short paper detrital mineral ages from the southern uplands using 40ar 39ar laser probe detrital mica ages in the southern uplands range from 458 to 502 ma the evidence favours a source in a basement which was part of an arc complex to the north rather than from the dalradian block which also has mica ages of this range no grenville ages have yet been recorded detrital volcanic clasts dispersed from the south have cooling ages of 560 and 530 ma indicating that they did not come from a contemporary arc but an older arc terrane of uncertain affinities

fossils from quaternary fluvial archives sources of biostratigraphical biogeographical and palaeoclimatic evidence fluvial sedimentary archives have the potential to preserve a wide variety of palaeontological evidence ranging from robust bones and teeth found in coarse gravel aggradations to delicate insect remains and plant macrofossils from fine grained deposits over the last decade advances in quaternary biostratigraphy based on vertebrate and invertebrate fossils primarily mammals and molluscs have been made in many parts of the world resulting in improved relative chronologies for fluviatile sequences complementary fossil groups such as insects ostracods and plant macrofossils are also increasingly used in multi proxy palaeoclimatic and palaeoenvironmental reconstructions allowing direct comparison of the climates and environments that prevailed at different times across widely separated regions this paper reviews these topics on a regional basis with an emphasis on the latest published information and represents an update to the 2007 review compiled by the flag inspired igcp 449 biostratigraphy subgroup disparities in the level of detail available for different regions can largely be attributed to varying potential for preservation of fossil material which is especially poor in areas of non calcareous bedrock but to some extent also reflect research priorities in different parts of the world recognition of the value of biostratigraphical and palaeoclimatic frameworks which have been refined over many decades in the core regions for such research particularly for the late middle and late pleistocene of nw europe has focussed attention on the need to accumulate similar palaeontological datasets in areas lacking such long research histories although the emerging datasets from these understudied regions currently allow only tentative conclusions to be drawn they represent an important stage in the development of independent biostratigraphical and palaeoenvironmental schemes which can then be compared and contrasted

the provenance of granite boulders in conglomerates of the northern and central belts of the southern uplands of scotland rb sr whole rock isochrons from several suites of granite boulders which occur in ordovician and silurian conglomerates in the southern uplands of scotland yield ages of around 1200 ma 600 to 700 ma and 470 to 490 ma the plutonic and tectonic history recorded by these clasts corresponds more closely with that of nw newfoundland than with that of scotland the petrography of the clasts can also be matched with exposed granite plutons in newfoundland since the conglomerates were derived from the nw it is concluded that the southern uplands lay to the se of newfoundland a total of 1500 km strike slip displacement occurred between the caradoc and the early devonian consistent with oblique subduction of the iapetus ocean below the north american continental margin

the oldest handaxes in europe fact or artefact abstract hominin presence is well documented in a number of early pleistocene and early middle pleistocene european localities however the evidence currently available indicates that acheulean handaxes spread in the fluvial basins of western europe during mis 11 400 kyr ago associated with homo heidelbergensis although a number of early middle pleistocene acheulean assemblages have been dated from mis 16 onwards for this reason the magnetostratigraphic dating in southeast spain of two archaeological localities the open air site of solana del zamborino sz and the rock shelter site of cueva negra del estrecho del quipar eq that put back the appearance of handaxes to the early middle pleistocene limit scott and gibert 2009 is of particular interest as the new ages suggest that h heidelbergensis was a contemporary of h antecessor that had the ability to produce levallois debitage and to control fire during the early middle pleistocene transition however we have detected a number of errors in the interpretation of the archaeological assemblage from the first site as well as striking discrepancies with the original faunal lists published for both localities with several large mammal species that are omitted or arbitrarily changed to make the assemblages consistent with the new ages deduced from magnetostratigraphy for this reason we suggest that 1 the finding of reverse polarity in the sediments sampled for paleomagnetism in sz may simply record one of the polarity reversals that took place during the brunhes chron although the use by scott and gibert 2009 of a composite stratigraphic column precludes correlating these levels with a specific reversal and 2 the fauna and tools of eq correspond to the late middle pleistocene sedimentary infillings of this karst site while the samples taken for paleomagnetism belong to a previous sedimentary cycle during the matuyama chron such interpretations would be in better agreement with the age estimates provided by biostratigraphy and also with the currently accepted chronology for the appearance of acheulean industries in western europe

evolution of the northern belt southern uplands implications for the southern uplands controversy conodont and graptolite dating provide a high resolution biostratigraphical framework for correlation across the southern upland fault the establishment of an early caradoc age for the red chert and volcanic sequences within the northern belt of the southern uplands confounds the accretionary prism model and our data support the view that following the obduction of the ballantrae ophiolite fan complexes prograded southeastwards across a narrow fault bounded shelf into the deep basin of the northern belt the fan complexes were initiated by uplift in the hinterland caused by the intrusion of plutons into the midland valley terrane sedimentation was controlled by regional extension subsidence and eustasy through the llanvirn and caradoc basic lavas with attenuated within plate geochemical signatures were erupted during the early caradoc peak of extension and may have just post dated the initiation of southwards subduction beneath the lake district

mesozoic and cenozoic deformation inferred from seismic stratigraphy in the southwestern intracontinental palmyride fold thrust belt syria this paper was published in the geological society of america bulletin the geological society of america retains the copyright to this paper geological society of america p o box 9140 boulder co 80301 9140 usa see also http www geosociety org http atlas geo cornell edu syria chaimov gsa bull 1992 html

garnet provenance studies juxtaposition of laurentian marginal terranes and timing of the grampian orogeny in scotland a study of the composition and zoning patterns of detrital garnets from ordovician greywackes from the northern belt of the southern uplands terrane of scotland reveals characteristics of the metamorphic sources very similar to the dalradian supergroup of the scottish grampian terrane the radiometric cooling and uplift ages of the dalradian metamorphic zones and the depositional ages of the southern uplands greywackes support the hypothesis for local provenance detrital metamorphic garnet identical to dalradian garnet has also been identified in the upper ordovican sandstones of the highland border complex these observations do not support proposals that the grampian midland valley and southern uplands terranes were exotic to each other in the late ordovician time these new results together with a review of published age dates clarify the late ordovician palaeogeography for this part of the laurentian margin the distances between the grampian midland valley and southern uplands terranes may have been similar to the present day it is concluded that large rivers flowed out of the uplifting mountainous grampian terrane and across the midland valley into a southern uplands trench during the late ordovician time the main orogeny i e mountain building in the grampian terrane was therefore post cambrian producing the first high mountains and resultant flysch in the caradoc

a geometric morphometric assessment of three dimensional models of experimental cut marks using flint and quartzite flakes and handaxes abstract developments in methodological approaches to high resolution morphometrical study of cut mark morphology further our understanding of butchering activities identification of micro morphological variability between different taphonomical alterations on ancient bone allows detection and comparison of bone surface modifications and associated taphonomical agents and activities by taking a geometrical morphometrical approach data from 3 d laser scanning and micro photogrammetrical models of experimental cut marks enable statistical analysis to classify and distinguish between cut marks by bifaces from those by flakes and in each case between marks made by flint from those made by quartzite tools analysis of two tool types each made from two raw materials as independent variables is a methodological advance in morphometrical studies of experimental cut marks which hitherto have tended to focus on the respective parts played by tool types or types of raw material in morphometrical characterization of experimental and archaeological cut marks

