recognition and distinction of normal and forced regression in cyclothemic strata a plio pleistocene case study from eastern north island new zealand

phosphate rich deposits associated with the mio pliocene unconformity in south east australia phosphates are present on the surface of the mio pliocene unconformity in the otway port phillip and gippsland basins of south east australia the phosphates occur as lenticular lag deposits and include reworked phosphatic intraclasts vertebrate bone and teeth in situ phosphatized burrows are also found in sediments of late miocene and early pliocene age the phosphatic intraclasts on the unconformity are interpreted as reworked phosphatized burrows derived from latest miocene sediments 6 to 5 ma the phosphatization of these intraclasts is temporally related to the unconformity the timing of phosphogenesis coincides with a period of transgression across the south east australian margin following late miocene uplift this transgression is responsible for initial marine erosion of the underlying miocene sequence creation of a period of very slow sedimentation that was favourable to phosphate formation and subsequent deposition of the latest miocene through to pliocene sediments the continental weathering of the uplifted highlands adjacent to the sedimentary basins global phosphorus enrichment in the late miocene oceans and localized upwelling may all have contributed to phosphatization in south eastern australia

high resolution surface and subsurface sequence stratigraphy of late middle to late ordovician late mohawkian cincinnatian foreland basin rocks kentucky and virginia the late middle to late ordovician late mohawkian to cincinnatian supersequence in kentucky and virginia was deposited in a tectonically active foreland basin during a transition from the ice free early ordovician to the glacial late ordovician this sequence was deposited in less than 12 m y is 250 500 m thick and is composed of four large third order sequences each 40 150 m thick that are regionally correlative in outcrops cores and gamma ray logs smaller scale third order parasequence sets up to 20 m thick and component parasequences 1 8 m thick make up the larger sequences and are only locally correlative subtidal dominated parasequences comprise the basal part of each sequence whereas shallower subtidal or peritidal dominated parasequences compose upper parts of sequences each large third order sequence is asymmetric and marked by lowstand transgressive and highstand systems tracts with unique lithologic and gamma ray log response characteristics ramp margin wedges rmw are poorly developed and consist of marine siltstone or grainstone packstone sheets extending into deep ramp settings these sheets have high gamma ray values in their base and lower blockier gamma ray responses in their tops transgressive systems tracts tst are thin composed of high energy locally phosphatic grainstone copyright 1997 the american association of petroleum geologists all rights reserved 1manuscript received february 7 1996 revised manuscript received may 27 1997 final acceptance june 16 1997 2department of geology virginia tech blacksburg virginia 24061 0420 present address department of earth atmospheric and planetary sciences massachusetts institute of technology cambridge massachusetts 02139 3department of geology virginia tech blacksburg virginia 24061 0420 this study was supported by nsf grant ear 9316057 to j f read a grant from mobil oil company and grants in aid of research from the geological society of america and appalachian basin industrial associates to mike pope we thank john haynes brian keith and rick major for thorough and insightful reviews of an earlier version of this manuscript

middle miocene serravallian temperate carbonates in a seaway connecting the atlantic ocean and the mediterranean sea north betic strait s spain abstract miocene deposits in the contact area between the prebetic and subbetic domains betic cordillera s spain record the last stages of marine deposition on the southern iberian margin and the final closure of the north betic strait in the early tortonian late miocene serravallian middle miocene shallow water carbonates and mixed carbonate siliciclastics formed on a platform at the southern margin of the north betic strait these shallow water deposits informally termed the la escalera formation onlap an erosion surface carved into underlying miocene and older rocks carbonate components are mainly bryozoans coralline red algae molluscs and benthic and planktonic foraminifers typical of heterozoan lithofacies several facies types can be distinguished based on different grain sizes and sedimentary structures large scale geometries and stratigraphic facies relationships indicate that the la escalera formation was deposited on a homoclinal ramp attached to a deeply eroded emergent relief to the south a beach system developed at the southern margin with backshore lagoons and local incursions of coarse terrigenous sediments seawards of the beach system was a submarine dune belt that extended over several square kilometres at the northeastern end of the la escalera formation longshore currents shifted submarine dunes to the northeast maximum production of carbonate skeletons took place seawards of the dune field from this factory area skeletal debris was moved landwards and incorporated into the dunes and beaches whereas other skeletal particles were transported downslope by storms and fed a facies belt with hummocky and swaley cross stratified sediments the finest grained particles accumulated below a storm wave base along with significant planktic debris carbonate deposits change laterally westwards to terrigenous sediments formed in similar facies belts terrigenous influx limited carbonate production on the western part of the ramp by disturbing the growth of coralline algae and bryozoans vertical variations of facies within the formation depict a major transgressive regressive cycle modulated by up to 10 higher frequency cycles despite its location in an atlantic linked basin the sedimentary model of the la escalera formation shows similarities to the models proposed for neogene mediterranean temperate carbonates which imply a relatively low energy regime on the ramp in comparison with the open ocean platforms this relatively low energy regime can be explained by the position of the north betic strait at the eastern end of the guadalquivir basin however hummocky and swaley cross stratified deposits are significantly more developed in la escalera deposits than in known examples of neogene mediterranean carbonates

downslope migrating large dunes in the chattian carbonate ramp of the majella mountains central apennines italy abstract this work is the result of detailed geological mapping and stratigraphic analysis of the lepidocyclina limestone in the northern sector of the majella mountains central apennines the lepidocyclina limestone represents an informal member of the bolognano formation chattian to messinian in age four main lithofacies have been recognized planar cross bedded grainstone fa moderate angle cross bedded grainstone to packstone fb sigmoidal cross bedded grainstone fc and bioturbated marly packstone to wackestone fd a detailed description of the recognized lithofacies and facies association of the lepidocyclina limestone is given in this work together with an interpretation of the corresponding depositional setting and a discussion of the related larger scale processes in summary the depositional profile of the lepidocyclina limestone is consistent with a carbonate ramp where most of the sediments appear to be parautochthonous in the middle ramp environment and autochthonous dominated in the outer ramp environment palaeocurrent patterns indicate a strong generally north west basin ward direction that affected the middle ramp environment and developed a wide down slope migrating dune field considering that the warm oligocene climate of the mediterranean area was favorable to tropical cyclone development both in terms of frequency and intensity it is suggested that return currents generated by strong winds or storms were common on the lepidocyclina carbonate ramp thus favoring the development of the observed dune field

