indian ocean summer monsoon iosm dynamics within the past 4 ka recorded in the sediments of lake nam co central tibetan plateau china abstract in september 2008 several cores 68 cm 115 cm length water depth 93 m were retrieved from lake nam co southern central tibetan plateau 4718 m a s l this study focuses on the interpretation of high resolution partly 0 2 cm data from three gravity cores and the upper part of a 10 4 m long piston core i e the past 4000 cal bp in terms of lake level changes hydrological variations in the catchment area and consequently variations in monsoon strength a wide spectrum of sedimentological geochemical and mineralogical investigations was carried out results are presented for xrf core scans grain size distribution xrd measurements and sem image analyses these data are complemented by an age depth model using 210pb and 137cs analyses as well as eleven ams 14c ages this model is supported by excellent agreement between secular variations determined on one of the gravity cores to geomagnetic field models this is a significant improvement of the chronology as most catchments of lacustrine systems on the tibetan plateau contain carbonates resulting in an unknown reservoir effect for radiocarbon dates the good correlation of our record to the geomagnetic field models confirms our age depth model and indicates only insignificant changes in the reservoir effect throughout the last 4 ka high summer monsoonal activity i e moist environmental conditions was detected in our record between approximately 4000 and 1950 cal bp as well as between 1480 and 1200 cal bp accordingly lower monsoon activity prevails in periods between the two intervals and thereafter this pattern shows a good correlation to the variability of the indian ocean summer monsoon iosm as recorded in a peat bog 1000 km in ne direction from lake nam co this is the first time that such a supra regional homogenous monsoon activity is shown on the tibetan plateau and beyond finally our data show a significant lake level rise after the little ice age lia in lake nam co which is suggested to be linked to glacier melting in consequence of rising temperatures occurring on the whole tibetan plateau during this time

latest miocene to quaternary horizontal and vertical displacement rates during simultaneous contraction and extension in the southern apennines orogen italy foreland contraction and hinterland extension in the southern apennines orogen of italy produced a complex spatial and temporal pattern of vertical and horizontal displacement remarkably late miocene to mid pleistocene foreland migration of the contractional front at 16 mm yr 1 was not accompanied by uplift and the frontal thrust belt remained at or below sea level only following a mid pleistocene reduction in horizontal displacement did the frontal thrust belt and foreland begin uplift at 0 5 mm yr 1 a rate that increased to 1 mm yr 1 after 125 ka although the extensional hinterland experienced net subsidence during formation of the tyrrhenian basin an extensional transition zone adjacent to the frontal thrust belt records sustained uplift at 0 3 mm yr 1 the interaction of preexisting crustal structure and deep tectonic processes resulted in time integrated displacement rates suggesting steady state deformation for periods of 106 years displacement rate changes were abrupt and occurred over intervals of 105 years or less

a debris flow calendar derived from sediments of lake lago di braies n italy abstract in this study lake sediments were used for developing a high resolution calendar of past debris flow events debris flows frequently occur in the high alpine catchment of the lake lago di braies n italy while the coarse grained material accumulates on the debris flow cones the fine grained material is flushed into the lake this material forms characteristic layers in the lake sediments which are different from the typical annual lamination by analysing thin sections of sediment debris flow events of the last 2250 years were reconstructed with an annual resolution since debris flow frequency varies strongly periods with high and low frequencies can be distinguished however neither a debris flow magnitude frequency relationship nor a strong reaction of debris flow activity to past climate changes was identifiable in this study

the puglia uplift se italy an anomaly in the foreland of the apenninic subduction due to buckling of a thick continental lithosphere the apenninic foreland shows two distinct structural signatures comparing the central adriatic sea and the puglia region during the pliocene pleistocene the central adriatic underwent high subsidence rates due to the eastward rollback of the hinge of the west dipping apenninic subduction the puglia region and the bradanic foredeep are located southward along strike in the same foreland but in contrast with the central adriatic after pliocene early pleistocene subsidence they underwent uplift since the middle pleistocene the geometry and the kinematics of the frontal accretionary wedge and related foreland changed from that moment on between the two areas at the front of the central northern apennines off scraping and subsidence continued whereas the foredeep and foreland of the southern apennines were buckled those differences are interpreted as being due to the larger subduction hinge rollback rate since middle pleistocene of the central adriatic lithosphere 70 km thick with respect to the thicker puglia 110 km the different thicknesses of the continental crust and lithosphere were inherited from the mesozoic rifting that disrupted the adriatic plate the different thicknesses appear to have controlled the variable degree of flexure of the lithosphere and its asthenospheric penetration rate the tremiti e w alignment is the right lateral lithospheric transfer zone of those different tectonic regimes the consequent different dip of the subduction in the two sections steeper west of puglia could also explain the lower elevation of the southern apennines compared to their central northern sector

modes of fault reactivation from analogue modeling experiments implications for the seismotectonics of the southern adriatic foreland italy abstract the active tectonics at the front of the southern apennines and in the adriatic foreland is characterized by e w striking right lateral seismogenic faults interpreted as reactivated inherited discontinuities the best studied among these is the molise gondola shear zone mgsz the interaction of these shear zones with the apennines chain is not yet clear to address this open question we developed a set of scaled analogue experiments aimed at analyzing 1 how dextral strike slip motion along a pre existing zone of weakness within the foreland propagates toward the surface and affects the orogenic wedge 2 the propagation of deformation as a function of increasing displacement 3 any insights on the active tectonics of southern italy our results stress the primary role played by these inherited structures when reactivated and confirm that regional e w dextral shear zones are a plausible way of explaining the seismotectonic setting of the external areas of the southern apennines

sediment dynamics and hydrologic events affecting small lacustrine systems on the southern central tibetan plateau the example of tt lake a sedimentological geochemical micropaleontological and palynological study of a lacustrine sediment record from the small tt lake southern central tibetan plateau shows that the background sedimentation was frequently interrupted by event related deposits these event related deposits are interpreted as the result of hydrologic events that are triggered by above average precipitation events in total 11 events were recorded in the tt lake sequence two types can be differentiated fluvial runoff events caused by precipitation that carried sediment in suspension into the lake and a sediment mass transport caused by torrential precipitation the hydrologic events appear to be decoupled from long term climate and environmental variations but there is evidence that anthropogenic impact in terms of pastoralism might have favored the runoff events the multi proxy approach proved to be valuable and allowed for a detailed study of sedimentary processes within the lake and its watershed in order to asse

segmentation and configuration of subducted lithosphere in italy an important control on thrust belt and foredeep basin evolution the apennine foredeep basin system located on continental crust consists of four roughly parallel basin segments each containing a flexural outer rise and an inner trough that deepens continuously toward the thrust belt flexural modeling of subsidence data across the basin indicates that this foredeep basin results mainly from deep subsurface loads acting on the subducted slab from within the subduction zone rather than from the topographic load of the apennine mountains the geometry of the four basin segments observed within the apennine foredeep is thus inferred to reflect subduction of segmented lithosphere where each lithospheric segment corresponds to a segment of the foredeep basin beneath the basin and in the foreland the lithosphere is continuous segmentation occurs only at depth beneath the thrust belt this pattern olf segmentation of the subducted lithosphere at depth is reflected in the large scale geometry of the outer part of the apennine thrust belt and appears to control it similarly the pattern of segmentation also appears to control the position of the eastern limit of back arc type extension in western italy these relations strongly suggest a genetic relation between subduction zone processes foredeep basin geometry and thrust belt evolution in which the configuration of the subducted lithosphere largely controls the large scale surface deformation observed in the apennine system

long term cooling drying record of north china since the middle pleistocene from geochemical evidence of a 150 m deep drill core beijing plain china the quaternary strata in north china primarily consist of fluvial sediments which react strongly to east asian monsoon circulation however the records of the quaternary climate change history in terms of these fluvial sedimentations were limited which impeded understanding the east asian monsoon evolution in north china thus a 150 m deep drill core was collected from changping in the beijing plain to reconstruct the quaternary palaeoenvironmental changes the core was chronologically well constrained using palaeomagnetic and thermoluminescence dating the magnetostratigraphic result indicated that the brunhes matuyama boundary is at 134 2 m 0 78 ma and the age at the bottom of the core is 1 07 ma the thermoluminescence tl dating of the upper sand at similar to 2 m was 10 4 ka the chemical weathering history since the middle pleistocene in beijing plain was reconstructed by using geochemical proxies including selected major element pairs chemical index of alteration and al2o3 cao na2o k2o diagrams the cia value of the changping core ranged from 50 3 to 69 4 average 59 2 which indicated that the sediment has experienced incipient to intermediate chemical weathering during the middle pleistocene the result of a cn k figure shows a high plagioclase to k feldspar ratio in the source which would be indicative of a granodiorite gd source from jundu mountains north of the beijing plain all the geochemical results revealed a long term gradual decrease of weathering since the middle pleistocene which implied a long term increasing aridification cooling in the beijing plain c 2014 elsevier ltd and inqua all rights reserved

correlation between climate man and debris flow events a palynological approach abstract debris flows occur frequently in the high alpine catchment area of lake lago di braies 1492 m a s l the sediments of the lake are used for detecting and dating past debris flow events during the last 4000 years and their driving factors comparing palynological and sedimentological data the results suggest that mainly heavy precipitation in winter and summer as well as snow melt events in spring enhance the release of debris flow events therefore especially longer periods with humid and cool climate conditions show a clearly higher debris flow activity the pollen diagram documents human impact on the catchment area since the late neolithic but the anthropogenic activities influenced the event activity only indirectly grazing and deforestation reduced the retention of debris by vegetation and results in thicker debris flow layers in the lake sediments

holocene climatic change and the nomadic anthropocene in eastern tibet palynological and geomorphological results from the nianbaoyeze mountains abstract our study provides detailed information on the lateglacial landscape and vegetation development of tibet based on a suite of geomorphological and palynological proxy data from the nianbaoyeze shan on the eastern margin of the tibetan plateau 33 n 101 e 3300 4500 m asl we reconstruct the current state as a function of climate history and the longevity of human influence study results constrain several major phases of aeolian sedimentation between 50 15 ka and various glacier advances during the late pleistocene the holocene and the little ice age increased aeolian deposition was primarily associated with periods of more extensive glacial ice extent fluvial and alluvial sediment pulses document an increase of erosion starting at 3926 79 cal yr b p coinciding with cooling neoglacial and a growing anthropo zoogenic influence evidence for periglacial mass movements indicate that the late holocene cooling started at around 2000 cal yr b p demonstrating increased surface activity under the combined effects of human influence and climate deterioration the onset of peat growth generally depended on local conditions that include relief meso climate and in more recent times also on soil compaction due to animal trampling we distinguish three initiation periods of peat growth 12 700 10 400 cal yr b p for flat basins inside last glacial terminal moraines 7000 5000 cal yr b p for the main valley floors and 3000 1000 cal yr b p for the higher terrace surfaces the holocene vegetation history started with an open landscape dominated by pioneer shrubs along braided rivers picea juniperus abies and betula trees accompanied by a successive closing of the vegetation cover by poaceae cyperaceae and herbs 9800 8300 cal yr b p first signs of nomadic presence appear as early as 7200 cal yr b p when temperatures were up to 2 c warmer than today forest remained very patchy with strong local contrasts during the following cooling phase 5900 2750 cal yr b p the natural vegetation was transformed by nomadic grazing to bistorta rich kobresia pygmaea pastures modern nomadic migration routes were established at least 2200 years ago overgrazing and trampling led to the shrinking of bistorta and the spreading of annual weeds short lived cold events 8000 6200 3500 cal yr b p impacted on the vegetation only temporarily as the transformation of the natural poaceae rich vegetation into kobresia pastures modified the influence of the tibetan plateau hot plate on the monsoon system our data even point to an early start of a nomadic anthropocene nearly 6000 years ago against the background of a very long grazing history modern tibet must be seen as a cultural landscape