new data from ambrona closing the hunting versus scavenging debate abstract this paper presents a taphonomic analysis of the faunal assemblages from the 1993 1999 excavations at ambrona spain directed by santonja and perez gonzalez the purpose of the new excavations was to achieve a better understanding of the stratigraphic sequence general geology sedimentary context and processes of accumulation of materials our objectives are to evaluate the opposing interpretations of the hominid subsistence activities at the site proposed by freeman and binford the faunal and lithic remains are found in different sedimentary contexts an alluvial fan lacustrine muds fluviatile clay sands and channel deposits faunal remains in the lacustrine muds are often but not always in primary context remains of elephant and deer carcasses may be found in partial articulation or proximity and represent natural occurrences without any clear evidence of hominid intervention in other contexts the faunal remains are occurrences of single anatomical elements either displaced by water or left isolated in situ there are no carnivore marks bones and stone artifacts show varying degrees of mechanical abrasion due to water transport limited evidence of human action on bones is provided by a few sem verified cutmarks and some anthropic fractures they document butchery of various animals including elephants we cannot prove hunting but we can definitely reject binford s idea of marginal scavenging of medium size ungulates from carnivore kills ambrona is a complex mix of natural and human components the remnant of a natural landscape regularly visited by hominids who transported some artifacts from nonlocal raw material sources and had an organized approach to meat acquisition however strong evidence of elephant hunting is provided only by sites younger than ambrona

changing competition dynamics among predators at the late early pleistocene site barranc de la boella tarragona spain abstract the late early pleistocene site barranc de la boella provides an unparalleled opportunity to assess the context of the activities of the hominin populations that inhabited the iberian peninsula at 1 ma recently strong evidence for access to mammoth meat has been described at the pit 1 locality at the la mina and el forn excavation areas little evidence exists for the anthropogenic processing of macromammals however the presence of humans is recorded and the available evidence suggests these populations had access to several interesting resources by analysing and comparing five separate assemblages at barranc de la boella we assess the fluctuating presence of hominins and carnivores and the levels of competition among predators in each assemblage our analysis reveals different levels of competition intensity during the formation of assemblages when hominin groups were present as evidenced by the abundance and diversity of stone artefacts the analyses of skeletal component ratios indicate several competitive contexts and the greatest presence of hominin groups is associated with the most competitive scenarios the palaeoenvironment at barranc de la boella was rich in resources that hominins could exploit the presence of hominin and carnivore groups appears to have been higher in levels with more inferred competition this scenario supports prior research that concludes that carnivore abundance and highly competitive contexts were two constants in the lives of these hominin groups thus the criteria determining whether hominins could inhabit a given landscape were most likely related to the presence or absence of resources such as animal resources water and raw materials rather than the dynamics of the carnivore populations to which the hominins were able to become habituated

ordovician faunas in mass flow deposits southern scotland in the ordovician northern belt of the southern uplands basal volcanics arenig are followed by cherts llanvirn llandeilo then by graptolite shales llandelio lower caradoc and finally by caradoc greywackes within the greywackes kirkcolm formation are a number of occurrences of fossiliferous conglomerate and overlying mudstone these can be traced along strike for some 30 km the conglomerates and especially the mudstones yield rich mid caradoc shelly assemblages brachiopods 20 spp trilobites 14 spp gastropods bivalves bryozoans and the first known palaeozoic scleractiniamorph coral these occurrences are interpreted as mass flow deposits derived by downslope movement from a now vanished shelf to the north and may belong either to a single gigantic debris flow event or to a series of smaller but roughly contemporaneous flows strong faunal similarities to faunas at girvan western scotland and tyrone northern ireland lying north of the southern upland fault may suggest sinistral strike slip movement of no more than a few hundred kilometres

early european mode 2 and the stone industry from the caune de l arago s archeostratigraphical levels p abstract the stratigraphical complex of the caune de l arago cave site france pyrenees orientales has been systematically excavated for over 40 years in 1981 foraging in the deposits revealed a 15 m thick quaternary infill with artefacts present throughout the stratigraphy all the way down to the basal stalagmitic floor 0 69 ma the infill most of which is correlated to mis 14 13 and 12 has yielded numerous distinct occupation floors exceptionally rich stone implements and animal fossils while some of the levels have also yielded hominin remains attributed to homo heidelbergensis over the years intensive interdisciplinary studies have contributed to defining the characteristics of these middle pleistocene occupations recently excavations have reached the so called p levels attributed to a series of occupation floors accumulated during short term stays by hominin groups during a cold dry phase of mis 14 artefact bearing levels are found intercalated between archeologically sterile sediments relatively rich in carnivore remains among the numerous large pleistocene mammals identified in the p levels horse reindeer and bison are most frequent in artefact yielding floors while argali brought into the cave by carnivores bear and panther remains are common in intercalating levels the study of the p levels stone assemblage provides new information about raw material selectivity technological behaviour and typological characteristics for one of the oldest known western european mode 2 industries it is interesting to consider the precise handiwork and care with which raw materials were selected for the confection of the fine quality instruments typical of the p levels assemblages whose acheulian character is underlined by a relative abundance of symmetrical and remarkably well worked handaxes the p levels industries seem to bear witness to long acquired technological capacities inherited perhaps from earlier african or eurasian populations

provenance of lower old red sandstone conglomerates se kincardineshire evidence for the timing of caledonian terrane accretion in central scotland northerly derived conglomerates dominate much of the thick lower old red sandstone ors succession of the ne midland valley of scotland these contain a diverse suite of granitoid boulders the provenance of which can be used to constrain the timing of the post caradoc displacements which juxtaposed the highland border complex against the grampian terrane rb sr muscovite whole rock ages for two mica granite boulders from the crawton group are 473 457 ma confirming the persistence of an ordovician two mica granite source first recognized in the dunnottar group the rb sr muscovite ages are supported by a u pb age of 475 5 ma for monazite separated from one of the clasts a rb sr biotite age of 412 4 ma for a clast of porphyritic biotite granite and geochemical evidence linking this clast to many of the other biotite granite clasts suggests that late silurian granitoids and related hypabyssal intrusions have also made an important hitherto unrecognized contribution to the conglomerates mica whole rock ages for accompanying psammitic clasts suggest the source included metamorphic rocks of up to at least staurolite grade whose uplift overlapped with the intrusion of crustally derived melts the chemistry chronology and sr and nd isotopic compositions of the various igneous clasts are shown to resemble closely the ordovician through to silurian magmatic history of a small area of the grampian terrane in ne scotland this is taken as strong evidence for a pre lower ors juxtaposition of the highland border complex and the grampian terrane to within several tens of kilometres of their present position ashgill silurian terrane displacements are invoked to achieve this discrepancies in the proportions and types of clast occurring in the conglomerates are explained by uplift and unroofing of the grampian terrane prior to docking the involvement of polycyclic sediment perhaps as a local veneer of pre existing sediment on the grampian terrane and the likelihood that the source involved parts of the local grampian terrane which are no longer exposed

