the molluscs record a tool for reconstruction of the late pleistocene mis 3 palaeoenvironment of the bol shoj naryn site area fore baikal region eastern siberia russia abstract a representative mollusc fauna attributed to the late phase of the karginian interstadial mis 3 has been found in the bol shoj naryn palaeolithic site fore baikal region the general organization of the strata at the bol shoj naryn site has been established through excavations realized during the previous field seasons it shows a modern soil made of sandy loess deposits 1 m thick dated from the sartan glacial stage and underlined by a high viscosity paleosol layers which is up to 1 m thick developed during the karginian interstadial the cultural layer has been correlated with the upper karginian soil contains numerous stone tools and animal fossils this paper focus on the mollusc assemblage attributed to the upper karginian sediment the mollusc assemblage 2460 determined specimens consists of six species and five genera of terrestrial molluscs succinella oblonga pupilla muscorum and vallonia tenuilabris are the best represented species the molluscs suggest the existence of landscapes corresponding with humid meadows and forests located in the relief depressions or along banks of the river molluscs of the bol shoj naryn site have been compared with equivalent mollusc complexes from siberian and southern fore uralian localities they display a distinctive poverty in the species composition and show similarity with the complex of the gornovo locality southern fore urals region comparison of the mollusc complex from the bol shoj naryn locality with molluscs from the last glacial period also showed similarity with the complex of the gornovo locality kudashevo period in the southern urals last phase of the late valdai equivalent mis 2 the climatic conditions which prevailed in the surroundings of the bol shoj naryn locality during the late phase of the karginian interglacial period 32 25 ka bp of the fore baikal region were cooler than those existing at the same time in europe and southern urals correlation between the data obtained after malacological investigations and other paleontological data obtained from palynology and vertebrate records suggest a moderate cold and humid climate in the fore baikal region during the second part of mis 3 with predominance of open landscapes of steppes and relatively limited taiga forest tundra and wetlands

late permian palaeomagnetic results from the brive basin massif central france abstract a palaeomagnetic study has been carried out in the brive basin in order to understand the continental deformation of the french massif central since the permian fifteen sites of permian age red sandstones have been sampled in the brive basin which is situated in the west of the sillon houiller fault france laboratory analyses have revealed well behaved and only reversed magnetic polarity for the higher temperature component the effects of positive folding test and kiaman reversal chron indicate that the magnetic remanent is probably primary the so called autunian and saxo thuringian stages show very close palaeomagnetic directions with an angular difference of 1 2 6 9 they likely correspond to the same geological period i e late permian and allow us to calculate one palaeomagnetic pole for this basin 48 8 n 162 5 e n 15 and a95 2 6 comparing this result with previous palaeomagnetic studies from other permian basins in the south massif central and stable europe we may conclude that 1 the brive basin has been part of stable europe since at least the late permian and no younger palaeomagnetically detectable movement of this basin has be found with respect to stable europe 2 no significant movement along the sillon houiller fault has been detected since the permian the relative latitudinal movement of the permian basins of the massif central i e brive saint affrique and lodeve is negligible no significant rotation for each of these basins with respect to stable europe has been observed except for the st affrique basin this later basin experienced a counter clockwise rotation of 7 with respect to stable europe which represents probably a local phenomenon

