radiocarbon studies of latest pleistocene and holocene lava flows of the snake river plain idaho data lessons interpretations abstract latest pleistocene holocene basaltic lava fields of the snake river plain idaho have been dated by the radiocarbon method backhoe excavations beneath lava flows typically yielded carbon bearing charred eolian sediment this material provided most of the samples for this study the sediment typically contains less than 0 2 carbon charcoal fragments were obtained from tree molds but only from a few backhoe excavations contamination of the charred sediments and charcoal by younger carbon components is extensive the effects of contamination were mitigated but appropriate pretreatment of samples using acid and alkali leaches twenty of the more than 60 lava flows of the craters of the moon lava field have been dated their ages range from about 15 000 to about 2000 yr b p the ages permit assignment of the flows to eight distinct eruptive periods with an average recurrence interval of about 2000 yr the seven other latest pleistocene holocene lava fields were all emplaced in short eruptive bursts their 14 c ages yr b p are kings bowl 2222 100 wapi 2270 50 hells half acre 5200 150 shoshone 10 130 350 north robbers and south robbers 11 980 300 and cerro grande 13 380 350

holocene subaqueous paleoseismology of lake tahoe gravity flow deposits recovered in a suite of sediment cores in lake tahoe were examined to determine if the event deposits were triggered by strong shaking from earthquakes on active faults within and in close proximity to the lake tahoe basin the acoustic character and distribution of individual lacustrine deposits as well as potential source regions were constrained by high resolution seismic chirp reflection and multibeam bathymetric data between 14 and 17 holocene event deposits have been identified in lake tahoe and examination of their source areas suggests they originated from different initiation points along the steep margin with some being synchronous around the basin as opposed to flood related deposits lithologic characteristics magnetic susceptibility carbon and nitrogen isotopic signatures opal content and 14 c dating indicate that these event deposits are reworked lacustrine material radiocarbon dates indicate that the emplacement of these event deposit sediments correlates well with the late holocene paleoseismic earthquake record developed for the tahoe basin when taken alone the causality of these events may appear ambiguous but when the evidence is examined comprehensively it suggests that strong shaking may likely have been the primary trigger for many of the event deposits observed in the lake throughout the holocene for example four event deposits are assigned to tahoe basin faults the most recent earthquakes occurred on the incline village fault between 630 and 120 cal yr b p the southern segment of the west tahoe fault between 4510 and 4070 cal yr b p on the central and northern segments of the west tahoe fault 5600 5330 cal yr b p and on the west tahoe fault between 7890 and 7190 cal yr b p the oldest of the four associated tahoe basin events coincides with the beginning of an extended period when lake tahoe was likely not spilling or spilling intermittently and this suggests that active faulting and footwall uplift cut off the outlet at this time exaggerating drought conditions downstream likewise the event between 5600 and 5330 cal yr b p on the west tahoe fault may have exaggerated a smaller drought reflected downstream in pyramid lake this event may also be the most recent event mre on the largest segment of the west tahoe fault if correct the period since the last rupture is approximately twice the estimated average recurrence interval for the rubicon segment of the west tahoe fault a more complete holocene record of strong shaking greatly extends the paleoseismic record in the region and indicates a combined recurrence interval of between 750 and 800 yr for all faults in the region

late holocene erosion in upland britain climatic deterioration or human influence the evidence for enhanced erosion in upland britain during the late holocene is evaluated though there is widespread evidence for recent soil erosion on high plateaux this has not been precisely dated radiocarbon dating confirms the occurrence of late holocene solifluction on high ground but at only one site has evidence been found for recent accelerated activity several areas however have yielded evidence of late holocene debris cone accumulation and parts of the scottish highlands experienced a drastic increase in debris flow activity over the past few centuries climatic deterioration and vegetation degradation resulting from overgrazing or burning are frequently cited as the causes of enhanced erosion but cause and effect are often related only by coincidence of timing in consequence only circumstantial evidence links erosion with climatic deterioration though anthropogenic influences have been more firmly established at a few sites the role of extreme events in initiating phases of uplan