detrital avalonian zircons in the laurentian southern uplands terrane scotland the silurian ordovician southern uplands terrane occupies a key position in the caledonian orogen yet its genesis is controversial marginal basin backarc and forearc tectonic regimes have all been invoked as operative at the laurentian margin of the iapetus ocean fresh andesitic detritus within turbidite sandstones has until now been assumed to provide evidence for an ordovician suprasubduction volcanic arc a central feature of most models however high precision thermal ionization mass spectrometer u pb and laser ablation data for detrital zircons from the sandstone prove neoproterozoic volcanism at 557 6 ma 2 and probably also at 613 12 ma 2 the complex crystallization history recorded by the zircons shows assimilation of 1043 7 ma 2 grenvillian basement into the andesite magma the fact that no zircons have been found having ages that overlap the caradocian depositional age of the host sedimentary rocks undermines all extant terrane models the age profile of the detrital zircons is typical of gondwana and avalonia this finding has important implications for the paleogeography of the iapetus ocean during the ordovician because the zircon data require the introduction of avalonian detritus into a sedimentary basin marginal to laurentia

displaced terranes in britain and ireland a meeting entitled displaced terranes in britain and ireland was held at burlington house on 2 november 1988 this was the third terranes meeting held in britain since the inception of international geological correlation project no 233 terranes in the circum atlantic palaeozoic orogens the others having been held at cardiff in 1986 and glasgow in 1987 igcp 233 grew out of igcp 27 the caledonide orogen many of the developments promoted by which are recorded within two special publications of the geological society harris et al 1979 harris fettes1988 over the last few years research on displaced terranes in the british caledonides has accelerated with new data now challenging what have become traditional applications of plate tectonic theory to the british caledonides the reports of work in progress on caledonian terranes and it was thought appropriate to take advantage of the rapid publication facilities afforded by the short papers scheme because of the four page limit on short papers much introductory material has had to be omitted so that we provide here an introduction to the concept of displaced terranes and its applications to british palaeozoic geology displaced terranes the essential value of the terrane concept lies in its recognition of the likelihood of large scale lateral fault movements occurring along active plate margins the concept of terrane tectonics is therefore no more than a fuller appreciation of the kinematic implications of plate tectonic theory the impact of this recognition upon our perception of geotectonic processes in general and the

fluvial deposits as an archive of early human activity progress during the 20 years of the fluvial archives group fluvial sedimentary archives are important repositories for lower and middle palaeolithic artefacts throughout the old world especially in europe where the beginning of their study coincided with the realisation that early humans were of great antiquity now that many river terrace sequences can be reliably dated and correlated with the globally valid marine isotope record potentially useful patterns can be recognized in the distribution of the find spots of the artefacts that constitute the large collections that were assembled during the years of manual gravel extraction this paper reviews the advances during the past two decades in knowledge of hominin occupation based on artefact occurrences in fluvial contexts in europe asia and africa as such it is an update of a comparable review in 2007 at the end of igcp project no 449 which had instigated the compilation of fluvial records from around the world during 2000 2004 under the auspices of the fluvial archives group an overarching finding is the confirmation of the well established view that in europe there is a demarcation between handaxe making in the west and flake core industries in the east although on a wider scale that pattern is undermined by the increased numbers of lower palaeolithic bifaces now recognized in east asia it is also apparent that although it seems to have appeared at different places and at different times in the later lower palaeolithic the arrival of levallois technology as a global phenomenon was similarly timed across the area occupied by middle pleistocene hominins at around 0 3 ma

tectonic map and geologic evolution of syria the role of gis this paper was published in the journal the leading edge by the society of exploration geophysicists seg retains the copyright to this paper see also http www edge online org http atlas geo cornell edu syria brew tle 2000 html

paleomagnetic results from volcanic rocks of the shelve inlier wales evidence for a wide late ordovician iapetus ocean in britain abstract in order to shed light on the early paleozoic paleogeography of iapetus bordering continents samples for paleomagnetic study were collected from middle ordovician llanvirn volcanic rocks of the shelve inlier welsh borderland the folding within the inlier is constrained to late ordovician ashgill time thus offering a fold test with tight age brackets after stepwise thermal demagnetization a pre folding characteristic magnetization component was isolated from 95 specimens the mean of 11 site mean directions for the characteristic magnetization gives d i 116 4 67 9 k 89 4 95 4 9 and the paleomagnetic pole lies at 26 6 n 36 1 e p 6 9 m 8 2 the fold test is positive at the 99 confidence level indicating that the magnetization was acquired during the middle or late ordovician we infer from geological considerations that this magnetization is not a primary thermoremanence but was acquired during late ordovician time as a result of a thermochemical disturbance of that age our results indicate that southern britain was near 51 south latitude during the later ordovician since middle to late ordovician paleolatitudes for gondwana and laurentia are well determined our result can be used to test various scenarios for the closure of iapetus we conclude that 1 the iapetus ocean in britain still had a latitudinal width of some 30 at this time thus rendering a postulated ordovician closure unlikely 2 southern britain avalon and hercynian europe all occupied high latitudes during the later ordovician consistent with a paleoposition near the northern margin of gondwana and 3 the acadian orogeny in britain and north america could have been the result of the collision of gondwana and laurentia during early devonian time

ongoing research at the late middle pleistocene site of la polledrara di cecanibbio central italy with emphasis on human elephant relationships abstract the site of la polledrara di cecanibbio latium italy is related to deposits of the pg6 sequence middle pleistocene aurelia formation mis 10 and 9 the sediments are mainly volcaniclastic in composition and constitute the filling of incised valleys mainly characterized by fluvial deposits at the base passing upward to fluvio lacustrine and palustrine deposits containing abundant fossil mammal remains and artifacts the arrangement of the specimens and taphonomic observations suggest that most of the transport of the bones occurred during flooding events followed by progressive swampy phases resulting in the formation of areas with stagnant and muddy waters where some elephants became trapped as indicated by remains in partial anatomical articulation recent excavations carried out at the site permit a better definition of the palaeoenvironmental reconstruction already partially outlined in previous publications in particular an area showing a close correlation between the skeleton of an elephant and human activity allows documentation and better understanding of some aspects of human elephant interaction probably mainly represented by scavenging activity

end silurian modifications of ordovician terranes in western ireland the ordovician elements in the caledonides of western ireland may be divided into the clew bay south mayo north connemara and south connemara sub zones evidence suggests the presence of a number of proximal suspect terranes and the remnants of one or possibly two arc complexes palaeontological and sedimentary evidence suggests an allochthonous relationship between the silurian rocks of croagh patrick and north galway these successions may therefore not represent a single sedimentary overlap to the ordovician suspect terranes end silurian deformation was the result of transpression which was responsible in part for the present configuration of the area s geology deep seated shear zones with fuchsite and gold mineralization were foci for lateral translation concomitant with southward directed thrusting northward directed back thrusts and variable degrees of metamorphism being of higher grade in the north the end silurian event is intermediate between the high grade metamorphism in parts of the appalachians and the non metamorphic silurian sequences of scotland

