integrating palaeocaves into palaeolandscapes an analysis of cave levels and karstification history across the gauteng malmani dolomite south africa abstract the drimolen palaeocave system in the fossil hominid sites of south africa unesco world heritage site is well known for numerous remains of early hominins such as paranthropus robustus and early homo these hominin fossils along with bone tools and notably diverse accumulation of non hominin primates and fauna have all been excavated from the main quarry area of the site where extensive lime mining took place here we report the first radiometric age of 1 712 0 269 ma for hominin bearing deposits associated with the dnh7 paranthropus robustus cranium in the main quarry area of the site which is consistent with recent biochronological estimates this age is similar to recent estimates for swartkrans member 1 hanging remnant somewhere between 2 3 and 1 8 ma which also contains paranthropus and early homo simultaneously we integrate the newly radiometrically dated main quarry deposits with a new fossil deposit the drimolen makondo discovered in 2013 that is situated some 50 m up the hill to the west from the main quarry it has experienced only limited disturbance from mining but much more extensive erosion preliminary excavations and analysis have revealed that the makondo infill is older than the main quarry dating to 2 706 0 428 ma its greater age is confirmed by biochronology the makondo thus overlap with the suggested end of deposition of australopithecus bearing sterkfontein deposits although it is yet to yield any hominin remains these new dates for the two drimolen palaeocave system deposits indicates that contrary to prior age estimates the drimolen site as a whole records the critical hominin and faunal turnover in south african palaeocommunities that occurred around 2 3 1 7 ma finally as the drimolen makondo represents a rare example of a pre 2 ma fossil bearing deposit in the gauteng exposures of the malmani dolomite we also integrate our results into the greater south african record of palaeodeposit formation most of which occur between 2 0 and 1 0 ma an analysis of the age of palaeocave infillings across the malmani dolomite suggests that as is classically the case with karst the height within the dolomite is broadly correlated to their age although with some notable exceptions that are likely related to localised geological features our analysis also indicates that most caves have undergone some form of secondary karstification related to a younger phase of cave formation contrasting with models that suggest the cavities all formed at the same time and that infill is related to erosion and the opening up of cave passages as such the reason that few pre 2 ma deposits have been identified in the gauteng exposures of the malmani dolomite is probably because these older caves have been eroded away identifying such early caves is critical in understanding whether earlier hominins may have once existed in south africa or if erosion of older deposits or an absence of speleogenesis at this time has made such early periods absent from the geological record

the geomorphologic evolution of the wilderness dune cordons south africa abstract the wilderness dune cordons consist of steep sided ridges up to 207 m high separated by coastal lakes they probably formed during the sea level highstands of the pleistocene interglacials three major dune cordons are developed there is an additional huge coalesced mass of older fossil dunes landward of these cordons forming hills up to 340 m high in places lying on the coastal platform 150 260 m generally locally 210 260 m the dunesand reaches thicknesses in excess of 300 m the cordons form by accretion of transgressive dunefields and large compound imbricate parabolic dunes an individual cordon can result from numerous phases of dune formation during periods of sea level highstand the dunes of the present interglacial are mostly accreting on top of the seaward cordon which was initiated during the last interglacial during the complex sea level history there have been numerous phases of dune building followed by coastal erosion that formed seacliffs in the dune cordons in some areas almost all the cordon was subsequently eroded away these fossil seacliffs form large steep seaward facing slopes parallel to the present coastline and form a major element in the morphology of the cordons trailing arms of parabolic dunes form another major topographic element oriented at 15 30 to the shoreline river erosion has altered the cordon morphology in places the geomorphology of the cordons is thus a function primarily of dune cordon construction accentuated by coastal erosion in the form of cliff cutting secondarily of dune morphology and thirdly of fluvial erosion the evolution of the cordons can be dated tentatively using palaeontologic stratigraphic and sediment dynamic data the seaward cordon formed during the eem and holocene a fairly reliable dating the middle cordon probably formed between 200 500 ka and the landward cordon probably formed between 600 900 ka the coalesced dune deposits lie inland of the cordons and are thus older this would place the minimum age of the younger coalesced dune deposits in the middle pleistocene about 1000 ka early miocene fossil plant remains in the knysna lignites which underlie the older coalesced dunes indicate their maximum possible age westerly winds dominated in the area for the past few million years