late permian palaeomagnetism of northern eurasia data evaluation and a single plate test of the geocentric axial dipole model summary how the first order structure of the magnetic field changed through geological time is one of the most long living and hotly debated questions in geomagnetism for the last 5 ma the geomagnetic field is found to be essentially dipolar with about 5 per cent quadrupole term and possibly still smaller octupole term proving this became possible after accumulation of a large set of globally distributed reliable palaeomagnetic data and their analysis in the coordinates tied to the rotation axis for older times the data are less reliable scarce and unevenly distributed while tectonic motions destroyed the global coordinates in this paper a method to determine the geomagnetic field structure for a single plate is discussed it is suggested that the coordinate system for analysis can be derived from great circles each being drawn through a sampling point and the corresponding palaeomagnetic pole sp circle such circles are to intersect at a true i e pure dipole pole that is largely purified from the contributions of non dipole zonal terms and inclination shallowing the scrutiny of late permian 270 250 ma palaeomagnetic poles from northern eurasia revealed two distinct groups one includes several poles from a limited area in south france sf and the other consists of tightly clustered nine poles from locations spread over a large part of eurasia tentatively the former group can be explained by either rotation of sf with respect to main eurasia or less likely remagnetization in early triassic time irrespectively these poles cannot be used for calculation of the true dipole pole nor for computation of the apparent polar wander path of eurasia the poles from the main part of eurasia were used to find the position of the true dipole pole of this plate and for analysis of the field the minimum of residual dispersion of the observed data is found for the quadrupole and octupole terms of less than 10 per cent when each term is varied separately when both terms are varied together the best fit is observed for the quadrupole and octupole terms of 4 and 12 per cent respectively our analysis shows that the position of the true dipole pole is robust while the estimates of non dipole terms are not we argue that these estimates should be regarded as the upper limits on the non dipole contributions to the late permian geomagnetic field at the same time we are pretty sure that octupole term of 20 per cent or more are not permitted by the data

a palaeomagnetic investigation of a permian redbed sequence from a mining drill core summary samples spanning 66 m of permian redbeds were collected from a vertical but azimuthally unoriented drill core obtained during a uranium exploration programme in the lodeve basin of southern france inclinations are well grouped 6 5 k 121 5 and consistent with the known permian palaeolatitude of europe declinations have been estimated by using a sedimentological model involving tectonically rotated cross bed laminations the results are very encouraging and suggest a pole at 151 e 53 n p 1 m 2 n 43 which agrees well with the eurasian apparent polar wander curve the small polar discrepancy could well be due to secular variation which is consistent with the small variance and presumed short time spanned by the sequence fully oriented surface samples confirm these findings and support the validity of the orientation model temporal variations revealed by the stratigraphic ordering can be interpreted as slow dipole wobble on a time scale of 105 yr or more on which is superimposed a more rapid nondipole secular variation it appears that the core stores of the world could become at least under favourable circumstances an important source of palaeomagnetic information

geomorphic mapping and taxonomy of fluvial landforms abstract fluvial geomorphologists use close to a 100 different terms to describe the landforms that make up riverscapes we identified 68 of these existing terms that describe truly distinctive landforms in which form is maintained under characteristic conditions and fluvial processes clear topographic definitions for these landforms to consistently identify and map them are lacking with the explosion of continuous high resolution topography and digital elevation models we have plenty of new basemaps in which these landforms are clearly visible but very few examples of manual or automated classification of fluvial landforms fluvial landforms are the building blocks of a river and are variously referred to as geomorphic units morphological units habitat units and channel units we present a tiered framework for describing geomorphic units with tier 1 differentiating units on the basis of their stage tier 2 separating shape e g concave convex or planar tier 3 using particular key attributes to narrow in on the likely specific geomorphic unit type and tier 4 differentiating those types on the basis of vegetative or roughness modifiers information on the assemblage and configuration of geomorphic units can be used to inform process based interpretations of the range of river behavior the accuracy and transferability of such analyses is fundamentally tied to the taxonomy we assign to these discrete building blocks in this paper we clarify the terminology and definitions relating to the identification and delineation of geomorphic units margins and structural elements we establish a set of procedures that can be used to manually map and identify these features the proposed framework provides a rigorous and repeatable approach to identification of topographically defined features of riverscapes we demonstrate the application of these systematic yet flexible procedures with a series of maps from rivers in differing valley settings

a comparison of detailed equatorial red bed records of secular variation during the permo carboniferous reversed superchron eve basin southern france also deposited at low latitudes additionally we critically review published data from low latitude permian red beds from the same basins we focus on records with a sufficient number of samples and acquire whenever possible the original data or as a second choice parametrically sampled published site means we test the distributions of these directions using a statistical secular variation field model tk03 gad the angular standard deviation asd of the virtual geomagnetic pole vgp distribution is a measure of palaeo secular variation and we compare our values of asd from the permian red beds to those from lavas erupted in the last 5 myr contrary to our previous studies we now conclude that secular variation during the permo carboniferous reversed superchron is slightly but significantly reduced at low latitudes compared with the recent field as based on a latest compilation that supercedes earlier compilations it also agrees with a new study which found that psv at low palaeolatitudes during the cretaceous normal superchron was also significantly lower than in periods with frequent reversals