the acheulean from atapuerca three steps forward one step back abstract in western europe acheulean cultural evidence is well attested by ca 0 5 ma however recent work has proven that it was present earlier at the end of the early pleistocene the timing and mode of the western european acheulean needs still to be investigated and this knowledge appears to be strongly dependent upon data from sites with sufficiently well preserved archeo stratigraphical sequences and or geophysical conditions that guarantee reliable dating the karstic deposits from the sierra de atapuerca burgos spain represent one such case they contain exceptionally long and continuous archeo paleontological deposits that have yielded hominins stone tools and faunal remains from a period covering the late early pleistocene up to the holocene previous work has allowed us to reconstruct the evolution of technology on a local scale from the late early to the middle pleistocene and to situate the appearance of the acheulean more or less simultaneously in the sites of galeria gran dolina td10 and the sima de los huesos at around 0 5 ma after a hiatus of archeological evidence of approximately 300 ka these acheulean assemblages appear in association with hominin fossils that have recently been identified as early members of the neandertal lineage delving further into the description of the acheulean from atapuerca we have recently focused on the technological features that we consider to be of particular evolutionary significance and attempted to identify them in other european key sites of comparable chronologies indeed we identified some internal evolutionary trends which led us to propose that there was a local transition at atapuerca from the acheulean to the early middle paleolithic techno complexes however the chronological setting resulting from the intensive dating programs carried out in the galeria and sima de los huesos sites and especially the correlation of these dates with the ones available from gran dolina td10 confronts us with some apparent paradoxes underlining the need to reconsider the technological interpretation of the lithic technical record from atapuerca while great efforts are being made in dating and analysis at many european middle pleistocene sites as well as in establishing correlations with which to build consistent regional sequences single long continuous and accurately excavated i e over a large surface area archeological successions remain crucial to properly interpret the appearance and evolution of the acheulean throughout europe we further stress the importance of taking into account conditioning factors such as raw material availability environmental constraints and site function issues

is the southern uplands of scotland really an accretionary prism we argue that there is little which demands the accretionary prism model for the widespread silurian rocks of the southern uplands of scotland and ireland with new data from ireland we reinterpret these rocks as the turbidite fill of a successor basin that formed after the subduction of iapetus oceanic crust finally stopped at the end of the ordovician the structure of the basin is a sinistral transcurrent imbricate stack the result of oblique terminal collision of cadomia with laurasia at the end of the silurian

the early acheulean technology of barranc de la boella catalonia spain abstract since 2007 excavations at barranc de la boella tarragona catalonia spain have revealed three localities with rich archaeo paleontological assemblages la mina el forn and pit 1 palaeontology palaeomagnetism and cosmogenic analyses have dated these localities to close to 1 ma the presence of mammuthus meridionalis hippopotamus antiquus stephanorhinus cf hundsheimensis mimomys savini and victoriamys chalinei stand out in the sample of macro and micro mammals the lithic assemblages from the three sites are made up of percussion cobbles choppers chopper cores cores simple flakes and some retouched flakes mainly denticulates and notches in the case of the el forn and pit 1 localities two large cutting tools have been recovered a cleaver like tool and a pick made of hard wearing schist the lithic assemblage of pit 1 which includes several refitting lithic sets is closely associated with the remains of a young adult mammuthus meridionalis in a clear butchering site context this evidence suggests that barranc de la boella is the oldest european early acheulean site and one of the oldest butchering site on the subcontinent during the late early pleistocene the study of the variability among these three localities in similar environmental conditions together with information from other sites are discussed in order to gain further knowledge about the appearance of the acheulean in europe and its continuity or discontinuity in relation to pre existing technologies

the onset and timing of caledonian sinistral shear in county down in the south westerly irish continuation of the southern uplands ample evidence of sinistral transpression includes a the clockwise transection of f 1 folds by s 1 cleavage combined with sub horizontal extension in the cleavage plane b local development of vein arrays deformed by sinistral simple shear and c an abundance of sinistral wrench faults the sinistral movements are dated relative to the local history of caledonian deformation and the intrusion of two suites of caledonian lamprophyre dykes clockwise transection of folds by cleavage is not a feature of the northern belt or of the northern tracts of the central belt in county down its geographic distribution suggests that sinistral transpression was first effective during the accretion of llandovery age tracts mid way south in the central belt sinistral movements continued episodically during the deformation of early pre and post s 1 vein sets and was finally expressed in widespread wrench faulting which continued beyond the date of intrusion of the younger dykes at about 400 ma

a review of the tectonics of the northern middle east region the structure of the northern part of the arabian platform is reviewed in the light of hitherto unpublished exploration data and the presently accepted kinematic model of plate motion in the region the palmyra and sinjar zones share a common history of development involving two stages of rifting one in the triassic jurassic and the other during late cretaceous to early tertiary times deformation of the palmyra zone during the mio pliocene is attributed to north south compression on the eastern block of the dead sea transcurrent system which occurred after continental collision in the north in southeast turkey the asymmetry of the palmyra zone is believed to result from northward underthrusting along the southern boundary facilitated by the presence of shallow triassic evaporites an important nw se cross plate shear zone has been identified which can be traced for 600 km and which controls the course of the river euphrates over long distances in syria and iraq transcurrent motion along this zone resulted in the formation of narrow grabens during the late cretaceous which were compressed during the mio pliocene to a large extent present day structures in the region result from compressional reactivation of old lineaments within the arabian plate by the transcurrent motion of the dead sea fault zone and subsequent continental collision

distinct taconic salinic and acadian deformation along the iapetus suture zone newfoundland appalachians structural mapping in central newfoundland has identified seven distinct phases of deformation d 1 to d 7 the most significant of which are d 1 d 2 and d 4 d 1 involved the formation of a middle and late ordovician southsoutheast directed thrust belt and concomitant development of mylonite and phyllonite a late ordovician to early silurian d 2 thrust and fold belt overprints d 1 mylonitic deformation and is the most distinctive deformation event in the study area late silurian to devonian d 4 is responsible for folds and north northwest directed dextral thrust and reverse faults that overprint d 1 to d 3 structures d 4 structures in central newfoundland include the exploits gander boundary subsequent deformation is generally of local significance only the arc back arc complexes making up the various terranes in central newfoundland are predominantly juxtaposed along d 1 shear zones which include the red indian line our data indicate that terrane boundaries initiated during d 1 may have protracted deformation histories spanning several deformation events this has important implications for the interpretation of terrane boundaries in newfoundland as d 1 terrane boundaries may be interpreted as d 2 or d 4 shear zones depending on the intensity of overprinting or reactivation the deformation history proposed in this paper corresponds closely to that of established appalachian orogenic cycles d 1 is correlated with the ordovician taconic orogeny and involved accretion of arc back arc complexes to the laurentian margin d 2 and d 4 are correlated with the ordovician silurian salinic and silurian devonian acadian orogenies which involved the subsequent accretion of the ganderia and avalonia microcontinents to the laurentian margin respectively