middle miocene isotope stratigraphy and paleoceanographic evolution of the northwest and southwest australian margins wombat plateau and great australian bight abstract the benthic stable isotope record from odp site 761 wombat plateau nw australia 2179 3 m water depth documents complete recovery of the middle miocene 13c excursion corresponding to the climatic optimum and subsequent expansion of the east antarctic ice sheet the six main 13c maxima of the monterey excursion between 16 4 and 13 6 ma and the characteristic stepped increase in 18o between 14 5 and 13 9 ma are clearly identified the sedimentary record of the shallower odp sites 1126 and 1134 great australian bight gab sw australia 783 8 and 701 m water depth respectively is truncated by several unconformities however a composite benthic stable isotope curve for these sites provides a first middle miocene bathyal record for southwest australia the 18o and 13c curves for sites 1126 and 1134 indicate a cooler better ventilated water mass at 700 m water depth in the great australian bight since approximately 16 ma this cooler and younger water mass probably originated from a close southern source cooling of the bottom water at 16 ma started much earlier than at other sites of equivalent paleodepths in the central and western parts of the indian ocean at site 761 the 18o curve shows an excellent match with the global sea level curve between 11 5 and 15 1 ma and thus closely reflects changes in global ice volume prior to 15 1 ma the mismatch between the 18o curve and the sea level curve indicates that 18o fluctuations are mainly due to changes in bottom water temperature

chemical investigation of mineralisation categories used to assess taphonomy abstract a recent case study from the geelbek dunes archaeological site in western cape province south africa revealed that counter to prevailing notions long term bone survivorship is not always linked to estimates of bone density porosity differences between modern cancellous and compact bones of different animals and skeletal parts provided density estimates for fossil bones taphonomic history was inferred from the physical condition and mineral burden of the fossil bones and represented by five mineralisation categories bones in mineralisation category one had the lowest secondary mineral burden whereas samples with very high secondary mineral contents were considered category five here we examine the proposed link between mineralisation category and taphonomic history by analysing fossils with non destructive energy dispersive x ray fluorescence spectroscopy we hypothesised that higher mineralisation categories should be evident as higher concentrations of elements associated with secondary minerals however chemical measurements could not distinguish fossil bones in mineralisation category one from those in category three furthermore bones in categories four and five could not be distinguished from one another a control of modern bone specimens and fossils in mineralisation category two formed separate and distinct clusters of principal component score values spectra from the geelbek dunes specimens were subsequently used to predict mineralisation categories for fossils from a nearby archaeological locality named anyskop blowout based on the surface chemistry anyskop fossils clustered in two principal groups low mineralisation categories one two and three and high mineralisation categories four and five energy dispersive x ray fluorescence spectroscopy provided useful taphonomic information for fossils from both the geelbek dunes and anyskop blowout although this surface biased technique was not well correlated with the five mineralisation categories

mid pleistocene hominin occupation at elandsfontein western cape south africa abstract the current understanding of landscape scale variation in mid pleistocene hominin behavior is limited most of our understanding derives from a few localities in eastern africa consequently we know very little about hominin landscape use outside this region despite the fact that mid pleistocene hominins occupied other climatic zones including temperate and mid latitude ecosystems the winter rainfall zone in south africa represents one of the world s most diverse ecosystems although mammal diversity is relatively low in these habitats this is compensated by the tremendous floral diversity buried pleistocene land surfaces in the region provide an opportunity to understand how humans adapted to this unique mid latitude environment prior to the last interglacial the dunefield locality of elandsfontein in the western cape of south africa is one of the richest known paleontological and archeological sites in southern africa it records details of landscape formation history enabling detailed reconstruction of the ancient environments in this winter rainfall dominated region this dunefield archive allows us to posit the taphonomic history of newly excavated archaeological material and previously collected specimens here we provide initial results from the excavation and geological analysis of the elandsfontein dunefield and provide new insights into the formation history of the archaeological and paleontological deposits this includes indications of multiple pedogenic intervals and groundwater table fluctuations the combination of geological paleontological and archaeological data provides a framework for evaluating how hominins interacted with the unique ecosystems of the cape floral region of south africa during the mid pleistocene