rock weathering rates as functions of time the scarcity of documented numerical relations between rock weathering and time has led to a common assumption that rates of weathering are linear this assumption has been strengthened by studies that have calculated long term average rates however little theoretical or empirical evidence exists to support linear rates for most chemical weathering processes with the exception of congruent dissolution processes the few previous studies of rock weathering rates that contain quantitative documentation of the relation between chemical weathering and time suggest that the rates of most weathering processes decrease with time recent studies of weathering rinds on basaltic and andesitic stones in glacial deposits in the western united states also clearly demonstrate that rock weathering processes slow with time some weathering processes appear to conform to exponential functions of time such as the square root time function for hydration of volcanic glass which conforms to the theoretical predictions of diffusion kinetics however weathering of mineralogically heterogeneous rocks involves complex physical and chemical processes that generally can be expressed only empirically commonly by way of logarithmic time functions incongruent dissolution and other weathering processes produce residues which are commonly used as measures of weathering these residues appear to slow movement of water to unaltered material and impede chemical transport away from it if weathering residues impede weathering processes then rates of weathering and rates of residue production are inversely proportional to some function of the residue thickness this results in simple mathematical analogs for weathering that imply nonlinear time functions the rate of weathering becomes constant only when an equilibrium thickness of the residue is reached because weathering residues are relatively stable chemically and because physical removal of residues below the ground surface is slight many weathering features require considerable time to reach constant rates of change for weathering rinds on volcanic stones in the western united states this time is at least 0 5 my

luminescence dating of recent dunes on inch spit dingle bay southwest ireland fifteen samples of dune sand and three samples from a core taken in the beach face were collected from a sand spit which protrudes into dingle bay in southwest ireland the potassium rich feldspar grains from the samples were dated using a single aliquot luminescence protocol for infrared stimulated luminescence irsl signals no ages over 600 years were obtained which demonstrates the youth of the dune forms currently observed the youngest ages were about 150 years old but for these samples the scatter in the equivalent dose obtained as the mean of 18 measurements was higher than for the older samples

the 1996 ad delta collapse and large turbidite in lake brienz abstract in spring 1996 ad the occurrence of a large mass transport was detected by a series of events which happened in lake brienz switzerland turbidity increase and oxygen depletion in deep waters release of an old corpse into surface waters and occurrence of a small tsunami like wave this mass transport generated a large turbidite deposit which is studied here by combining high resolution seismic and sedimentary cores this turbidite deposit correlates to a prominent onlapping unit in the seismic record attaining a maximum of 90 cm in thickness it is longitudinally graded and thins out towards the end of the lake basin thickness distribution map shows that the turbidite extends over 8 5 km2 and has a total volume of 2 72 106 m3 which amounts to 8 7 yr of the lake s annual sediment input it consists of normally graded sand to silt sized sediment containing clasts of hemipelagic sediments topped by a thin white clay sized layer the source area the exact dating and the possible trigger of this turbidite deposit as well as its flow mechanism and ecological impact are presented along with environmental data river inflow wind and lake level measurements the combined results indicate that no particular cause i e earthquake explosion flood wind storm lake level change seiche or sediment dredging triggered the 1996 ad large turbidite deposit instead it was due to a delta slope failure most likely caused by normal sediment accumulation

origin of turbidites in deep lake geneva france switzerland in the last 1500 years abstract turbidites in lacustrine sediments are commonly used to assess the frequencies of flood events and or earthquakes understanding the origin of those deposits is key to adequately assess the sources and triggers of such events in large lacustrine systems ca ti x ray fluorescence core scanner and magnetic susceptibility values on sediment cores of the deep basin of lake geneva are used as a provenance indicator of the turbidites either from the dranse or rhone deltas or from the slopes not influenced by deltaic input this tool is validated by mineralogical analyses x ray diffraction major and trace element geochemistry x ray fluorescence based on this discrimination method the turbidites deposited in the central part of the deep basin can be classified regarding their origin from all identified turbidites four turbidites are chosen based on their large depositional area and volumes and are studied in more detail in order to better understand the processes leading to turbidite deposition in the deep basin the age intervals of these turbidites were compared to the historical records of extreme events in the region of lake geneva these turbidites can be related to extreme floods earthquakes and spontaneous delta collapses the cause of two turbidites could not be identified precisely due to large dating intervals that did not allow attributing a specific historical event to the turbidite layer overall this study provides a tool in classifying the turbidites in deep lake geneva and exemplifies that defining the cause of turbidites is complex although it remains a prerequisite for paleohydrology and paleoseismology studies