changes in bryozoan assemblages and bathymetric variations examples from the messinian of northwest algeria abstract studies of recent bryozoan faunas have shown that there is a correlation between colonial growth forms and various physical factors of the environment especially bathymetry each given assemblage of zoarial forms can thus be related to a certain depth interval in marine neogene deposits numerous extant bryozoan species occur and some of them have more or less restricted depth ranges they are used here to complement the indications given by the analysis of growth forms in the messinian uppermost miocene of northwestern algeria a general feature is the occurrence of well developed diatomaceous deposits interbedded with marl beds where benthic invertebrate remains are often abundant in the five sections under study bryozoans are represented by 87 species belonging to nine different colonial growth forms four different assemblages of these zoarial forms characterised by presence absence and number of fragments are distinguished corresponding to four depth intervals the first and deepest assemblage upper bathyal to lower circalittoral occurs in the bottom part of the sections where colonies of a conescharelliniform species strongly predominate the second assemblage lower circalittoral is represented by several species belonging to various zoarial forms conescharelliniform cellariiform vinculariiform adeoniform and reteporiform the third assemblage upper circalittoral is characterised by the absence of conescharelliniforms but membraniporiforms and celleporiforms are abundantly represented together with numerous erect colony fragments in the fourth assemblage infralittoral membraniporiforms and celleporiforms predominate although a number of erect zoarial forms are sometimes associated in various proportions the presence of several extant bryozoan species associated with each of these four assemblages is used as a confirmation for the suggested depth intervals a gradual shallowing is thus indicated by the study of the bryozoan assemblages through the five messinian sections the discussion shows that modern data on zoarial forms and species bathymetric distributions are clearly applicable to cenozoic faunas but that caution must be exercised when using results obtained from different oceanographic regions

diagenetic comparisons between non tropical cenozoic limestones of new zealand and tropical mississippian limestones from indiana usa is the non tropical model better than the tropical model abstract mississippian limestones exposed in indiana u s a were deposited in a shallow tropical ocean however many properties of these limestones are more like those of modern and cenozoic non tropical limestones such as those found in new zealand the dominant skeletal grains in the indiana limestones are calcitic echinoderms bryozoans and brachiopods the dominant skeletal grains in most cenozoic limestones of new zealand are calcitic bryozoans echinoderms bivalve molluscs and foraminifera in contrast modern and cenozoic tropical limestones contain an abundance of aragonitic green algae corals and molluscs early in diagenesis the metastable aragonite dissolves and reprecipitates as calcite causing early cementation of the sediments originally aragonitic fossils that have dissolved can be identified as molds that are commonly filled with secondary calcite because they contained little aragonite most of the indiana and new zealand limestones did not have an abundant source of early cement except for local cases in which grains were cemented in contact with carbonate supersaturated seawater grainstones were relatively deeply buried with little cement between the grains this resulted in mechanical and chemical compaction of skeletal grains producing a fitted fabric with greatly reduced pore space either open or filled with cement between the grains cement in these aragonite poor grainstones comes largely from pressure dissolution between grains and along stylolitic seams in the rock features that are common only after burial beyond a few hundred meters the final product of deeply buried up to 2000 m cenozoic new zealand grainstones is similar to the mississippian grainstones of indiana in the indiana limestones we have only the final product of this extensive burial diagenesis however the new zealand sediments and rocks reveal all steps of formation of the final deeply buried limestone the reason for the scarcity of originally aragonitic fossil grains in paleozoic rocks worldwide is unknown organisms with aragonitic skeletons such as some molluscan groups and calcareous green algae were present but seldom in much abundance the aragonitic scleractinian corals had not yet evolved previous researchers have noted that non skeletal precipitates such as ooids and cements have at times during the paleozoic been predominantly aragonite and at other times calcite they have attributed this difference to secular variation in seawater chemistry icehouse vs greenhouse seas abundance of aragonitic and calcitic skeletal grains does not follow this pattern

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

burial dolomitisation in a non tropical carbonate petroleum reservoir the oligocene tikorangi formation taranaki basin new zealand abstract the oligocene tikorangi formation is a subsurface non tropical limestone rich fracture producing oil reservoir in taranaki basin new zealand the formation is distinct from uplifted and exposed age equivalent new zealand limestones due to partial dolomitisation by modest quantities of silt sized scattered inclusion rich euhedral dolomite rhombs occasionally displaying idiotopic fabrics rhombs commonly have dull luminescent fe rich cores and oscillatory bright and dull concentric outers the dolomites are non stoichiometric high calcian and highly ferroan varieties dolomite 18 o and 13 c values are moderately depleted while associated precursor calcite phases are less depleted petrographic geochemical and geohistory evidence suggest that the dolomite formed during and following the later stages of pressure dissolution cementation in a relatively closed moderately deep burial environment ca 0 85 1 9 km burial depth ca 33 65 c in the early miocene ca 24 18 ma from warm saline enriched pore fluids by mainly mimic fabric selective replacement of interparticle and rarely intraparticle micrite matrix dolomitisation did not affect skeletal grains or calcite cements or develop any secondary porosity mg supply was restricted and was likely sourced internally from micritic inter and intraparticle precursor material and from the pressure dissolution of calcitic skeletons importantly dolomitisation occurred prior to compression related brittle fracturing of the carbonates responsible for creating extensive hydrocarbon bearing fracture networks because of the greater susceptibility of the dolomitised limestones to brittle fracturing their location and distribution may have important implications for hydrocarbon prospectivity and production within the tikorangi formation

an epeiric ramp low energy cool water carbonate facies in a tertiary inland sea murray basin south australia the murray supergroup records temperate water carbonate deposition within a shallow mesotrophic oligo miocene inland sea protected from high energy waves and swells of the open ocean by a granitic archipelago at its southern margin rocks are very well preserved and exposed in nearly continuous outcrop along the river murray in south australia most facies are rich in carbonate silt contain a background assemblage of gastropods especially turritellids and infaunal bivalves and are packaged on a decimetre scale defined by firmground and hardground omission surfaces bioturbation is pervasive and overprinted resulting in rare preservation of physical sedimentary structures facies are grouped into four associations large foraminiferan bryozoan echinoid bryozoan mollusc and clay facies interpreted to represent shallow water 50 m deposition under progressively higher trophic resource levels from low mesotrophy to eutrophy and restricted marine conditions from relatively offshore to nearshore regions a large scale shift from high to low mesotrophic conditions within lower miocene strata reflects a change in climate from wet to seasonally dry conditions and highlights the influence terrestrially derived nutrients had upon this shallow land locked sea overall low trophic resource levels during periods of seasonally dry climate resulted in a deepening of the euphotic zone a widespread proliferation of foraminiferan photozoan fauna and a relatively high carbonate productivity inshore heterozoan facies became progressively muddier and restricted towards the shoreline in contrast periods of wet climate led to rising trophic resource levels resulting in a shallowing of the euphotic zone a decrease in epifaunal and seagrass cover and widespread development of a mostly heterozoan biota dominated by infaunal echinoids rates of carbonate production and accumulation were relatively low the murray basin is best described as an epeiric ramp wide facies belts developed in a shallow sea on a low angled slope reaching many hundreds of kilometres in length grainy shoal and back barrier facies were absent internally generated waves impinged the sea floor in offshore regions and because of friction along a wide and shallow sea floor created a low energy expanse of waters across the proximal ramp storms were the dominating depositional process capable of disrupting the entire sea floor