a late precambrian rift related igneous suite in western newfoundland a granite that yields a u pb zircon age of 602 10 ma is associated with mafic and silicic volcanic rocks and metamorphic equivalents near deer lake in western newfoundland the granitic rocks are named the round pond granite and the combined granite volcanic suite is assigned to the hughes lake complex all of the rocks are contained in the hughes lake structural slice that occurs above other allochthonous rocks and the autochthonous cambrian ordovician carbonate sequence of western newfoundland the round pond granite is cut by metadiabase dykes mafic volcanic rocks interpreted as coeval with the dykes occur along the southeast side of the granite a thick sequence of arkosic metagreywackes and psammitic to pelitic schists of the mount musgrave group occurs stratigraphically above the mafic volcanic rocks regional correlations imply that the mount musgrave group is of late precambrian early cambrian age thus setting an upper stratigraphic limit to the age of the hughes lake complex perthitic and

elephants at the middle pleistocene acheulian open air site of revadim quarry israel abstract lower paleolithic faunal and lithic assemblages serve as a major source of information on the behavior and capabilities of early and middle pleistocene hominins the multi layered late acheulian site of revadim quarry provides a rare opportunity to study hominin elephant interactions during the late lower paleolithic period in the levant a large proportion of this open air site was excavated ca 250 m 2 and yielded a wealth of lithic and faunal remains in this paper the proboscideans from revadim are presented for the first time within the broader geomorphological stratigraphic and archaeological context in order to allow a better understanding of elephants within the acheulian in the southern levant the unprecedented quantity of elephant remains at the site is accompanied by large and rich lithic assemblages of special interest are several elephant bones with cut marks and the earliest appearance in the southern levant of bones that seem to have been shaped to resemble tools the site bears testimony to complex exploitation of proboscideans

geochronology of the baie verte peninsula newfoundland implications for the tectonic evolution of the humber and dunnage zones of the appalachian orogen u pb analyses of zircon from the burlington granodiorite suggest intrusion at c 460 465 ma hornblende and biotite from central portions of the pluton record markedly younger sup 40 ar sup 39 ar plateau dates 410 420 ma which are interpreted to date contact metamorphic effects associated with the widespread emplacement of silurian devonian igneous suites northern portions of the burlington granodiorite are polydeformed and regionally metamorphosed hornblende and biotite from this terrane yield sup 40 ar sup 39 ar plateau ages of 345 350 ma u pb analyses of zircon from the dunamagon granite indicate emplacement at c 440 460 ma thereby providing an upper limit for tectonic juxtapositioning of the humber and dunnage zones along the baie verte line similar ages are also recorded by hornblende and biotite throughout northerly portions of the mings bight humber zone and pacquet harbour dunnage zone groups these results indicate that the tectonic evolution of the baie verte line as polygenetic and involved 1 regionally significant tectonothermal activity prior to the middle ordovician and 2 middle to late paleozoic tectonothermal activity centered along easterly segments of the baie verte line the regional metamorphism associated with this orogenic activity altered primary u pb and rb sr isotopic systems within various igneous suites exposed in northeastern portions ofmore the burlington peninsula which may explain some inconsistent geochronological results previously obtained 54 references 6 figures 5 tables less

a sequential back arc and foreland basin thrust duplex model for the southern uplands of scotland thrust imbrication of ordovician and silurian submarine fan sequences overlapping pelagic deposits in the southern uplands has been interpreted in terms of an accretionary prism formed above a nw directed subduction zone structural features invoked to support accretion are not definitive and could be explained in terms of a thin skinned thrusting model new palaeocurrent and compositional evidence from llandeilo to mid llandovery age turbidites in the northern part of the southern uplands proves interdigitation of sediments with strongly contrasting petrography turbidites derived from the south contain significant quantities of fresh andesitic detritus whereas those from the north form more mature quartz rich formations this implies a back arc situation the turbidites being deposited in a basin with a relatively mature continental landmass to the north and a rifted continental fragment containing an active volcanic arc to the south oblique collision of the opposing continental margins of the iapetus ocean during the llandovery caused the cessation of subduction underthrusting of the southern margin initiated a se propagating thrust stack which deformed the back arc basin sequence and may eventually have ramped over the eroded and faulted remains of the volcanic arc a southward migrating foreland basin formed ahead of the rising thrust stack and is now represented by the late llandovery hawick group and wenlock sequences mid to end silurian sinistral strike slip resulted from oblique collision and produced a transpressional regime during which reactivation of deep seated structures allowed the intrusion of lamprophyre dykes and granites

tumbling effects on bone surface modifications bsm an experimental application on archaeological deposits from the barranc de la boella site tarragona spain abstract tumbling is defined as a process in which hyper concentrated flows alter bone remains producing changes in their morphology and original structure although the process is well known little experimental research has focused on describing the effects this process has on bone surface modifications bsm which can subsequently be applied to the fossil record water currents may have played an important role in altering the surfaces of bones from barranc de la boella which were deposited in a deltaic fan context striae of undetermined origin have been documented on bones at the la mina locality and possible cut marks found on bones at pit 1 locality in our experiments both fresh and dry bones with reproduced trampling striae and cut marks were tumbled in a tumbling machine combining different types of movement and proportions of water to sediment the bones were examined after each of the five cycles of the modification process which lasted 30 30 1 h 2 h and 4 h our results show a considerable diminishing of trampling striae while the majority of cut marks were preserved the marks on fresh bones were more severely altered than those on dry bones based on the results of this experiment the marks from pit 1 appear to be morphologically close to the experimentally altered cut marks while the majority of those from la mina are more similar to the altered trampling striae

constraints on arabian plate motion and extensional history of the red sea analysis of the geologic and geophysical data from the western and northern margin of the arabian plate combined with data from the red sea gulf of aden leads to an interpretation of arabian plate motion that supports an episodic extensional history in the red sea and gulf of aden phase 1 extension began in medial to late eocene and was caused by the nw propagation of the reoriented central indian ridge spreading center it stretched and thinned continental crust along numerous wrench and normal faults that reactivated preexisting structures first phase extension stopped when the arabian plate terminally sutured to eurasia in the medial miocene and halted northward movement of arabia relative to africa the combined african arabian plates moved north more slowly constricting and thickening continental crust in the bitlis zagros sutures while the red sea remained technically quiescent and accumulated salt by the early pliocene continued northward movement was accommodated by lateral extrusion of large continental wedges north of the bitlis zagros sutures this allowed arabia to move northward faster than africa and reopen the red sea where phase 2 extension was expressed by seafloor spreading extension within the red sea gulf of aden rift system has been controlled by the interactions and effects of two factors 1 convergent processes between the north margin of the arabian plate and the eurasian plate to the north and 2 northwest propagation of extension associated with the medial eocene reorganization of the central indian spreading center