abrupt environmental changes within a late holocene lacustrine sequence south of the marmara sea lake manyas n w turkey possible links with seismic events abstract a coring campaign in lake manyas kus golu on the southern coast of the sea of marmara turkey has provided insights into basin infilling processes during the upper 11 metres of the sedimentary record combined sedimentary features between 5 and 4 m depth have been explained by a seismite a brittle mixed layer uniquely rich in seeds and ostracod valves was widely detected at 4 m downcore this has been interpreted as being the result of a seiche either through a salt inundation linked to a tsunami in the sea of marmara the large scale scenario or a local hydrothermal fluid discharge the small scale scenario ostracod valves which are usually not preserved in lake manyas sediment are either incorporated here as tsunami debris providing a spatially averaged snapshot of the regional assemblage or are locally preserved following a temporary geochemical hydrochemical change of the water of unknown duration but probably several decades the brittle mixed layer overlies cracks resulting from the direct effects of the seismic shock wave on slightly compacted sediment at around 964 cm depth palynological and particle size analyses indicate a change from backswamp to open lacustrine conditions the end of the backswamp has been correlated with a decrease in the level of the sea of marmara from 4000 to 3000 2800 yr ago uncal caused by regional tectonic movements an age depth model is presented based on two ams radiocarbon dates on the palynological detection of the end of the beysehir occupation phase 130 cm above the event and on maximal sedimentation accumulation rates obtained by radionuclide analyses the entire study sequence covers the last 4300 yr the paper examines the possibility of an early byzantine age for the seismic event this may have been the historical event at ad 460 that destroyed cyzicus the ancient erdek 20 km north of the lake and various villages in the interior and was felt widely in the then known world other possibilities include various local and regional events in that same period the early byzantine tectonic paroxysm and the large earthquake in ad 447 that affected the entire sea of marmara region

interplay between redox conditions and hydrological changes in sediments from lake nam co tibetan plateau during the past 4000 cal bp inferred from geochemical and micropaleontological analyses abstract this study focuses on the analysis of lake sediments retrieved from the deepest part of lake nam co tibetan plateau one gravity core of 115 cm length covering the last 4000 cal bp was analyzed for geochemical and biological parameters high organic content at 4000 cal bp and the coinciding presence of pyrite framboids until 2000 cal bp point to hampered decomposition of organic material due to anoxic conditions within the lake sediments at the same time sedimentological and biological proxies suggest a rather high lake level but still 5 m below the recent one with less saline lake water due to enhanced monsoonal activity during this time a change in the source of organic matter to lowered input of terrestrial components is observed a rather quick shift to a dry environment with less monsoonal influence and a lake level 15 m lower than today at 2000 cal bp lead to the oxygenation of sediment the degradation of organic matter and the absence of pyrite oscillations of the lake level thereafter were of minor amplitude and not able to establish anoxia at the lake bottom again a wet spell between 1500 cal bp and 1150 cal bp is visible in proxies referring to catchment hydrology and the ostracod based water depth transfer function gives only a slightly elevated lake level the last 300 years are characterized by low toc and rising tn values reflecting enhanced nutrient supply and hence an advancing influence of human activity in the catchment decreasing toc tn values point to a complete shift to almost solely aquatic biomass production these results show that hydrological variations in terms of lake level change based on monsoonal strength can be linked to redox conditions at the lake bottom of nam co comparison with other archives over larger parts of the tibetan plateau and beyond exhibits a rather homogeneous climatic pattern throughout the late holocene

holocene climate variability as reflected by mid european lake level fluctuations and its probable impact on prehistoric human settlements abstract a data set of 180 radiocarbon tree ring and archaeological dates obtained from sediment sequences of 26 lakes in the jura mountains the northern french pre alps and the swiss plateau was used to construct a holocene mid european lake level record the dates do not indicate a random distribution over the holocene but form clusters suggesting an alternation of lower and higher climatically driven lake level phases they provide evidence of a rather unstable holocene climate punctuated by 15 phases of higher lake level 11 250 11 050 10 300 10 000 9550 9150 8300 8050 7550 7250 6350 5900 5650 5200 4850 4800 4150 3950 3500 3100 2750 2350 1800 1700 1300 1100 750 650 cal bp and after 1394 ad a comparison of this mid european lake level record with the gisp2 polar circulation index pci record the north atlantic ice rafting debris ird events and the 14 c record suggests teleconnections in a complex cryosphere ocean atmosphere system correlations between the gisp2 pci the mid european lake level the north atlantic ird and the residual 14 c records suggest that changes in the solar activity played a major role in holocene climate oscillations over the north atlantic area

fault plane solutions and seismicity of the italian peninsula abstract a new fault plane solution map of the italian peninsula is presented in this paper the earthquakes analyzed are included in the period 1905 1980 with magnitudes ranging 4 7 75 earthquakes are located in the crust while 31 are related to the deep and intermediate zone of the calabrian arc the large seismic events of the italian peninsula are generally associated with normal faulting while strike slip motion is mostly related to small earthquakes located along lateral segments of the mountain chain the deep and intermediate earthquakes of the tyrrhenian sea indicate predominant down dip compression and strike slip motion at the boundaries of this benioff zone this last is interpreted as a remnant of a subduction zone active since oligocene extending to 500 km depth with a very small lateral size about 300 km the present tectonics of this benioff zone is strongly conditioned by the lateral bending more so than the gravitational sinking process the coexistence of thrust and normal faulting motion associated to the earthquakes within a few tens of kilometers of each other seems to be explained by the strong lateral inhomogeneities of the crustal rocks present in this region more so than to the depth of the seismogenetic zone and the nature of the faulting process

stacked 2 6 ma grain size record from the chinese loess based on five sections and correlation with the deep sea δ18o record 1 this study aims to establish a stacked climate record of the quaternary period from the chinese loess sequence and to address the forcing mechanisms for the regional climate history of the loess plateau by correlating the stacked record with a composite 18o record in deep sea sediments a total of 18 352 samples were obtained from five loess sections located at baoji lingtai jingchuan puxian and pingliang in the southern and middle loess plateau these yielded high resolution grain size records between section correlation of these shows that although small depositional hiatuses are present in places within a single section most parts of the sections display near continuous dust deposition throughout the quaternary the grain size records were tuned simultaneously to the theoretical variations in obliquity and precession of the earth s orbit the grain size records plotted on their orbital timescales were then averaged to form a stacked loess grain size time series termed the chiloparts record this resolves most of the orbital timescale paleoclimate events buried in the loess soil sequences of the southern and middle loess plateau and can be used as a regional archive of the pleistocene climate history in the loess plateau comparison of the chiloparts record with a composite marine 18o record shows that for the past 1 8 ma the loess paleosol record can be correlated almost cycle by cycle with the marine record several discrepancies in the climatic events between the two records have also been identified implying that regional forcing mechanisms may have played a part in the climatic evolution of the chinese loess plateau

high resolution paleomagnetic and sedimentological investigations on the tibetan plateau for the past 16 ka cal b p the tangra yumco record the spatial distribution of paleomagnetic secular variation psv records on the tibetan plateau and adjacent areas covering the holocene and late glacial is sparse in order to reconstruct psv in this area a piston core covering the past 17 5 ka cal b p retrieved from lake tangra yumco southern central tibetan plateau was analyzed in the laminated sediments several event layers are intercalated those were identified by sedimentological analysis and excluded for age depth modeling and interpretation paleomagnetic measurements on u channels reveal two contrasting core sections the lower section dated to 17 5 15 9 ka cal b p is very coarse grained up to 220 m and characterized by low intensities 0 8 ma m 1 and high maximum angular deviation values mean 25 making it unsuitable for psv reconstruction in contrast the upper unit dated to 15 9 ka cal b p yields ideal properties with a well defined magnetization carried by low coercivity minerals in the pseudo single domain state making those younger sediments a proper record for psv studies the robustness of the psv reconstruction for the past 3000 years is highlighted by a comparable inclination and declination pattern of three short sediment cores 2 m from tangra yumco on a regional scale the obtained inclination signal for the past 15 9 ka cal b p is in good agreement with the lake baikal record 3000 km to the north psv stack for east asia as well as with predictions of geomagnetic field models this study is a step forward in constructing a psv reference curve for central asia keywords paleomagnetic secular variations psv magnetostratigraphy tibetan plateau lake sediments tangra yumco inclination

itrax description and evaluation of a new multi function x ray core scanner a new automated multi function core scanning instrument named itrax has been developed that records optical radiographic and elemental variations from sediment half cores up to 1 8 m long at a resolution as fine as 200 m an intense micro x ray beam focused through a flat capillary waveguide is used to irradiate samples to enable both x radiography and x ray fluorescence xrf analysis data are acquired incrementally by advancing a split core via a programmable stepped motor drive through the flat rectangular section x ray beam traditional xrf determination of element composition in sediments provides high quality data but it takes a considerable time and normally consumes gram quantities of material that is often only available in limited quantities the itrax core scanner non destructively collects optical and x radiographic images and provides high resolution elemental profiles that are invaluable for guiding sample selection for further destructive detailed sampling this paper presents a description of the construction characteristics and capabilities of the itrax system high resolution itrax data obtained from sediment cores are also presented and compared with results from traditional wavelength dispersive xrf analysis at lower resolution finally some recent technical developments linked to the second generation itrax are presented

hydroclimatic changes over the past 900 years documented by the sediments of tiewaike lake altai mountains northwestern china abstract the reconstruction of variations in effective moisture over the past millennium are important for assessing potential future climatic trends in environmentally sensitive arid central asia aca especially in the context of ongoing global warming however high resolution time series reflecting past moisture variability in the region are scarce thus preventing a full understanding of the hydroclimatic evolution here we present the results of multi proxy analysis of a sediment core spanning the past 900 years from tiewaike lake in the altai mountains northern xinjiang the climatic proxies measured include grain size organic matter and carbonate content c n ratio and the stable carbon isotope composition of bulk organic matter the results show that over the past 900 years the climatic evolution of the study area can be divided into distinct hydroclimatic phases the arid medieval climate anomaly mca 1090 1430 ad the humid little ice age lia 1430 1940 ad and the arid current warm period cwp 1940 2012 ad during the lia the water level at tiewaike lake was overall higher than during the other climatic intervals in addition the lia climate was unstable and characterized by six intervals with the occurrence of heavy precipitation events on a multi decadal timescale a humid unstable climate during the lia is also suggested by climatic records from adjacent regions our results support the view that over the past millennium on a multi centennial timescale the moisture variations in aca were generally out of phase with those in the region affected by the asian summer monsoon the humid unstable lia climate in aca may have been associated with changes in the north atlantic oscillation nao index and or with variations in solar irradiance