stratigraphic sedimentology of tertiary cool water limestones se australia abstract mid tertiary limestones exposed as sea cliffs along the coast of victoria southeastern australia accumulated on the inner part of a cool water distally steepened ramp or open shelf all sediments are bioclastic dominated by particles of bryozoans echinoderms benthic foraminifers brachiopods and molluscs shallow grainy facies also contain coralline algae quartz and glauconite while deep muddy facies include ahermatypic corals ostracodes sponge spicules planktic foraminifers and terrigenous clays the fundamental depositional unit is a meter scale subtidal cycle or rhythm shallow shelf cycles are shallowing upward cross bedded or burrowed grainstone capped by a marine cemented hardground or quartz granule lag while mid shelf cycles are upward coarsening and thickening proximal to distal tempestites such cycles are interpreted to form by eustatically driven climatically controlled oscillations in abrasion wave base and swell wave base deep shelf rhythms are interbedded bryozoan marl and calcareous clay thought to be generated by climatically influenced fluctuations in carbonate productivity and terrigenous dilution lowstand systems tracts are depositional or erosional sequence boundaries are complex multigeneration mostly submarine surfaces condensed cycle boundaries that can be traced offshore into multiple omission surfaces and conformable contacts basinward facies shifts result in deposition of condensed lowstand wedges of stacked shallowing upward grainstone cycles transgressive systems tracts are thick bryozoan marl calcareous clay rhythms associated with facies backstepping and abrupt deepening such rhythmites typically grade stratigraphically upward into tempestite cycles highstand systems tracts are highly progradational wedge shaped rock bodies of shallowing upward grainy cycles these limestones provide the critical link of stratigraphy between modern cool water carbonate shelf deposits and the older mesozoic and paleozoic record of similar sediments

sedimentary characteristics and interactions among volcanic terrigenous and marine processes in the late permian kuishan member eastern block of the north china craton abstract understanding the variability of depositional environment and depositional processes of the late permian kuishan member north china craton is crucial for unraveling the evolution of sedimentary basin and epicontinental sea in shandong tectonic domain the kuishan member in the eastern block of the north china craton formed in association with general regression of an epicontinental sea is composed of abundant volcanic deposits and nearshore sedimentary deposits three lithofacies assemblages together with eleven lithofacies are identified in the study area including volcanic deposits of the turbidity lithofacies assemblage epiclastic deposits of the nearshore lithofacies assemblage and mixed volcaniclastic and epiclastic sedimentary deposits of the terrestrial lithofacies assemblage these alternating volcanic epiclastic lithofacies assemblages illustrate the depositional environments induced by volcanic activities and nearshore wave influence syn eruptive lithofacies in the shallow water area were formed by high density turbidity currents and ash fall into water introduced by rising sea levels and high rainfall due to volcanic eruptions to the north whereas thin bedded shallow marine silty mud developed in the distal area inter eruptive lithofacies were represented by tuffaceous mudstone deposited in an exposed and oxidized setting due to falling sea level whereas epiclastic nearshore deposits accumulated by wave or current flow regimes paleocurrent measurements show that the predominant regression direction changes from uniform southwest to divergent southwest and southeast during volcanic inter eruptive periods the kuishan succession therefore can be regarded as a volcano related sequence in which the input of volcaniclastic and epiclastic deposits were significantly modulated by controls of volcanism with frequently changing coastline position of the epicontinental sea and alternating depositional environments

sedimentation rates and growth potential of tropical cool water and mud mound carbonate systems carbonate fixation in the ocean proceeds in three basic modes abiotically biotically induced with organic trigger and biotically controlled where organisms determine timing location and composition of the product the three modes combine in a variety of ways to produce carbonate sediment when viewed on the scale of formations and global facies belts three benthic carbonate production systems or factories emerge 1 the tropical shallow water system dominated by biotically controlled mainly photoautotrophic and abiotic precipitates 2 the cool water system dominated by biotically controlled mainly heterotrophic precipitates and 3 the mud mound system dominated by abiotic and biotically induced mainly microbial precipitates the sedimentation rates of all three factories decrease as the time span of observation increases this scaling trend is not just an artifact of ratio correlation it is almost certainly related to the episodic pulsating nature of sedimentation the growth potential of the three systems can be estimated by drawing the envelope of the maximum observed rates of aggradation the tropical system shows the highest rates 10

rb sr isotopic study of archean gneisses north of the cape smith fold belt ungava quebec the cape smith volcanic fold belt extends across the ungava peninsula of quebec and is part of the aphebian circum ungava geosyncline the contact with the superior province to the south is an unc