deep electrical resistivity tomography for the prospection of low to medium enthalpy geothermal resources summary the growth of the geothermal industry sector requires innovative methods to reduce explo ration costs whilst minimizing uncertainty during subsurface exploration until now geoelec trical prospection had to trade between logistically complex cabled technologies reaching a few hundreds meters deep versus shallow reaching prospecting methods commonly used in hydro geophysical studies we present a recent technology for geoelectrical prospection and show how geoelectrical methods may allow the investigation of medium enthalpy geothermal resources until about 1 km depth the use of the new acquisition system which is made of a distributed set of independent electrical potential recorders enabled us to tackle logistics and noise data issues typical of urbanized areas we acquired a 4 5 km long 2 d geoelectrical survey in an industrial area to investigate the subsurface structure of a sedimentary sequence that was the target of a 700 m geothermal exploration well geo 01 satigny in the greater geneva basin western switzerland to show the reliability of this new method we compared the acquired resistivity data against reflection seismic and gravimetric data and well logs the processed resistivity model is consistent with the interpretation of the active seismic data and density variations computed from the inversion of the residual bouguer anomaly the combination of the resistivity and gravity models suggest the presence of a low resistivity and low density body crossing mesozoic geological units up to palaeogene neogene units that can be used for medium enthalpy geothermal exploitation our work points out how new geoelectrical methods may be used to identify thermal groundwater at depth this new cost efficient technology may become an effective and reliable exploration method for the imaging of shallow geothermal resources

photomosaics of the cathodoluminescence of 60 sections of meteorites and lunar samples 1 cathodoluminescence cl petrography provides a means of observing petrographic and compositional properties of geological samples not readily observable by other techniques we report the low magnification cl images of 60 sections of extraterrestrial materials the images we report include ordinary chondrites including type 3 ordinary chondrites and gas rich regolith breccias enstatite chondrites co chondrites and a cm chondrite eucrites and a howardite lunar highland regolith breccias and lunar soils the cl images show how primitive materials respond to parent body metamorphism how the metamorphic history of el chondrites differs from that of eh chondrites how dark matrix and light clasts of regolith breccias relate to each other how metamorphism affects eucrites the texture of lunar regolith breccias and the distribution of crystallized lunar spherules lunar chondrules and how regolith working affects the mineral properties of lunar soils more particularly we argue that such images are a rich source of new information on the nature and history of these materials and that our efforts to date are a small fraction of what can be done

late holocene post 4000 years bp coastal dune development in northumberland northeast england the recent environmental history of coastal dune systems in northumberland northeast england has been examined using geomorphological stratigraphical and sedimentological techniques linked to radiocarbon and infrared stimulated luminescence irsl dating stratigraphies were determined from 22 vibracores and three sections and dune chronology was based on 28 14 c dates from peat and soil organic horizons and 26 irsl dates on k feldspar grains from within sand layers almost all dune systems are associated with regressive shorelines consequent upon a fall in relative sea level rsl from its holocene peak and indicate rsl functioned as a macroscale control on dune development where dunes are anchored on terrestrial sediment dune expansion may have been either transgressive or regressive in nature where near shore marine sediments form the dune substrate a regressive prograding dune model seems most likely most dune building occurred during the little ice age lia probably in a

evidence of a strong paleoearthquake in 9 1 ka cal bp interpreted from mass transport deposits western quebec northeastern ontario canada this paper reviews and expands upon stratigraphic and chronologic evidence supporting the interpretation of a strong early postglacial paleoearthquake in western quebec northeastern ontario canada event horizon mapping at dasserat dufresnoy and duparquet lakes quebec coring at chassignolle and malartic lakes quebec analysis of varve exposures near both the twin falls and frederick house dams ontario and review of published and unpublished logs of varve exposures reveal that mass transport deposits formed in or are inferred to have formed in varve year vyr 1483 relative to the timiskaming varve series and about 9 1 ka cal bp are present at numerous locations within the study area the spatial extent of the vyr 1483 mass transport deposit signature covers at least 14 600 km2 and is best explained by shaking from a paleoearthquake the magnitude of the event is estimated to be a minimum of m 7 3 which is indicative of a strong paleoearthquake the vyr 1483 paleoearthquake is one of 11 events of m 5 occurring within a 425 varve year period between 9 4 and 8 95 ka cal bp and is likely part of a period of elevated early postglacial seismicity associated with rapid crustal unloading the absence of an equivalent signature within the younger portion of the glaciolacustrine or lacustrine deposits in local lakes implies that this paleoearthquake is the strongest to occur within the study area since about 9 1 ka cal bp the highly precise correlation of widely spaced mass transport and disturbed deposits provided by varves is essential to the paleoearthquake interpretation

