotic carbonates both landward and basinward and the consequent formation of a small elliptical platform 87sr 86sr ages place the dagpazari reef system exactly within the middle miocene climatic optimum phase the most recent warm phase of the earth this suggests that zooxanthellate corals were able to exert their reef building capacity in shallow water settings even during periods of global warming thus being not exclusively an adaptation to cooling climates as proposed in the recent debates

nearshore temperate carbonate depositional systems lower tortonian agua amarga basin southern spain implications for carbonate sequence stratigraphy abstract the bryozoan rich lower tortonian carbonates of the agua amarga basin in southern spain province of almeria provide an example of sediments formed in a nearshore non tropical depositional setting based on data derived from logging of sections and from field mapping these lower tortonian carbonates form a depositional sequence which is subdivided into several depositional systems a lowstand systems tract which consists of volcaniclastic fan deltas and washover deposits formed on the leeward side of a basement shoal which delimited the basin towards the south a transgressive systems tract which is characterised by a landward encroachment of deposits is represented by submarine bars and dune deposits a highstand systems tract consists of progradational beach deposits owing to strong reworking and re distribution of the particles by currents and waves microfacies differentiation of the deposits in poor these tortonian non tropical carbonates display a style of deposition similar to siliciclastics suggesting that sequence stratigraphic concepts derived from tropical carbonates do not apply to non tropical carbonates

paleobiogeography of scleractinian reef corals changing patterns during the oligocene miocene climatic transition in the mediterranean abstract during the oligocene miocene greenhouse to icehouse climatic transition the biogeography of reef corals or zooxanthellate like scleractinian corals was gradually changing from a pan tropical tethyan province in the eocene to three reef coral provinces of the western atlantic caribbean indo pacific and mediterranean our reefcoral database encompasses updated and homogenized data on paleoenvironmental and systematics of scleractinian corals occurring in the oligocene and miocene outcrops from circum mediterranean regions provided by most of relatively recently published data in the literature and by the study of published and unpublished collections of coral specimens from the same area including the important collections housed at the mnhn paris and our own collections as there is no validated direct criterion for the identification of the coral zooxanthellate symbiosis in the fossil record and considering the difficulty to use the biogeochemical approaches in the context of this study the subjectivity of the morphological criteria and the relative recent age of the fossil corals we are dealing with a uniformitarian approach has been used for inferring the symbiotic status of scleractinian genera in reefcoral among the 158 genera included in our database 93 can be considered as zooxanthellate and 10 have a doubtful zooxanthellate status this relatively exhaustive database was used to reconstruct the temporal and spatial distribution of scleractinian corals in the mediterranean during the oligocene miocene time in order to discuss the interplaying effects of the global cooling at that time the re organization of the tethyan realm resulting from the african arabian and eurasian plate collision and the emergence of the alpine chains driving the gradual northward movement of the whole region outside the tropical subtropical belt it is shown that the structure of the mediterranean z coral oligocene miocene paleobiodiversity was characterized by many geographically restricted genera with a moderate to short stratigraphical range and a few long ranging widespread genera a major consequence of this structure is that the extinction pattern has proceeded through the preferential extinction of rare occurrence genera through time the potential rapid long distance dispersal of most coral larvae compared to the size of the oligocene miocene mediterranean explains why no biogeographical subprovinces can be distinguished for the z coral fauna on a local scale ecological processes tend to sort coral taxa by limiting z coral development to geographically restricted and discontinuous areas this accounts for the large amount of geographically restricted taxa forming the mediterranean coral fauna the interaction of plate tectonics alpine orogenesis and climate at local to subregional scales exerts strong controls over the spatio temporal distribution of z coral assemblages within the circum mediterranean realm in particular we suggest that the richness and composition of the eastern atlantic coral fauna are indirectly related to the opening and closure of the eastern seaway connection with the indian ocean which controlled the e w circulation of surface waters and hence the westwards dispersal of pelagic larvae at the scale of the whole region the gradual regional climatic change produced by the northwards migration of the entire area superimposed on the global cooling appears in large part responsible for the extinction pattern of z corals through time in the mediterranean biogeographical province

internal structure of segment reefs halimeda algal mounds in the mediterranean miocene halimeda reefs in the upper miocene strata 6 ma of the sorbas basin southeastern spain shed light on the internal structure of more extensive but less accessible holocene counterparts and challenge conventional reef concepts coarse discoid segments released by halimeda during life or immediately after death dominate the lenslike mounds their chaotic loose appearance disguises the reefal nature of the mounds segments accumulating at or very close to sites of growth were quickly stabilized by microbial and cement crusts that bound them into distinctive rigid gravel fabrics this early lithification generated relief but inhibited off mound export of sediment although large blocks detached locally and moved downslope encrustation of parautochthonous halimeda gravel created a unique reef type segment reefs

contrasting isotopic signatures between anthropogenic and geogenic zn and evidence for post depositional fractionation processes in smelter impacted soils from northern france abstract zinc isotopes have been studied along two smelter impacted soil profiles sampled near one of the largest pb and zn processing plants in europe located in northern france about 50 km south of lille mean 66zn values along these two soil profiles range from 0 22 0 17 2 to 0 34 0 17 2 at the lowest horizons and from 0 38 0 45 2 to 0 76 0 14 2 near the surface the 66zn values in the lowest horizons of the soils are interpreted as being representative of the local geochemical background mean value 0 31 0 38 whereas heavier 66zn values near the surface of the two soils are related to anthropogenic zn this anthropogenic zn occurs in the form of franklinite znfe2o4 bearing slag grains originating from processing wastes at the smelter site and exhibiting 66zn values of 0 81 0 20 2 the presence of franklinite is indicated by exafs analysis of the topsoil samples from both soil profiles as well as by micro xanes analysis of the surface horizon of a third smelter impacted soil from a distant site these results indicate that naturally occurring zn and smelter derived zn exhibit significantly different 66zn values which suggests that zinc isotopes can be used to distinguish between geogenic and anthropogenic sources of zn in smelter impacted soils in addition to a possible influence of additional past sources of light zn likely zn sulfides and zn sulfates directly emitted by the smelter the light 66zn values in the surface horizons compared to smelter derived slag materials are interpreted as resulting mainly from fractionation processes associated with biotic and or abiotic pedological processes zn bearing mineral precipitation zn complexation by organic matter and plant uptake of zn this conclusion emphasizes the need for additional zn isotopic studies before being able to use zn isotopes to trace sources and pathways of this element in surface environments

record of climatic change in neritic carbonates turnover in biogenic associations and depositional modes late miocene southern spain in order to evaluate the geological record of climatic change in neritic carbonates we studied late miocene rock outcrops in southern spain six episodes of reef growth are documented burdigalian to messinian in neogene basins of the betic cordillera which were located close to the margin of the global reef belt the reefs are characterized by various zooxanthellate corals which decrease in diversity with time andhalimeda the youngest reefs of the latest messinian are characterized by the dominance of the genusporites late miocene coral reefs and reef rimmed platforms alternate over time with non reefal carbonate ramps characterized by skeletal calcirudites or with gypsum such as that formed during the messinian salinity crisis the calcirudites lack reef corals calcified green algae and extensive marine cement but exhibit skeletal components described from both modern and fossil nontropical carbonates these include bryozoans mollusks foraminifers echinoderms and minor balanids as well as coralline algae of a bryomol association the presence of some larger foraminifers indicates high temperatures close to the lower temperature threshold of the reef assemblage sea level lowstands and highstands are documented by wedges of bryomol carbonate and chlorozoan patch reefs or prograding platforms thus temperate climate depositional modes correspond to relatively low sea levels and warm water modes to high sea levels the neogene infill of the agua amarga and sorbas basins documents two of these cycles other climate sea level cycles including messinian gypsum in the cool water depositional mode are well established in adjacent neogene basins in southern spain this type of composite sequence seems to occur only along the margin of the global reef belt and indicates an oscillatory latitudinal movement of the margin which is associated with global climatic change the analysis of turnover in neritic depositional carbonate systems may therefore be considered a sensitive tool for reconstructing climatic change from the fossil record however warm water modes and temperate water modes of carbonate sedimentation and diagenesis differ significantly for this reason the interpretation of composite system sequences by sequence stratigraphy requires an extended concept the particular type of mixed bryomolchlorozoan depositional sequence also bears some potential for drowning because sea level rise may be faster than the net production rate of temperate carbonate systems