punishment for the sinner holocene episodic subsidence and steady tectonic motion at ancient sybaris calabria southern italy abstract although the calabria region in southern italy experienced quaternary uplift intense holocene subsidence is documented at ancient sybaris one of the most powerful among the greek colonies collectively known as magna greacia sybaris flourished along the ionian sea coast of north eastern calabria since 2 7 ka bp and until the end of the roman empire when it went progressively concealed below the ground study of the latest pleistocene holocene evolution of this area involved analysis of the relative sea level history for individual borehole logs based on re calibration of published ages and stipulation of nominal sea level positions related to each marker for investigation of the short term evolution a novel compilation of geological and archaeological sea level markers was supported by new radiometric ages appraisal of the position of dated markers when compared to a sea level curve built on purpose for this coast using an updated glacio hydro isostatic model indicates a locally intense difference in vertical motion between boreholes located away from or close to the ancient town specifically whereas data from the basement of the archaeological layers document large subsidence more distant sites behaved differently a site 2 km to the nw of the settlement was apparently stable throughout the holocene and a site 6 km to the se experienced uplift at 1 5 mm y since 0 6 ka bp in addition analysis reveals temporal changes in subsidence pattern in the archaeological area large 5 6 mm y early holocene subsidence at sybaris slowed to 1 5 mm y during the middle part of the holocene the slowing down trend continued during and after historical occupation at 0 8 mm y a value similar to the long term 35 40 ka bp rate established from the deepest borehole samples these data are interpreted as suggesting that sediment compaction affected the basement of sybaris during the early holocene and progressively ceased during historical times when a tectonic signal prevailed during historical time the spatial difference in vertical motion is chiefly attributed to differential growth of nearby folds documented by morpho tectonic studies on land and seismic profiles analysis in the offshore of sybaris whereas location above a syncline caused tectonic subsidence at sybaris the regions to the north and south record stability or uplift that reflects transition to growing anticlines in the short term 1 10 ka scale these local tectonic processes prevail over the regional uplift pattern which is expressed at the 100 ka scale or over

later pleistocene holocene climate conditions of qinghai xizhang plateau tibet based on carbon and oxygen stable isotopes of zabuye lake sediments abstract we present a time series of carbon and oxygen stable isotope records of the last 30 000 14c years throughout the last glacial postglacial cycle from western qinghai xizhang tibet plateau a 20 m core drilled in the south basin of zabuye salt lake was analyzed for inorganic and organic carbon and total sulfur contents 13c and 18o values of carbonates our results indicate that climatic changes have led to a drastic negative shift of stable isotope ratios at the transition between the last full glacial and the postglacial phase during later pleistocene times 16 2 kyr bp and a rapid positive shift at the transition from pleistocene to holocene 10 6 kyr bp the first shift is marked by the drop of 18ocarb values of about 10 from 2 to 8 and 13ccarb values of about 3 from 5 to 2 the second shift which occurred at the transition from pleistocene to holocene was of similar magnitude but in the opposite direction isotope data combined with total organic and inorganic carbon contents and the lithological composition of the core suggest this lake was an alluvial pre lake environment prior to ca 28 14c kyr bp during ca 28 16 2 14c kyr bp zabuye lake was likely a moderately deep lake with limited outflow the cool and arid glacial climate led the lake level to drop drastically extended residence time overwhelmed the lower temperature and caused a steady increase of 13ccarb and 18ocarb values and total inorganic carbon content in the sediments during ca 16 2 10 6 14c kyr bp this lake probably overflowed and received abundant recharge from melting glaciers when the deglaciation was in its full speed a spike of markedly enhanced 13ccarb and 18ocarb is seen at 11 5 kyr bp probably due to the isotopic effects left behind by the short but severe younger dryas yd event after ca 10 6 14c kyr bp zabuye lake probably closed its surface outflow due to strong desiccation and drastic climate warming the early and middle holocene were characterized by unstable climatic conditions with alternating warmer cooler episodes as indicated by the severe fluctuations of total organic carbon 13c and 18o values a hypersaline salt lake environment was finally formed at zabuye after 5 14c kyr bp when the mirabilite and halite concentrations steadily increased and became the dominant minerals in the sediments severe imbalance of inflow outflow resulted in the drastic increase of total sulfur 13ccarb and 18ocarb values and dominance of halite in the lake since ca 3 8 kyr bp to present

trace element variability in single ostracod valves as a proxy for hydrochemical change in nam co central tibet during the holocene ostracod shells belonging to three taxa leucocytherella sinensis huang 1982 leucocythere dorsotuberosa huang 1982 and l dorsotuberosa f postilirata sensu pang 1985 were collected from two sediment cores from lake nam co on the central tibetan plateau two variants of la icp ms laser ablation inductively coupled plasma mass spectrometry spot and line scan analyses were used to investigate trace element concentrations mg sr ba u and rare earth elements rees in single ostracod shells the results suggest that the line scan method can provide better precision than the spot analysis and is therefore preferred no significant difference in trace element composition between taxa was detected in our study fluctuations of mg ca and sr ca in the shells show good agreement with the reported lake level changes during the holocene indicating that ostracod mg and sr can be related to palaeohydrochemical processes in this area a high correlation between ba ca and sr ca was detected in our study perhaps implying that both metals were controlled by the same mechanisms a possible relationship between ostracod u ca and the past redox conditions on the lake bottom is discussed relatively low and constant la ca was observed which could be due to the ree characteristics in the lake water or ostracod biological processes or even the associated fe mn and or organic contaminants future studies on more specimens from this area especially shells from living ostracods are essential to investigate the potential of ostracod ba u and rees for use as palaeoenvironmental indicators

cosmogenic 10be and 26al dating of paleolake shorelines in tibet abstract we have used in situ produced cosmogenic nuclides 10be and 26al to date lacustrine shorelines around eight lakes in tibet two lakes located south of the yarlung tsangpo river discharged at high lake levels one of them drolung co co is a local term meaning lake became closed its water level fell below its outlet channel at 3 8 ka and lowered over 120 m vertically since then this implies a significant change in intensity of precipitation driven by the indian monsoon over southern tibet in the middle late holocene nam co and dajia co located to the north of the yarlung tsangpo river also drained at high lake levels and became closed 53 36 ka and 48 ka respectively of four other lakes developed closely in the qiangtang basin north of the yarlung tsangpo river tangra yum co and siling co located at 31 32 n show exposure ages for high lake shorelines of over 220 ka the oldest lake shorelines reported for tibet while towards the north and west the high lake of zhari nam co appeared after the last glacial maximum lgm the different pattern of lake development to the north of yarlung tsangpo river may reflect regional climate effects

the gargano promontory a neogene contractional belt within the adriatic plate the gargano promontory lies on the adriatic plate between the dinaride and apennine fold and thrust belts and associated foredeeps neogene sediments and structures in the gargano promontory demonstrate the existence of significant contrac tional structures which have not been reported previously beginning in early miocene times the future gargano promontory experienced shortening along nw trending mainly sw vergent folds and thrusts deformation persisted until the tortonian and most likely until the messinian limited nw directed contraction affected the promontory probably during pliocene times morphological relief was minimal until the messinian but from the middle pliocene onwards it was substantially similar to the present day one partly as a consequence of extension along ne sw trending normal faults the along strike projection of kinematic relationships and quantities observed in the gargano might call for a re interpretation of previously underestimated structures nw and se of the promontory

crustal and uppermost mantle structure in italy from the inversion of p wave arrival times geodynamic implications summary in this paper we present a 3 d image of the p wave velocity structure in the crust and uppermost mantle beneath italy obtained by inverting p wave arrival times of crustal earthquakes we used about 48000 arrival times at stations close to the epicentres within 200 km to mitigate the eiects of both reading errors and intrinsic complexity for long distance ray paths due to the scale of heterogeneities in the earth structure beneath italy whereas two of the inverted layers located in the lower crust and beneath the moho are well resolved by the data the upper crustal layer has regions of relatively poor resolution beneath the central apennines due to the sparse station spacing we made several attempts varying the moho geometry to obtain reliable and stable results without introducing too complex and unconstrained ap rioriinformation one of the most important results is the discovery of low velocity anomalies at 38 km depth beneath the northern apenninic and calabrian arcs which we interpret as subducted crustal material of the adriatic and ionian lithospheres in the lower crust beneath the entire apennines a pronounced low velocitybelt is present suggesting high temperatures in front of the bent adriatic lithosphere based on our results and on those previously obtained from seismic tomography we propose amodel for the geodynamic evolution of the apenninic system in which the present day scenario re ects lateral heterogeneities in the subducting ionian oceanic and adriatic continental lithosphere

extensional basins in the tectonically bimodal central apennines fold thrust belt italy response to corner flow above a subducting slab in retrograde motion the apennines fold thrust belt has developed over the past 20 m y in response to southeastward retrograde migration of the adriatic trench in a region of ongoing subduction but little plate convergence the orogenic belt is characterized by a gently sloping southwestern flank in a state of regional extensional collapse and a steeply sloping northeastern flank in regional contraction in any given area in the central apennines the chronologies of thrusting and subsequent extension provide an estimate of the time required for attainment of high elevation 2 5 3 0 km the time between initial extension and eruption of local ultramafic lavas provides an estimate of the time required to collapse by regional crustal thinning these estimates suggest that the northeastern contractional flank of the range is rising at least twice as fast as the southwestern flank is collapsing we propose that the bimodal state of stress in the apennines is maintained by corner flow in the mantle wedge beneath the crest of the range

prediction of some weathering trends of plutonic and volcanic rocks based on thermodynamic and kinetic considerations abstract the exposed crust consists mainly of plagioclase 35 quartz 20 k feldspar 11 volcanic glass 12 biotite 8 and muscovite 5 quartz is a resistate thus feldspars and glass represent approximately 75 percent of the labile minerals the weathering characteristics of these constituents are summarized in the context of thermodynamic mass balance and kinetic considerations experimentally determined release rate constants were used to predict the proportions of ca na and k released by feldspars of plutonic rocks granites to gabbros to weathering solutions the chemical weathering trends of the weathered residues calculated from the kinetic data conform closely to the initial trends observed in some recent weathering profiles demonstrating the accuracy of the predictions since the weathering of feldspars is controlled by processes that should not change through geological time the relative release rates of ca na and k from the feldspars of granitic rocks can be calculated for future and past episodes of continental weathering experimentally determined release rate constants are not available for a wide range of volcanic glass compositions but the limited data indicate that compositional trends are predictable in weathering profiles developed on volcanic rocks the kinetic data available for rhyolitic glasses accurately predict the initial weathering trends observed in a recent rhyolite weathering profile

raised coastal terraces along the ionian sea coast of northern calabria italy suggest space and time variability of tectonic uplift rates abstract a detailed study of uplifted middle late pleistocene marine terraces on the eastern side of northern calabria southern italy provides insights into the temporal and spatial scale variability of vertical displacement rates over a time span of 400 ka calabria is located in the frontal orogen of southern italy above the westerly plunging ionian slab and a combination of lithospheric crustal and surface processes concurred to rapid late quaternary uplift eleven terrace orders and a raised holocene beach were mapped up to 480 m a s l and were correlated between the coastal slopes of pollino and sila mountain ranges across the sibari plain facing the ionian sea side of northeastern calabria precise corrections were applied to the measured shoreline angles in order to account for uncertainty in measurement erosion of marine deposits recent debris shedding and bathymetric range of markers radiometric esr and 14 c dating of shells provides a crono stratigraphic scheme although many samples were found to be resedimented in younger terraces terrace t4 whose inner margin stands at elevations of 94 130 m is assigned to mis 5 5 124 ka based on new esr dating and previous amino acid racemization estimations the underlying terraces t3 t2 and t1 are attributed to mis 5 3 100 ka 5 1 80 ka and 3 60 ka as inferred from their relative position supplemented by esr and 14 c age determinations the age of higher terraces is poorly constrained but conceivably is tracked back to mis 11 400 ka the reconstructed depositional sequence of terraces attributed to mis 5 5 and 7 reveals two regressive marine cycles separated by an alluvial fanglomerate which given the steady uplift regime points to minor sub orbital sea level changes during interstadial highstands based on the terrace chronology uplift in the last 400 ka occurred at an average rate of 1 mm a but was characterized by the alternation of more rapid up to 3 5 mm a and slower down to 0 5 mm a periods of displacement spatial variability in uplift rates is recorded by the deformation profile of terraces parallel to the coast which document the growth of local fold structures