induced thermoluminescence as a method for dating recent volcanism hawaii county hawaii usa abstract we have measured the induced thermoluminescence tl properties of fifteen samples of basalts collected from the big island of hawaii in order to continue our investigation into the possible utility of this technique as a chronometer previous studies of basalts from idaho have suggested the induced tl of basalts increases with age meteorite data suggest two possible explanations for this observation which are that 1 the initial glassy or amorphous phases crystalize with time to produce feldspar the mineral producing the tl signal and 2 feldspars lose fe as they equilibrate and since fe is a quencher of tl this would cause an increase in tl the old basalts from kohala 100 ka which are mostly alkali basalts have tl sensitivities 10 100 times higher than the much younger tholeiites from kilauea and mauna loa

sand drift and soil formation along an exposed north atlantic coastline 14 000 years of diverse geomorphological climatic and human impacts this paper sets out the history of aeolian deposition and soil formation over the last 14 15 000 calendar years along the exposed and gale prone atlantic coastlines of the southern isles of the outer hebrides of scotland detailed palaeoenvironmental interpretation and chronological control have been provided by field mapping soil micromorphological analyses and radiocarbon and optically stimulated luminescence osl dating programmes two dominant types of aeolian sands are described in this region quartzose sands are shown to originate mainly as periglacial wind blown sands derived from glacial and periglacial deposits of late devensian age which were formerly exposed on the present continental shelf this aeolian deposition did however continue into the early holocene with re working perhaps by slope wash taking place as recently as the 4th millenniumbp quartzose sands mantle valley floors and hillslopes by the end of the devensian and early holocene a variety of soil types with extensive horizonation had developed upon them including podzolic brown earths peaty gleys and peat soils radiocarbon and osl dating demonstrate that the carbonate sands of the machair sand sheets which characterize the present atlantic shorelines began to accumulate very early for a european shoreline from approximately 8700 calendar years ago on benbecula and north uist whereas further south deposition began later osl dating suggests that non sequences and diastems are common in greater part these machair sand sheets are best interpreted as a composite of separate slivers of sand reflecting small scale and local episodes of sand drift rather than distinct layers of region wide distribution which might reflect past major storms or significant palaeoclimatic fluctuations the new evidence presented here provides little support for the following explanatory geomorphic or stratigraphic models which have previously sought to explain the development of these coastal machair landscapes continuous development layer cake or step wise prograding coastal barrier qualified support is given for the explanations that emphasize i the long term spasmodic input and re cycling of sands and ii that the present smoothed landscapes and distinctive machair grassland vegetation are essentially recent in age and reflect the interactions of natural and human processes in a stormy environment characterized by re working widespread layers of thick organic materials within the carbonate sands in the study area which have previously been regarded as dune palaeosols dating to the bronze age and iron age are suggested by soil micromorphological analysis to be in significant part anthropogenic in origin they are organically enriched layers or midden soils the consequence of human activities notably the disposal of organic wastes and other forms of soil modification during times of significant settlement in these coastal sands these periods of relatively intense human activity are therefore shown to be associated at least locally with periods of soil formation and stability not universal instability and dune drift along these shorelines in general these extensive layers of midden soil do not necessarily imply periods of decreased storminess relatively widespread soil formation in these coastal dunes did however take place in the period between 400 and 100 years ago essentially within the period of increased storminess associated with the little ice age it is suggested that at some point s within the following periods of time broadly defined in calendar yearsbp notable sand drift affecting the quartzose sands the carbonate sands or both took place within the study area 13 700 13 000 11 000 10 500 9000 8300 7500 7000 6900 6400 5800 4200 one of the most notable episodes of drift in the outer hebrides as well as elsewhere on the coast of north west europe 3800 3300 1700 1300 600 200 with individual great storms being recorded in the 17th and 18th centuries and 100 present day limited drift associated with machair stratification