facies analysis of an upper cretaceous high energy rudist dominated carbonate ramp matese mountains central southern italy subtidal and peritidal cycles abstract upper cretaceous shallow water limestones rich in rudists have been studied in the matese mountains they show a preponderance of skeletal components molluscs and benthic foraminifers and a lack of non skeletal grains the most prominent sediments of the studied stratigraphic interval are rudist dominated fine to coarse grained lithologies most of the senonian successions are characterized by massive neritic limestones rich in molluscs mostly rudists and subordinate gastropods and a few corals the sediments were generated in situ on shelves where rudist bivalves were the primary sediment producers these sediments were actively moved by storms waves and swells the finer fractions were probably winnowed out and deposited in deeper water well bedded dolomitized mudstones wackestones microbial laminites and benthic foraminifer wackestones characterize some successions where they rhythmically alternate and testify to deposition in tidal flat environments the lithofacies faunal and taphonomic characters and the sedimentary structures are typical of a ramp like open shelf with local peritidal deposition the vertical lithofacies organization consists of numerous decimetre to metre scale shallowing upward subtidal and peritidal cycles a complete transition from peritidal to subtidal cycles has been recognized and documented the peritidal cycles are usually bounded by desiccation surfaces and or dolomitized crusts followed by shallow subtidal to peritidal facies of the next cycle the subtidal cycles are typified by rudist floatstones passing to large scale cross bedded bioclastic packstones grainstones current and storm structures are distinctive features in shallower water environments the effects of submarine erosion prevail hardgrounds commonly developed and the resulting cycles are usually truncated the formation of the peritidal cycles appears to have been controlled by accommodation space in response to fluctuations in relative sea level the formation of the subtidal cycles was determined by sedimentation rates in response to fluctuations in the zones of fair weather and storm wave reworking in turn controlled by relative sea level this indicates that sediment production and supply were important controlling factors in the cycle formation during the early senonian stratigraphic interval the recognition of similar depositional styles in other early senonian successions cropping out in the southern apennines suggests that this type of sedimentation is a recurring attribute of the upper cretaceous open shelves

sequence stratigraphic context of syndepositional diagenesis in cool water shelf carbonates pliocene limestones new zealand abstract pliocene limestones in eastern north island new zealand are cool water deposits composed of barnacle epifaunal bivalve bryozoan dominated calcitic biota formed in shoal areas about the margins of a tectonically active forearc basin seaway vertical changes in the thickness and depositional facies of the limestones and fundamentally the position and nature of internal bounding discontinuities within them have enabled identification of high order likely 41 ka transgressive deepening upwards and transgressive regressive deepening then shallowing upwards sequences within the formations syndepositional or sea floor or pre compaction diagenesis in the limestones involves a spectrum of destructive to constructive features including skeletal abrasion bioerosion encrustation dissolution and cementation upward changes in the type and extent of these pre compaction diagenetic features within the discontinuity bounded sequences relate closely to the stacking patterns of depositional facies and their associated skeletal and mineralogical composition consequently it has been possible to develop a series of predictive diagenetic models for cool water shelf carbonates deposited upon and about upthrust antiforms in the forearc that integrate their patterns of syndepositional diagenesis into a sequence stratigraphy based framework driven ultimately by relative sea level changes marine constructive diagenesis characterized by bioencrustation turbid cements and interstratified internal sediments occurs most commonly in those facies close to the sequence bounding discontinuities within the lower levels of transgressive systems tracts tsts and the uppermost levels of regressive systems tracts rsts these sediments equate to the highest energy facies upon antiform tops close to the wave abrasion base where sedimentation rates were low in contrast destructive diagenetic processes typically dominate over constructive ones often exclusively so in the upper part of tsts in highstand systems tracts hsts and in the lower portion of rst carbonates where the sediments were not so influenced by active fluid circulation or strong reworking for prolonged periods but were more rapidly buried within accommodation traps below wave abrasion base about the antiforms the link between the facies motifs and synsedimentary diagenesis in these cool water pliocene limestones helps unlock their otherwise often cryptic high order sedimentary architecture such an interpretive opportunity is not afforded by the subsequent post compaction diagenetic features in the limestones because these are no longer closely related to the sedimentation realm

isotopic constraints on the genesis and age of autochthonous glaucony in the oligo miocene torquay group south eastern australia the oligo miocene torquay group at bird rock in south eastern australia comprises a sequence of fine grained skeletal carbonates and argillaceous and glauconitic sandstones deposited in a cool water mid shelf environment the bird rock glaucony is autochthonous and consists predominantly of randomly interstratified glauconitic smectite which constitutes bioclast infills and faecal pellet replacements the results of rb sr and oxygen isotopic analysis of samples taken from a single glauconitic horizon the bw horizon indicate that the glaucony developed through a series of simultaneous dissolution crystallization reactions which occurred during very early diagenesis in a closed or isochemical system isolated from the ambient marine environment the constituent ions of the glaucony were derived primarily from terrigenous clay minerals but considerable potassium may have been sourced indirectly from sea water through potassium enrichment of clay precursors the pore fluids associated with glauconitization were marine derived but progressively modified by the dissolution crystallization of detrital clay minerals and autochthonous glaucony rb sr data for the bw horizon indicate that dating glauconies may be somewhat problematic as co genetic glauconitic minerals can show a range of initial strontium compositions which reflect the incorporation of strontium derived from mineralogical precursors and or contemporaneous sea water rb sr isochrons indicate that the glaucony of the bw horizon formed at 23 a 3 ma this age is in good agreement with both the established biostratigraphy and a 87 sr 86 sr age for the horizon 23 a 1 ma but could only be determined using the independent age constraint and the estimate of the 87 sr 86 sr ratio of contemporaneous sea water provided by

facies analysis and sequence stratigraphy of a miocene warm temperate carbonate ramp montagna della maiella italy abstract the uppermost oligocene lower miocene to upper miocene ramp carbonates from montagna della maiella italy form a supersequence bounded by deeply incised truncation surfaces this supersequence is subdivided into four sequences each sequence is composed of skeletal limestones in its lower part and marly limestones in its upper part the lower parts of the sequences are foramol limestones which suggest deposition in the warm temperate climate zone changes in climate oceanography and relative sea level combined to control sedimentation in the four sequences in the lower parts of the two older sequences the skeletal sands built dunes suggesting high energy conditions the dominant skeletal grains in the oldest sequence are larger foraminifers and in the next sequence they are bryozoans this change reflects cooling around the time of the aquitanian burdigalian boundary in the lower parts of the two younger sequences of middle and late miocene age sediment sheets with red algal bryozoan oncoids suggest deposition under calmer conditions transgressive and highstand systems tracts are recognized in all sequences a shelf margin systems tract may be exposed in the second oldest sequence in contrast to the situation that exists when warm water carbonates are deposited sedimentation of the foramol limestones on this isolated ramp was unable to balance accommodation during sea level rise this led to hemipelagic sedimentation during sea level highstands conglomerates resulted from reworking along flooding surfaces