late miocene breccia of menorca balearic islands a basis for the interpretation of a neogene ramp deposit abstract neogene tortonian ramp facies associations crop out in the southern sector of menorca balearic island these are made mainly by sigmoidal and oblique clinoform units comprising rhodoliths bryozoans molluscs and foraminifera these units are interpreted as outer ramp deposits a breccia deposit infilling an erosional surface is found at the top of the carbonate ramp sequence the breccia components mainly rhodoliths and oolite clasts may represent erosion of the underlying ramp deposits and inner ramp counterparts which do not crop out on the island the study of components in the breccia deposits confirms the indigenous character of the outer ramp facies associations which suggests that the ramp was steepened distally the breccia deposits correspond laterally to a discontinuity surface locally showing karstic features transgressive sediments including a phosphatic crust are found above the discontinuity surface all together these features and the dolomitisation of the uppermost ramp sediments and breccia deposits suggest that the breccia originated from erosion of the ramp after a major relative sea level fall the breccia and discontinuity surface separate the ramp sequence from an overlying prograding sequence a correlation of this sequence boundary to other areas in the western mediterranean is proposed

a new type of messinian composite microbialitic build up salemi sicily italy abstract a new type of metric scale composite patch reef is described in the messinian sedimentary rocks from the vicinity of salemi western sicily these build ups are composed of two distinctive parts 1 a steep sided dome shaped microbial mound with thrombolitic fabric and encrusting organisms 2 a coral microbial build up covering the microbialitic mound in which coral colonies are coated with microbialites these are associated with various encrusting organisms the accretion of the microbialitic mound is characterized by the development of botryoidal micritic aggregates and skeletons of melobesians encrusting foraminifers bryozoans serpulids and cemented bivalves the accretionary process involving the microbialite development appears to have been homogeneous within different parts of the composite microbialitic build up as in other similar messinian build ups of the mediterranean consequently it is considered that microbial growth continued throughout messinian times in mediterranean regions being recorded in a wide range of habitats and paleoenvironments

a gastropod based biogeographic scheme for the european neogene freshwater systems abstract for the first time a palaeobiogeographic framework is proposed for european neogene freshwater systems the distribution of 2226 species group taxa of freshwater gastropods from over 2700 miocene and pliocene localities was evaluated the localities were grouped into palaeo freshwater systems based on latest palaeogeographic reconstructions cluster analyses were computed for four time slices i e early miocene middle miocene late miocene and pliocene the analyses demonstrate a generally high degree of provincialism for the neogene freshwater systems and allow the definition of biogeographic units the delimitations are based on the cluster analyses the degree of endemicity and geographical coherence the early miocene is characterised by a relatively low degree of provincialism suggesting the distinction of three regions coinciding with the development of many endemic systems on the dinarian anatolian island and in central europe the middle miocene demonstrates a higher degree of provincialism allowing the definition of six biogeographic regions with the onset of the late miocene the retreat of the central paratethys and development of the huge lake pannon massively shaped faunal evolution and palaeobiogeography in general the formation of the lago mare environment fringing the mediterranean basin as well as the development of several restricted freshwater systems in western europe additionally promoted biogeographic division the increasing provincialism allowed the delimitation of six biogeographic regions three of which could be subdivided into seven dominions with the disappearance of lake pannon and the decline of western european and mediterranean faunas at the miocene pliocene boundary biodiversity hotspots shifted towards eastern and southeastern europe for the pliocene four biogeographic regions five dominions and four provinces were defined most of the here proposed biogeographic units and faunal differences are governed by the varied existence of large long lived systems because of their prolonged duration they immensely influenced the community composition on the family level differences of the relative species richnesses per biogeographic region and the rising rate of endemicity the underlying mechanism for this pattern is the ongoing continentalization of europe triggered by the alpidic orogenesis and the simultaneous retreat of the paratethys sea the continuing restriction of this huge intracontinental sea from the mediterranean promoted the evolution of endemic freshwater faunas the arising long lived systems like lake pannon lake dacia or lake slavonia persisted over several millions of years and stimulated the evolution of highly diverse and endemic faunas

climatic signatures in shallow water carbonates high resolution stratigraphic markers in structurally controlled carbonate buildups late miocene southern spain abstract neogene intramontane basins of the betic cordillera se spain have a complex tectonic and sedimentary history in the eastern almeria province movements along the carboneras strike slip fault system n50 e and its conjugated faults n140 e controlled the distributions of depocenters and stratigraphic architectures of late miocene sediments we have chosen the agua amarga area 1 to exemplify the potential of climatic signatures of biogenic associations in shallow water carbonates for high resolution chronostratigraphic correlations and 2 to describe stratigraphic architectures and facies distributions in a setting subject to synsedimentary tectonics the southwestern margin la higuera is formed by a gentle ramp dipping in a n50 e direction late tortonian and messinian deep and shallow water carbonates divide into eight depositional units neptunian autoclastic breccias neptunian dikes and submarine biogenic pavements unit h 1 document rapid flooding of the basin during a phase of intense tectonic dilatation late tortonian units h 2 7 late tortonian early messinian form wedges which dip and thicken in a basinward direction little lateral facies change and internal stratifications parallel with the basal surfaces imply deposition on a subhorizontal substratum the upper bounding surfaces are erosional and formed by truncation of tilted strata from wedge to wedge the angle of dip decreases upsection and is near zero in between the last units which have parallel bounding surfaces and rest subhorizontally unit h 7 8 this pattern results from cumulative rotational uplift which decreased upward but does not necessarily exclude vertical displacements of the youngest units the southeastern margin of the basin is mostly eroded but may have trended n50 e as indicated by the distribution of slumped reef blocks a relict of the margin is preserved at mesa de roldan and exhibits steep clinoforms dipping towards the nw n300 e and w n250 e synsedimentary tectonics are documented by nine shallow marine depositional units unit r 1 conglomerates associated with neptunian dikes units r 2 9 skeletal carbonates and reefs bounded by deep erosion surfaces and or truncation of individual units along a miocene fault at both flanks the shallow water biofacies record an identical trend of climatic warming and therefore bracket a similar amount of time temperate conditions prevailed during the latest tortonian and earliest messinian whereas tropical temperatures existed during the early and late messinian and perhaps during the tortonian messinian transition the number of depositional units reflecting these climatic periods of time and the stratal geometries however differ at both sites and within the basin which implies spatial variations in the generation of accomodation space on independent fault blocks these data also suggest that there cannot be any universal sequence stratigraphic model for late miocene shallow water carbonates of se spain and that the downstepping geometries observed in many other early messinian reefs of the betic cordillera reflect tectonic uplift

miocene to pleistocene transatlantic dispersal of ceratoconcha coral dwelling barnacles and north atlantic island biogeography coral dwelling pyrgomatid barnacles subfamily ceratoconchinae were widely dispersed throughout the paratethys and mediterranean seas as well as the atlantic ocean during the neogene but today are limited to the western atlantic herein the paleobiogeographic origin and dispersal of the genus ceratoconcha is studied based on a combination of field taxonomic and literature studies the first confirmed appearances of ceratoconcha occur in lower miocene strata burdigalian with two closely related species on both sides of the atlantic in western france and florida fossils from the miocene of lanzarote in the canary islands and pleistocene of maio in the cape verde islands extend the known geographical and temporal range of the ceratoconcha barnacles in the eastern atlantic during the neogene dispersal of marine taxa was a two way process due to tectonic changes both influencing oceanic circulation and appearance and disappearance of oceanic islands during the early miocene gyre formation was weak and the atlantic ocean mid latitudes were warmer than today this resulted in increased hurricane activity and the expansion of hermatypic coral hosts farther north in the north atlantic normal ocean circulation transported barnacle larvae from east to west but currents generated by hurricanes may have transported them in the opposite direction towards the margins of the northeastern atlantic islands in between abetted barnacle contact and dispersal the temporal range for ceratoconcha is extended considerably in the eastern atlantic from the early pliocene to the pleistocene the hermatypic host corals of ceratoconcha suffered a severe decline in the eastern atlantic and the mediterranean after the miocene corals were present during the pliocene and pleistocene in the cape verde islands this suggests that the southernmost oceanic islands acted as a tropical refuge for host corals and their likely barnacle symbionts

nutrient influence on fossil carbonate factories evidence from sedex extractions on burdigalian limestones miocene nw italy and s france abstract different miocene shallow water carbonate successions have been examined to test the potential of phosphorus sequential extraction sedex in studying palaeo nutrient levels and to investigate nutrient influence on carbonate factories during this epoch the coralline algal dominated sequence of the pietra da cantoni group nw italy and the bryozoan dominated sequence of the sommieres basin s france have been targeted for this study actually albeit they both developed during the burdigalian in the very same latitudinal zone they present remarkably different carbonate factories palaeontological analyses have investigated the distribution of the major groups of carbonate producing organisms throughout the successions these results have been compared with those of geochemical analyses on phosphorus and organic matter abundance testifying a clear relationship between the skeletal assemblage and the availability of nutrients as expected on the basis of modern oceanography and benthic ecology bioavailable phosphorus concentration was higher in the bryozoan dominated basin than in the coralline algal dominated basin this result strongly supports sedex sequential extraction as a viable instrument to investigate the nutrient supply in the geological record this also proves that the early miocene mediterranean carbonate factories were deeply controlled by nutrient influence with patterns similar to those observed in present day oceans moderate nutrient concentrations resulted in coralline algal dominance while high nutrient concentrations produced carbonate factories dominated by heterotrophs suspension feeders like bryozoans the euphotic zone producers which dominate in classical tropical associations were probably restricted to areas with low nutrient concentrations