lake sediments as natural seismographs a compiled record of late quaternary earthquakes in central switzerland and its implication for alpine deformation central switzerland lies tectonically in an intraplate area and recurrence rates of strong earthquakes exceed the time span covered by historic chronicles however many lakes are present in the area that act as natural seismographs their continuous datable and high resolution sediment succession allows extension of the earthquake catalogue to pre historic times this study reviews and compiles available data sets and results from more than 10 years of lacustrine palaeoseismological research in lakes of northern and central switzerland the concept of using lacustrine mass movement event stratigraphy to identify palaeo earthquakes is showcased by presenting new data and results from lake zurich the late glacial to holocene mass movement units in this lake document a complex history of varying tectonic and environmental impacts results include sedimentary evidence of three major and three minor simultaneously triggered basin wide lateral slope failure events interpreted as the fingerprints of palaeoseismic activity a refined earthquake catalogue which includes results from previous lake studies reveals a non uniform temporal distribution of earthquakes in northern and central switzerland a higher frequency of earthquakes in the late glacial and late holocene period documents two different phases of neotectonic activity they are interpreted to be related to isostatic post glacial rebound and relatively recent re activation of seismogenic zones respectively magnitudes and epicentre reconstructions for the largest identified earthquakes provide evidence for two possible earthquake sources i a source area in the region of the alpine or sub alpine front due to release of accumulated north west south east compressional stress related to an active basal thrust beneath the aar massif and ii a source area beneath the alpine foreland due to reactivation of deep seated strike slip faults such activity has been repeatedly observed instrumentally for example during the most recent magnitude 4 2 and 3 5 earthquakes of february 2012 near zug the combined lacustrine record from northern and central switzerland indicates that at least one of these potential sources has been capable of producing magnitude 6 2 to 6 7 events in the past

interactions of climate and land use documented in the varved sediments of seebergsee in the swiss alps this paper presents a multiproxy high resolution study of the past 2600 years for seebergsee a small swiss lake with varved sediments at the present tree line ecotone the laminae were identieed as varves by a numerical analysis of diatom counts in the thin sections the hypothesis of two diatom blooms per year was corroborated by the 210 pb and 137 cs chronology a period of intensive pasturing during the little ice age between ad 1346 and ad 1595 is suggested by coprophilous fungal spores as well as by pollen indicators of grazing by the diatom inferred total phosphorus by geochemistry and by documentary data the subsequent re oligotrophication of the lake took about 88 years as determined by the timelag between the decline of coprophile fungal spores and the restoration of pre eutrophic nutrient conditions according to previous studies of latewood densities from the same region cold summers around ad 1600 limited the pasturing at this altitude this demonstrated the socio economic impact of a single climatic event however the variance partitioning between the effects of land use and climate which was applied for the whole core revealed that climate independent of land use and time explained only 1 32 of the diatom data while land use independent of climate and time explained 15 7 clearly land use ineuenced the lake but land use was not always driven by climate other factors beside climate such as politics or the introduction of fertilizers in the seventeenth and eighteenth centuries also ine uenced the development of alpine pasturing

an active oblique contractional belt at the transition between the southern apennines and calabrian arc the amendolara ridge ionian sea italy high resolution single channel seismic and multibeam bathymetry data collected at the amendolara ridge a key submarine area marking the junction between the apennine collision belt and the calabrian subduction forearc reveal active deformation in a supposedly stable crustal sector new data integrated with existing multichannel seismic profiles calibrated with oil exploratory wells show that middle to late pleistocene sediments are deformed in growth folds above blind oblique reverse faults that bound a regional pop up data analysis indicates that 10 to 20 km long banks that top the 80 km long nw se trending ridge are structural culminations above en echelon fault segments numeric modeling of bathymetry and stratigraphic markers suggests that three 45 dipping upper crustal 2 10 km fault segments underlie the ridge with slip rates up to 0 5 mm yr segments may be capable with m 6 1 6 3 earthquakes although an unknown fraction of aseismic slip undoubtedly contributes to deformation the fault array that bounds the southern flank of the ridge amendolara fault system parallels a belt of mw 4 7 strike slip and thrust earthquakes which suggest current left oblique reverse motion on the array the eastern segment of the array shows apparent morphologic evidence of deformation and might be responsible for mw 5 2 historic events late pliocene quaternary growth of the oblique contractional belt is related to the combined effects of stalling of adriatic slab retreat underneath the apennines and subduction retreat of the ionian slab underneath calabria deformation localization was controlled by an inherited mechanical interface between the thick apulian adriatic platform crust and the attenuated ionian basin crust

a proposal for the kinematic modelling of w dipping subductions possible applications to the tyrrhenian apennines system in w dipping subduction zones there is a general eastward progression of the back arc basin accretionary wedge foredeep complex with the forward progression early stages of the complex are revealed by slices of upper crust and sedimentary cover abandoned to the west left floating above a new section of mantle a major shear zone should form at the new moho separating upper crust slices of earlier accretionary stages and the eastward flowing mantle the mantle wedging at the top of the subduction plane could be responsible for the uplift of the central parts of the belt the retreating of the subduction hinge is interpreted as due to the push generated by the eastward mantle flow detected in the hot spot reference frame the foredeep depth is mainly a function of the radius of curvature of the subduction hinge the frontal wedge is constructed from the stacking of the upper layers of the subducting plate and the syntectonic clastics that fill the foredeep which are progressively involved in thrusting and later by extension in order to preserve volume balance the lithosphere of the eastern plate before subduction has to be the same size as that which has been subducted due to the longer length of the arc with respect to the original length of the linear margin between the two converging plates laterally stretched subducted lithosphere is predicted at depth w dipping subductions usually have a short life probably due to their inherent capability to produce new lateral heterogeneities of the lithosphere the thin back arc which are a key factor in controlling and generating new subductions both e and w dipping this model is applied to the apennines tyrrhenian sea system

seismotectonics of the southern apennines and adriatic foreland insights on active regional e w shear zones from analogue modeling 1 the active tectonics at the front of the southern apennines and in the adriatic foreland is characterized by e w striking right lateral seismogenic faults interpreted as reactivated inherited discontinuities the best studied among these is the molise gondola shear zone the interaction of these shear zones with the apennines chain is not yet clear to address this open question we developed a set of scaled analogue experiments aimed at analyzing 1 how dextral strike slip motion along a preexisting zone of weakness within the foreland propagates toward the surface and affects the orogenic wedge 2 the propagation of deformation as a function of displacement and 3 any insights on the active tectonics of southern italy our results stress the primary role played by these inherited structures when reactivated and confirm that regional e w dextral shear zones are a plausible way of explaining the seismotectonic setting of the external areas of the southern apennines

deformed pleistocene marine terraces along the ionian sea margin of southern italy unveiling blind fault related folds contribution to coastal uplift 1 morphotectonic analysis and fault numeric modeling of uplifted marine terraces along the ionian sea coast of the southern apennines allowed us to place quantitative constraints on middle pleistocene holocene deformation ten terrace orders uplifted to as much as 660 m were mapped along 80 km of the taranto gulf coastline the shorelines document both a regional and a local fault induced contribution to uplift the intermingling between the two deformation sources is attested by three 10 km scale undulations superimposed on a 100 km scale northeastward tilt the undulations spatially coincide with the trace of nw se striking transpressional faults that affected the coastal range during the early pleistocene to test whether fault activity continued to the present we modeled the differential uplift of marine terraces as progressive elastic displacement above blind oblique thrust ramps seated beneath the coast through an iterative and mathematically based procedure we defined the best geometric and kinematic fault parameters as well as the number and position of fault segments fault numerical models predict two fault propagation folds cored by blind thrusts with slip rates ranging from 0 5 to 0 7 mm yr and capable of generating an earthquake with a maximum moment magnitude of 5 9 6 3 notably we find that the locus of predominant activity has repeatedly shifted between the two fault systems during time and that slip rates on each fault have temporally changed it is not clear if the active deformation is seismogenic or dominated by aseismic creep however the modeled faults are embedded in an offshore transpressional belt that may have sourced historical earthquakes

variability of the 14c reservoir effects in lake tangra yumco central tibet china determined from recent sedimentation rates and dating of plant fossils abstract sediments from lakes provide one of the most important archives for past environmental changes on the tibetan plateau the recent sedimentation rate of modern lakes is widely used as an independent method to calibrate 14 c derived chronologies because 14 c values are often affected by a reservoir effect terrestrial plant residues in lake sediments are believed to be the ideal material for 14 c dating because they normally provide the true ages of the sediments in this study we present the spatial and temporal variations in modern sedimentation rates over the past 150 years and evaluate the reservoir effects of 14 c ages determined from bulk sediments and plant residues from lake tangra yumco on the central tibetan plateau the results show that ages determined from plant residues are systematically younger than those of the bulk sediments however the reservoir effects associated with the bulk sediments are much more constant than those of the plant residues highlighting the complicated composition of these macro remains and the fact that they might not be the best dating materials in tangra yumco especially in southern part a similar reservoir effect of 2200 years is observed in the southern and northern parts of tangra yumco based on the dating of modern surface sediments and aquatic plants this study demonstrates the complexity of the reservoir effect in a closed lake on the tibetan plateau and careful consideration must be paid to the use of different approaches to date different materials in order to establish a reliable chronology

quantitative characterization and elevation estimation of lake lahontan shoreline terraces from high resolution digital elevation models the precision with which the elevation of a feature such as a terrace can be measured depends on the characterization of the noise contaminating the measurement a method for identification and extraction of terrace feature elevations is presented and the topographic noise due to erosion as well as measurement error is quantified high resolution digital elevation models dem are acquired at six wave cut volcanic bedrock terrace sites from around the highstand of paleo lake lahontan in the western great basin local dems which are tied to regional geodetic control were acquired using conventional total station rapid postprocessed and real time kinematic global positioning system methods the topographic signal is processed with derivative filters for geomorphic feature recognition and averaging for noise reduction results indicate that noise levels for identifiable features such as riser crest knickpoint and slope inflection point are statistically equivalent and on the order of 0 5 m standard deviation averaging within topographic bins spanning 50 m along terrace strike yields feature elevation estimates with standard errors on the order of 0 12 m the mean bench window elevation between the riser crest and knickpoint has the lowest standard error and is systematically related to water level propagation of surveying geoid estimation and terrace feature elevation estimation errors indicates that displacements on the order of 0 5 m may be resolved using these methods elevation estimate interpretation involves terrace development degradation and neotectonics but this new methodology has significant advantages in studies of neotectonic or geomorphic processes using local terrace elevation measurements