plio pleistocene cliff bound wedge shaped warm temperate carbonate deposits from rhodes greece sedimentology and facies abstract the pliocene to pleistocene temperate carbonates of rhodes were deposited in a tectonically active region strongly influenced by a complicated and rapidly changing topography provided by the highly tectonised late cretaceous lindos limestone as basement rock deposition on this basement took place in accommodation loci restricted to micrograbens and their downslope extension to the foot of steep submarine cliffs to basement neptunian dykes and depressions in the basement rock consequently the sediments comprise a high degree of facies variability and are typically thin and laterally discontinuous the integration of several outcrops is necessary for the reconstruction of the stratigraphy and the relative sea level changes the sediments were deposited during a large scale tectonically driven transgressive regressive cycle in water depths changing from zero to several hundreds of metres at the studied lindos pefkos road cutting the kolymbia limestone bound to the foot of lindos limestone cliffs marks the onset of the marine deposition in the late pliocene its fabric is a rudstone consisting of unsorted angular lindos limestone clasts up to boulder size with a matrix dominated by molluscs and coralline algae the overlying plio pleistocene st paul s bay limestone consists of deep water float and rudstones containing the white coral community dominated by the coral lophelia pertusa its matrix shows a complex fabric of up to five sediment zones separated by differing states of lithification in this maximum flooding phase mineralised hardgrounds indicate depositional hiati the subsequent shallowing phase is represented by the cape arkhangelos calcarenite a series of distinctive facies of very patchy distribution they are characterised by the bryozoan brachiopod facies overlain by a facies heavily dominated by the bivalve mytilaster sp mytilaster facies conspicuous for the mytilaster facies is the inverse concave up stacking pattern of shelly material this facies is followed by a serpulid framestone and associated serpulid rudstone neptunian dykes cut through the first two facies and are filled with an intraformational breccia grading into a breccia with abundant mytilaster facies clasts neptunian dyke facies the sedimentology and interpretation of each facies include a description of the ichnology in particular the bioerosion peculiar to each facies the separation of different gravity transport processes in steep submarine environments is rarely described and most of the literature concentrates on siliciclastic dominated coarse grained sandy or gravely sand delta environments for a classification of the transport processes of the examined deposits the following criteria were evaluated sediment body symmetry inclination of the palaeorelief sediment constituents fabric complexity sedimentary structures and availability of fine matrix sedimentary structures and grading can be camouflaged in carbonates due to density differences of bioclasts however bioclast orientations such as bivalve stacking patterns can give information about the sedimentary process we suggest the inverse concave up stacking pattern of bivalve shells to be a texture potentially indicative for debris falls because of the above mentioned criteria we classified the kolymbia limestone as rock fall deposits and the st paul s bay limestone as well as the mytilaster facies of the cape arkhangelos calcarenite as debris fall deposits the bryozoan brachiopod facies could not be classified with certainty because of the lack of sedimentary structures and bioclast orientation however a grain flow or most likely a debris fall transport process seems probable

the effects of sea level and palaeotopography on lithofacies distribution and geometries in heterozoan carbonates south eastern spain this study utilized three dimensional exposures to evaluate how sea level position and palaeotopography control the facies and geometries of heterozoan carbonates heterozoan carbonates were deposited on top of a neogene volcanic substrate characterized by palaeotopographic highs palaeovalleys and straits that were formed by subaerial erosion possibly original volcanic topography and faults prior to carbonate deposition the depositional sequence that is the focus of this study ds1b consists of 7 10 fining upward cycles that developed in response to relative sea level fluctuations a complete cycle has a basal erosion surface overlain by deposits of debrisflows and high density turbidity currents which formed during relative sea level fall overlying tractive deposits most likely formed during the lowest relative position of sea level overlying these are debrites grading upward to high density turbidites and low density turbidites that formed during relative sea level rise the tops of the cycles consist of hemipelagic deposits that formed during the highest relative position of sea level the cycles fine upward because upslope carbonate production decreased as relative sea level rose due to less surface area available for shallow water carbonate production and partial drowning of substrates the cycles are dominated by two end member types of facies associations and stratal geometries that formed in response to fluctuating sea level position over variable substrate palaeotopography one end member is termed flank flow cycle because this type of cycle indicates dominant sediment transport down the flanks of palaeovalleys those cycles drape the substrate have more debrites high density turbidites and erosion on palaeovalley flanks and in general the lithofacies fine down the palaeovalley flanks into the palaeovalley axes the second end member is termed axial flow cycle because it indicates a dominance of sediment transport down the axes of palaeovalleys those cycles are characterized by debrites and high density turbidites in palaeovalley axes and lap out of strata against the flanks of palaeovalleys where and when an axial flow cycle or flank flow cycle developed appears to be related to the intersection of sea level with areas of gentle or steep substrate slopes during an overall relative rise in sea level results from this study provide a model for similar systems that must combine carbonate principles for sediment production palaeotopographic controls and physical principles of sediment remobilization into deep water

the genesis of glaucony in the oligo miocene torquay group southeastern australia petrographic and geochemical evidence abstract the oligo miocene torquay group at bird rock in southeastern australia comprises a sequence of fine grained skeletal carbonates and argillaceous and glauconitic sandstones which were deposited in a cool water mid shelf environment the bird rock glaucony consists predominantly of randomly interstratified glauconitic smectite which constitutes bioclast infills and faecal pellet replacements petrographic and geochemical evidence indicates that the glaucony is autochthonous and comprises chemical components derived primarily from argillaceous matrix material seawater is unlikely to be a significant source of ions the glauconitization of the bird rock sediments occurred under sub oxic partially reducing conditions in the very shallow burial environment and involved local iron redistribution sub oxic conditions favour glauconitization because iron is stable in the soluble ferrous state and can be fixed in authigenic silicates due to the negligible concentrations of hydrogen sulphide it is likely that localised acidic conditions were initiated during the glauconitization process this acidity appears to have been buffered by the dissolution of bioclastic carbonate the fact that glaucony predominantly occurs as bioclast infills and faecal pellet replacements implies that the physico chemical conditions appropriate for glauconitization develop preferentially in such biogenic detritus the development of appropriate micro environments within such sediments probably relates to their physical confinement and or high organic matter content the bird rock glaucony developed during intervals of slow sedimentation and environmental quiescence associated with marine flooding events these conditions facilitated glauconitization by allowing the favoured clay rich sediments to accumulate and remain in the appropriate physico chemical regime sufficiently long for the complex glauconitic structures to form