late tortonian lower messinian miocene palaeogeography of se sicily information from two new formations of the sorting group abstract a thick volcanoclastic biohermal and lagoonal sequence of strata succeeds the siracusa limestone member monti climiti formation of se sicily this overlying sequence may be divided into two new formations on the basis of lithostratigraphy petrology and palaeontology the older formation here named the carlentini formation is predominantly a thick volcanoclastic sequence but with two intervening carbonate horizons faunas are rare within the volcanic strata but may be abundant and associated with corals and patch reefs within the two carbonate levels the younger formation here named the monte carrubba formation is almost exclusively composed of oolitic grainstones and lagoonal wackestones peritidal carbonates are developed in the northeast of the area faunas are frequently of low diversity euryhaline mollusc associations are dominant although pecten vigolenesis occurs in the lower beds collectively the new formations span the late tortonian lower messinian time interval and may be correlated with the calcare di base of the main sicilian basin to the west the palaeoenvironmental reconstruction suggests that both formations were deposited around the sw margins to a low island or landmass lying to the north of the hyblean region

gravity slide and resedimentation processes in a miocene carbonate ramp hyblean platcau southeastern sicily abstract more than twenty sharp based channel form structures occur in the miocene palazzolo formation carbonates within a distally steepened se sicilian miocene carbonate ramp contemporaneous biota indicate deposition in water depths of 70 150 m fully exposed structures commonly exceed one kilometre along palacostrike their bases are concordant with the host strata but these steepen to 15 in proximity of their margins internal bedding planes generally are concordant with the basal truncation surface the lithologies of the channel fills are similar to the host sediment there is little evidence that these structures are erosional since they contain neither breccias nor turbidites rather they are interpreted as the product of gravitational sliding involving thin detached sheets of consolidated ramp carbonates the resulting irregular topography was draped by redeposited fine grained carbonate sediments once healed and further oversteepened renewed gravity sliding occurred this resulted in a 250 m thick slide dominated succession in a zone 4 km wide located between the outer ramp apron comprised of coralline algal and foraminifera rich sediments and basin margin pelagic marls this phenomenon although unusual in shallow water settings is well known from modern continental slope environments sliding was probably triggered by seismicity in the region associated with two known mesozoic basement faults an alternative hypothesis involving pressure gradient build up along distally steepened ramp zones during storm surges is dismissed as a cause although this mechanism may have facilitated resedimentation of seafloor sediments over the slide zone

testing models for the messinian salinity crisis the messinian record in almeria se spain abstract neogene intermontane basins in almeria province se spain display excellent exposures of messinian late miocene sequences the sorbas almeria nijar and vera basins maintained connection with the mediterranean throughout the messinian except during the major desiccation phase leading to the formation of salt in the deep centre of the western mediterranean these basins were part of the western mediterranean with no separate link to the atlantic ocean the presence of normal marine sediments in these basins reflects the western mediterranean watermass messinian pre evaporitic sediments in the basins of southeastern almeria do not show gradual change towards evaporite deposits instead they contain stenohaline invertebrates right up to a major erosion surface that separates them from overlying gypsum deposits this contradicts suggestion of progressive salinity increase in this part of the western mediterranean prior to the messinian salinity crisis msc it also indicates that initiation of evaporite precipitation was not synchronous throughout the mediterranean basin there is no major erosion surface within or at the top of the evaporites in these almeria basins and the gypsum beds exhibit upward transition to siliciclastic and carbonate deposits this is inconsistent with a model of messinian mediterranean evaporite formation whereby deposition of marginal evaporites was followed by their erosion during drawdown that resulted in formation of evaporites in the centre of the western mediterranean the presence of stenohaline biotas in siliciclastic deposits interbedded with the gypsum and in the messinian post evaporitic sediments challenges the view that a long standing large body of brackish water the lago mare filled the western mediterranean following the msc and prior to early pliocene flooding it also contradicts the concept of many relatively small brackish basins spread across an otherwise desiccated western mediterranean basin the basins of southeastern almeria record normal marine early messinian sedimentation that was abruptly interrupted by sealevel fall this drawdown most likely resulted in precipitation of evaporites in the central deep western mediterranean basin following this episode final marine reflooding of the western mediterranean took place during the late messinian and the mediterranean sea rose to a level similar to or higher than that preceding the salinity crisis

messinian astrochronology of the melilla basin stepwise restriction of the mediterranean atlantic connection through morocco the melilla basin ne morocco formed the easternmost part of the rifian corridor which was an important mediterranean atlantic gateway during the late miocene the sedimentary infill of the basin consists of a shallow marine precession related cyclic marl diatomite succession laterally grading into a marginal carbonate complex three bio sedimentary events have been recorded within the marl succession 1 onset of diatomite deposition 2 major change in foraminiferal assemblages and 3 transition to halimeda rich carbonates and porites coral reef build ups recent 40 ar 39 ar dating has provided a good age control for the melilla carbonate sequences but a high resolution astronomical time frame is necessary to solve the climatic signature of the basin sediments this study focuses on the shallow marine marl succession of the melilla basin integrated magneto cyclo and biostratigraphy allowed a detailed correlation to the astronomical target curve resulting in a high resolution time frame for the late miocene evolution of the basin comparison of the melilla data with previous results from other moroccan and mediterranean basins indicates that the input of atlantic waters through the rifian corridor became restricted after 6 84 ma and was minimized by 6 58 ma in the final period 6 58 5 96 ma towards the messinian salinity crisis the melilla basin can be considered as a marginal basin of the mediterranean the astronomical time frame for the marl sequences of the melilla basin moreover enables a direct comparison between the independent isotopic and astrochronological dating techniques as astronomical ages have also been assigned to intercalated volcanic tuffs for which 40 ar 39 ar ages were previously determined we conclude that the isotopic ages are systematically younger

non tropical carbonates related to rocky submarine cliffs miocene almeria southern spain abstract upper miocene deposits in the cabo de gata region se spain provide a unique opportunity to study cliff related temperate carbonates a poorly known type of fossil non tropical carbonates the studied submarine cliffs lie on the western flank of the monte ricardillo volcanic dome two main biocenoses colonised the cliff walls vertical and subvertical walls were either overgrown by vermetid gastropods forming a vermetid framestone or colonised by robust branching bryozoans which were reworked post mortem and accumulated as aprons at the foot of the submarine cliffs coralline algae in the vermetid build up indicate palaeodepths below 15 20 m depressions in front of the cliffs were occupied by nodular bryozoans and bivalves within these depressions barnacles settled on secondary hard substrates with progressive flooding of the depositional area substrate relief was filled in and a carbonate ramp with facies belts following the palaeobathymetric gradient evolved a delicate branching bryozoan facies occurs in the proximal part of the ramp and a nodular bryozoan bivalve facies in its middle part distally these deposits give way to a coralline algal facies these results provide a first insight into temperate water carbonates related to rocky submarine cliffs this work also reveals a major control of substrate relief on temperate carbonate facies and biofacies

estimating mediterranean oligocene miocene sea surface temperatures an approach based on coral taxonomic richness abstract during the oligocene and miocene shallow water carbonates of the mediterranean region were rich in scleractinian corals thriving within various depositional settings including different reef types their diversity patterns although related to a complex interplay between a suite of environmental factors and palaeobiogeography are considered to be strongly controlled by climate variability and changes in sea surface water temperature by using the quantitative relationship between present day coral taxonomic richness and prevailing sea water temperature underlined by the so called energy hypothesis we test zooxanthellate coral generic richness values from a selection of 102 oligocene miocene localities of the mediterranean region as a proxy for relative palaeotemperatures for each oligocene miocene stage generic richness values per z coral site are firstly examined together with variations of the mediterranean z coral generic pool for better testing the method and assessing its potential application patterns of generic richness and inferred palaeotemperatures are then compared with global palaeoclimatic curves based on marine oxygen stable isotopes data or other climate proxies such as palaeoclimatic records from european continental floras and from fossil coral linear extension rate results clearly show that fluctuations of coral richness derived palaeotemperatures correspond relatively well with global changes of sea water temperature especially for the entire oligocene the chattian aquitanian boundary and the late miocene the well known mid miocene climatic optimum however is not recorded suggesting that regional factors acting together with important palaeogeographical changes exerted a strong control on the generic richness of mediterranean z coral communities a remarkable decline of taxonomic richness is recorded after the burdigalian together with a gradual decrease of palaeotemperatures in the region from the middle miocene onwards to the messinian however an increase in the temperature range of z coral localities is clearly visible indicating that z coral communities were able to thrive and adapt to a wider temperature range as the mediterranean was gradually migrating northwards outside the tropical belt the energy hypothesis if used at global or regional scale can be considered a promising and reliable method for estimating cenozoic palaeotemperatures from coral or other suitable fossil assemblages of shallow water carbonates