palaeomagnetic results from the permian saint affrique basin france and implications for late and post hercynian tectonics abstract palaeomagnetic analyses have been carried out in sedimentary formations of the permian saint affrique basin of france and indicate a late saxonian early thuringian age the dourdou sandstones and at the top of the succession a middle thuringian age the saint pierre pelites important rotations clockwise and anticlockwise respectively on the northern and southern borders of the basin affected the saint affrique area between the late autunian and saxonian the opening of the basin occurred without rotation from the saxonian to the middle thuringian comparison with corresponding results from stable europe and in particular from the neighbouring lodeve basin indicates an anticlockwise rotation of the entire saint affrique area of the order of 7 after the middle thuringian palatine phase or a more recent tectonic event

a review of biostratigraphical investigations of palaeolithic localities in the southern urals region at present there are more than 15 palaeolithic type localities in the southern urals region most of these are located in karst cavities in the mountain area in the flat part of the country palaeolithic type localities are extremely rare and are situated in the deposits of the second river terraces results of biostratigraphical investigations of the main localities are given in this short review

a pure dipole analysis of the gondwana apparent polar wander path paleogeographic implications in the evolution of pangea the paleogeography of prebreakup pangea at the beginning of the atlantic spreading has been a subject of debate for the past 50 years reconciling this debate involves theoretical corrections that cast doubt on available data and paleomagnetism as an effective tool for performing paleoreconstructions this 50 year old debate focuses specifically on magnetic remanence and its ability to correctly record the inclination of the paleomagnetic field in this paper a selection of paleopoles was made to find the great circles containing the paleomagnetic pole and the respective sampling site the true dipole pole tdp was then calculated by intersecting these great circles effectively avoiding nondipolar contributions and inclination shallowing in an innovative method the great circle distance between each of these tdps and the paleomagnetic means show the accuracy of paleomagnetic determinations in the context of a dominantly geocentric axial and dipolar geomagnetic field the tdps calculated allowed a bootstrap analysis to be performed to further consider the flattening factor that should be applied to the sedimentary derived paleopoles it is argued that the application of a single theoretical correction factor for clastic sedimentary derived records could lead to a bias in the paleolatitude calculation and therefore to incorrect paleogeographic reconstructions the unbiased apwp makes it necessary to slide laurentia to the west in relation to gondwana in a b type pangea during the upper carboniferous later evolving during the early permian to reach the final a type pangea configuration of the upper permian 2017 american geophysical union all rights reserved

rock magnetic evidence for inclination shallowing in the early carboniferous deer lake group red beds of western newfoundland summary a paleomagnetic and rock magnetic study of the carboniferous deer lake group red beds of newfoundland was performed to detect and correct for inclination shallowing results indicate a primary remanence carried by magnetite with a mean direction of d 179 7 i 33 7 95 7 2 which corresponds to a paleopole position of 22 2 n 122 3 e a95 7 6 correcting the inclination using anisotropy of anhysteretic remanence and the measured individual particle anisotropy gives a corrected direction of d 178 8 i 50 9 95 6 3 corresponding to a paleopole position at 8 4 n 122 7 e a95 7 2 this correction is larger than that of other red beds from the maritime provinces of canada but is consistent with paleoenvironmental reconstructions placing north america in a more arid climate zone our inclination corrected results have important implications for this portion of north america s apparent polar wander path and suggest a correction is needed for other red bed derived apwps we have determined the range of flattening factors f defined as the proportionality constant between the tangents of the measured i m and field i o inclinations tan i m f tan i 0 from this study and previous inclination correction studies to estimate inclination corrections using the range of haematite f factors observed in this study to correct the neogene red bed inclinations from the vall es pened es basin ne spain yields inclinations consistent with the known geomagnetic field inclination in the neogene thus indicating that the range of f factors reported here may be used to estimate the magnitude of inclination shallowing in red beds