stable isotopic composition of fossil mammal teeth and environmental change in southwestern south africa during the pliocene and pleistocene abstract the past 5 million years mark a global change from the warmer more stable climate of the pliocene to the initiation of glacial interglacial cycles during the pleistocene marine core sediment records located off the coast of southwestern africa indicate aridification and intensified upwelling in the benguela current over the pliocene and pleistocene however few terrestrial records document environmental change in southwestern africa over this time interval here we synthesize new and published carbon and oxygen isotope data of the teeth from large mammals 6 kg at langebaanweg 5 million years ago ma elandsfontein 1 0 0 6 ma and hoedjiespunt 0 35 0 20 ma to evaluate environmental change in southwestern africa between the pliocene and pleistocene the majority of browsing and grazing herbivores from these sites yield enamel 13c values within the range expected for animals with a pure c3 diet however some taxa have enamel 13c values that suggest the presence of small amounts c4 grasses at times during the pleistocene considering that significant amounts of c4 grasses require a warm growing season these results indicate that the winter rainfall zone characteristic of the region today could have been in place for the past 5 million years the average 18o value of the herbivore teeth increases 4 4 between langebaanweg and elandsfontein for all taxa except suids this increase may solely be a function of a change in hydrology between the fluvial system at langebaanweg and the spring fed environments at elandsfontein or a combination of factors that include depositional context regional circulation and global climate however an increase in regional aridity or global cooling between the early pliocene and mid pleistocene cannot explain the entire increase in enamel 18o values spring fed environments like those at elandsfontein may have provided critical resources for mammalian fauna in the mid pleistocene within an increasingly arid southwestern africa ecosystem

tertiary sea level movements around southern africa sedimentological micropaleontological and seismic profiling data elucidate the history of tertiary sea level movements around southern africa these new data show that landward movement of the sea began in early paleocene time and continued into the early eocene the sea probably reached its maximum paleocene height during the early eocene and is today represented by outcrops up to at least 204 m and probably as high as 360 m above modern sea level a brief regressive pulse occurred during the middle eocene with renewed transgression in the late eocene a major regression followed probably spanning all of oligocene and early miocene times this regression exposed much of the continental shelf and is clearly represented on seismic reflection profiles by a widespread unconformity the major neogene transgression began in the middle miocene and probably reached its greatest extent in the late miocene or early pliocene the overall middle miocene to early pliocene transgression was interrupted by a brie

miocene fluvial systems and palynofloras at the southwestern tip of africa implications for regional and global fluctuations in climate and ecosystems abstract high amplitude climate fluctuations have been inferred from marine isotope data in the early neogene but few well documented terrestrial records exist from this era to gauge the effects of these high latitude events on continental climates and ecosystems the extensive three dimensional exposures of miocene fluvial and fluvio lacustrine sediments in the rondeberg clay pit near cape town provide a unique window on this era palaeomagnetic data suggests that the deposits accumulated over a period of ilex type euphorb type rhamnaceae and mesothermic podocarpus type palynofloras suggests a humid subtropical tropical climate however abundant charcoal charred in situ tree stumps overall poor preservation of organics evidence for upward drying lacustrine successions and an appreciable fynbos presence point to cyclical periods of drought we suggest that these climate fluctuations may have been influenced by the orbital pacing seen in the marine isotope record of the earlier miocene pointing to a high latitude link with mid latitude terrestrial climate patterns earlier studies of pollen spectra from the nearby slightly older noordhoek deposits show cyclical alternations from tropical to cooler climates and more recent biogeochemical work has shown dramatic coincident fluctuations in depositional temperature these vegetation changes were previously correlated with major global events embracing the entire neogene from the oligo miocene late oligocene to early miocene to the pliocene we offer a different interpretation suggesting that the deposits represent a much shorter time interval in the earlier miocene and that these climate fluctuations may have been influenced by orbital forcing evinced in the marine isotope record along the northern west coast the arrisdrift vertebrate fossil assemblage in early middle miocene terrace deposits of the orange river indicate a tropical climate but possibly less humid than in the south with more open vegetation patterns the presence of pedogenic calcretes and gypcretes in the deposits suggests periodic extremes of aridity not seen in south the current pronounced north aridity gradient from humid temperate to hyper arid may have had its inception in the earlier miocene

geochemistry and palaeoclimatic reconstruction of a palaeosol sequence at langebaanweg south africa abstract neogene langebaanweg lbw palaeosol sediment sequences at the west coast of south africa are well known for their well preserved rich palaeontological heritage the palaeosols developed on estuarine marine coastal alluvial deposits stacked on each other ranging in age from the mid miocene to quaternary elemental mobility and redistribution based on major and minor element geochemistry of 11 horizons of the 18 m sequences were studied to evaluate the degree of chemical weathering a major process of soil formation and to reveal important palaeoenvironments in which the palaeosols developed elemental geochemistry was carried out on 2 50 mean wt two wi 1 and wi 2 of the four weathering indices applied to evaluate weathering intensity proved unsuitable for use in an alluvial palaeosol sediment sequences such as lbw chemical index of alteration cia and chemical index of weathering ciw values were relatively more consistent in distribution pattern across the pedocomplex but caution should be applied when using them in similar cases the pedogenic carbonate horizons on average had the lowest values for both cia and ciw 1 12 2 60 suggesting more advanced weathering plots of geochemical ratios quantifying pedogenic processes against depth show striking variations among and within the palaeosol and sediment sections soil formation was more advanced in the mid miocene and pliocene than in the quaternary suggesting a more humid and warmer climate than present we evaluated selected geochemical climofunctions and conclude that more data are obviously needed for a more robust calibration of the models in langebaanweg palaeosols