identification of earthquakes and explosions using amplitude ratios the vogtland area revisited identification of seismic events is a major scientific issue in the framework of verification of the comprehensive nuclear test ban treaty ctbt of special interest in this context is the identification of the numerous low yield mining or blasting events especially those occurring in the same area as earthquakes such as the vogtland area in the border region of germany and the czech republic seismic events in this area were investigated by wuster 1993 1995 who achieved complete discrimination using measures of spectral decay and spectral variance at the geress array and a quadratic discrimination function

reef geometries erosion surfaces and high frequency sea level changes upper miocene reef complex mallorca spain the upper miocene reef complex of mallorca is a 20 km prograding unit which crops out in sea cliffs along the southern side of the island these vertical and exceptionally clean outcrops permit i identification of different facies lagoon reef front reef slope and open platform and their geometries and boundaries at different scales ranging from metre to kilometre and ii construction of a 6 km long high resolution cross section in the direction of reef progradation this cross section shows vertical shifts of the reefal facies and erosion surfaces linked to a general progradational pattern that defines the accretional units four hierarchical orders of magnitude 1 m to 4 m of accretional units are identified by consideration of the vertical facies shifts and by which erosion surfaces are truncated by other erosion surfaces all these orders show similar patterns horizontal beds of lagoonal facies in the upper part landward reefal and slope facies with sigmoidal bedding in the central part and open platform facies with subhorizontal bedding in the lower part basinwards the boundaries are erosion surfaces horizontal over the lagoon facies dipping basinwards over the reef front facies and connecting basinwards with their correlative conformities over the reef slope and open platform facies the four orders of accretional units are interpreted in terms of four 1 m to 4 m hierarchies of sea level cycles because i there is a close relation between the coral growth and the sea surface ii there are vertical shifts in the reefal facies and their relation to the erosion surfaces and iii there was very little tectonic subsidence in the study area during the late miocene additionally all these units can be described in terms of their position relative to the sea level cycle i the reefs prograde on the open platform sediments during low stands of sea level ii aggradation of the lagoon reef and open platform facies dominates during sea level rises and the lagoonal beds onlap landwards upon the previous erosion surface iii reefal progradation occurs during high stands of sea level and iv the 2 m sea level fall produces an off lapping reef and there is progradation with downward shifts of the reefal facies and erosion landward on the emerged older reefal units a erosion surfaces the 3 m and 4 m sea level falls produce only erosion b and c erosion surfaces although precise age data do not exist at present some speculations upon the frequency of these miocene relative sea level cycles can be made by comparisons with pleistocene cyclicity there is a good correlation between the miocene 2 m cycles and the 100 ka pleistocene cycles consequently the 1 m cycles can be assigned to a fourth order in relation to previously proposed global cycles and the 2 m to fifth order cycles all these accretional units could be defined as sequences according to the definition as commonly used in sequence stratigraphy however they represent higher than third order sea level cycles but are not parasequences the term subsequence therefore is suggested to define a part of a sequence bounded by erosion surfaces mostly subaerial and their correlative conformities basinwards a hierarchy of subsequences can be established

porites corals from crete greece open a window into late miocene 10 ma seasonal and interannual climate variability variations in the biotic composition of marine shallow water carbonates document global climatic changes however a discontinuous stratigraphic record and uncertainties regarding the ages limit the significance of shallow water carbonates as palaeoclimatic archives on geological time scales notwithstanding these deficits the environmental information stored in the skeleton of reef biota is a unique source of information that resolves seasonal to interannual climate variability in geological time application of the method to corals from carbonate rocks is usually restricted to the past 130 000yr because the aragonite skeleton undergoes rapid diagenetic alteration consequently reconstructions resolving seasonal to interannual climate variability of the more distant geological time are rare we describe exceptionally well preserved corals porites as old as late miocene 10million years from the island of crete eastern mediterranean greece stable isotope records 18 o 13 c reflect seasonal changes in sea surface temperature and symbiont autotrophy spectral analysis of a 67 yr coral 18 o record reveals significant variance at interannual time scales 2 5yr that show similarities to late quaternary eastern mediterranean climate variability supported by simulations with a complex atmospheric general circulation model coupled to a mixed layer ocean model we suggest that climate dynamics in the eastern mediterranean may reflect atmospheric variability related to the icelandic low 10 million years ago

near source characterization of the seismic wavefield radiated from quarry blasts summary a series of controlled seismic experiments performed in a limestone quarry demonstrate the utility of high precision electronic detonators in studying source characteristics of multiple explosive arrays at near source ranges 80 130m where source dimensions are on the same order as source receiver distances the influence of the difference in travel path length among individual explosions on the seismograms is significant focusing of the seismic energy is observed as a function of station location with respect to the source array and is attributed to the extended source length 68 94 m and firing time of the source 380 544 ms we examine two methods for modelling ripple fired explosions at near source ranges using the principles of superpositioning the first method is based primarily on acquisition of an adequate single shot signal and requires well constrained shot times amplitude variations which result from travel path differences are not modelled which restricts use of this technique for purposes of blast vibration reduction to larger distances 2 3 source dimensions where the spatial finiteness effects of the source begin to diminish for near source distances 2 source dimensions we successfully model multiple source seismograms by convolving a synthetic seismic source signal for a single explosion with individual half space green s functions calculated for each explosion in the array our single source model for a cylindrically shaped single charge borehole length of 17 5 m and diameter of 90 mm of 68 kg consists of a modified mueller murphy approximation which utilizes source parameter estimates taken from chemical explosion study results model parameters include a final cavity radius of 0 25 m and an elastic radius of 18 m the final model is obtained by convolving the simulated single source time series with half space green s functions calculated for several source depths and superposed to approximate the spatial extent of the borehole the relative amplitude and phase characteristics of the observed single source signal at the same distance 80 6 m are reproduced by this model multiple source synthetic seismograms contain individual green s functions for each source receiver distance but utilize identical sources for the explosive array focusing effects are shown to be due to the effect of propagation path differences between individual explosions in agreement with the results of anderson stump 1989 in simulating multiple source seismograms good fits to the measured production shot amplitude spectra are obtained with the synthetic spectra spectral peaks are well matched due to precision of the firing times which were controlled by electronic detonators our example of delay time variances for 32 ms production shot appendix argues for better constraint of firing times for contolled seismic experiments such constraint requires a 1 per cent error or less in cap firing times which can be realized by the use of firing systems with an order of magnitude increase in precision compared to pyrotechnic detonators

depositional sequences and correlation of middle to late miocene carbonate complexes las negras and nijar areas southeastern spain during serravallian through messinian time marine carbonates flanked topographic highs that rimmed neogene basins in the western mediterranean middle to upper miocene carbonate strata in the las negras and nijar areas southeastern spain are 50 150 m thick and display 50 200 m of shelf to basin relief over 1 2 km detailed studies in those areas document the effects of relative sea level change on sedimentation biotic composition and reef development we identify three previously unrecognized regionally correlatable depositional sequences ds1 ds2 ds3 that occur between the underlying basement and the overlying terminal carbonate complex the lower depositional sequences ds1 ds2 are mostly normal marine shelf ramp carbonates deposited on the flanks of basement highs the basal part of ds2 locally contains some megabreccia reef blocks composed of tarbellastraea and porites these blocks are the first evidence of reef growth in the area and represent a previously unrecognized period of reef development prior to the fringing reef development the reef blocks probably formed as upslope patch reefs that were eroded and transported to distal slope locations the upper sequence ds3 is characterized by clinoform strata of a porites dominated fringing reef complex that prograded basinward in a downstepping style with successively younger reefs forming in a topographically lower and more basinward position as a result of a net sea level drop regional correlation of miocene shallow marine strata between basins in spain and elsewhere in the western mediterranean is complicated because basins were semi isolated from adjacent basins making physical correlation impossible in addition age definitive biostratigraphic markers are poorly preserved in most of the miocene shallow water strata basinal sediments that are more easily dated by microfossils do not typically interfinger with the shallow marine strata in outcrop even where datable microfossils are found resolution of dating is poor our studies in the las negras and nijar areas illustrate the usefulness of integrating sedimentological geometric and biotic data with locally derived relative sea level accommodation space curves for correlation the relative sea level curves for each area show remarkable similarities in shape and magnitude of sea level changes these curves indicate several relative sea level fluctuations during miocene carbonate deposition prior to the major sea level drop at the end of ds3 deposition that culminated in the exposure of the basin margin deposits and the deposition of evaporites in basinal areas during the messinian the depositional sequences in the las negras and nijar areas may correlate with depositional sequences of similar age throughout the southern cabo de gata area in mallorca some 600 km to the northeast and possibly in other mediterranean locations the widespread occurrence and possible correlation of the depositional sequences suggest regional processes such as eustacy or tectonism for their formation the integration of sedimentological palaeontological and sequence stratigraphic studies and the construction of relative sea level accommodation space curves may help in the interpretation of depositional histories of shallow marine carbonate complexes and correlation of these strata between isolated areas other dating methods in addition to microfossil dating may allow for better age determination of the sequences and aid in identifying the importance of eustacy and tectonism in sequence development