constraining the permian triassic transition in continental environments stratigraphic and paleontological record from the catalan pyrenees ne iberian peninsula abstract the continental permian triassic transition in southern europe presents little paleontological evidence of the permian mass extinction and the subsequent faunal recovery during the early stages of the triassic new stratigraphic sedimentological and paleontological analyses from middle upper permian to lower middle triassic deposits of the catalan pyrenees ne iberian peninsula allow to better constrain the permian triassic succession in the western tethys basins and provide new bio chronologic data for the first time a large vertebra attributed to a caseid synapsid from the middle permian is reported from the iberian peninsula one of the few reported from western europe osteological and ichnological records from the triassic buntsandstein facies reveal a great tetrapod ichnodiversity dominated by small to medium archosauromorphs and lepidosauromorphs rhynchosauroides cf schochardti r isp 1 and 2 prorotodactylus rotodactylus an undetermined morphotype a and to a lesser degree large archosaurians chirotheriids overall suggesting a late early triassic early middle triassic age this is in agreement with recent palynological analyses in the buntsandstein basal beds that identify different lycopod spores and other bisaccate and taeniate pollen types of late olenekian age early triassic the permian caseid vertebra was found in a playa lake setting with a low influence of fluvial water channels and related to the distal parts of alluvial fans in contrast the triassic buntsandstein facies correspond to complex alluvial fan systems dominated by high energy channels and crevasse splay deposits hence a faunal and environmental turnover is observed the pyrenean biostratigraphical data show similarities with those of the nearby western tethys basins and can be tentatively correlated with north african and european basins the triassic pyrenean fossil remains might rank among the oldest continental records of the western tethys providing new keys to decipher the triassic faunal biogeography and recovery

successions of quaternary mollusc fauna in easternmost continental europe southern urals russia the evolution of the mollusc fauna found in the easternmost part of europe was affected by three main stages of development during the quaternary the early eopleistocene mollusc assemblage consists of rare terrestrial and numerous freshwater species with numerous thermophilic pliocene species the late eopleistocene early neopleistocene is characterized by terrestrial and freshwater molluscs with few warm stenothermic pliocene species the early neopleistocene holocene assemblage is characterized by terrestrial and freshwater molluscs of modern affinities

early middle pleistocene mammalian and molluscan assemblages from the novokhopersk locality don river basin russia the central part of the russian plain is famous for its pleistocene deposits this paper describes the geological structure and mollusc and small mammal faunas of one of the most important middle pleistocene localities on the russian plain the novokhopersk the new data on molluscs and small mammals place the novokhopersk fauna directly between the more archaic veretio and ilyinka faunas and more advanced volnaya vershina and kuznetsovka faunas both mollusc and small mammal faunas from the alluvial deposits that underlie the donian till belong to the tiraspolian faunal complex biharian faunal stage and are early middle pleistocene in age among small mammals this placement is confirmed by the presence of mimomys voles along with archaic representatives of terricola and microtus the mollusc fauna contains several extinct gastropod species such as tanousia krasnenkovi borysthenia intermedia viviparus diluvianus and litoglyphus jahni which also indicate that the fauna belongs to the tiraspolian faunal complex further the mollusc fauna indicates moderate climatic conditions and corresponds to the modern boreal fauna the pollen analysis and small mammal data suggest that during that time broadleaf deciduous forests existed on that territory with scattered steppe landscapes which probably occupied the watersheds when compared to central and western european faunas the novokhopersk fauna correlates well with the stranska skala and zlaty kun faunas in the czech republic with the fauna of the betfia 7 locality in romania with the sussenborn fauna in germany with the cromerian sensu lato fauna in great britain and corresponds to mis 18