late quaternary lacustrine paleo seismic archives in north western alps examples of earthquake origin assessment of sedimentary disturbances abstract the late quaternary sedimentary fills of several lakes of the north western alps are revealed to be possible paleo seismological archives in a moderately active seismo tectonic region the strongest historically reported events can be correlated with specific layers whose textures result from different processes i mass failures of sub aqueous slope deposits especially delta foresets evolving into hyperpycnal currents influenced by seiche effects and or multiple reflections on lake basin slopes ii in situ liquefaction and flowage and iii micro fracturing based on identification of the sedimentary signature of a well documented historical earthquake the paleoseismic interpretation can be extrapolated back to 16 000 yrs bp with a reconstruction of a time series and textural identification of slope failure related turbidites the most frequent earthquake signature the obtained time series are compatible with historical seismicity in terms of recurrence interval

a 450 year record of spring summer flood layers in annually laminated sediments from lake ammersee southern germany 1 a 450 year spring summer flood layer time series at seasonal resolution has been established from the varved sediment record of lake ammersee southern germany applying a novel methodological approach the main results are 1 the attainment of a precise chronology by microscopic varve counting 2 the identification of detrital layers representing flood triggered fluxes of catchment material into the lake and 3 the recognition of the seasonality of these flood layers from their microstratigraphic position within a varve tracing flood layers in a proximal and a distal core and correlating them by application of the precise chronology provided information on the depositional processes comparing the seasonal flood layer record with daily runoff data of the inflowing river ammer for the period from 1926 to 1999 allowed the definition of an approximate threshold in flood magnitude above which the formation of flood layers becomes very likely moreover it was possible for the first time to estimate the completeness of the flood layer time series and to recognize that mainly floods in spring and summer representing the main flood seasons in this region are well preserved in the sediment archive their frequency distribution over the entire 450 year time series is not stationary but reveals maxima for colder periods of the little ice age when solar activity was reduced the observed spring summer flood layer frequency further shows trends similar to those of the occurrence of flood prone weather regimes since a d 1881 probably suggesting a causal link between solar variability and changes in midlatitude atmospheric circulation patterns

palaeoclimatic changes in the qinghai lake area during the last 18 000 years abstract multi proxy analysis of a sediment core from qinghai lake including pollen carbonate toc tn and 13 c of organic matter was used to document regional climatic changes during the last 18 000 years climate was very cold and dry before 16 9 cal kyr bp the warm and wet period which began at about 14 1 cal kyr bp culminated at 6 5 cal kyr bp and came to its end at about 4 5 cal kyr bp after that the climate gradually became colder and drier during the transitional period from the late glacial to the holocene the climate fluctuated frequently the short term climatic oscillations including the bolling allerod younger dryas and the cooling event at ca 8 2 cal kyr bp appear to be recorded in the qinghai lake sedimentary record the climatic evolution in the qinghai lake area during the past 18 000 years indicates that solar insolation changes on the ten thousand year scale are the likely driving force of the east asia monsoon

frequency and intensity of high altitude floods over the last 3 5 ka in northwestern french alps lake anterne in central western europe several studies have shown that colder holocene periods such as the little ice age also correspond to wet periods however in mountain areas which are highly sensitive to erosion processes and where precipitation events can be localized past evolution of hydrological activity might be more complicated to assess these past hydrological changes a paleolimnological approach was applied on a 13 4 m long sediment core taken in alpine lake anterne 2063 m asl and representing the last 3 5 ka lake sedimentation is mainly composed of ood deposits triggered by precipitation events sedimentological and geochemical analyses show that oods were more frequent during cold periods while high intensity ood events occurred preferentially during warmer periods in mild temperature conditions both ood patterns are present this underlines the complex relationship between ood hazards and climatic change in mountain areas during the warmer and or dryer times of the end of iron age and the roman period both the frequency and intensity of oods increased this is interpreted as an effect of human induced clearing for grazing activities and reveals that anthropogenic interferences must be taken into account when reconstructing climatic signals from natural archives

how old is pastoralism in tibet an ecological approach to the making of a tibetan landscape abstract the tibetan highlands host one of the world s largest pastoral ecosystems but the evolutionary impact of the tibetan nomadic livestock economy on the environment has not yet been investigated despite this grazing impact the vegetation of the tibetan highlands is widely believed to be natural our ecological approach to reconstructing the making of a pastoral environment uses the present composition of the plant cover as a baseline today s prevailing plant functional types are grazing weeds highly adapted to grazing the first pollen record of grazing weeds can thus be assumed to mark the onset of pastoralism supposedly with goats and sheep introduced from the middle east and the endemic large bovid of the yak domesticated in the tibetan highlands this study represents the first attempt to determine the age of pastoralism with the help of palynomorphs using the indicator species approach this is independently corroborated 1 by the synchronous occurrence of pollen clumps indicating disturbance effects from trampling and 2 the precipitous decline of forest pollen on the eastern declivity of the highland during the mid holocene climatic optimum as all pollen core sites currently have a climatic potential of forest as demonstrated by fruiting and progenitive forest relicts it is suggested that early livestock holders continued to burn these forests to obtain pastures the charcoal record supports this conclusion it is hypothesized that the making of a pastoral environment in the tibetan highlands started around 8 8 ka cal bp during the mid holocene climatic optimum as the pattern of arboreal pollen decline at these sites contrasts with 13c 18o toc content c n ratio and ostracod assemblages that are independent of rangeland management decisions of early pastoralists we may conclude that pastoralists took advantage of the mid holocene climatic optimum to convert forests into high yield pastures using pollen clumps as a proxy for herbivore load suggests a tenfold higher amount of livestock than of wildlife before the introduction of pastoralism in contrast to pastoralism in arid environments of the old world s desert belt pastoralists in the eastern tibetan highlands created their own environment transforming forests and tall grassland into the present golf course like pastures

a sedimentary record of holocene surface runoff events and earthquake activity from lake iseo southern alps italy this study presents a record of holocene surface runoff events and several large earthquakes preserved in the sediments of pre alpine lake iseo northern italy a combination of high resolution seismic surveying detailed sediment microfacies analysis non destructive core scanning techniques and ams 14c dating of terrestrial macrofossils was used to detect and date these events based on this approach our data shed light on past seismic activity in the vicinity of lake iseo and the influence of climate variability and human impact on allochthonous detrital matter flux into the lake the 19 m long investigated sediment sequence of faintly layered lake marl contains frequent centimetre to decimetre scale sandy silty detrital layers during the early to mid holocene these small scale detrital layers reflecting sediment supply by extreme surface runoff events reveal a distinct centennial scale recurrence pattern this is in accordance with regional lake level highstands and minima in solar activity and thus apparently mainly climate controlled after c 4200 cal yr bp intervals of high detrital flux occasionally also correlate with periods of enhanced human settlement activity in consequence deposition of small scale detrital layers during the late holocene apparently reflects a rather complex interplay between climatic and anthropogenic influences on catchment erosion processes besides the small scale detrital layers five up to 2 40 m thick large scale detrital event layers composed of basal mass wasting deposits overlain by large scale turbidites were identified which are supposed to be triggered by strong earthquakes the uppermost large scale event layer can be correlated to a documented mw 6 0 earthquake in ad 1222 in brescia the four other large scale event layers are supposed to correspond to previously undocumented local earthquakes these occurred around 350 bc 570 bc 2540 bc and 6210 bc and most probably also reached magnitudes in the order of mw 5 0 6 5

10 000 yr record of extreme hydrologic events well dated lacustrine sediments provide a hydrologic record indicating that the frequency and magnitude of runoff events and by inference storms have varied over the past 10 k y in northern new england we used five sediment cores and radiocarbon dating to develop a chronology of holocene hydrologic events for the ritterbush pond basin northern vermont chemical and physical analyses allow us to identify 52 distinct layers of predominately inorganic sediment that represent terrestrially derived material delivered to the pond by runoff events the thickness of some layers suggests hydrologic events at least equal in size to and probably much larger than any storm or flood recorded during nearly 300 yr of written regional history layer thickness and frequency and by analogy storm size and recurrence change through the holocene the largest events occurred 2620 6840 and 9440 calibrated 14c years before present cal 14c yr b p the most frequent hydrologic events occurred in three periods 1750 to 2620 6330 to 6840 and 8600 cal yr b p the recurrence interval of layer deposition during stormy periods averages 130 100 cal yr whereas the recurrence interval during less stormy periods is longer 270 170 cal yr the ritterbush pond event record illustrates the potential of inorganic lacustrine sediment to serve as a proxy record for estimating paleoflood frequency and deciphering climate change

constraining holocene lake level highstands on the tibetan plateau by 10be exposure dating a case study at tangra yumco southern tibet abstract many lakes on the tibetan plateau are surrounded by palaeo shorelines that document former lake level highstands and hence past changes in climate establishing accurate chronologies for these shorelines is crucial to correlate lake level fluctuations with palaeo environmental histories that are commonly inferred from lake sedimentary records here we apply surface exposure dating to constrain the age of two lake level highstands at one of the largest tibetan lakes tangra yumco which has well developed palaeo shorelines located up to 185 m above the current lake for sampling we focussed on wave cut bedrock terraces that vary considerably in width because they were carved into rocks of different erodibility samples from the highest strath terrace 180 185 m above the lake at three different sites yield tightly clustered 10 be ages between 7 39 0 19 ka and 7 87 0 27 ka internal errors which constrain the end of an early holocene lake level highstand at 7 6 0 6 ka external error the consistency of the 10 be ages indicates that bedrock erosion by wave attack reduced the inherited 10 be component to negligible amounts because otherwise samples would show considerable age scatter two bedrock samples from a lower terrace 140 145 m above the lake and one amalgamated clast sample from a beach ridge on the same terrace yield 10 be ages between 4 04 0 14 ka and 4 50 0 15 ka these ages document that the lake level dropped by 40 m between 7 6 ka and 4 3 ka granite boulders from the two investigated terraces yield apparent 10 be ages that are 6 ka and 27 ka older than the ages of the respective terraces indicating that this sample type is not reliable in this setting overall our results demonstrate that exposure dating of bedrock terraces provides a valuable tool to reconstruct lake level histories on the tibetan plateau

relationship between topography rates of extension and mantle dynamics in the actively extending italian apennines to investigate the mechanism driving active extension in the central and southern italian apennines and the geography of seismic hazard we compare spatial variations in upper crustal strain rate measured across exposed fault scarps since 15 3 ka with data on cumulative upper crustal strain and topographic elevation and free air gravity p wave tomography and sks splitting delay times that are a proxy for strain in the mantle high extensional strain rates across the apennines since 15 3 ka 0 4 3 1 mm yr along 90 km transects occur in two areas lazio abruzzo se campania and basilicata where values for finite extensional strains that have developed since 2 3 ma are highest 2 7 km cumulative throw and where mean elevation in 5 90 km ne sw boxes is 600 m the intervening area nw campania and molise with 600 m mean elevation in 5 90 km boxes has extension rates 0 4 mm yr and lower values for finite extensional strains 2 km cumulative throw these two areas with high upper crustal strain rates overlie mantle that has relatively long spatially interpolated sks delay times 1 2 1 8 s indicating relatively high mantle strains and free air gravity values 140 160 mgals the intervening area of lower extension rate has shorter spatially interpolated sks delay times 0 8 1 2 s and lower free air gravity values 120 mgals the two areas with high upper crustal strain rates and strain mean elevation and mantle strain coincide with the northern and southern edges of a slab window in the tyrrhenian apennines subducting plate that has been inferred from published p wave tomography together these correlations suggest that dynamic support of the topography by mantle flow through the slab window may control the present day upper crustal strain rate field in the apennines and the geography of seismic hazard in the region