lower to middle ordovician evolution of peri laurentian arc and backarc complexes in iapetus constraints from the annieopsquotch accretionary tract central newfoundland the annieopsquotch accretionary tract in newfoundland is composed of a series of west dipping structural panels each containing remnants of ophiolitic and arc backarc complexes of laurentian affinity formed during the ordovician closure of iapetus panels were transferred from an upper plate to a lower plate setting during their middle to late ordovician accretion to the laurentian margin and become progressively younger eastward geochronological data indicate a complex and rapid history of generation and accretion of peri laurentian suprasubduction zone rocks the rapid changes in tectonic environments and the complexity of the relationships are analogous to the complex arc backarc relationships observed in the western pacific today the recognition of the peri laurentian provenance of these units based on stratigraphy geochronology isotopes and geochemistry defines the position of the red indian line the fundamental suture zone in the northern appalachians but more importantly enables the development of a realistic tectonic model for the annieopsquotch accretionary tract involving both thrust and sinistral transcurrent displacements the oldest and most inboard unit in the annieopsquotch accretionary tract is the annieopsquotch ophiolite belt ca 480 ma which marks the initiation of subduction outboard of the laurentian margin the lloyds river ophiolite complex ca 473 ma preserves a fragment of younger more mid ocean ridge like backarc oceanic crust than the adjacent structurally overlying annieopsquotch ophiolite belt the lloyds river ophiolite complex originated as a backarc to the buchans group ca 473 ma ensialic bimodal calc alkaline arc the panels containing the annieopsquotch ophiolite belt and lloyds river ophiolite complex were stitched and overlain by ensialic arc rocks of the otter pond complex ca 468 ma immediately after their accretion to composite laurentia together with the structurally underlying buchans group the youngest structurally lowest two panels comprise the elements of the red indian lake group 465 460 ma which record the opening of a backarc basin and the subsequent establishment of a bimodal ensialic calc alkaline arc sequence the observed relationships indicate that the annieopsquotch accretionary tract was generated above a single west dipping subduction zone outboard of the laurentian margin over 20 m y accretion mainly took place in two stages at ca 468 and 450 ma which correspond with the collision between laurentia and the dashwoods ribbon continent and the collision with the peri gondwanan victoria arc along the red indian line respectively both collisions form part of the taconic orogeny the latter late ordovician collision terminated the relatively rapid closure of the main iapetan tract the proposed model is similar to the correlative tracts in the british and irish caledonides and may encourage a new look at the new england appalachians

deep seismic reflection profile across the northern appalachians a marine seismic reflection line across the northeast extremity of the canadian appalachians in newfoundland indicates a collisional suture in the lower crust beneath the central ophiolitic dunnage terrane the thrust and fold belt miogeocline above the grenville basement and the dunnage and gander tectonostratigraphic terranes all appear to be allochthonous with respect to lower crustal basement the gander avalon terrane boundary to the east is a near vertical feature that penetrates the crust the data also suggest that the ancient passive margin of north america extends eastward under the dunnage terrane for about 70 km the newfoundland deep seismic experiment indicates major tectonic differences compared to results for the southern appalachians

the early to middle pleistocene boundary in the baza basin spain abstract the continental vertebrate fauna of cullar baza 1 granada spain occur immediately above the matuyama brunhes polarity boundary and therefore represent an initial record for the middle pleistocene all polarity zones for the late pliocene through middle pleistocene are found in an 80 m section which includes this fossil quarry the existing collection of abundant remains of micro mammals macro mammals and lithic artifacts indicating human activity can now be assigned an earliest middle pleistocene age of 0 75 ma another section 25 km across the neogene baza basin also has the matuyama brunhes polarity boundary however in this case the huescar 1 fossil quarry and the puerto lobo sites are both below the polarity boundary thus representing a record of the late early pleistocene at 0 9 ma differences in micro mammal species across these matuyama brunhes boundaries are significant and justify an approximately coincident biostratigraphic boundary between the biharian and toringian stages

nd isotope study of provenance patterns across the british sector of the iapetus suture the southern uplands greywacke succession scotland accumulated at the laurentian margin of the iapetus ocean it was sequentially incorporated into an imbricate accretionary thrust complex until closure of the ocean thereafter the thrust belt propagated across the suture zone as a foreland thrust belt directed towards the hinterland of avalonia a foreland basin migrating ahead of the thrust belt was the depositional site for the southernmost southern uplands units and the windermere supergroup english lake district a nd isotope study has shown that juvenile ophiolitic detritus was introduced into the oldest mid ordovician southern uplands greywackes before two distinct provenance areas evolved one supply ing juvenile andesitic detritus in addition to a quartzo feldspathic component the other proterozoic and exclusively quartzo feldspathic bimodal composition continued into the early silurian but was overlapped from late in the ordovician by greywackes with intermediate nd isotope composition this was not a sim ple mixing effect since the andesitic component is not represented and the necessary juvenile component comes from granodioritic and felsitic lithologies intermediate end values are then a consistent feature through the silurian both in the younger strata of the southern uplands and in the earliest foreland basin tur bidites of the windermere supergroup the transition suggests cessation of volcanicity and erosion of deeper levels of the provenance terrane s possibly linked to the evolution of the basin system from active margin accretion related to a foreland setting to the north of the southern uplands terrane beyond the southern upland fault a caradoc to wenlock turbidite sequence occupies inliers within the midland valley the older greywackes contain abundant juvenile ophiolite and plutonic detritus in addition to a quartzo feldspathic metamorphic component there are similarities with the most northerly part of the southern uplands from the late ordovician end values systematically decline so that early llandovery midland valley greywackes are exclusively quartzo feldspathic derived from an ancient source indistinguishable in isotopic terms from that periodically supplying the southern uplands in general the llandovery midland valley provenance was significantly more mature than that contemporaneously supplying the southern uplands thereafter the midland valley latest llandovery and early wenlock greywackes contain a higher proportion of a juvenile component and by the early wenlock greywackes from the midland valley southern uplands and lake district terranes are similar in terms of end a common provenance seems likely and suggests that by the mid silurian all three terrenes were in close proximity

palaeomagnetism of silurian sediments in w ireland evidence for block rotation in the caledonides summary a palaeomagnetic study of mid silurian wenlock sediments of the salrock formation in nw galway yields a reliable silurian palaeomagnetic pole position for w ireland at latitude 1 6 s longitude 287 7 e dp 2 5 dm 4 6 n 27 sites a further 12 sampling sites were located in silurian redbeds on clare island s mayo where a palaeomagnetic remanence of silurian age was also identified both remanences pre date local late caledonian folding however the clare island result has an anomalous azimuth when compared with the salrock result and with published silurian results for britain the two irish results can be reconciled by anticlockwise block rotation of the clare island region through 40 50 the rotation brings both palaeomagnetic and structural trends within the two sampling regions into alignment strike slip displacement across the clew bay fault zone producing a sinistral shear couple might have enabled such a rotation the timing and geographic extent of the proposed block rotation is as yet poorly defined however a younger age limit for rotation is provided by a late devonian or carboniferous partial magnetic overprint observed throughout both study areas and from geological evidence it seems likely that rotation is confined to the clew bay fault zone the dalradian rocks of the connemara massif located to the south of the salrock district have an e w structural grain some workers have proposed clockwise rotation of the connemara massif of ca 30 at between 500 and 390 ma which would bring the structural trends in w ireland into parallelism with caledonian trends in scotland because the silurian salrock succession which rests unconformably on the dalradian basement of connemara shows no such anomaly it provides a younger age limit for the possible rotation of connemara