coral reefs in coarse terrigenous sedimentary environments upper tortonian granada basin southern spain abstract during the upper tortonian coral reefs developed on fan deltas and braid deltas along the active eastern edge of the granada basin the corals grew in environments characterized by deposition of coarse sands and conglomerates frequency of sedimentation together with sea level rises controlled reef development and determined the architecture and composition of the carbonate deposits in direct contrast to these reefs others flourished at the same time along stable coastal margins of the basin their structure was influenced mainly by periodic rises in sea level the mapping of all these reefs serves as an accurate guide to the upper tortonian geography of the granada basin

patterns of reef sedimentation and diagenesis in the miocene of cyprus abstract an early tertiary regressive sedimentary succession developed along an active plate margin in cyprus a varied clastic and carbonate succession of the miocene pakhna formation and then messinian evaporites culminate the regression within the pakhna formation two phases of reef growth were developed the aquitanian burdigalian terra member and the tortonian koronia member the terra member is exposed only in west and southeast cyprus mainly between pelagic carbonates the koronia member is exposed around the margins of the troodos massif in north south and west cyprus and on the akamas peninsula in northwest cyprus there was little tectonic influence on the growth pattern of the terra member reefs the koronia member reefs however are developed on up faulted blocks most of the koronia member fore reef facies and associated clastic input was shed into downfaulted basinal depocentres there are differences between the first and second miocene reef phases in cyprus in primary reef construction and in the level of background carbonate pelagic sedimentation the terra member reefs are dominantly framestones comprising faviids and domal poritids with several types of secondary reef dwelling corals there is no indication of a connection with the indo pacific coral faunal province benthonic foraminifera and fragments of crustose coralline algae are abundant in the off reef by contrast the koronia member is a bindstone comprising virtually monospecific laminar poritid corals but with coralline algae also playing a role in encrustation the koronia member off reef facies comprises decimetre thick beds of bioclastic reef detritus in north cyprus however beds of similar detritus centimetres in thickness are overlain by progressively thicker up to several metres debris flow sheets the terra member reefs have limited acicular fringe cement probably aragonitic this is overlain by an abundant marine bladed formerly high mg calcite cement later cements present in the reef facies include micritised calcite spars perhaps indicating microboring in cements during their precipitation neomorphism was extensive converting most cements to low mg calcite stable isotopic data for all the cyprus calcites exhibit depletion in the heavier isotopes 18 o and 13 c indicative of meteoric alteration the koronia member limestones show abundant indication of early lithification with fringing acicular aragonite and micrite cements stable isotopic data of the botryoidal aragonite cements indicate a marine origin the dolomite is thought to result from marine freshwater mixing and to be of pliocene age on the basis of stratigraphical solution replacement fabric and stable isotopic data sr isotopic data do not contradict a pliocene age dolomite characteristically replaces the pliocene fissure fill contents in southeast cyprus and off reef horizons in the terra member of west cyprus and koronia member of north cyprus the growth and burial history of miocene reefs contribute to the understanding of the tectonic history and palaeogeographical evolution of cyprus

late miocene stratigraphy and palaeogeographic evolution of the intramontane guadix basin central betic cordillera spain implications for an atlantic mediterranean connection abstract the guadix basin is an intramontane basin located in the central sector of the betic cordillera its late miocene stratigraphic record is divided into three depositional sequences limited by unconformities representing tectonic and or eustatic events depositional sequence i late tortonian is composed by two systems tracts the lower marks the beginning of marine sedimentation in the basin and comprises three retrograding lithological complexes or depositional systems coastal shallow platform and pelagic basin and is interpreted as a transgressive systems tract the upper systems tract consists of a shallow shelf prograding into a pelagic basin this systems tract exhibits a typically regressive pattern and was deposited during high sea level and is therefore interpreted as a highstand systems tract depositional sequence ii late tortonian is composed of both continental alluvial cones and shallow marine gilbert type delta shallow shelf and reef depositional systems the deposits of this sequence record a significant fall in sea level and are interpreted as a lowstand systems tract depositional sequence iii late turolian ventian or late tortonian messinian was formed of solely retrograding continental depositional systems alluvial fan lacustrine fan delta mud flat and lacustrine with this sequence begins the continental sedimentation in guadix basin in an endorheic context the palaeogeographic evolution of the guadix basin during the late miocene can thus be divided into three stages the first corresponds to depositional sequence i and is characterised by the development of shallow marine environments on the basin margins and deep water deposits in its centre during this stage the basin was connected to the west with the atlantic ocean via the granada and guadalquivir basins and toward the east with the mediterranean sea through the almanzora and campo coy basins in the second stage represented by depositional sequence ii most of the basin was occupied by shallow marine environments during this stage the connection with the atlantic and mediterranean was only open through the guadalquivir and campo coy basins respectively finally the third and last stage corresponding to depositional sequence iii is characterised by the development of continental environments throughout the basin this stage records the definitive closing of the connections with the atlantic ocean and the mediterranean sea

benchmark data of a changing sea palaeogeography palaeobiogeography and events in the central paratethys during the miocene abstract the reconstruction and interpretation of terrestrial ecosystems and vegetational patterns in the central european miocene have to take into account the influence of a vast landlocked water body namely the paratethys sea as a northern appendage of the early mediterranean sea it spanned a north south gradient of at least 4 latitude and has been suggested to represent some kind of palaeothermometer which reflected slight expansions or restrictions of climatic belts due to its vulnerable marine connections it was also highly susceptible to major global sea level fluctuations which are reflected in phases of endemism hence a fairly continuous record of marine nearshore assemblages throughout the miocene reflects an extraordinary interplay of sea level fluctuations changes in climate immigrations and blooms in autochthonous elements whilst biostratigraphic implications of these patterns were recognised early in palaeontology a biogeographic model is still lacking the intermingling of palaeogeographic terms with those restricted to biogeography is still commonly used a situation which can be overcome by integrating data from different biota into a new palaeobiogeographic scheme herein a data set of 1809 species level taxa gastropoda and foraminifera serves as the base for interpretations gastropods in particular turned out to be of greatest value for the differentiation of palaeobiogeographic units due to sensitive reactions to all environmental parameters and occupying a wide range of ecological niches based on the excellent gastropod record the proto danubian province early danubian p danubian p balatonian p and a proto caspian subprovince are defined the biogeographic reorganisations are associated with five major biotic events within the gastropod faunas these big five comprise four extinctions the late ottnangian extinction event loee the mid badenian extinction event mbee the badenian sarmatian extinction event bsee the sarmatian pannonian extinction event spee and one exceptional immigration origination event termed the early badenian build up event ebbe foraminifera are less valuable for palaeobiogeographic purposes in the area and time slice studied endemisms are generally lower and turn over rates less dramatic they are however very useful for stratigraphic correlations with the mediterranean and atlantic areas this fairly well calibrated marine biostratigraphy of the central paratethys serves as stratigraphic backbone and control for continental stratigraphy

the myth of the brackish sarmatian sea the biota of the 1 5 ma period of the middle miocene sarmatian of the central paratethys lack stenohaline components this was the reason to interpret the sarmatian stage as transitional between the marine badenian and the lacustrine pannonian stages however our new data indicate that brackish water conditions could not have prevailed sarmatian foraminifera molluscs serpulids bryozoans dasycladacean and corallinacean algae as well as diatoms clearly indicate normal marine conditions for the entire sarmatian during the lower sarmatian however a sea level lowstand forced the development of many marginal marine environments during the late sarmatian a highly productive carbonate factory of oolite shoals mass occurrences of thick shelled molluscs and larger foraminifera as well as marine cements clearly point to normal marine to hypersaline conditions this trend is not restricted to the western margin of the pannonian basin system but can be observed in the entire central and even eastern paratethys