middle pliocene sea surface temperatures a global reconstruction identification and analyses of pliocene marine microfossils from 64 globally distributed stratigraphic sequences have been used to produce a middle pliocene sea surface temperature reconstruction of the earth this reconstruction shows little or no change from current conditions in low latitude regions and significant warming of the ocean surface at mid and higher latitudes of both hemispheres this pattern of warming is consistent with terrestrial records and suggests a combination of enhanced meridional ocean heat transport and enhanced greenhouse effect were responsible for the middle pliocene warmth

geoarchaeological and 3d visualisation approaches for contextualising in situ fossil bearing palaeokarst in south africa a case study from the 2 61 ma drimolen makondo abstract south africa contains a wealth of palaeokarst deposits that have yielded hominin fossils and early stone age archaeology despite the complex nature of deposition within many of these caves there has been a dearth of detailed geoarchaeological studies undertaken on these sites many sites in south africa have been interpreted using an overly simplistic member system based on simplified sedimentological attributes rather than chronostratigrahic units many of the defined members thus identify different but contemporary geological processes occurring in the caves this has caused serious confusion in reconstructing the life histories of palaeocaves and the ages of the fossil remains interned within them it is critical to uncover new sites that have not been extensively altered by decades of data collection and destructive mining techniques employed early in their discovery although unmined sites present their own problems with regards to extensive colluvium cover and access to fossil bearing units analysing strata that is found in situ enhances overall confidence of interpretations drawn a wealth of geoarchaeological and 3d visualisation techniques can now be employed to aid in the understanding of cave life histories as well as their excavation in this paper we present the first attempt to integrate and publish data from a range of such methods on south african fossil bearing palaeokarst using the newly discovered drimolen makondo deposit as a case study this includes the use of ground penetrating radar 3d visualisation through photogrammetry and multi scale 3d scanning micromophology and petrography palaeomagnetism mineral magnetism synchrotron radiation electron spin resonance uranium lead dating and biochronology our analysis has allowed us to successfully uncover the full extent of this new 2 61 ma fossil bearing palaeokarst deposit and to visualise and interpret its chronostratigraphy

melting ice sheets 400 000 yr ago raised sea level by 13 m past analogue for future trends abstract marine isotope stage mis 11 was possibly the longest 423 000 362 000 yr ago and warmest interglacial of the entire quaternary period this resulted from a special arrangement of earth s orbital parameters similar to the present interglacial mis 1 suggesting that mis 11 provides an analogue for future natural climate forcing and sea levels although precise documentation of mis 11 sea level history is therefore crucial especially considering additional impetus from anthropogenic warming the maximum mis 11 sea level remains highly contentious estimates from onshore indicators have ranged from below present sea level to about 20 m resulting from uncertainties in reliability of sea level indicators estimates of their subsequent displacement by vertical crustal motion and in dating we used a clear and unambiguous sea level indicator interface between subtidal and intertidal deposits in well exposed regressive raised shoreline deposits along south africa s southern coast the coast is stable in terms of tectonic setting and falls within a zone of low predicted glacio isostatic adjustment gia and low sensitivity for plausible model parameters the sea level indicators were directly dated using thermally transferred optically stimulated luminescence tt osl which gave a mean age of 390 ka corresponding with mis 11 we determined a precise maximum elevation of 14 m for the mis 11 sea level indicator which corrected for minor crustal uplift and gia yielded a eustatic sea level of 13 m 2 m the complete mis 11 transgressive regressive shoreline succession is preserved and the wave cut platform extends 950 m inland from the present shoreline indicating a prolonged highstand we have also documented sea level fluctuations during mis 11 including an earlier lower highstand close to present sea level which may explain the lower elevation range of some previous estimates at one locality mis 11 deposits form a sea cliff against which mis 5e sediments at an elevation of 6 2 m abut the 13 m mis 11 sea level tallies with total melting of the greenland and west antarctica ice sheets regarded as most susceptible to melting our data predict notably higher sea levels in the future regardless of anthropogenic influence on climate