tectonic evolution of the ne palmyride mountain belt syria the bishri crustal block investigation of the bishri block centrally positioned amid the diverse tectonic and structural zones of syria reveals details of the intraplate phanerozoic development of the northern arabian platform the bishri block is a broad ne plunging inverted basin located at the ne portion of the palmyride mountain belt where the mountains intersect the euphrates fault system well and seismic data show that subsidence and sedimentation in the bishri area was generally continuous from carboniferous to paleocene time with the bishri block part of the extensive palmyride sinjar trough major bounding faults and a rift type environment are documented in the permo triassic jurassic and cretaceous the present bishri structural and topographic high has been formed through transpressive structural inversion since the mid miocene high angle mesozoic bounding normal faults now have net reverse offsets with a significant dextral strike slip component east of the bishri block towards the euphrates fault system nnw sse striking normal faults exhibit less reverse movement this deformation history correlates with the opening and closing of the nearby neotethys ocean that has driven the evolution of intracontinental syria

continental margin evolution of the northern arabian platform in syria copyright aapg 1993 reprinted by permission of the aapg whose permission is required for further use see also http atlas geo cornell edu syria best 1993 html

the provenance and crustal residence ages of british sediments in relation to palaeogeographic reconstructions 24 smnd isotope analyses of fine grained phanerozoic and modern clastic sediments from britain and quebec are presented in combination with published data they have been used to calculate crustal residence ages tcr and to assess the provenance of the british sedimentary mass sediments now preserved on either side of the suture formed by the closure of the iapetus ocean ca 400 ma ago were derived from isotopically distinct source regions sediments north of the suture are characterised by1 7 tcr 2 8 ga whereas those to the south exhibit a smaller range and an average value of 1 6 ga the northern and southern source regions were most probably laurentia and gondwana respectively it seems likely that a third source perhaps baltica provided the lower palaeozoic southern uplands succession sediments deposited in southern britain after the closure of iapetus were derived mainly from the recycling of older sediments the tectonic rearrangements which occurred during the phanerozoic are not reflected in the smnd isotopic structure of the southern british sedimentary mass suggesting that the caledonian and hercynian orogenies and even the grenville orogeny involved minimal accretion of new mantle derived material into the british and adjacent continental crust smnd analyses of fine grained clastic sediments provide a powerful sedimentological tool for elucidating palaeogeography clastic source areas sediment recycling and maturity and some aspects of sediment transport

geometry and kinematic evolution of inversion structures positive inversion structures form by the compressional reactivation of preexisting extensional structures experimental models and observations of natural structures are used to develop quantitative models for the geometry and kinematic evolution of inversion structures in this paper i analyze two main formation mechanisms of inversion structures 1 fault propagation folding on planar faults and 2 fault bend folding on listric faults inversion structures formed by fault propagation folding occur in the southern north sea the central montana platform and the kangean basin during extension a broad fault propagation or drape fold develops above the master fault with the fault subsequently breaking through the fold synextensional growth units deposited in the hanging wall typically thicken into the basin compressional reactivation results in slip reversal on the master and secondary faults their rotation to shallower dips and the development of a compressional fault propagation fold inversion structures formed by fault bend folding on listric faults occur in the taranaki basin and possibly in the southern north sea rollover folding in the hanging wall occurs during extension possibly accompanied by a small component of fault propagation folding in the vicinity of the fault tip deformation is primarily localized along a system of antithetic faults synextensional growth sediments typically thicken into the fault but also show thinning in the immediate vicinity of the fault during compression the extensional fold is first unfolded and then folded into a compressional fault bend fold the characteristic variations in bed geometry and thickness provide predictive models for interpreting the subsurface geometries of these two classes of inversion structures in areas with poor seismic data these models are particularly useful in exploring for structural traps in the complex and relatively unexplored synextensional growth units

barranc de la boella catalonia spain an acheulean elephant butchering site from the european late early pleistocene evidence of late early pleistocene elephant butchery activity has been excavated in the pit 1 locality at barranc de la boella catalonia spain the fossil assemblage mainly comprises the remains of one prime adult individual of mammuthus meridionalis together with 125 lithic artefacts among which several refitting groups of chert have been identified the lithic assemblage from the pit 1 locality is composed of cobbles cores simple and retouched flakes together with a large well fashioned pick of hard wearing schist spatial zooarchaeological taphonomic technical and use wear analyses confirm that the occupation was devoted to butchery of the mammoth carcass the activity zone is in a fluvio deltaic area that incises the terrace t 60 of the lower francoli river basin 50 m a s l palaeomagnetic and cosmogenic analyses as well as microfaunal mimomys savini victoriamys chalinei and macrofaunal biostratigraphy mammuthus meridionalis support the timing of the occupation to the late matuyama chron these various lines of evidence point to barranc de la boella being the oldest early acheulean butchering site in europe ongoing excavations at several localities at barranc de la boella are yielding new data on the palaeoenvironmental geochronological and technological framework of these occupations finally the evidence is integrated into current understanding of the subsistence strategies practised by early pleistocene hominins

sm nd isotopic characteristics of sedimentary provenance the windermere supergroup of nw england nd model ages of windermere supergroup sediments increase from the upper ashgill to the upper ludlow below the lower llandovery increasing t dm reflects mixing between the underlying borrowdale volcanic group and hemipelagic detritus possibly sourced from the lauren tian margin the ongoing rise of t dm into the upper ludlow probably reflects the growing influence of sediment sourced from the scandian orogen a poiadoli drop in t dm is interpreted as recording the re establishment of supply from the local laurentian margin north to south sediment dispersal indicating the effective demise of the iapetus ocean as a barrier to sediment dispersal

the iapetus suture in the british isles the position of the iapetus ocean suture can be traced between ordovician fossil localities in the southern uplands and the lake district which contain respectively distinct north american and european faunas the southern uplands contains north american caradoc faunas in the northern belt and is considered to have been accreted onto the laurentian north american margin between the llandeilo and the end of the wenlock deep seismic reflection profiling shows that a surface probably parallel to the suture zone dips down to the northwest from the solway line in eastern ireland the surface trace of the suture coincides with the navan fault which separates the longford down massif from ordovician sediments containing european faunas the navan silvermines fault may represent the surface expression of the suture but it is masked by wenlock turbidites which appear to have crossed over the plate boundary northward subduction of continental crust below the margin of laurentia during the late silurian may explain the influx of turbidite fans from the north or north west onto depressed crust to the south of the suture termination of subduction coincides with the widespread acadian orogeny in the emsian at 395 5 ma

an ordovician ophiolite in county tyrone ireland ophiolites are regarded widely by geologists as remnants of old oceanic crust that has been obducted onto the continental margins during ocean or marginal basin closure and orogeny therefore they provide evidence for the existence of old oceans and oceanic basins and are a key to the extension of plate tectonic modelling into pre mesozoic rock assemblages in the caledonide appalachian orogen ophiolites are known although very few of these are dated well enough to provide accurate constraints on plate tectonic kinematics we report here the discovery of an ophiolitic sequence within the rocks of the tyrone igneous complex in northern ireland u pb dating combined with field evidence indicates that the tyrone ophiolite was formed and then obducted onto the northern margins of the iapetus ocean close to 470 myr bp arenig