pliocene sedimentation in a shallow cool water estuarine gulf murray basin south australia the pliocene norwest bend formation is a well preserved succession of terrestrial and shallow marine deposits in the murray basin south australia sediments in this unit consist of two discrete terrigenous clastic rich decametre scale sequences or informal members which record episodes of marine incursion during the early and late pliocene respectively the base of each sequence is a transgressive lag and or strandline deposit that is transitional upwards into a highstand subtidal terrigenous clastic and cool water carbonate sediment accumulation the top of each sequence is incised by fluvial channels that are filled by river deposits which formed as relative sea level fell and terrestrial environments prograded basinward sedimentological data suggest that gross stratigraphic architecture was primarily determined by glacioeustasy differences in sedimentary style between these two sequences however reflect a major climatic change that took place in southern australia during the mid pliocene the lower quartzose sand member is formed of siliciclastic sediment derived from prolonged deep subaerial weathering and contains a bivalve dominated cool temperate open marine mollusc assemblage these sediments accumulated under an equitable relatively warm humid climate the murray basin during this time because of high fluvial discharge was a salt wedge estuary with typical estuarine circulation in contrast the upper oyster rich member is typified by large monospecific oyster buildups that grew in restricted coastal environments strandline deposits contain a warm temperate skeletal assemblage contemporaneous aeolian sediments accumulated under warm semi arid climatic conditions well developed ferricrete silcrete and calcrete horizons reflect cyclic conditions of rainwater infiltration and evaporation in the seasonally dry climate that typifies southern australia today highly seasonal rainfall produced an estuary that fluctuated annually from being well to partially mixed these pliocene sediments support the notion that mollusc rich facies are the signature of cool water carbonate accumulations in inboard neritic environments unlike bryozoans that dominate the outer parts of cenozoic cool water carbonate shelves molluscs evolved to exploit an array of coastal ecosystems with wide salinity variations and variable sedimentation rates

spit platform temperate carbonates the origin of landward downlapping beds along a basin margin lower pliocene carboneras basin se spain lower pliocene temperate carbonates exhibit landward downlapping beds at the southern margin of the carboneras basin in south eastern spain this rarely documented stratal geometry resulted from the accumulation of bedded bioclastic carbonate sand and gravel by longshore currents along a spit platform located a few hundred metres from the palaeoshoreline the top of the spit platform was covered by shoals that extended over a gently dipping ramp inclined to the north on the landward slope of the spit sediments washed over from the shoal area were deposited in parallel laminated beds with a southward dip of 8 11 these beds aggraded and retrograded after an increase in accommodation space probably related to an early pliocene eustatic sea level rise as a result the beds downlap onto the underlying unconformity surface in a shoreward direction eventually the depression between the shoreline and the spit platform was filled and a gentle ramp became established these pliocene exposures in the carboneras basin and a similar upper miocene example in southern spain suggest that landward downlapping stratal geometries can be expected in nearshore temperate carbonates along basin margins and demonstrate a similarity in sedimentary dynamics to siliciclastic sands and gravels

transgressive surfaces of erosion as sequence boundary markers in cool water shelf carbonates abstract although sequence stratigraphy was first conceptualized in and applied to siliciclastic successions its methodology and concepts are applicable to the carbonate regimen provided that potential modifications to the existing models are appreciated that take into account the specificities of carbonate systems we demonstrate that some properties inherent to isolated i e continent detached shallow water temperate carbonate systems including their typical low diagenetic potential due to the prevalance of calcitic mineralogies the critical role exerted by storm waves and tidal currents on sediment dynamics e g shedding of sediments at wave abrasion depth during highstand and lowstand conditions and uneven sea bed topographies cause both the genesis and preservation of subaerial unconformities to be uncommon thereby rendering their use as sequence boundaries inappropriate instead transgressive surfaces of erosion tses that formed as wave base shifts upwards during early rise of relative sea level are readily identifiable in the field extensive and by their very nature are preserved in the rock record typically at the base of upward deepening stacked facies in pliocene cool water carbonate successions from new zealand the tses are characterized by starved sedimentation and burrowed network development and are overlain by coarse bioclastic shoreface sediments and shell beds in most cases the surfaces top truncate shoaling upward deposits but also deepening upward stacking facies in places emersive events rarely correspond to actual physical surfaces but diagenetic evidence preserved beneath tses indicates that occasionally subaerial surfaces had previously developed and were later modified into tses therefore we propose that tses are the most adequate unconformities to define high order depositional sequences 20 250 ka in the studied successions because by contrast with emersion surfaces their formation and preservation are not dependent upon cool water sedimentary facies and mineralogy and are favoured by the dynamics of the setting i e wave base shift and accommodation creation during relative sea level rise

the eocene storm dominated foralgal ramp of the western pyrenees urbasa andia formation an analogue of future shallow marine carbonate systems abstract if the ongoing phenomenon of global warming prevails three main consequences are expected in tropical seas a higher sea level a reduction in coral reefs and more intense cyclones what will shallow marine carbonate systems be like insights can be gained from the pyrenean urbasa andia formation a transgressive heterozoan like foralgal larger foraminiferal and red algal ramp that formed in middle eocene times a greenhouse interval characterized by high atmospheric co 2 content firstly the evolution of future tropical shallow marine systems subject to a sea level rise is very likely to be similar to that seen in the backstepping architecture of the urbasa andia formation secondly eocene larger foraminifers rose when the paleocene eocene hyperthermal event caused a decline in corals in tropical seas coral reefs are again among the ecosystems that are likely to be particularly affected by current global warming it is therefore probable that future shallow marine tropical ecosystems will be devoid of platform margin coral reefs heterozoan ramps being far more common thirdly strong storm influence was common on the urbasa andia carbonate ramp the most distinctive feature being a distal dune field that was formed below storm wave base by high energy return currents similar features also characterize other eocene carbonate ramps furthermore numerical simulations highlighted the effect of strong tropical cyclones during the equable climate of the eocene together this information supports the hypothesis that tropical cyclone activity may increase under future greenhouse conditions taking everything into account the transgressive storm dominated foralgal ramp represented by the urbasa andia formation can be used as a virtual analogue of future shallow marine carbonate sedimentary environments developed under greenhouse conditions