aeolianite and barrier dune construction spanning the last two glacial interglacial cycles from the southern cape coast south africa the southern cape region of south africa has extensive coastal aeolianites and barrier dunes whilst previously reported limited knowledge of their age has precluded an understanding of their relationship with the climatic and sea level fluctuations that have taken place during the late quaternary sedimentological and geomorphological studies combined with an optical dating programme reveal aeolianite development and barrier dune construction spanning at least the last two glacial interglacial cycles aeolianite deposition has occurred on the southern cape coast at ca 67 80 88 90 104 128 160 189 and 200 ka before the present using this and other published data coupled with a better understanding of late quaternary sea level fluctuations and palaeocoastline configurations it is concluded that these depositional phases appear to be controlled by interglacial and subsequent interstadial sea level high stands these marine transgressions and regressions allowed onshore carbonate rich sediment movement and subsequent aeolian reworking to occur at similar points in the landscape on a number of occasions the lack of carbonates in more recent dunes oxygen isotope stages 1 2 and 4 5 is attributed not to leaching but to changes to carbonate production in the sediment source area caused by increased terrigenous material and or changes in the balance between the warm agulhas and nutrient rich benguela ocean currents

west coast dune plumes climate driven contrasts in dunefield morphogenesis along the western and southern south african coasts abstract this study examines two major late quaternary coastal dune systems situated in the southwestern most extremity of africa the false bay and duinefontyn dune plumes formed in close proximity but under contrasting oceanographic regimes warm agulhas and cold benguela oceanic current systems respectively the false bay and duinefontyn dune plumes have hitherto lacked the objective numerical chronology required to realize their full potential in unraveling the complex palaeo oceanographic and palaeoclimatic history of the region here we present a dual amino acid racemizationn aar and optically stimulated luminescence osl chronological framework from the extensive three dimensional exposures in sea cliffs at false bay three generations of dune deposition corresponding with orbitally forced climatic sea level cycles mis 7 mis 5 and holocene were resolved whereas the duinefontyn plume is dominated by mis 5 and holocene sedimentation at false bay and duinefontyn glacial periods are marked by the development of mature palaeosols confirming the link between glacio eustacy and dune deposition determined previously on the west and southern coasts of south africa along the west coast dune plumes typify dunefield morphology whereas shoreline parallel dune cordons are commonly developed on the southern coast these regional variations in dune system morphogenesis are largely controlled by contrasting wind and rainfall patterns the attenuated dimensions of the mis 5 plumes at false bay and duinefontyn may indicate a weakening of the south atlantic anticyclone during the last interglacial at false bay stone artifacts illustrate a human presence in the region during mis 7

155 000 years of west african monsoon and ocean thermal evolution a detailed reconstruction of west african monsoon hydrology over the past 155 000 years suggests a close linkage to northern high latitude climate oscillations ba ca ratio and oxygen isotope composition of planktonic foraminifera in a marine sediment core from the gulf of guinea in the eastern equatorial atlantic eea reveal centennial scale variations of riverine freshwater input that are synchronous with northern high latitude stadials and interstadials of the penultimate interglacial and the last deglaciation eea mg ca based sea surface temperatures ssts were decoupled from northern high latitude millennial scale fluctuation and primarily responded to changes in atmospheric greenhouse gases and low latitude solar insolation the onset of enhanced monsoon precipitation lags behind the changes in eea ssts by up to 7000 years during glacial interglacial transitions this study demonstrates that the stadial interstadial and deglacial climate instability of the northern high latitudes exerts dominant control on the west african monsoon dynamics through an atmospheric linkage

trace metals in contemporary and seventeenth century galapagos coral records of seasonal and annual variations we report trace element calcium ratios for modern cuca mnca cdca and pbca and seventeenth century cuca mnca and pbca specimens of pavona clavus collected in the galapagos islands these data include the first reliable measurements of cuca ratios in coralline aragonite we estimate that the ratio of cuca in the lattice to that in seawater i e the effective distribution coefficient is 0 3 lower than the value of 1 observed for several other divalent elements we estimate the effective distribution coefficient for mn is 1 distribution coefficients in coral aragonite for 8 divalent metals are near unity despite different ionic radii and chemical speciation in seawater investigation of where these substituents are incorporated in the aragonite lattice is clearly warranted in a modern hood island coral quarter annually sampled from 1964 73 cuca ratios decrease twofold from the late 1960s to early 1970s mnca and cdca ratios vary seasonally with upwelling and the generic el nino the el nino southern oscillation enso events of 1965 1969 and 1972 are marked by suppression of cdca ratios by about 2 5 nmol mol while the mnca ratio is highest during the strong 1972 enso pbca ratios were relatively constant throughout this period from the cuca record of a seventeenth century urvina bay coral annually sampled from 1600 1725 and the estimated cu distribution coefficient surface seawater cu concentrations at galapagos during the seventeenth century were similar to present day at 0 7 1 4 nmol kg estimated pb concentrations were lower at 5 20 pmol kg and mn concentrations were slightly higher at 1 6 2 8 nmol kg