strike slip terranes and a model for the evolution of the british and irish caledonides evidence is presented that many of the major strike faults in the british and irish caledonides were active as sinistral strike slip zones in the end silurian to pre mid devonian period some such as the highland boundary fault moved in this way at an earlier stage in the ordovician these data allow the caledonian rocks lying between the laurentian miogeocline whose basement is represented by the lewisian moine and possibly the dalradian and the gondwanaland miogeocline midland platform and welsh basin to be re analysed as a group of disorganized terranes which originated to the southwest in north america and southwest europe africa prior to the silurian the highland border terrane and northern belt terrane are interpreted as duplicated pieces of a mid ordovician sequence which was a back are to northwest subduction the midland valley terrane is interpreted as a slice of laurentian foreland onto which ophiolites were obducted in the lower ordovician but which became the basement of a continental margin arc to northwest subduction in the mid ordovician the cockburnland terrane is inferred to be part of the same arc repeated and then broken up and dispersed by continuing strike slip the connemara terrane is regarded as an allochthonous piece of the dalradian miogeocline and the south mayo terrane as a remnant of an early ordovician arc and fore arc which in mid ordovician times became a back arc marginal basin to northwest subduction the lake district wexford terrane is part of an arc to southeast subduction under gondwanaland whose activity climaxed in the mid ordovician the central terrane is interpreted as a silurian overstep assemblage which blankets the junction between laurentian and gondwanaland derived oceanic terranes and therefore iapetus is regarded as an ordovician ocean which closed prior to the silurian the model suggests that at the end of the silurian a clockwise rotating gondwanaland having carried laurentia into collision with baltica broke free and created a major sinistral strike slip zone which disrupted the ordovician palaeogeography in the british isles north american sector of iapetus

tectonics and magmatism associated with mesozoic passive continental margin development in the middle east early triassic cretaceous rifting and magmatism occurred along the western edge of the arabian peninsula from egypt in the south to syria in the north associated with the development of the neotethyan passive continental margin which is preserved in the present day eastern mediterranean a change in the direction and rate of extension during the early cretaceous had a profound effect upon the developing continental margin and controlled the pattern of rifting magmatism and sedimentation extensive late jurassic early cretaceous volcanism occurred throughout the region and is clearly rift related major and trace element including rare earth element and sr nd isotopic compositions suggest derivation of the most primitive mafic magmas from an enriched mantle source with minimal evidence of crustal contamination the magmas appear to have ascended rapidly to the surface through large scale faults isopach maps have been constructed for a series of time intervals during the mesozoic using well data from egypt israel iraq jordan lebanon and syria these reveal the distribution and orientation of the main depocentres the main tectonic feature from the late triassic until the late jurassic was a basin which extended northeastwards from northern israel to the palmyrides in central syria by the early cretaceous however deposition switched to a n s oriented basin in central and northern israel and lebanon the distribution of late jurassic early cretaceous magmatism coincides with this new basin and indicates the location of the major extensional fault zones

tephro stratigraphy and the age of ancient southern italian acheulean settlements the sites of loreto and notarchirico venosa basilicata italy the stratigraphic and chronological positions of the palaeolithic sites of loreto and notarchirico have been revised by adopting a litho tephro stratigraphic approach applied to the deposits of the venosa basin relating them to the evolution of volcanic eruptions of mount vulture the notarchirico tephra dated to around 640 ka is a geological marker of paramount importance in the study of ancient southern italia settlements and identifies the assemblage from level f at notarchirico as one of the oldest acheulean in europe

new chronological data esr and esr u series for the earliest acheulian sites of north western europe increasing evidence suggests that bifacial technology acheulian mode 2 arrived in europe during the early middle pleistocene i e significantly earlier than previously proposed in northern france and britain much of the age attribution for these assemblages has been based on biostratigraphy and lithostratigraphy rather than absolute dates this study presents a systematic application of electron spin resonance esr dating of sedimentary quartz and esr u series dating of fossil tooth enamel to key acheulian sites of this area although the age estimates have large associated uncertainties most of the derived dates are consistent with existing age estimates the new chronologies and the problems associated with dating material of early middle pleistocene age are discussed in britain the earliest archaeology cores and flakes mode 1 is older than marine isotope stage mis 15 whereas localities containing acheulian technologies span late mis 15 mis 13 through to mis 9 a similar pattern is seen in northern france although age estimates from sites such as la noira suggest the possible appearance of the acheulian in central france as early as mis 17 the dates presented here support the suggestion that the earliest acheulian appeared in nw europe during the early middle pleistocene significantly after its appearance in the southern parts of the continent

the use of quartz during the lower palaeolithic in northeastern iberia abstract this article analyses the use of quartz as a raw material during the lower palaeolithic in the northeast of the iberian peninsula we studied the use of quartz at 9 sites with chronologies ranging from the end of the early pleistocene to the end of the middle pleistocene quartz was used in all assemblages studied and was always collected close to the sites most of all in the form of pebbles from river basins there was a differential selection of raw materials including quartz according to the technical strategy that humans wanted to implement despite the apparent simplicity of operational schemes carried out using quartz we found factors that point to a remarkable conceptual complexity in the handling of this rock as for example knowledge of the characteristics and mechanical possibilities of quartz and the adaptation of operational schemes to the properties of this raw material

the structure of the western part of the southern uplands of scotland the structures of two areas one in the northern belt and one in the central belt of the southern uplands are described and compared the main structural histories are the same both show a main deformation phase related to se directed thrusting with associated fold and cleavage formation both areas exhibit late minor nw directed thrusting with related refolding and crenulation cleavage development in the case of the central belt both areas also show evidence of sinistral strike slip or transpressive deformation which reactivates steepened thrust faults when these deformation histories are reviewed in the context of geophysical radiometric and biostratigraphical data from the region a forearc accretionary setting for the whole of the southern uplands appears the most likely the strike slip deformation has internally disrupted an accretionary prism but has not juxtaposed originally unrelated terranes the effects of the late silurian closure of iapetus and subsequent events are also represented in the southern uplands

rare earth elements in chert clasts as provenance indicators in the ordovician and silurian of the southern uplands of scotland abstract rare earth element ree patterns in chert clasts provide both an indication of the environment of deposition of the source succession and a means of recognising their provenance the ree compositions of chert clasts in three ordovician and silurian conglomerates in the southern uplands of scotland are compared to the ree fingerprints of their possible sources the ree patterns of the clasts show that they were derived from successions deposited close to a continental margin the absence of clasts with large positive cerium anomalies suggests that the ballantrae complex was not exposed and supplying material to the basin from at least the mid caradoc onwards although a single chert clast from the lower llandovery conglomerate on pinstane hill has an almost identical ree pattern to a black chert from the ballantrae complex a chert clast from a monomict chert conglomerate in the mid caradoc kirkcolm formation has an ree signature identical to that of bedded cherts in that formation indicating an intrabasinal provenance the ree patterns of a chert clast from the caradoc blackcraig formation and of some of the clasts from the pinstane conglomerate lie at the extreme end of those of the bedded arenig and caradoc cherts in the southern uplands but the ree patterns of other clasts from pinstane and one from caradoc ashgill shinnel formation lie beyond this suggesting an extrabasinal source