facies successions in the pre evaporitic late miocene of the lorca basin se spain abstract pre evaporitic uppermost tortonian to messinian carbonate siliciclastic deposits have been studied in the western part of the lorca basin individual lithofacies facies associations as well as facies successions and stratal architecture indicate a gravel rich fluvial dominated gilbert type delta environment during periods of decreasing terrigenous supply carbonate sedimentation predominated including formation of patch reefs and fringing reefs the observed progradational stacking pattern of facies successions is attributed to a 3rd order eustatic highstand that pre dates the messinian lowstand evaporites of the well known salinity crisis five facies successions have been recognized each succession is composed of three facies associations that are mixed carbonate siliciclastic mcs carbonate dominated cd and siliciclastic dominated sd they show retrogradation aggradation progradation architecture and represent 4th order transgressive regressive cycles the five successions can be correlated through the whole basin and are interpreted as a useful tool for basinwide sequence stratigraphic correlation if in addition other recently published data from se spain are considered it may turn out that future correlations between different neogene basins at this cycle scale 4th order will be possible higher frequency successions or cycles at a bed or bedset scale 5th or higher order are noticeable but are clearly related to local depositional processes facies dynamics they do not have any significance for a basinwide sequence stratigraphic correlation

the coral reef of nijar messinian uppermost miocene almeria province s e spain abstract the nijar reef is a thoroughly exposed and representative example of the messinian coral reefs outcropping along the periphery of the western mediterranean facies patterns in the nijar reef complex are presented in this paper as a generalized guide or model for the study of other messinian reefs messinian paleogeography of this area was characterized by an archipelago whose islands are present day sierras at the beginning of the messinian and before development of the reefs marine terrigenous sediments marginal terrigenous complex were deposited on an irregular erosion surface on the metamorphic basement the reef complex developed as a belt fringing the positive areas islands when terrigenous deposition decreased the reef complex consists of 1 reef core constructed by a framework of vertical branching colonies of porites coated by laminated micrite probably submarine cements which form pinnacles as well as thickets and 2 fore reef made of sloping beds of broken skeletons and debris the fore reef is subdivided into i reef talus slope ii proximal slope and iii distal slope the reef talus forms massive strata with dips of 20 30 and abundant pebble to boulder size slumped blocks of reef core and coral breccia the proximal slope shows dips of 10 20 of well bedded thick strata with internal parallel layering of granule to sand size skeletal calcarenites the distal slope is made of predominant bioturbated skeletal calcisiltites and fine grained calcarenites with ngles lower than 10 the distal slope grades into the basinal pelagic marls of the nijar plains the original reef morphology is well preserved in present day topography with relicts of pinnacles reef valleys and slopes messinian volcanic highlands located to seaward complicated the local paleogeography with atoll like features reef growth was concomitant with a gradual fall of sea level and occurred before the messinian gypsum was deposited on top of the basinal marls in what is now the plains area the reef complex is partially truncated by a major erosion surface and it is overlain by oolitic shoals and stromatolites of the so called terminal carbonate complex the terminal complex is interpreted as an upslope equivalent in age to the messinian upper evaporite and it implies a new cycle of sea level rise

late miocene halimeda alga microbial segment reefs in the marginal mediterranean sorbas basin spain a 6 ma messinian late miocene bioherm unit on the southern slope of the sorbas basin se spain contains numerous biotically diverse lensoid patch reefs that formed on a shelf to basin slope during a cycle of relative sea level change halimeda reefs are the largest and most complex of the patch reefs and are divisible into core cap and flank facies on the upper and midslope they are up to 40 m thick and 400 m long they become smaller downslope the core consists of jumbled halimeda segments released by spontaneous disaggregation of the alga the segments were stabilized close to their sites of growth and rapidly lithified by micritic and peloidal microbial crusts residual cavities were further veneered by isopachous marine cements flank facies consisting of bedded packstones to rudstones form wedge shaped units lateral to the mounds cap facies consist of bioclastic calcarenites calcirudites and microbial carbonates synsedimentary lithification assisted rapid accretion and inhibited off mound export of sediment allochthonous reef derived blocks on the mid slope reflect penecontemporaneous rigidity of the halimeda bioherms proximal porites coral frame patch reefs associated with calcarenites were located near the shelf margin during the initial lowstand stage halimeda segment reefs associated with calcarenites and silty marls developed on the midslope and bivalve bryozoan serpulid reefs formed on the lower slope in silty marls with occasional turbidites during the transgressive stage coral patch reefs near the shelfbreak were overgrown by halimeda during highstand progradation cap facies spread basinward as a sheet connecting many of the midslope patch reefs these ancient analogues differ from most modern halimeda reefs in being discrete laterally restricted patch reefs surrounded by marly sediment and located on a slope they are however broadly comparable in biota thickness and depositional depth intense early lithification by microbial crusts and marine cements is an important feature of these messinian segment reefs it has not been reported from modern examples

carbonate ramp evolution during the late oligocene chattian salento peninsula southern italy abstract oligocene carbonate ramps and platforms are widespread and though they are important carbonate reservoirs detailed studies on the facies organization platform type and internal architecture are scarce within this context the chattian carbonate units cropping out in salento southern italy allow detailed study of the distribution of skeletal components and facies architecture the lower chattian castro limestone previously considered as a fringing reef is reinterpreted as a distally steepened ramp with a distal talus induced by a paleo escarpment in the substrate epiphytic biota and sediment dweller organisms thriving in seagrass meadows dominated production in the shallow water euphotic zone seawards large rotalid foraminifers dominated a detritic mesophotic zone near the edge of the escarpment also in the mesophotic zone luxurious growth of corals built discrete mounds with no evidences of wave resistant growth fabrics basinward 25 to 30 dipping clinobeds abut against the escarpment where coral rudstone floatstone textures resulted from downfall of corals and sediments the upper chattian porto badisco calcarenite represents a homoclinal ramp dominated by packstone textures in the euphotic inner ramp autochthonous biota suggests the occurrence of extensive seagrass meadows basinward large rotalid packstone and small coral mounds developed in mesophotic conditions and rhodolithic floatstone to rudstone and large lepidocyclinid packstone characterize the sediments of the deeper oligophotic zone comminuted skeletal debris depleted of light dependent organisms typifies deposition in the dysphotic aphotic zone in both examples the middle ramp meso oligophotic zones was the most prolific in terms of carbonate production whereas shallow water seagrass related production euphotic was much less important corals built mounds also in the mesophotic zone but never reached sea level hydrodynamic conditions in the meso oligophotic zone are better explained by breaking of internal waves and their induced up and down slope currents instead of the surface storm waves

classification of local and regional events in central europe based on estimates of s wave spectral variance summary the vogtland region in the border region of germany and the czech republic is of special interest for the identification of seismic events on a local and regional scale since both earthquakes and explosions occur frequently in the same area and thus are relevant for discrimination research for verification of the comprehensive nuclear test ban treaty previous research on event discrimination using spectral decay and variance from data recorded by the geress array indicated that spectral variance determined for the s phase for the seismic events in the vogtland region seems to be the most promising parameter for event discrimination because this parameter provides for almost complete separation of the earthquake and explosion populations almost the entire set of vogtland events used in this research and more than 3000 local events detected in germany in 1998 and 1999 were analysed to determine spectral slopes and variance for the p and s wave windows from stacked spectra of recordings at the geress array the results suggest that small values for the spectral variance are associated not only with earthquakes in the vogtland region but also with earthquakes in other parts of germany and neighbouring countries while mining blasts show larger spectral variance values mininginduced events yield a wide range of values for example in the lubin area a threshold based identification scheme was applied almost all events classified as earthquakes are found in seismically active regions while the earthquakes are uniformly distributed throughout the day events classified as explosions correlate with normal working hours which is when blasting is done in germany in this study spectral variance provides good event discrimination for events in other parts of germany not only for the vogtland region showing that this identification parameter may be transported to other geological regions