relations between monterey formation deposition and middle miocene global cooling naples beach section california an oxygen and carbon isotopic stratigraphy has been established for the miocene monterey formation 18 to 8 ma at naples beach santa barbara county california correlation to the deep sea climatic record provides a test of the monterey hypothesis which suggests that organic carbon rich deposition in the monterey formation fostered middle miocene global cooling through drawdown of atmospheric partial co 2 oxygen isotopic correlation of the naples beach section to the deep sea record suggests that increased organic carbon rich deposition coincided closely with deep water cooling and major east antarctic ice sheet growth from 14 5 to 14 1 ma and with a 13 c maximum in deep sea records these results support a corollary of the monterey hypothesis that episodic organic carbon rich deposition within the monterey formation contributed to deep sea 13 c maxima and to synchronous global cooling

multi proxy palaeosol evidence for late quaternary mis 4 environmental and climate shifts on the coasts of south africa abstract palaeosols are common along the coastline of southern south africa as stacked aeolian dune deposits but have rarely been studied we selected two late quaternary palaeosols exposed in a marine cliff face at koeberg and coastal barrier dune at goukamma south africa in order to improve our understanding of their pedogenesis and palaeoclimate dynamics palaeosol based proxies explored include elemental geochemistry by x ray fluorescence spectrophotometry 13 c and 18 o isotopes micromorphology and clay mineralogy by x ray diffraction selected physico chemical soil properties were analyzed by routine laboratory procedures the palaeosols comprise predominantly loamy sand to sandy clay loam textures have a high ph 6 5 and very low electrical conductivity 1 sio 2 and cao are the most abundant of all the elements in the cambic and calcic horizons respectively the low levels of al in the parent materials most likely invalidated the applicability of chemical weathering indices cia to assess weathering intensity in the case of chemical index of weathering ciw the age and sedimentary settings of the palaeosols overruled the possibility for k metasomatism and illitization by metamorphism the indices wi 1 and w1 2 developed by darmody et al 2005 appear more consistent with depth the palaeo mat computed from palaeosol carbonate oxygen isotope is 14 and 11 c for koeberg and goukamma respectively while the maximum map obtained from the cambic horizon bw of the goukamma coastal barrier is 653 mm y 1 the layering seen in the thin section of the calcic layer at goukamma indicates deposition possibly by sedimentary differentiation across a palaeo slope clastic calcite and muscovite mica are the dominant minerals in these palaeosols indicating impeded chemical weathering similar to many other parts of the world the coastlines of south africa has experienced environmental and climate oscillations in the quaternary we conclude that along the southern south africa coasts a palaeosol based approach to palaeoenvironmental and palaeoclimate reconstruction in combination with other proxies such as pollen and marine based isotopes can provide insights into the environmental oscillations of the late quaternary

palynological and lithological evidence for the miocene palaeoenvironment in the saldanha region south africa abstract palynological and lithological studies were carried out on a section of clays of the elandsfontyn formation in the langebaanweg area the pollen assemblages suggest a middle miocene age for these clays which is supported by fossil faunal evidence in the overlying gravel member of the late miocene saldanha formation the pollen sequence indicates the retrogressive succession of subtropical tropical gallery forest to dominant palm vegetation and finally to marsh these changes are clearly related to the lithological evidence for the progressive lateral northward migration of the palaeo berg river it is possible that the middle miocene global high sea level cycle may have influenced these palaeoenvironmental changes

post rift stratigraphic evolution of the atlantic margin of namibia and south africa implications for the vertical movements of the margin and the uplift history of the south african plateau abstract the aim of this study is to constrain the post rift deformations of the atlantic passive margin of namibia and south africa using an extensive industrial 2d reflection seismic dataset calibrated by wells and onshore outcrops that have been revaluated in age biostratigraphy in order to discuss the evolution of the south african plateau uplift the first order evolution of the margin is tectonically driven and can be divided into three principal phases the first 131 93 5 ma comprises an overall retrogradational trend that results from a rate of accommodation created by the thermal flexure of the margin that is higher than the sediment supply the second 93 5 66 ma comprises an overall aggradational progradational trend that results from a relative increase in sediment supply due to an uplift and subsequent erosion of the margin and the inland domain the third 66 0 ma is retrogradational again in response to a decrease in sediment supply induced by a relative stability of the margin and climate conditions this study demonstrates that the present day configuration of the margin is acquired during the late cretaceous from 81 to 66 ma with a strike long wavelength and seaward tilt of the margin which could be related to the growth of the onshore main escarpment we also characterize a regional oligocene unconformity marked by a significant downward shift of the shoreline which suggests a moderate uplift of the inland domain and could be associated with a reactivation of the relic late cretaceous relief