neogene to quaternary sedimentary basins in the south adriatic central mediterranean foredeeps and lithospheric buckling up to several kilometers deep sedimentary basins of neogene to quaternary age are found in the south adriatic between the apennines and the dinarides albanides they are the apennines foredeep the central adriatic basin and the south adriatic basin two regional seismic lines 260 and 170 km long across the entire system provide hitherto unavailable constraints on the kinematics and dynamics of basin development the apennine foredeep imaged along the lines formed in middle to late pliocene times through a rapid westward tilting of the basin floor a paleobathymetry of few kilometers was created in which allochthonous bodies were emplaced and sediments deposited unaffected by deformation and farther rotations the central and south adriatic basins formed in neogene to quaternary times and are both characterized by strong subsidence in their central parts gradually diminishing toward the edges in the sw and ne depocenters did not shift laterally through time subsidence rates increase through time and subsidence continued also following the end of main shortening episodes in the dinarides albanides the central and south adriatic basins form two crustal scale synclines with subsidence concentrated in their central parts basins geometries and subsidence patterns indicate that the adriatic crust has undergone episodes of buckling since miocene times wavelengths and amplitudes of such folds change along strike corresponding to mechanical changes of the folded medium

improving geomagnetic field reconstructions for 0 3 ka global geomagnetic field reconstructions on millennial time scales can be based on comprehensive paleomagnetic data compilations but especially for older data these still suffer from limitations in data quality and age controls as well as poor temporal and spatial coverage here we present updated global models for the time interval 0 3 ka where additions to the data basis mainly impact the south east asian alaskan and siberian regions we summarize recent progress in millennial scale modelling documenting the cumulative results from incremental modifications to the standard algorithms used to produce regularized time varying spherical harmonic models spanning 1000 bc to 1990 ad from 1590 to 1990 ad gauss coefficients from the historical gufm1 model supplement the paleomagnetic information in addition to absolute paleointensities calibrated relative paleointensity data from sediments are now routinely included iterative data rejection and recalibration of relative intensity records from sediments ensure stable results bootstrap experiments to generate uncertainty estimates for the model take account of uncertainties in both age and magnetic elements and additionally assess the impact of sampling in both time and space based on averaged results from bootstrap experiments taking account of data and age uncertainties we distinguish more conservative model estimates cals3k nb representing robust field structure at the core mantle boundary from relatively high resolution models cals3k n for model versions n 3 and 4 we assess the impact of newly available data and modifications to the modelling method by comparing the previous cals3k 3 the new cals3k 4 and the conservative new model cals3k 4b we conclude that with presently available data it is not feasible to produce a model that is equally suitable for relatively high resolution field predictions at earth s surface and robust reconstruction of field evolution avoiding spurious structure at the core mantle boundary cmb we presently consider cals3k 4 the best high resolution model and recommend the more conservative lower resolution version for studies of field evolution at the cmb

holocene climate variability and vegetation dynamics inferred from the 11700 cal yr bp laguna rabadilla de vaca sediment record southeastern ecuadorian andes palaeoenvironmental changes inferred from a 492 cm long lake sediment core from laguna rabadilla de vaca 3312 m in podocarpus national park southeastern ecuadorian andes were investigated usin

vertical movements on the eastern margin of the tyrrhenian extensional basin new data from mt bulgheria southern apennines italy abstract in this paper we present the results of an integrated stratigraphical geomorphological and morphotectonic study carried out in mt bulgheria a rocky headland located on the eastern margin of the tyrrhenian extensional basin in southern italy such a margin is characterised by the occurrence of uplifted headlands alternated with subsiding half grabens in particular mt bulgheria constitutes the northeastern margin of the gulf of policastro peri tyrrhenian depression in the study area pliocene quaternary continental deposits and erosional landforms are present together with pleistocene wave cut and wave built marine terraces the integrated study of pliocene pleistocene deposits and landforms allowed a detailed reconstruction of the geomorphological evolution of mt bulgheria to be made furthermore the tectonic behaviour of this portion of the tyrrhenian margin during plio quaternary times could be characterised in particular we recognised that a succession of alternated uplift and subsidence episodes affected the headland since the beginning of early pleistocene when the eastward migrating coastline of the tyrrhenian extensional basin reached mt bulgheria the alternated uplift and subsidence events lasted for early and middle pleistocene their cessation in late pleistocene is demonstrated by the occurrence of late pleistocene strandlines at an elevation comparable with that of the 130 ka sea level highstand as recorded in stable areas of the mediterranean region the occurrence of marine terraces allowed the absolute vertical movements to be estimated their summation produced an uplift of the headland of 400 m since the beginning of the santernian 150 m of which occurred in the middle pleistocene along the onshore belt of the tyrrhenian margin of southern apennines other structural highs bordering the peri tyrrhenian depressions provide evidence for subsidence episodes interrupting the prevailing uplift trend recorded during the quaternary this together with the distribution of quaternary marine deposits both downthrown and raised and terraces shows that the tyrrhenian margin of southern apennines was affected by strongly variable vertical movements

the seismogenic structure of the 2013 2014 matese seismic sequence southern italy implication for the geometry of the apennines active extensional belt

active fragmentation of adria the north african promontory central mediterranean orogen global positioning system gps velocities indicate that adria no longer behaves as a rigid tectonic indenter into southern europe and is divided into northwestern and southeastern velocity domains differential motions are recognized in a velocity field determined from the peri tyrrhenian geodetic array ptga and international gps service igs sites in the circum tyrrhenian region of the central mediterranean and published gps velocities from the eastern adriatic coast in a fixed eurasian reference frame ptga and igs site velocities in sicily and southern italy are as much as 10 mm yr in a northward direction similar to gps velocities along the eastern coast of the adriatic sea in contrast velocities in northern italy are small or statistically insignificant and similar to velocities in sardinia and corsica outboard of western adria the tectonic boundary dividing adria is seismically active and passes around the southern and eastern margins of the tyrrhenian basin crosses central italy extends into the adriatic sea and follows the western margin of the dinaride tectonic belt north to the gulf of venice the eastern margin of adria is approximately located and follows the axis of the central dinaric alps southeast to the hellenic arc southeastern adria has a velocity related to northward motion of africa whereas northwestern adria has negligible differential motion in the eurasian frame and now is part of the alpine collage of southern europe

different foreland basins in italy examples from the central and southern adriatic sea abstract the central adriatic basin cab and the southern adriatic basin sab are foreland or foredeep basins relative to the non coeval apenninic and dinaric hellenic orogenic systems and currently characterized by different physiographies these are separated by a major forebulge of the adriatic lithosphere running throughout the adriatic region from istria to the gargano promontory the clastic basin filling of the cab is mostly plio pleistocene whereas it is upper oligocene pleistocene in the sab stratigraphy reveals that the cab has experienced an overfilling regime throughout the plio pleistocene whereas the sab has been probably continuously underfilled during the same time span in the cab the foreland plate dips westward at an average angle of 5 6 whereas in the sab the basement dips to the east at an angle of 1 2 this discrepancy is congruent with the already noticed distinction between east and west dipping subduction systems and possibly has geodynamical implications in the cab the non homogeneous distribution of thrust sheets suggests strike slip tectonic movements along roughly ne trending lineaments that occurred up to the middle late pliocene on the western part of the sab the overall structural assemblage recalls the fabric typical to strike slip regimes and includesboth extensional and contractional structures it is proposed that the messinian salinity crisis and relative eustatic lowstand affected the subsequent tectono sedimentary evolution of the cab in terms of subsidence rate and depositional style one still tentative hypothesis is that water and sediment removal in the basin lasted for a sufficient time span to promote viscoelastic relaxation temporary migration of the forebulge towards the thrust belt and downwarping of the foreland plate

holocene variations in the asian monsoon inferred from the geochemistry of lake sediments in central tibet we present a record of monsoon variations for the early and middle holocene that is inferred from the geochemistry of sediment cores from ahung co a lake in central tibet the resolution of this record is better than 50 yr and the age model is derived from radiocarbon ages of terrestrial charcoal which eliminates errors associated with the lake hard water effect we made down core geochemical measurements of carbonate organic carbon c n and 13c of bulk organic matter 13c and 18o of carbonate and dolomite proxy calibration and modern water balance reconstruction show that these are proxies for lake depth and the amount of monsoon precipitation we find that lake level and monsoon precipitation have been decreasing at ahung co since the early holocene 7500 cal yr b p superimposed on this trend are rapid declines in monsoon rainfall at 7000 7500 and 4700 cal yr b p and seven century scale wet dry oscillations the cores do not contain sediment from the last 4000 yr surface sediments from the lake accumulated during the 20th century however from this we argue that lake levels have risen again recently following a late holocene dry period

holocene landslides and a 3500 year record of pacific northwest earthquakes from sediments in lake washington lake washington which forms the eastern boundary of seattle is located in a tectonically active area containing several strands of the seattle fault high resolution seismic reflection profiling sidescan swath imagery and sediment coring were used to define deformation of holocene lake sediments and the distribution geometry age and causes of submarine landslides numerous large block slides sediment slumps and debris flows are present throughout the lake and large landslides obscure the surficial structure of seattle fault strands as they pass through the lake in addition most bays along the lake margin are the headwalls of large submarine slides submerged forests show evidence of deep seated block failures that have exposed glacial sediments and tertiary rocks the massive submarine block slides and retrogressive submarine slope failures were triggered most likely by large m b 7 earthquakes on the seattle fault and or large to great m b 8 temblors occurring elsewhere in cascadia buried landslides suggest that submarine slope failures and mass wasting occurred more than once in the last 11 000 yr sediments in lake washington preserve a record of episodic deposition of turbidites possibly caused by seismically induced submarine landslides magnetic susceptibility profiles on 36 gravity cores show a characteristic series of magnetic peaks that can be traced throughout the lake x radiography and grain size analyses suggest that the magnetic peaks represent anomalous detrital layers that in some cases are turbidites the areal extent and magnetic signatures of many of the deposits suggest multiple sources which is consistent with numerous local landslides caused by large earthquakes radiocarbon dating and correlation of the downcore magnetic profiles establish a sediment record in which episodic sedimentary disturbances occurred seven times in the last 3500 yr if these deposits are seismically induced turbidites seismites then large earthquakes have occurred about every 300 500 yr in the puget sound region

piggyback basin development and thrust belt evolution structural and palaeostress analyses of plio quaternary basins in the southern apennines abstract in southern italy structural analysis of the intramontane pliocene quaternary terrigenous basins of sant arcangelo and ofanto shows that they are piggyback basins the recent uplift of the southern apennines provides good conditions for carrying out detailed studies of palaeostresses in relation to structure and sediment accumulation in such piggyback basins we demonstrate that in the pleistocene sant arcangelo marine basin a single n70 compression induced a complex pattern of folds and strike slip faults in contrast the older pliocene ofanto basin reveals a polyphase history characterized by successive tilts and palaeostresses according to different compressions in both basins compressional stresses are syn depositional the geometry of the sedimentary infill of these basins provides information on the thrusting activity in terms of location geometry and age we point out that in addition to sedimentary and structural studies including interpretation of seismic reflection data palaeostress analyses provide a valuable tool for deciphering development and evolution of compressional basins in a fold and thrust belt