temporal and spatial patterns of sedimentation within the batture lands of the middle mississippi river usa abstract sediment deposition and storage are important functions of batture lands the land between the channel s low water elevation and the flood mitigation levee however sedimentation processes within these areas are not fully understood in this paper we explore the spatiotemporal patterns rates and volume of sedimentation within the batture lands along the middle mississippi river mmr between the confluence of the missouri and ohio rivers using three approaches 1 comparison of historical to modern elevation data in order to estimate long term 100 yr sedimentation rates 2 estimation of medium to short term 70 attributed largely to sediment trapping by dams during the second half of the twentieth century the increase in mmr batture land sedimentation rates are attributed to at least two potential mechanisms 1 the above average frequency and duration of low magnitude floods 2 yr and 5 yr flood during the short term assessment periods which allowed for more suspended sediment to be deposited within the batture lands and 2 the construction of levees that substantially reduced the floodplain area 75 available for storage of overbank deposits increasing the vertical accumulation and consequently the detectability of a given volume of sediment the gcd estimated batture land sediment volumes were 9 0 of the suspended load at st louis this substantial storage of sediment 8 5 mt yr 1 along the mmr suggests batture lands are an important sink for suspended sediments

palaeoenvironment of the middle and upper neopleistocene at the gornovo upper palaeolithic site southern ural foreland russia abstract complex biostratigraphical methods and radiocarbon dates were used to reconstruct the middle late middle pleistocene and late neopleistocene late pleistocene palaeoenvironments covering the palaeolithic period in the western foreland of the urals the gornovo palaeolithic settlement is located on the lowest terrace of the belaya river from the base to the top this terrace consists of fluvial and lacustrine deposits of the belaya horizon middle neopleistocene 427 364 ka alluvial and lacustrine deposits of the larevka horizon middle neopleistocene 364 334 ka fluvial and lacustrine deposits of the tabulda horizon late neopleistocene 57 24 ka water slope deposits of the kudashevo horizon late neopleistocene 24 11 ka and chernozem soil of the holocene the small and large mammals insects molluscs and ostracods discovered in the deposits complete the palaeoecological characteristics of these periods a diverse herbaceous steppe vegetation dominated during the belaya interglacial a mixed coniferous forests with broad leaved trees occurred in wet areas the ostracoda species clearly indicate a cooling at the end of this time span molluscs inhabited the rivers and shores of freshwater ponds the large mammals belong to the middle pleistocene fauna complex during larevka time span vegetation and fauna indicate cold climate conditions the cold steppe communities typical of the beginning of this period changed gradually into communities that show an increasing role of the taiga the ostracoda species confirm these cold conditions forest steppe landscapes dominated during the second part of the tabulda time span numerous ostracods as well as molluscs populated the lakes and floodplain basins entomological data show that the palaeoenvironment conditions were somewhat cooler than modern environment existing in the southern ural foreland the large mammals of the gornovo site belong to the late palaeolithic complex with the specific presence of camelus sp the gornovo forest steppe small mammalian fauna developed in cool continental climate conditions when coniferous forests grew in the river valleys and when forest steppe landscapes dominated in the water interfluves the artefacts are characteristic of the beginning of the late palaeolithic 32 24 ka the kudashevo time is correlated with the late valdai late late pleistocene 24 11 ka the herbage artemisia chenopodiaceae grassland steppe association covered most of the territory and a picea forest with betula and a small quantity of broad leaved trees grew in wet depressions the climate at the end of this period became colder freshwater and terrestrial molluscs were represented by rare widespread species while the ostracoda species indicate cold conditions

paleomagnetic evidence for rotation during stephano permian extension in southern massif central france we present results of a preliminary paleomagnetic study devised as a test of a tectonic model proposed by van den driessche and brun 1 to interpret the main structural features of the montagne noire south massif central france this model suggests that crustal extension during stephanian to permian times is responsible for a major fiat lying detachment the inferred geometrical relationships between fault azimuth and extension direction is befieved to induce a counter clockwise rotation of the paleozoic cover during its northward motion in order to test this model we have sampled autunian lower permian grey and red sandstone beds within two basins opened during the extension the lod ve and the st affrique basins the paleomagnetic study of six sites three in each basin using thermal demagnetization procedures reveals the presence of 3 magnetization components a first one a which is unblocked below 400 o c is interpreted as a recent overprint due to weathering of the sandstones the b component is unblocked between 400 o and 575 o c this b component is assumed to be primary although the gentle dip of the beds does not allow a fold test it fits the lower permian field direction in the lod ve basin in situ d m 194 i m 6 o k 50 tilt corrected d m 194 i m 10 o k 53 in contrast it shows a systematic difference in declination in the st affrique basin in situ d m 173 i m 2 5 o k 101 tilt corrected d m 172 lm 6 o k 37 this is interpreted as a post autunian counter clockwise rotation of at least 20 o of the st affrique basin thus supporting one of the main implications of the tectonic model finally red sediments from two sites of the lod ve basin yield a third component c with unblocking temperatures up to 670 c and carried by hematite its direction is also consistent with the permian field direction showing that hematite crystallisation occurred early in the diagenesis history of the sediments