post glacial sea level control and sequence stratigraphy of carbonate terrigenous sediments wanganui shelf new zealand abstract shallow marine mixed carbonate terrigenous sediments have been accumulating in water depths of 20 110 m on wanganui shelf central western new zealand during the latest quaternary post glacial sea level rise since about 18 000 years bp cores show an upward change from coarse mostly terrigenous dominated sands and gravels to shell rich sediments and then to terrigenous dominated muddy very fine sands and sandy muds these post glacial carbonate terrigenous sediments are a modern analogue for similar episodes of cyclothemic shelf deposition that characterise onland plio pleistocene sections in central western new zealand like their ancient counterparts the latest quaternary sediments can be interpreted in a sequence stratigraphic context a transgressive systems tract 4 15 m thick overlies a transgressive erosion surface evident on seismic reflection records and is represented by slightly shelly coarse sands and gravels at the base of several cores and as palimpsest surficial deposits on the modern shallow shelf out to a depth of about 50 m the overlying shelly deposits both shell rich and matrix rich are equivalent to mid cycle or backlap shellbeds described elsewhere they comprise a diverse in situ or locally transported bivalve molluscan and bryozoan biota typical of temperate latitude cool water carbonate shelf facies these condensed section shellbeds are up to at least 1 5 m thick gradationally overlie the transgressive sediments in cores and occur as modern surficial shelf facies between about 25 and 100 m water depth cores are locally capped by up to a few metres of terrigenous sands or muds that represent highstand systems tract deposits fed onto the shelf from opposing onshore and offshore directions in the nearshore region north island derived felsic fine sands are beginning to prograde seawards westwards across the shellbeds while in the offshore zone south island derived micaceous very fine sands and muds are encroaching upon and covering the shellbeds from the west and south

deepening upward subtidal cycles murray basin south australia abstract decimeter scale deepening upward cycles are the basic depositional motif of oligocene miocene murray supergroup limestones in the murray basin southeastern australia cycles formed in this large intracratonic basin on a centripetal temperate water epeiric ramp they reflect generation by trophic resource influenced carbonate production under mostly transgressive conditions listed from the base up each cycle is ideally composed of five parts part a biotically depauperate carbonates reflecting relatively shallow water restricted variably stressed highly mesotrophic environments part b increasingly biotically diverse limestones recording progressively more physical energy and less mesotrophic conditions upward om1 a conspicuous hardground to firmground surface formed during late transgression to stillstand during which wave sweeping and reworking contributed to omission and lithification part c relatively biotically diverse epifauna dominant sediments that were highly abraded during periods of condensed sedimentation under marginally oligotrophic conditions and om2 cycle boundary a rarely conspicuous surface representing arrested sedimentation and variable cementation as trophic resources increased and conditions for carbonate production deteriorated ten cycle types are grouped into four major styles clay cycles mollusc cycles echinoid cycles and bryozoan cycles these are interpreted to form a lithological continuum from inner restricted terrigenous locales to outer open marine bryozoan colonized environments deepening upward cycles were profoundly sensitive to autogenic factors such as nutrient influx terrigenous content and turbidity hydrodynamic energy water temperature salinity and water depth manifested in this intracratonic setting although these cycles share a similar sedimentological motif and hydrodynamic energy based cycle capping process with open shelf epicratonic shallowing upward subtidal cycles of tertiary age they formed in a very different way reflecting the distinctive intracratonic environment in which they formed murray basin cycles preserve a record of relative sea level rise whereas open shelf cycles accumulated mostly during relative sea level fall

a depositional and sequence stratigraphic model for cold water spiculitic strata based on the kapp starostin formation permian of spitsbergen and equivalent deposits from the barents sea this article summarizes the lithostratigraphy of two sections through the kapp starostin formation on spitsbergen having contrasting distal and proximal depositional settings these outcrop sections are compared with an approximately age equivalent spiculitic unit penetrated in two exploration wells 800 km to the southeast on the finnmark platform eight main facies associations comprise these strata including limestones matrix rich matrix poor and mudstone siliciclastics shale and sandstone spiculite dark tight and light colored porous and phosphatized surfaces a sequence stratigraphic model is proposed wherein siliciclastic limestone intervals represent lowstands of relative sea level and the spiculites are mainly highstand deposits based on this model seven depositional cycles sequences are recognized in the distal high accommodation locality on spitsbergen akseloya four in the proximal locality dickson land and two on the finnmark platform a speculative model for correlation between these localities is presented wherein lateral amalgamation of sequences due to landward pinch out of some lowstand intervals results in recognition of fewer sequences in areas of lower accommodation on both dickson land and the finnmark platform an upward change in spiculite lithology from dark tight to light porous is shown and dickson land also shows an upward change in siliciclastic lithology from shale to glauconitic sandstone these changes record a long term shoaling trend approaching the permian triassic boundary this model provides a basis for interpreting the basin scale begin page 2062 distribution of lithofacies and predicting the occurrence of porous zones representing potential hydrocarbon reservoirs

cool water eocene oligocene carbonate sedimentation on a paleobathymetric high kangaroo island southern australia abstract the kingscote limestone is a thin biofragmental 41 m thick paleogene subtropical to cool temperate carbonate interpreted to have accumulated in a seaway developed between a series of mid shelf islands it is a pivotal section that allows interpretation of a region in which there is little exposure of early cenozoic shelf sediments sedimentation occurred on part of the shelf along the northern margin of an extensive eocene embayment that evolved into a narrow oligocene ocean following collapse of the tasman gateway eocene strata are subtropical echinoid rich floatstones with conspicuous bryozoans and mollusks together with large and small benthic foraminifers numerous echinoid rudstone storm deposits punctuate the succession correlation with coeval eocene strata across southern australia supports a regional facies model wherein inner neritic biosiliceous spiculitic sediments passed outboard into calcareous facies the silica was derived from land covered by a thriving subtropical forest and attendant deep weathering oligocene rocks are distinctively cooler cyclic cross bedded bryozoan rudstones and floatstones with a similar benthic biota but dominated by bryozoans and containing no large benthic foraminifers these deposits are interpreted as flood dominated tidal subaqueous dunes that formed in a flood tide dominated inter island strait omission surfaces at the top of the eocene and at the top of most oligocene cycles are fe stained hardgrounds that underwent extensive multigeneration seafloor and meteoric diagenesis prior to deposition of the next cycle cycles in the kingscote limestone although mostly m scale and compositionally distinct are similar to those across the region and point to a recurring cycle motif controlled by icehouse eustasy and local paleogeography 1