convective support of long wavelength topography in the apennines italy two different free air gravity datasets from the apennines have been analysed in the frequency domain to investigate the mechanisms of support of topography at short wavelength 150 km shows that such topography is not supported by elastic stresses in the lithosphere but is dynamically supported by mantle convection the distribution of gravity anomalies and topography suggests that the mantle is rising beneath the main topographic bulge of the apennines and that this flow is maintained by buoyancy forces rather than being driven by movement of the subducted slab

event layers in the japanese lake suigetsu sg06 sediment core description interpretation and climatic implications event layers in lake sediments are indicators of past extreme events mostly the results of floods or earthquakes detailed characterisation of the layers allows the discrimination of the sedimentation processes involved such as surface runoff landslides or subaqueous slope failures these processes can then be interpreted in terms of their triggering mechanisms here we present a 40 ka event layer chronology from lake suigetsu japan the event layers were characterised using a multi proxy approach employing light microscopy and xrf for microfacies analysis the vast majority of event layers in lake suigetsu was produced by flood events 362 out of 369 allowing the construction of the first long term quantitative with respect to recurrence and well dated flood chronology from the region the flood layer frequency shows a high variability over the last 40 ka and it appears that extreme precipitation events were decoupled from the average long term precipitation for instance the flood layer frequency is highest in the glacial at around 25 ka bp at which time japan was experiencing a generally cold and dry climate other cold episodes such as heinrich event 1 or the late glacial stadial show a low flood layer frequency both observations together exclude a simple straightforward relationship with average precipitation and temperature we argue that especially during glacial times changes in typhoon genesis typhoon tracks are the most likely control on the flood layer frequency rather than changes in the monsoon front or snow melts spectral analysis of the flood chronology revealed periodic variations on centennial and millennial time scales with 220 yr 450 yr and a 2000 yr cyclicity most pronounced however the flood layer frequency appears to have not only been influenced by climate changes but also by changes in erosion rates due to for instance earthquakes

deformation of the 125 ka marine terrace in italy tectonic implications in peninsular italy marine terraces and shorelines created during oxygenisotope substage 5e known historically as the tyrrhenian highstand provide a reliable and homogeneous datum of vertical motions during the past 125 000 years published accounts of 121 locations on the tyrrhenian inner edge were reinterpreted and used to calculate both local and regional uplift rates the data show arching of southern italy between the tyrrhenian and the adriatic coasts and of the calabrian arc between the sangineto and the longi taormina tectonic lineaments at rates of up to 1 2 mm yr for the past 125 ka they also suggest that the present configuration of the southern apennines is the product of post early pleistocene regional uplift superimposed on tortonian to early pleistocene thrusting uplift patterns are characterised by different wavelength in different geodynamic settings suggesting a close link with the depth of the causative tectonic sources

rates of geodetic deformation across active faults in southern italy abstract active deformation in southern italy is accommodated by a distributed number of faults with low moderate slip rates outcropping extensional faults and mostly blind transcurrent faults are mapped within a western or axial and an eastern domain respectively we use a combination of continuous 2001 00 2011 84 and episodic 1995 68 2010 79 gnss observations to firstly estimate the geodetic deformation rate on 32 faults geodetic results were successively compared with geological displacement estimates in agreement with seismological and geological information a net spatial segregation emerges between the extensional axial belt and the eastern domain where strike slip faults are geodetically active although uncertainties are at times large average displacement rates show broadly consistent patterns within both domains a longitudinal gradient in extension rate is observed for the axial fault array with two sectors of higher magnitude 0 8 1 7 mm yr for individual faults this result is consistent with geological observations and supports the notion that extension occurs in discrete patches faults of the eastern domain have lower few 0 1 to 1 2 mm yr strike slip rates and an eastward decreasing extensional component but significant geodetic displacement is detected in areas lacking clear evidence of activity few faults with 1 2 mm yr extension rate are locally found in the eastern domain but based on their limited length and on inconsistency with seismology and geology they are considered as due to deep seated gravitational spreading for crustal faults although geodetic slip and moment rates are larger than geological rates the broad trend of long to short term rates is similar indicating the feasibility of geodetic analysis to contribute estimating fault slip rate and testing tectonic models in the region whereas the western domain extension is thought to be controlled by potential energy related to the tyrrhenian moho uplift beneath the apennines strike slip in the east is related to shear on inherited faults within the adriatic crust

strain and stress fields in the southern apennines italy constrained by geodetic seismological and borehole data summary we present an improved evaluation of the current strain and stress fields in the southern apennines italy obtained through a careful analysis of geodetic seismological and borehole data in particular our analysis provides an updated comparison between the accrued strain recorded by geodetic data and the strain released by seismic activity in a region hit by destructive historical earthquakes to this end we have used nine years of gps observations 2001 2010 from a dense network of permanent stations a data set of 73 well constrained stress indicators borehole breakouts and focal mechanisms of moderate to large earthquakes and published estimations of the geological strain accommodated by active faults in the region although geodetic data are generally consistent with seismic and geological information previously unknown features of the current deformation in southern italy emerge from this analysis the newly obtained gps velocity field supports the well established notion of a dominant ne sw oriented extension concentrated in a 50 km wide belt along the topographic relief of the apennines as outlined by the distribution of seismogenic normal faults geodetic deformation is however non uniform along the belt with two patches of higher strain rate and shear stress accumulation in the north matese mountains and in the south irpinia area low geodetic strain rates are found in the bradano basin and apulia plateau to the east along the ionian sea margin of southern italy in southern apulia and eastern basilicata and calabria geodetic velocities indicate nw se extension that is consistent with active shallow crustal gravitational motion documented by geological studies in the west along the tyrrhenian margin of the campania region the tectonic geodetic field is disturbed by volcanic processes comparison between the magnitude of the geodetic and the seismic strain rates computed using a long historical seismicity catalogue allow detecting areas of high correlation particularly along the axis of the mountain chain indicating that most of the geodetic strain is released by earthquakes this relation does not hold for the instrumental seismic catalogue as a consequence of the limited time span covered by instrumental data in other areas e g murge plateau in central apulia where seismicity is very low or absent the yet appreciable geodetic deformation might be accommodated in aseismic mode overall the excellent match between the stress and the strain rate directions in much of the apennines indicates that both earthquakes and ground deformation patterns are driven by the same crustal forces

mineralogy and geochemistry of the holocene lacustrine sediments in nam co tibet abstract the carbonates clays and major chemical compositions of lacustrine sediments in nam co lake were examined by x ray diffraction scanning electron microscopy and chemical analysis carbonates include monohydrocalcite mhc first report from china and in a high altitude lake low mg calcite and traces of dolomite mhc in nam co is developed in water 1 8 g l with high mg ca molar ratios 10 03 15 03 high ph 8 04 9 72 and the presence of bacteria algae diatom and ostracoda illite and mg chlorite provide a strong evidence for physical weathering in the holocene most ca and sr in sediments originate from carbonates as the molar ratios of ca and co32 are all less than 1 and the curve of sr is very similar to that of ca however most of the mg fe and rb are from clays the lake water shifted from a fresh water environment to an evaporative alkaline environment by 2 06 cal ka bp there was a depositional event that the depositional rate changed from 0 134 to 1 639 mm a at about 2 cal ka bp

history and tectonic implications of low angle detachment faults and orogen parallel extension picentini mountains southern apennines fold and thrust belt italy late miocene to pliocene movement on low angle extensional faults within the internal southern apennines orogenic belt was superposed on an earlier miocene imbricate thrust stack the low angle faults formed within the interior of the belt during orogen parallel extension as thrust imbrication continued in the foreland extreme tectonic thinning defines discrete structural domains of hyperextension which are linked by a complex system of extensional and transcurrent faults some of the best examples of hyperextension structures in the southern apennines are exposed in the picentini mountains in this area detailed mapping fault kinematic analysis and excellent stratigraphie control contributed to the construction of restorable cross sections and forward models of deformation with these constraints it is possible to document extensional displacement on shallowly dipping supercrustal faults whose orientation is a primary feature and is not due to later tilting during movement upper plate rocks were disarticulated by listric and planar normal faults that soled into a ramp flat detachment system the depth of the basal detachment increased in the direction of upper plate motion and ranged from 5 to 10 km displacement on the low angle detachment was accompanied by block tilting in the upper plate assemblage incisement and excisement of the upper and lower plate rocks as fault trajectories changed through time and the progressive cataclasis of hanging wall and footwall assemblages preexisting thrusts were only locally reactivated during extension and faults emanating from the underlying decollement systems cross the imbricated thrust sheets at moderate to high angles longitudinal extension resulted in thinning of the thrust stack to less than half the original thickness and had a cumulative magnitude of between 200 and 250 beta 2

paleoclimatic changes on the southern tibetan plateau over the past 19 000 years recorded in lake pumoyum co and their implications for the southwest monsoon evolution abstract the paleoclimatic changes in the southern region on the tibetan plateau tp after the lgm were studied by multi proxy analysis including pollen ca carbonates toc 13 c toc plant macrofossils and sands with sediment cores from lake pumoyum co close to the east end of the himalayas the following paleoclimatic changes characteristic of the southern tp were suggested by comparing with the paleoclimatic records from various regions within the southwest sw monsoon domain on the tp soon after the lgm deglaciation in the southern tp had already started at 18 5 ka bp and more actively increased after ca 16 5 ka bp with the hydrological circulation oscillating in ca 1200 2000 and 4000 year periods an abrupt increase in humidity under the reduced sw monsoon intensity occurred at 15 0 ka bp as part of further deglaciation processes subsequently the climate amelioration in the southern region started from 15 0 ka bp a few centuries earlier than other regions of the tp and then was further intensified by synchronizing with the bolling allored b a event over the b a period the sw monsoon intensity in the southern region almost continuously and sharply increased unlike many regions on the tp the southern region experienced almost no or substantially small impact of the younger dryas yd event and also other major dry cold reversals such as heinrich 1 event the 8 2 kyr event and an abrupt spell occurring between 5 and 4 ka bp the monsoon intensity in the southern region after the yd event started to rapidly increase from 11 4 ka bp and reached a maximum between 10 8 and 10 0 ka bp after the lgm which lagged about 1200 years behind the maximum insolation in the northern hemisphere from ca 9 6 ka bp the gradual decrease in humidity in the southern tp started and continued until 4 2 ka bp it s aridification trend was characterized by three stepwise transition observed at 9 6 7 7 and 5 5 ka bp however the aridification in the southern tp was rather weak and the climatic conditions were sustained fairly humid and comparably stable the humidity between 4 2 and 2 5 ka bp essentially increased despite the weakened sw monsoon intensity at that time whereas from 2 5 ka bp to the present the climatic conditions became most arid and instable during the holocene as a consequence the holocene climate optimum in the southern region lasted from 11 4 ka bp until 2 5 ka bp and was marked by the earliest start and the latest end timings within the sw monsoon domain on the tp the comparison of the start timings from various paleoclimatic records indicated that the first sw monsoon on the tp after the yd event generated at 11 4 ka bp in the southern region subsequently according to the degree of the recovery of positive vegetation albedo feedback system in each region the monsoon probably extended from the southern tp over the entire tp taking 3000 4000 years based on these results the possible key factors and mechanisms responsible for the paleoclimatic changes in the southern region and also the possible processes as to the evolution of the sw monsoon over the tp are discussed