paleoenvironment of the fore baikal region in the karginian interstadial results of the interdisciplinary studies of the bol shoj naryn site abstract as a result of integrated researches on two paleolithic sites of the fore baikal region bol shoj naryn and gerasimov s the first representative mammal fauna of the karginian interstadial been dated and characterized that provided the basis for reconstructing the paleoenvironments in the fore baikal region during mis 3 the species composition of the faunal remains recovered from the bol shoj naryn site in the course of five year excavations since 2003 was examined in details since 2010 the cultural layer was studied layer by layer at 5 cm intervals all the artifacts and faunal remains of mollusks birds and mammals being described in addition the lower middle and upper parts of cultural layer were sampled for palynological analysis the geological and paleontological data thus obtained suggest a moderately cold and humid climate in the fore baikal region during mis 3 with predominant open landscapes of steppes and relatively limited areas under taiga forest tundra and wetlands there are abundant data on significant environmental changes in the fore baikal region during mis 3 previously obtained by investigators such as pollen spectra recovered from the lake kotokel bottom sediments or faunal remains including small mammals excavated from the bol shoj naryn site the present study however differs from the earlier ones in that it included multidisciplinary analysis of a large number of faunal and floral remains recovered from the same section and characterizing the same region the data thus obtained from the bol shoj naryn site are extremely important for better understanding of the late pleistocene environments of the fore baikal region

the late palaeozoic early mesozoic from the catalan pyrenees spain 60 myr of environmental evolution in the frame of the western peri tethyan palaeogeography the eastern catalan pyrenees form the southernmost segment of the pyrenean axial zone they experienced complex multistage process as the result of both the variscan and the pyrenean orogenic cycles after the late palaeozoic several small extensional sub basins were filled by continental successions as a response to the changing tectonic setting within the frame of the southwestern europe this stratigraphic record perfectly exposed in the studied eastern pyrenean areas preserves the signatures of the late palaeozoic pangea break up during the progressive dismantling of the variscan chain up to the triassic diffused extension despite structural network being severely affected by cenozoic reworking the stratigraphic framework can be unravelled by the detailed sedimentological and stratigraphical analysis of the well exposed sequences in short this paper addresses facies patterns and architectural elements of late carboniferous permian triassic continental sections studied in the catalan pyrenees and aims to use these signatures for correlation not only at a regional scale but also within the broader picture of the southwestern europe our stratigraphical reconstruction clearly demonstrates that the thick studied succession consists of fluvial lacustrine basal units affected by intense volcanic activity and overlaying predominantly fluvial fining upwards units for each unit several lithofacies architectural elements and bounding surfaces of different order have been identified and their lateral and vertical staking characterized deposition and erosion processes are controlled by alternating periods of tectonic activity producing different stages of high and low subsidence the uplift of the sub basin margins and subsequent extended erosive events marked by angular unconformities on the strength of the major rank bounding surfaces analysis the studied sedimentary packages have been grouped into different tectono stratigraphic units and then correlated they have been contextualized within the latest palaeogeographic reconstructions of the studied sector contributing to detail the role of the study area within the frame of the s european palaeogeography