upper cretaceous campanian phosphorites in jordan implications for the formation of a south tethyan phosphorite giant a record of sedimentary authigenic and biological processes are preserved within the upper cretaceous campanian alhisa phosphorite formation ap in central and northern jordan the ap formed near the eastern extremity of the south tethyan phosphorite province stpp a carbonate dominated upper cretaceous to eocene phosphorite giant that extends from colombia north africa to the middle east multidisciplinary research of the ap and associated cherts chalks and oyster buildups indicate that phosphatic strata formed on a highly productive storm dominated east west trending epeiric platform along the south tethyan margin the onset of phosphogenesis and the accumulation of economic phosphorite coincided with a rise in relative sea level that onlapped peritidal carbonates of the ajlun group pristine phosphates are associated with well developed micrite concretionary horizons and contain abundant non keeled spiral planktic foraminifera and a low diversity benthic assemblage of buliminacean foraminifera suggesting that pristine phosphates are a condensed facies and phosphogenesis was stimulated by the effects of a highly productive surface ocean and the suboxic diagenesis of sedimentary organic matter the bulk sediment composition and absence of fe bearing authigenic phases such as glauconite pyrite including pyrite molds siderite and goethite within pristine phosphates suggests that deposition and authigenesis occurred under conditions of detrital starvation and that iron pumping played a minimal role in phosphogenesis authigenic precipitation of phosphate occurred in a broad array of sedimentary environments herein termed a phosphorite nursery that spanned the entire platform this is a non uniformitarian phenomenon reflecting precipitation of sedimentary apatite across a wide depositional spectrum in a variety of depositional settings wherever the conditions were suitable for phosphogenesis sedimentologic data indicate that pristine phosphates were concentrated into phosphatic grainstones through storm wave winnowing and storm generated shelf parallel geostrophic currents economic phosphorites formed through the amalgamation of storm induced event beds stratigraphic packaging of phosphatic strata indicates that temporal variations in storm frequency were a prerequisite for the formation of economic phosphorite syndepositional phosphogenesis reworking and amalgamation to form phosphorites contrasts sharply with the principles of baturin cycling a transgressive systems tract coupled with high surface productivity created detritally starved settings favourable for phosphogenesis storm reworking of pristine

facies and stratigraphic anatomy of a temperate carbonate sequence capo colonna terrace late pleistocene southern italy abstract accurate interpretation of ancient non tropical carbonate systems requires the development of appropriate facies and sequence stratigraphic models these models should account for the marked differences in sedimentation style among non tropical carbonates formed under different energy settings this paper presents data and a conceptual model of the sequence architecture of non tropical carbonates of moderate energy environments based on the late pleistocene deposits of capo colonna marine terrace calabria southern italy these deposits have the advantage of being continuously exposed along a proximal distal transect across the paleo shelf and their geometry has not been disturbed by later tectonic activity they consist of a transgressive regressive t r cycle whose genesis can confidently be related to one of the interstadial glacio eustatic fluctuations of marine isotope stage mis 5 eight different mixed carbonate siliciclastic and carbonate facies are present in the studied sequence of these biogenic dominated facies are invariably made up of skeletal remains of light independent organisms plus or minus red calcareous algae the heterozoan association the relatively young age of the deposits allows calibration of the paleoecological significance of observed facies by direct comparison with modern analogues from the mediterranean sea four laterally persistent discontinuity surfaces were identified along the transect and interpreted from bottom to top as 1 a basal ravinement surface 2 a submarine hardground locally acting as a substrate for algal boundstones 3 a regressive surface of marine erosion and 4 a surface of subaerial exposure sequence stratigraphic analysis indicates that the preserved t r cycle is asymmetric with a thicker regressive portion highstand deposits can be subdivided into a shore connected sandy prism and more distal autochthonous and parautochthonous skeletal accumulations and algal boundstones during forced regression a thin sharp based strongly progradational unit of calcarenites was deposited above the regressive surface of marine erosion the deposits of capo colonna terrace document the response of non tropical moderate energy carbonate ramps to sea level fluctuations during icehouse conditions their architecture can facilitate the interpretation of other successions from similar settings and provide an end member to be compared and contrasted with high wave energy cool water carbonates

sequence stratigraphy basin morphology and sea level history for the permian kapp starostin formation of svalbard norway based on seven measured sections from svalbard the marine strata of the permian kapp starostin formation are arranged into seven transgressive regressive sequences tr1 tr7 of c 4 5 ma average duration each bound by a maximum regressive surface facies including heterozoan dominated limestones spiculitic cherts sandstones siltstones and shales record deposition within inner middle and outer shelf areas the lowermost sequence tr1 comprises most of the basal voringen member which records a transgression across the gipshuken formation following a hiatus of unknown duration temperate to cold storm dominated facies established in inner to middle shelf areas between the latest artinskian and kungurian prolonged deepening during sequences tr2 and tr3 was succeeded by a long term shallowing upward trend that lasted until the latest permian tr4 tr7 a major depocentre existed in central and western spitsbergen while to the north dickson land remained a shallow platform leading to a shallow homoclinal ramp in ne spitsbergen and nordaustlandet the middle permian extinction late capitanian is recorded near the base of tr6 in deeper parts of the basin only elsewhere this sequence is not recorded likewise the youngest sequence tr7 extending to the upper formational contact of latest permian age is found only in the basin depocentre comparison with age equivalent strata in the sverdrup basin of canada reveals a remarkably similar depositional history with for example two third order sea level cycles recorded in the late permian of both regions in keeping with the global record sequence stratigraphy may therefore be a powerful correlative tool for onshore and offshore permian deposits across nw pangaea

soft sediment deformation induced by sinkhole activity in shallow marine environments a fossil example in the apulian foreland southern italy abstract soft sediment deformation structures are exposed in sea cliffs in the lower part of the calcarenite di gravina formation late pliocene early pleistocene in the cala corvino area n of monopoli adriatic sector of the apulian foreland southern italy deformation affects a thickness of about 5 m involving a lower calcareous terrigenous sand and gravel unit and an upper heavily bioturbated grainstone and packstone unit deformation is absent from the overlying part of the succession large scale soft sediment deformation structures are collapse features comprising irregularly elongated conical zones of sinking in vertical section narrow drop zones occur in the lower sandy gravelly facies and large gentle folds in the upper grainstone packstone beds the degree of deformation decreases upwards small scale soft sediment deformation structures adjacent to the large scale conical collapse structures are narrow vertically elongated load structures about 2 m high and 30 50 cm wide that involve only the basal terrigenous facies the distribution of small and large scale soft sediment deformation structures corresponds closely to zones of fracturing in the underlying cretaceous limestones and the elongation directions of soft sediment deformation structures correspond to the orientation of major fractures in the limestones the soft sediment deformation occurred due to collapse associated with karstic sinkhole formation along fractures in the bedrock geometrical relationships between deformed and undeformed sedimentary units show that deformation occurred in a shallow marine environment the structures at cala corvino provide a rare outcrop scale record of sinkhole induced soft sediment deformation occurring in a shallow marine environment