mineralogy and micromorphology of a late neogene paleosol sequence at langebaanweg south africa inference of paleoclimates abstract paleosol sediment sequences at the west coast fossil park in langebaanweg south africa have a stratigraphy extending over ten units occupying a total depth of 18 m ranging in age from mid miocene to holocene six of these units qualify as paleosols the mineralogical assemblages and micromorphology of the paleosols and pedofacies have been studied with the objective of interpreting and reconstructing the paleoenvironments of the area physico chemical parameters mineralogical properties and micromorphology described from thin sections of the paleosols and pedofacies were analyzed using routine laboratory methods the units are named following the fao and soil survey staff classification systems an alternating stack of paleosols and sediments preserve repeated phases of paleoenvironmental changes rhizoliths in the pleistocene ck layer lend credence to a shallow standing paleowatertable during the pliocene remarkable differences are observed in the mineralogy of the paleosols and sediments paleosols of the middle miocene have mixed clay mineralogy of halloysite chlorite muscovite mica and kaolinite an indication that the clay sources could have either formed pedogenically or from different parent materials which may have taken place during transportation allophane and imogolite in the early pliocene paleosols are most likely to be stream deposited while palygorskite and sepiolite indicate dry paleoclimates vertic properties of the paleosols were observed from their open porphyric c f related distribution blocky microstructure and striated b fabrics properties including calcareousness vertic gleyic illuviation suggest cyclic patterns of erosion and deposition which correlates with paleoenvironmental and climatic changes the observed pedofeatures indicate the reddish mid miocene paleosols and pliocene pedogenic carbonates possibly formed under subtropical and mediterranean climate conditions while the pedosediments reflect a semi arid climate

miocene climate and vegetation changes in the cape peninsula south africa evidence from biogeochemistry and palynology organic material from the noordhoek area on the western margin of the cape peninsula south africa was obtained from a 50 m long drill core dominated by fluvio lacustrine siliciclastic sediments the aim of this study is to constrain fluctuations in climate and the decline of tropical vegetation elements along the southwestern coast and the cape peninsula of south africa during the late cenozoic phase when the benguela upwelling system was established the approach was to combine palynological biogeochemical tetraether lipids and stable isotope c n studies of the organic bearing record from the noordhoek area on the western margin of the cape peninsula bulk c and n isotope data of sediment organic matter point to a predominantly c3 higher plant source vegetation mean annual air temperature mat from the analyses of tetraether lipids mbt cbt index was compared with palynomorphs from partly unpublished data of a previously drilled core adjacent to the study site the palynomorphs are of subtropical affinities and suggest that an open riparian forest would have existed in the early to middle miocene of the southwestern coast of south africa together these data sources allow vegetation and climate reconstructions of subtropical conditions during the early to middle miocene which comprised fluctuating open riparian forest and swamp vegetation temperatures rose in the middle miocene and were higher than those of the present day