volcanic maars long quaternary sequences and the work of the inqua subcommission on european quaternary stratigraphy abstract for several years the inqua subcommission on european quaternary stratigraphy seqs has been actively fostering debate on the stratigraphy and typification of the middle pleistocene in europe palynological investigations of deep sediment cores from maar lakes in italy and the french massif central have now provided a stratigraphical framework conclusively correlated with the deep ocean record confirming the occurrence of two clearly temperate intervals between the holsteinian and eemian interglacials this places interglacial deposits from localities such as schoningen pritzwalk domnitz wacken and maastricht belvedere into a clearer perspective all major saalian glacial advances probably relate to oxygen isotope stage 6 reasons for the relative paucity of continental interglacial deposits equivalent to oxygen isotope stages 7 and 9 are discussed these stages were not preceded by major glacial events in northern europe so suitable basins of deposition were largely absent in contrast fluvial erosion was very active with much downcutting and drainage re organisation finally evidence from the sea surface temperature record of the norwegian sea does suggest a less powerful pattern of oceanic circulation in the north atlantic during these interglacial intervals within the saalian complex stage when compared to those of the eemian and holocene this difference would certainly have affected environments on the adjacent european continent

late permian paleomagnetic results from the lodeve le luc and bas argens basins southern france magnetostratigraphy and geomagnetic field morphology paleomagnetic results are presented from 271 stratigraphically ordered horizons at four locations in southern france our focus is mainly on the late permian 258 horizons but results from 13 horizons in the triassic buntsandstein are also reported we argue that the permian results extend magnetostratigraphic coverage up to the upper capitanian stage some 6 million years after the end of the permocarboniferous reversed superchron defined by the illawarra reversal in the wordian stage when combined with published data an overall mean paleopole at 49n 161 e a95 4 n 9 is obtained this is virtually identical to the upper permian pole obtained by bazhenov and shatsillo 2010 using the intersecting great circle method agreement between the two procedures which are based on entirely independent data supports the geocentric axial dipole gad model

biostratigraphy of the upper pleistocene upper neopleistocene of the southern urals abstract this paper is a synthesis of the previously published and unpublished materials dealing with the stratigraphy of the upper pleistocene upper neopleistocene according to the russian stratigraphic scheme of the southern urals it is the second review about the characteristics of the pleistocene deposits of the easternmost part of europe it follows a previous paper concerning the biostratigraphy of the late middle pleistocene of this region the deposits which constitue the regional stratigraphic units are characterized the results of the mammalian malacological and palynological investigations as well as the radiocarbon data provide the basis for the stratigraphical subdivision and the reconstruction of the palaeoenvironments the main geological and biotical events of the southern urals region which took place during late pleistocene are characterized in the paper erosional processes became active at the beginning of kushnarenkovo time when uplift took place in the urals and when the late chosarian regression began on the caspian sea basin territory fluvial deposits can be observed at the base of the second terrace which developed above the floodplain a soil was formed on the subhorizontal surfaces forest steppe and steppe landscapes characterized this interval the climate was warm and humid the saigatka horizon formed under cold conditions slope processes and solifluction were the main relief forming processes and fluvial erosion processes became weaker floodplain sediments accumulated in the river valleys and formed the upper parts of the second terraces above the floodpain which were intensively eroded the plains were covered by steppe and the mountainous areas were occupied by tundra and forest tundra landscapes the next erosional cycle began during the following tabulda period because of the lowering of base level of the erosion and increased uplift of the territory the fluvial sediments now form the lower parts of the first terraces above the floodplain a soil was formed on the watersheds sites contain late palaeolithic artifacts the floral association was close to southern uralian flora of the present day the climate was moderately warm in the plains and drier and cooler in the mountains the subsequent kudashevo event can be correlated with the late glacial when the climate became colder loess like sediments and floodplain deposits form the upper parts of the first terrace above the floodplain and cover the watersheds where they contain cryogenic structures the climate was moderately cold late palaeolithic sites attributed to the kudashevo time are known in the southern urals region the stratigraphical positions of the main upper neopleistocene localities of the southern urals are discussed the southern urals subdivisions are correlated with the western european stratigraphical scheme eemian weichselian interval