erosional landsurfaces of the campano lucano apennines s italy genesis evolution and tectonic implications abstract within the campano lucano apennines small but widespread relics of gentle erosional landsurfaces gels occur that are elevated several hundred metres above the present valley floors on the basis of our observations the old idea that all these relict landforms can be traced back to a single phase of quasi planation that affected the entire belt after thrust stacking and before a phase of final uplift must be rejected new field evidence and chronological constraints support the conclusion that the gel relics belong to various uncompleted cycles of erosion that occurred just during the construction of the chain i e late miocene to early pleistocene as many recent geological studies have pointed out the southern apennines chain is an arc shaped accretionary wedge that migrated as a thrusting system towards its retreating foreland by means of addition of thrust units to the front and loss of rifted portions at the rear tyrrhenian back arc basin also the spatial distribution of the various generations of gels their ages and their relations to the main structures and syn orogenic formations of the belt seem to agree with this geodynamic scenario here we propose a first approximation conceptual model that considers each generation of campano lucano apennines gels as largely formed when the thrust units on which they rest were located at low elevation near the coastline of the foredeep basin i e shortly after the entrance of those thrust units into the tectonic wedge then each gel as a matter of fact the compartment on which it rested was taken towards more and more internal parts of the wedge as frontal accretion continued owing to this relative migration the fate of each gel carrying compartment was to reach the part of the belt that was affected by extensional block faulting i e the tyrrhenian side of the chain each gel eventually reaching this domain was tectonically fragmented deeply cut by waves of fluvial dissection proceeding from the steep tectonic coast toward the ne and finally also rifted under the tyrrhenian sea other causes of gels fragmentation and dissection were probably the breaching of the chain s outer flank by out of sequence thrust and the up arching of the roof thrust system caused by the formation of deep anticlinal stacks on the contrary when forward propagation of thrusts continued for long periods the gels being carried toward the inner zone of the wedge could not have experienced deep dissection because the increase of their elevation a s l was compensated by their increasing distance from the foredeep coastline maintenance of low gradient along the river valleys thanks to a very low critical taper

deep structure of the campanian lucanian arc southern apennine italy abstract recent exploration activities and successful discovery of large oil fields in the upper val d agri area southern apennine italy have encouraged the collection of large quantities of geological and geophysical data and their integration into comprehensive geological models here we present a series of structural profiles based on several hundred kilometres of seismic lines two and three dimensional and the results of many deep wells the best seismic lines have been extensively reprocessed and also tied to magnetotelluric data geological interpretations of those lines have been interactively tested and verified by gravity and magnetic modelling and structural balancing the wells and seismic data demonstrate that the fundamental tracts of the deep architecture of the orogen as it appears today were developed only at the end of the late pliocene the final closure of the ensialic shear zone responsible for the subduction of at least 150 km of continental lithosphere originally underlying the lagonegro basin can be dated as early pliocene the involvement of the inner apulian platform in the core of the belt and the activation of a new and more external left lateral oblique ensialic shear zone can be constrained to the late pliocene pleistocene the seismic profiles clearly show the underthrusting of the outer apulian platform unit beneath the inner apulian platform unit the thick skinned character of the plio pleistocene contractional structures is evident from the structural profiles this geometry is constrained by gravity magnetic data and structural considerations according to the relatively steep angle of dip about 10 of the apulian foreland beneath the chain the structural profiles depict the general architecture of the campanian lucanian arc the apennine platform and lagonegro unit are largely allochthonous and a part of the lagonegro basement could be buried below the apennine platform sole thrust the neogene plastic successions of the apennine platform and lagonegro basin were detached and now outcrop in the bradanic foredeep the inner apulian platform constitutes a huge thrust sheet structured as a wide antiform in the core of the belt its regional culmination roughly corresponds to the val d agri area extensional and transtensional structures cross cut the pre existing compressional structures as shown by the quaternary valleys of vallo di diano and val d agri the profiles shown also highlight the existing contrast between the deep structures in the core of the belt and the tectonic style of the lagonegro liguride and sicilide units these units were in fact subjected to brittle ductile deformation under metamorphic part of liguridi units and deep diagenetic to anchizonal conditions lagonegro units and were affected by a general overthrust shear directed towards the ne the inner apulian platform was on the contrary involved in the thrust belt together with its basement whereas the outer apulian platform affected by a subduction underwent a regional bending with associated normal faulting

sea level changes since the middle ages along the coast of the adriatic sea the case of st nicholas basilica bari southern italy abstract during the last decade several papers have been published to estimate the relative sea level change from coastal archaeological indicators of the last 3 4 ka bp in many locations of the italian coasts and the mediterranean sea the use of the archaeological information has been poorly focused for the middle ages due to the few available coastal installations for this period thus not allowing precise sea level estimation for the last 1000 years to complement the instrumental data available for the last 100 120 years this study discusses an archaeological marker of the middle ages used to reconstruct the story of the sea level changes in the last 1000 years at the st nicholas basilica built in 1087 ad along the coast of bari apulia southern italy the elevations of the ancient floor levels of the crypt underwent repeated flooding due to a continuous rising of the groundwater table which required restoration and uplifting of pavements between 1087 and 1956 to keep them dry the palaeo sea levels have been obtained by measuring the position of the groundwater table the elevation of which is mainly driven by sea level since the time of the construction of the basilica the elevation of the archaeological markers and the water table were compared against the latest predicted sea level curve for the holocene along the coast of bari as this coastal area is unaffected by significant vertical tectonic motion over the last 125 ky the data detail the timing of the relative sea level rise since the middle ages and can be used to improve the predicted sea level curve for this region for the last 1000 years

provenance and earthquake signature of the last deglacial xinmocun lacustrine sediments at diexi east tibet abstract well preserved lacustrine sediments are found in some areas in east tibet this region is characterized by a windy and semi arid climate alpine valleys and frequent earthquakes measurements of rare earth elements observations from a scanning electron microscope and a high resolution record of grain size measurements allowed us to compare fine sediments from the xinmocun section in the diexi lake with loess from the chinese loess plateau and south china results indicate that fine grains of the xinmocun lacustrine sediments were transported by wind and trapped in the lake whereas the 16 m fraction was likely from local sources the grain size changes within the section repeatedly show abrupt coarsening and upward fining probably due to palaeoearthquake events large earthquakes in the study area often caused rockfalls and landslides exposing fine sediments that had accumulated on mountains slopes the fine grains were then retransported by wind to the diexi lake optically stimulated luminescence dating of the xinmocun section indicates continuous deposition from 18 65 to 10 63 ka these results indicate that palaeoearthquakes in the study area had a mean recurrence interval of 0 32 ka therefore we propose that lacustrine sediments in a tectonically active region have the potential to record a continuous history of palaeoearthquakes palaeoearthquakes probably produced numerous rockfalls and landslides in alpine valleys and provided significant sources of regional eolian dust

geotechnical aspects of soil slips in alpine regions abstract slope movements are due to many different causes numerous investigations carried out during the last ten years have led to the supposition that almost all slope movements and particularly those occurring in soils are conditioned by a significant combination of factors for the alpine regions quantity duration and kind of precipitation have to be considered as direct mechanical causes combined with such contributing factors as geological and soil mechanical properties aspect vegetation slope inclination and slope morphology they will determine the type dimensions and process of slope movements the detailed investigation of 140 slope movements in slightly cohesive soils show that the process of movement is represented by sliding and flow events in particular it was found out that shallow scars with planar slides predominate so that the supposition of an infinite slope model for slope stability appears to be justified in many cases debris flows and debris avalanches continued downslope of the source area of the scars

ground deformation due to tectonic hydrothermal gravity hydrogeological and anthropic processes in the campania region southern italy from permanent scatterers synthetic aperture radar interferometry abstract we apply the permanent scatterers synthetic aperture radar interferometry ps insar technique to the campania region southern italy which includes the southern apennines chain and plio quaternary structural depressions with the aim to detect ground displacements at a regional scale the study area which extends for 13 600 km 2 is characterized by intense urbanization active volcanoes phlegraean fields vesuvius and ischia seismogenic structures landslides hydrogeological instability ps insar technique allows us to identify a set of radar benchmarks ps where accurate displacement measurements can be carried out about 1 7 10 6 ps are identified by processing synthetic aperture radar sar images acquired in ascending and descending orbits from 1992 to 2001 by the european remote sensing satellites ers the ps insar application at regional scale detected ground deformations ranging from 28 to 39 mm yr the calculated velocity values are consistent with the available gps and levelling data from selected areas we identify volcanic areas in which the deformation is mainly related to the depressurization of the local hydrothermal systems and recognize deformations along seismogenic and aseismic nnw sse and nw se faults the deformations localized along the southern apennines chain are mainly related to landslides while those occurring in the plains are due to subsidence processes induced by intensive drainage from wells i e anthropic activity the review of 9 years of sar data shows that tectonic volcanic hydrothermal gravity and anthropic processes are responsible for the ground deformation of campania the proposed joint interpretation of deformation fields related to natural and anthopogenic factors provides a comprehensive view of the dynamics of the earth s surface

middle pleistocene to holocene activity of the gondola fault zone southern adriatic foreland deformation of a regional shear zone and seismotectonic implications abstract recent seismicity in and around the gargano promontory an uplifted portion of the southern adriatic foreland domain indicates active e w strike slip faulting in a region that has also been struck by large historical earthquakes particularly along the mattinata fault seismic profiles published in the past two decades show that the pattern of tectonic deformation along the e w trending segment of the gondola fault zone the offshore counterpart of the mattinata fault is strikingly similar to that observed onshore during the eocene pliocene interval based on the lack of instrumental seismicity in the south adriatic offshore however and on standard seismic reflection data showing an undisturbed quaternary succession above the gondola fault zone this fault zone has been interpreted as essentially inactive since the pliocene nevertheless many investigators emphasised the genetic relationships and physical continuity between the mattinata fault a positively active tectonic feature and the gondola fault zone the seismotectonic potential of the system formed by these two faults has never been investigated in detail recent investigations of quaternary sedimentary successions on the adriatic shelf by means of very high resolution seismic stratigraphic data have led to the identification of fold growth and fault propagation in middle upper pleistocene and holocene units the inferred pattern of gentle folding and shallow faulting indicates that sediments deposited during the past ca 450 ka were recurrently deformed along the e w branch of the gondola fault zone we performed a detailed reconstruction and kinematic interpretation of the most recent deformation observed along the gondola fault zone and interpret it in the broader context of the seismotectonic setting of the southern apennines foreland region we hypothesise that the entire 180 km long molise gondola shear zone is presently active and speculate that also its offshore portion the gondola fault zone has a seismogenic behaviour

reconciliation of late quaternary sea levels derived from coral terraces at huon peninsula with deep sea oxygen isotope records a major discrepancy between the late quaternary sea level changes derived from raised coral reef terraces at the huon peninsula in papua new guinea and from oxygen isotopes in deep sea cores is resolved the two methods agree closely from 120 ka to 80 ka and from 20 ka to 0 ka ka 1000 yr before present but between 70 and 30 ka the isotopic sea levels are 20 40 m lower than the huon peninsula sea levels derived in earlier studies new high precision u series age measurements and revised stratigraphic data for huon peninsula terraces aged between 30 and 70 ka now give similar sea levels to those based on deep sea oxygen isotope data planktonic and benthic 18o data using the sea level and deep sea isotopic data oxygen isotope ratios are calculated for the northern continental ice sheets through the last glacial cycle and are consistent with results from greenland ice cores the record of ice volume changes through the last glacial cycle now appears to be reasonably complete