regional and global context of the late cenozoic langebaanweg lbw palaeontological site west coast of south africa the palaeontological site of langebaanweg lbw is internationally renowned for its prolific diverse and exceptionally well preserved mio pliocene vertebrate faunas the site is located on the southern west coast of south africa which represents a passive intraplate trailing edge setting the southern african subcontinent is also removed from glacial influence and has experienced no cenozoic volcanic activity rates of vertical crustal motion are consequently low and late cenozoic shoreline datums at lbw chiefly reflect glacio eustatic sea level history the primary aim of this study is to clarify the chronology as well as the regional and global context of lbw and to review previous work on these aspects lbw is ideally situated to document the complex interactions of ocean atmosphere and land and their respective influence on climate evolution given its location near the coast and mix of marine estuarine and terrestrial faunas and depositional settings this paper also provides a background to the study of the vast existing faunal collections and a guide to undiscovered fossil deposits towards these ends the first detailed geological topographic maps of the site and surrounds accompanied by a summary stratigraphic column are provided virtual geological modelling using a subsurface database has clarified the spatial and temporal relationships of sedimentary facies as well as their depositional settings the geological and palaeontological record at lbw tracks and documents the major regional and global climatic oceanographic events of the late cenozoic during the oligocene drawdown in sea levels the landscape was etched by river incision fluctuating sea levels of the neogene periodically reversed the trend from erosion to deposition preserving contemporary faunas and floras in the oligocene palaeovalleys earlier miocene pollen from fluvial facies indicates a humid sub tropical climate reflecting a warm southern atlantic ocean the abrupt late middle miocene global cooling monterey excursion coincided with intensified cold upwelling in the benguela current and extensive phosphate authigenesis a globally documented early pliocene highstand possibly related to the shoaling of the isthmus of panama reached 90 m above sea level asl implying extensive melting of the cryosphere palaeomagnetic data in tandem with global sea level reconstructions suggested an age of 5 15 0 1 ma for the faunas and a correlation with the earlier part of this transgression a subtropical c3 vegetation is indicated by the faunas and floras but with a significant contribution by sclerophytic fynbos pointing to a cooler and more seasonal climate than in the miocene a mid pliocene highstand to 50 m asl truncated the early pliocene succession at lbw and the globally documented late pliocene highstand to 30 m asl saw the atlantic shoreline approaching lbw for the last time with the progressive climatic cooling and instability of the terminal pliocene culminating in the growth of the arctic ice cap strengthening southerly winds driven by a tighter coiled south atlantic anticyclone deposited extensive coastal dune fields over the region

community evolution of neogene micromammals from langebaanweg e quarry and other west coast fossil sites south western cape south africa abstract this paper provides an overview of the micromammalian palaeocommunities found in fossil bearing palaeontological and archaeological west coast sites dating from the mio pliocene as represented by the site of langebaanweg e quarry and other sites dating from the late middle pleistocene until the late holocene recent excavations at langebaanweg have resulted in the addition of more murid genera to previously compiled faunal lists an updated faunal list is presented and a comparison is made on a generic level between the micromammals from langebaanweg and the considerably younger west coast fossil sites of elands bay cave steenbokfontein cave the saldanha bay yacht club site and hoedjiespunt 1 and some modern owl pellet collections the palaeobiogeographical and palaeoenvironmental significance of the different west coast micromammal communities and the evolution of the west coast rodent community is examined nine of the micromammal genera found at lbw are present in some or all of the west coast fossil sites dating from the late middle pleistocene until the holocene this indicates the endurance of many of the genera present at lbw and in the kalahari south west arid and namib regions from the mio pliocene up until the present

discussion evidence for a transgressive barrier within a regressive strandplain system implications for complex response to environmental change by hein et al 2013 sedimentology 60 469 502

effect of the formation of the isthmus of panama on atlantic ocean thermohaline circulation the late cenozoic closure of the seaway between the north andsouth american continents is thought to have caused extensive changes in ocean circulation and northern hemisphere climate1 2 but the timing and consequences of the emergence of the isthmus of panama which closed the seaway remain controversial1 2 3 4 5 here we present stable isotope and carbonate sand fraction records from caribbean sediments which when compared to atlantic and pacific palaeoceanographic records indicate that the closure caused a marked reorganization of ocean circulation starting 4 6 million years ago shallowing of the seaway intensified the gulf stream and introduced warm and saline water masses to high northern latitudes these changes strengthened deep water formation in the labrador sea over the next million years as indicated by an increased deep water ventilation and carbonate preservation in the caribbean sea and favoured early pliocene warming of the northern hemisphere the evaporative cooling of surface waters during north atlantic deep water formation would have introduced moisture to the northern hemisphere although the pronounced intensification of northern hemisphere glaciation between 3 1 and 2 5 million years ago substantially lagged the full development of north atlantic deep water formation we propose that the increased atmospheric moisture content was a necessary precondition for ice sheet growth which was then triggered by the incremental changes in the earth s orbital obliquity

sea surface temperature fluctuations during the holocene off the south coast of africa implications for terrestrial climate and rainfall models of southern african palaeoclimate implicate surface atmospheric circulation anoma lies as forcing large scale changes during the late quaternary the available proxy data are insufficient to test the models since they provide information about temperature and rainfall rather than surface circulation a conceptual model is proposed which links coastal ocean temperatures with atmospheric circulation and allows a history of surface circulation to be inferred from sea temperature data a holocene sea surface temperature sst record was constructed by measuring the oxygen isotope composition of marine mollusc shells preserved in an archaeological cave deposit on the coast of the eastern agulhas bank southern africa radiocarbon dating of individual shells allowed definition of the timing and timespan of events in the record by serially sampling along the growth axis of each shell information was obtained about intra annual variability as well as millennial scale trends during the early holocene th