flow duration of a dike constrained by palaeomagnetic data summary we have conducted a palaeomagnetic study of a permian red sandstone layer intruded by a 70cm wide plio pleistocene basaltic dike with the ultimate goal of estimating the flow duration of the magma before its solidification 31 samples were collected at various distances from the dike sandstone interface and were thermally demagnetized in order to separate the overprinted pliopleistocene magnetization component from the primary permian one and to determine for each sample the unblocking temperature tub necessary to erase totally the overprint this temperature can be used to determine the maximum palaeotemperature reached at any distance from the contact provided the secondary magnetization is a p trm and the thermal fluctuation effects and actual cooling rates are taken into account examination of various magnetic parameters nrm intensity 15 days vrm intensity initial magnetic susceptibility and hysteresis curves allowed us to establish the nature of the overprinted magnetization and consequently to exclude samples carrying a crm overprint an apparent palaeotemperature profile and two corrected ones were thus deduced from the samples in which the dike emplacement produced no crystallization of new magnetic minerals these profiles were compared with the calculations of a new conductive thermal model which includes the basalt s latent heat of crystallization the flow duration of the dike the width of the circulating magma and the temperature dependence of the thermal conductivity k in the basalt and in the sandstone or alternatively convection simulated by an increase of the k values good fits with the experimental data are obtained for a flowing width consistent with field observations and when the latent heat is taken into account in the two following cases first when k is temperature dependent in the basalt and in the sandstone which implies a magma flow duration of 5 days second when a limited convection process is assumed in the sandstone only here a flowing time of only 1 day is required the corrected palaeotemperature profiles argue in favour of the second hypothesis suggesting that when a dike is emplaced heat transfer by fluids may play an important role in the surrounding rock

a paleomagnetic study of permian and triassic rocks from the toulon cuers basin se france evidence for intra pangea block rotations in the permian 1 the identification of a massive shear zone separating gondwana from laurasia during late palaeozoic times is one of the prerequisites for the controversial pangea b to a transition here we present new paleomagnetic data from permian and triassic sediments and volcanic rocks from the toulon cuers basin se france likely to be situated within this intra pangea shear zone a total of 150 samples from 14 sites were collected in the field 108 samples yielded reliable paleomagnetic component directions based on stepwise thermal demagnetization up to maximum temperatures of 690 c after removal of an initial viscous magnetic component from room temperature up to 200 c a second component of reverse polarity oriented to the south and up was identified in almost all samples of permian age the triassic samples behave similarly with the notable difference that here two polarities of magnetization are present positive field tests suggest the primary character of this characteristic magnetization the latitudes of the resulting early to mid permian paleopoles agree well with the corresponding segment of the apparent polar wander path apwp for europe whereas the longitudes are strung out along a small circle segment indicating relative rotations between the sampled regions and stable europe the triassic poles instead plot close to the triassic segment of the european apwp and provide an upper time limit for the observed rotations these results suggest a wrench faulting event associated with intra pangea crustal instability and transformation during the permian

secular variation in permian red beds from dome de barrot se france the do me de barrot red beds se france were deposited during the permo carboniferous reversed superchron pcrs near the palaeo equator the natural remanent magnetisation nrm resides in detrital hematite which is very resistant against thermal demagnetisation microprobe analyses reveal the presence of titanium in hematite grains indicating the volcanic and thus detrital origin therefore the nrm is a detrital remanent magnetisation and nrm variations reflect changes in the geomagnetic field tuning of the proxy parameter magnetic susceptibility to periods of the earth orbit during permian times provides relative time control the inferred average sedimentation rate is 11 8 cm 1000 yr 31 the variation in nrm directions is similar to present day secular variation sv this suggests that sv was not suppressed during at least part of the pcrs fl 2000 elsevier science b v all rights reserved

palaeomagnetic studies in the permian basin of largentiere and implications for the late variscan rotations in the french massif central summary detailed geological observations and palaeomagnetic analyses were carried out in the largentiere stephano autunian basin and on the stephanian deposits of the ales coalfield both located at the southeastern margin of the french massif central because of unfavourable rock types the ales stephanian deposits did not yield any results the palaeomagnetic pole 164 9 e 45 4 n k 89 a 95 4 1 deduced from a study of the autunian sediments of the largentiere basin agrees very well with the reference pole for stable europe the lodeve largentiere area that is the southeastern border of the massif central has been stable since early permian time with respect to stable europe whereas the western part the saint avrique rodez basin and probably the brive basin has been rotated counterclockwise