messinian reef building assemblages of the salento peninsula southern italy palaeobathymetric and palaeoclimatic significance abstract this paper mainly addresses the description and interpretation of different reef building assemblages recognised within an early messinian reef complex recently discovered along the eastern margin of the apulia platform salento peninsula southern italy it is the first late miocene reef recorded for the adriatic region and its location partly changes boundaries of coral reef distribution during this time in the mediterranean the messinian reef complex novaglie formation is interpreted as a succession of fringing reefs accommodated in palaeo reentrances or palaeo embayments of the original messinian rocky shore and overlying discordantly the underlying cretaceous to oligocene units it consists of a discontinuous reef tract and associated clinostratified fore reef slope relatively precise dating of the reef complex has been achieved using benthic foraminifera and ostracods associations three main different reef building assemblages have been recognised 1 halimeda bioherms 2 porites reef and 3 vermetid microbial trottoirs each assemblage is described in detail according to its architecture and structure setting shape quantitative estimation of the framework density biotic components taxonomic composition and relative abundance of the reef builders growth form associated fauna and intra reef sediment texture and fabric palaeoecologic analysis based on physical observation within the margin slope of the reef complex and in comparison with present day analogues and their ecological demands indicates that distribution and vertical succession of the three different reef assemblages are strictly depth related suggesting an ecological replacement consequent on small relative sea level changes fourth order closely comparable with those already indicated for the early messinian special attention is given to the remarkable abundance of vermetids that together with microbial crusts formed scattered trottoirs along the shoreline vermetid occurrences have been extensively cited in the literature for the late miocene of the mediterranean but poorly studied in detail here their palaeoecologic significance is emphasised indicating that these organisms can be used as reliable palaeobathymetric and palaeoclimatic indicators regarding the miocene of the mediterranean development of vermetid microbial reefs so far recorded for the messinian is preferentially associated with low diversity coral reefs and is interpreted as being mainly controlled by climatic constraints

paleoecological constraints on reef coral morphologies in the tortonian early messinian of the lorca basin se spain abstract coral reefs represent one of the main carbonate factories that contributed to the control of the stratigraphic architecture of carbonate platforms which had a widespread development during the late miocene in the paleo mediterranean area the late miocene reef complexes of the lorca basin in southeastern spain are composed of five mixed siliciclastic carbonate units middle tortonian to early messinian in age the development of coral reefs probably ceased when the first evaporitic event occurred in the basin centre in the early messinian this study mainly focuses on the response of reef communities and the modifications of reef organisation to global and regional parameters at the platform scale the carbonates are intermixed with terrigenous deposits related to two main types of clastic systems torrential fans and fluvial to deltaic systems the amount of clastic input greatly affected reef growth and coral morphologies three different types of stratal geometries were delineated in the reef complex sigmoids bioherms and patches and carpets the reef frameworks are mainly constructed by a poorly diversified assemblage of corals composed of poritids faviids and mussids porites is the principal reef builder of the sigmoids and carpets where it is widely distributed tarbellastraea is common in bioherms and acanthrastraea appears generally associated with porites in patches five basic growth forms of porites are observed thin branching or finger shaped thick branching to columnar domed to hemispheric encrusting and platy to dish differences in coral morphology are used to define a relative water depth zonation in monogeneric reefs the distribution of these growth forms was principally controlled by water depth the reef flat is dominated by small thin branching or finger shaped corals that are replaced towards the reef front by domed to hemispheric corals commonly encrusted by coralline algae downslope columnar morphologies grade into thin branching shapes the reef morphologies are variable throughout the five mixed siliciclastic carbonate units at the platform scale the first and oldest unit is dominated by bioclasts whereas units 2 3 and 5 are porites dominated sigmoid complexes unit 4 is a well developed biohermal complex mainly composed of tarbellastraea these units started to develop as early as middle tortonian and stopped as late as early messinian and show a progradational trend where the two latest units are well developed thus carbonate production changed from grain producing biota in the basal unit to framework producing biota in the overlying units consistent with evolution from a distally steepened ramp to a reef rimmed shelf at the scale of individual reef units the relative water depth zonation of the corals is controlled by ecological changes substrate nutrients synecologic relations and diversification of coral species in the transects across the carbonate platform related to the different units the coral zonation records changes in spatial distribution of corals in response to ecological stresses and changes in regional and global environments tectonic relative sea level changes and runoff

oligocene and early miocene coral faunas from iran palaeoecology and palaeobiogeography oligocene and early miocene coral assemblages from three sections of central iran are investigated with respect to their palaeoecological and palaeobiogeographic implications these corals are compared with faunas from the mediterranean tethys and the indopacific associated larger foraminifers are used for biostratigraphy and to support the palaeoecological interpretation the studied sections are situated in the foreland basins of the iranian plate which is structured into a fore arc and a back arc basin separated by a volcanic arc the coral assemblages from abadeh indicate a shallowing upward trend infrequently distributed solitary corals at the base of the section indicate a turbid environment above a distinct horizon characterised by a leptoseris stylophora assemblage associated with lepidocyclinids and planktonic foraminifers is interpreted as maximum flooding surface small patch reefs with a porites faviidae assemblage are a common feature of late oligocene to early miocene coral occurrences and indicate water depths of less than 20 m the diversity of the coral faunas shows marked differences oligocene corals from the esfahan sirjan fore arc basin comprise more than 45 species of 32 genera and occur in a wide range of environments early miocene corals from the qom back arc basin are less frequent show a lower diversity 13 genera with 15 species and occur in single horizons or small patch reefs

magnetostratigraphy of the zobzit and koudiat zarga sections taza guercif basin morocco implications for the evolution of the rifian corridor magnetostratigraphic analyses for two neogene post nappes successions of the taza guercif basin enable a reliable correlation of the sedimentary sequence to the astronomical polarity time scale rock magnetic analyses indicate that hematite is the dominant carrier of the magnetisation in the marine marls of the melloulou formation whereas both magnetite and hematite contribute to the nrm of the near shore and continental sediments of the kef ed deba and bou irhardaiene formations anisotropy of magnetic susceptibility ams measurements indicate that the maximum axes of the magnetic fabric are aligned in a direction sw ne this suggests that the ams is tectonically induced related to se nw compression in agreement with the major fold and fault systems in the basin our magnetostratigraphic correlation shows that the oldest marine sediments in the basin which are related to the development of the rifian corridor are dated at approximately 8 ma between 7 2 and 7 1 ma just after the tortonian messinian boundary an important shallowing of the taza guercif basin takes place this shallowing phase is primarily related to active tectonics although a small glacio eustatic sea level lowering also took place our results indicate that at least the taza guercif basin and perhaps the entire rifian corridor became emerged at an age between 6 7 and 6 0 ma continental deposits separated from the underlying deposits by a considerable hiatus of 700 kyr extend into the pliocene up to 4 7 ma 2000 elsevier science ltd all rights reserved

reef building and carbonate production modes in the west central tethys during the cenozoic abstract changing components rock textures lithofacies platform types and architecture throughout time are unique characteristics of carbonate rocks characterizing these attributes has been approached by 1 building reference models for specific phanerozoic intervals 2 recognizing the climatic impact in modulating carbonate production and 3 analyzing the influence of changing bio geochemical conditions the reference model approach is mostly based on biological evolution the climatic impact approach emphasizes temperature and the bio geochemical approach considers the changes in mg ca ratios and ca concentrations in the oceans to date however an analysis integrating all of these factors is still missing the analysis presented here includes all these factors but also co 2 which is fundamental for both photosynthesis and caco 3 precipitation here we analyze the waxing and waning of cenozoic reef limestones from the central tethys region through several steps 1 on the basis of rock volume rock textures associated sediments and light dependent skeletal components as records of light penetration and wave energy depth 2 on global environmental conditions 13 c 18 o p co 2 temperature and 3 on the basis of functionality nutritional requirements and available resources through the cenozoic water motion whether induced by surface or internal waves or by currents increased as the thermal gradients strengthened both with depth and with latitude active water motion is essential for plankton catchers such as corals but less so for many larger benthic foraminifers lbf pycnoclines in the meso oligophotic zone would then favor the benthic plankton catchers such as corals but would be detrimental for many lbf warm temperatures favored lbf the eocene lbf families predominated during lowering of atmospheric p co 2 by using respiratory co 2 to enhance the symbiont production of photosynthates under oligotrophic conditions and limited turbulence whereas the miocene families had to adapt to a progressive increase in turbulence the eurythermal coralline red algae however became preponderant producers in the mesophotic zone during times when the 13 c was relatively high this explains two apparent paradoxes 1 corals thrive best when the earth s high latitudes cool and 2 the dominance of corals and lbf is inversely correlated despite they both require tropical conditions and have similar trophic strategies mixotrophy

origin and evolution of halite based on stable isotopes δ37cl δ81br δ11b and δ7li and trace elements in tuz golu basin turkey abstract the tuz golu basin located in central anatolia contains ancient miocene and recent evaporite deposits the aim of this study is to determine the origin and evolution of the ancient halite deposits in the basin particularly whether there is a marine origin for this purpose the mineralogical geochemical and isotopic properties of halite samples taken from three different drillings at the southern part of the tuz golu basin were determined halite samples in the tuz golu basin are characterized by cl 60 20 61 00 na 39 00 39 40 and br 5 637 ppm contents the cl br ca mg2 so42 and k values and cl br 948 86428 ratios indicated that during the formation of the ancient halites in the tuz golu basin the mixture of solutions had different compositions origins and that the dissolution recrystallization and dedolomitization mechanisms were effective the 81br 37cl 7li and 11b isotopic compositions of the pure halites range from 0 06 to 0 82 0 80 to 1 28 0 70 to 30 60 and 14 70 to 11 60 respectively the low 37cl from 0 06 to 0 06 low 81br from 0 03 to 0 95 high 11b from 6 40 11 60 and high 7li from 26 00 to 30 60 values clearly indicate that the brine involved in the formation of the halites of the tuz golu basin was largely derived from seawater during the mid miocene climatic optimum mmco period additionally the cl br ca2 mg2 and so42 contents as well as the intermediate 81br 0 34 0 95 values of the tuz golu samples indicated that the origin of the ancient halites in the basin is not only a marine composition but also a mixture of solutions having different compositions ratios or origins e g seawater or saline water and groundwater fresh water

the sedimentology and development of terravecchia formation carbonates upper miocene of north central sicily possible eustatic influence on facies development abstract on at least two occasions during the late tortonian siliciclastic deposition ceased and carbonates accumulated at the northern margin of the caltanissetta basin in north central sicily bioclastics dominated in the shallower proximal areas while coral reef facies developed where shallow water sand and cobble substrates existed or where sea floor highs has created local shallows the genetic model proposed is that siliciclastic deposition was repeatedly terminated during the late tortonian by rises in sea level which transgressed fluviatile and deltaic environments carbonate deposition was widespread but later erosion and reworking removed much of the sediments except within abandoned delta distributary channels and minor sea floor depressions reef developments associated with channel mouths and the shelf slope break have been preserved in situ whereas channels in more proximal locations are filled with siliciclastic bioclastic and intraclastic rubble from elsewhere on the delta top the wide lateral extent of the truncated tops of the carbonate beds argues for eustatic rather than tectonic controls of erosion and subsequent reworking these events may be closely related in time to other recorded late tortonian eustatic events in the foreland zones such as the hyblean plateau and the maltese islands further south collectively they give some support to a model involving multiple eustatic fluctuations associated with the onset of the messinian desiccation of the mediterranean

oyster shells as recorders of short term oscillations of salinity and temperature during deposition of coral bioherms and reefs in the miocene lorca basin se spain abstract we use 18 o and 13 c of oyster shells inferred seawater 18 o w and temperature tolerance ranges of modern zooxanthellate coral communities to constrain and model paleo salinities of marginal marine waters of the miocene lorca basin spain salinities ranged from 22 to 32 psu during growth of coral bioherms and carpets of the soriana and parrilla formations and from 35 to 39 psu during deposition of the hondo formation reef complex the periods with lower modeled salinities correspond with deltaic and alluvial fan sedimentation in the area the modeling is supported by 87 sr 86 sr data and provides new insights into the evolution of the local depositional settings departures of sr isotope values from the global oceanic curve occur within the intervals with the lowest modeled salinities and the non oceanic 87 sr 86 sr preserved in individual oyster shells was probably sourced from uplifted aquitanian burdigalian limestones 87 sr 86 sr values that plot along the global ocean sr isotope curve for the late miocene indicate a tortonian age for the upper part of the soriana formation and the parrilla formation and a messinian age for the hondo formation more generally we demonstrate how the chemical analyses of oyster shells provide additional information regarding short term oscillations of salinity and temperature of seawater beyond what can be obtained by traditional paleoecological methods

guild structure and aggradation pattern of messinian porites patch reefs ecological succession and external environmental control san miguel de salinas basin se spain abstract small and isolated messinian patch reefs showing a typical internal succession and an oligospecific reef building community are described from the western margin of the san miguel de salinas basin se spain these thrived in a mixed carbonate siliciclastic environment and are known from two different stratigraphic levels the reef growth is characterized by a shallowing upward sequence and can be subdivided into four divisions reef debris zone coralline algal zone branching coral zone and reef crest zone this ecological succession of messinian reefs reflects an increasing water turbulence and the accommodation of the reef building organisms to shallower water settings which is conditioned by its own upward growth the start of reef growth is controlled by a reduced influx of terrigenous deposits which derived from fan sediments reworked by waves the reefs were killed by smothering with quartzose calcarenites the low diversity of the reef building community indicates an arrested ecological succession without climax stages controlled by sedimentation rate and siliciclastic supply a salinity increase can be excluded because the reef associated fauna indicates normal marine conditions during reef growth there is no evidence for subaerial exposure of the reefs during the formation of evaporites at the end of the messinian

sedimentology and palaeoecology of a miocene coralline algal biostrome from the maltese islands abstract a large coralline algal biostrome 20 km 5 km 16 m thick is well exposed in western malta and eastern gozo the biostrome is composed of limestones largely constructed by in situ coralline algae or transported algal debris some sediments are dominated by rhodoliths and others by crustose coralline frameworks six facies are distinguished crustose algal marl crustose algal wackestone rhodolith pavement algal branch packstone crustose pavement and algal crust packstone each facies is characterised by different rhodolith morphologies and coralline crusts which are constructed mainly bymesophyllum commune the coralline morphogenesis is related to the palaeoenvironmental conditions the biostrome is thought to have developed from a series of relic sand ridges to form a low relief platform of moderate depths containing a mosaic of sedimentary facies the sequence is affected by growth faulting which divides the biostrome into eight units

the time frequency characteristics of quarry blasts and calibration explosions recorded in kazakhstan ussr summary in this paper we consider two fundamentally different processes that can be responsible for the organization of energy in seismic coda into discrete time independent frequency bands one process involves the resonance of energy in low velocity horizons and the other requires the interaction of time offset wavefields produced by subevents within multiple event mine explosions ripple fired quarry blasts we examined data collected by high frequency seismometers in kazakhstan ussr and observed regular time independent spectral modulations in coda resulting from events strongly suspected to be soviet quarry blasts but not in the coda from single event calibration explosions detonated at similar ranges we conclude these modulations are a source effect and due to ripple firing this modulation is independent of the source receiver azimuth and we infer that the spatial array of subshots in each event must be small we demonstrate that simple linear superposition theory can be used to reproduce effectively the spectral modulation observed in real quarry blasts on the basis of these observations we attempt to discriminate between the two types of events using a spectral pattern based algorithm that seeks time independent features we consider the detrimental effect that resonant energy in low velocity horizons can have on the successful application of our algorithm

seismic event identification of earthquakes and explosions in germany using spectral lg ratios at the german ndc initial work on seismic event identification has focused on the application of spectral amplitude ratios for lg in order to discriminate naturally occurring seismic events from other events associated with mining and quarry activities only about 10 of all seismic events occurring in germany and adjacent areas are due to natural seismicity and are mostly constrained to the alpine regions and areas along the rhinegraben rhenish massif swabian jura and the bohemian massif vogtland region using data from the broadband grsn network spectral amplitude ratios are calculated from maximum trace amplitudes in the 1 2 hz and 6 8 hz frequency bands which are within the passbands of the deployed sts 2 instruments and the recorded 20 hz data streams these amplitude ratios then must be corrected with an appropriate attenuation model in order to remove propagation paths effects for event identification a scoring scheme is applied across the grsn network based on station dependent scoring thresholds in a case study aimed at testing the identification scheme events are investigated from a quarry in southern germany that provided ground truth information for six events in 1997 to demonstrate the suitability of this identification approach except for one event with a rather strong earthquake signature i e a low spectral lg ratio these events could be screened out from the earthquake population by their large lg ratios in a second step aimed at applying the identification scheme all events in germany and neighboring areas that occurred in 1995 were processed with approximately 800 out of more than 1200 events showing explosion type lg ratios while only 10 remain in the earthquake population however specific mining areas appear to consistently produce earthquake type spectral ratios indicative of particular blasting practices

the depth of pelagic deposits in the tethyan jurassic and the use of corals an example from the apennines abstract assessing the palaeobathymery of pelagic deposits is rather speculative as proof through lithology or fossils significant for depth estimates is sparse this is unfortunate as the bathymetric history of pelagic successions allows to conceive the evolution of continental margins and oceanic basins discoveries in coral biology bring an unexpected impact on basin analysis evidence strongly suggests that pennular corals fossil and modern constitute a zooxanthellate group with an outstanding specialization in colonizing deeper parts of the marine photic zone this adaptation includes light amplification by autofluorescent pigmented cells and particular feeding witnessed by peculiar gastric ducts and skeletal features such corals occur in the umbria marche and sabina apennines on top of late jurassic submarine highs and at basin margins values of palaeodepth relative to pelagic deposits are provided by corals and other environmental data because depth reconstruction involves classical tethyan facies such as ammonitico rosso aptychus limestone and radiolarian cherts we must note that these results do not meet with actualistic models relying on carbonate dissolution for estimating depth deposits viewed as bathyal to abyssal could also have accumulated within or just below the photic zone thus a new insight opens on mesozoic bathymetries regarding vast areas middle east to caribbean and on subjects ranging from platform drowning to regional extension styles