magnitudes and source areas of large prehistoric northern alpine earthquakes revealed by slope failures in lakes we identify evidence for three large paleo earthquakes in central switzerland with moment magnitudes m 6 5 7 0 significantly exceeding historically known values these earthquakes occurred during the past 15 k y and were strong enough to simultaneously affect a large region that includes the present day major cities of lucerne and zurich we reconstruct the chronology magnitudes and epicenters of these prehistoric earthquakes using temporal and spatial correlation of multiple subaqueous landslide deposits in lake zurich and lake lucerne through high resolution seismic surveys radiocarbon dated sediment cores and spatial calculations using an empirical seismic attenuation model our data indicate ongoing alpine deformation that generated and could potentially generate destructive events in heavily populated regions that have been unaccustomed to seismic activity during historic time

multidirectional synchronously triggered seismo turbidites and debrites revealed by x ray computed tomography ct on 21 april 2007 a mw 6 2 earthquake struck aysen fjord chilean patagonia and caused onshore and offshore mass movements which triggered tsunamis and density flows in the fjord to better understand the facies successions in and the intercalation of the density flow deposits a study was made of the 2007 deposits in 22 short sediment cores taken in the inner aysen fjord by combining grain size analysis with x ray computed tomography scanning it was possible to demonstrate that the encountered facies correspond to classical divisions of debrites and turbidites the single event deposits consist of a succession of several sub deposits deposited under different flow directions and can be interpreted as stacked turbidites orientations of i folds ii imbricated mud clasts iii backsets and foresets of climbing ripples and iv asymmetrical convolute lamination were used to determine relative flow directions at the location of the cores by assigning the basal flow of the stacked debrites and turbidites to the closest principal mass flow the absolute flow directions of the sub deposits were determined which in combination with multibeam basin floor morphology allowed reconstruction of the 2007 density flow successions in aysen fjord furthermore alternating flow directions provide evidence for a seiche induced by the density flows it was concluded that x ray computed tomography scans provide crucial information for reconstructing palaeoflows and can be a useful tool in marine and lacustrine sedimentology and palaeoseismology the multidirectionality of sub deposits in turbidites is next to differences in mineralogy a new criterion to identify stacked turbidites these multidirectional stacked turbidites are an indication of simultaneous triggering of density flows and can therefore in most cases be attributed to earthquakes ruling out other triggers such as floods storms or other sediment failures this article is protected by copyright all rights reserved

thermoluminescence constraints on the metamorphic shock and brecciation history of basaltic meteorites abstract induced thermoluminescence measurements have been performed on eighteen eucrites thirteen howardites plus seven splits from the bholghati howardite six diogenites and fifteen mesosiderites in order to help clarify their metamorphic shock and brecciation history the tl sensitivities of the basaltic meteorites reflect their bulk composition and the effects of 1 igneous processes diogenites and mesosiderites and 2 the mixing of materials of different compositions e g diogenitic and eucritic during brecciation howardites can be observed two previously unclassified mesosiderites lew87006 and eet87500 are assigned to class a and b respectively on the basis of their tl sensitivities the eucrites show a 15 fold range of tl sensitivities which correlate with petrographie indicators of metamorphic intensity we therefore describe a petrologic type scale based on tl and petrographie evidence where the least metamorphosed eucrites are type 1 and most equilibrated are type 8 we see no evidence for two discrete metamorphic environments corresponding to the equilibrated and unequilibrated eucrites the temperature of the dominant tl peak observed for basaltic meteorites and experiments in which four eucrites with diverse petrographie properties were annealed at various temperatures in the laboratory suggests the metamorphic equilibration temperatures for most basaltic meteorites were 800 c this estimate is generally consistent with palaeotemperatures determined from two pyroxene olivine pyroxene and oxygen isotope equilibria assuming this temperature was typical of conditions during metamorphism then burial depths for type 5 eucrites were 350 m and

late holocene inland dune activity in the uk a case study from breckland east anglia inland dune fields found in breckland east anglia uk have previously been correlated with the widespread late devensian coversands of the region and a seventeenth century sandflood which is known to have inundated the village of santon downham a programme of optically stimulated luminescence and radiocarbon dating undertaken on the dunes at wangford warren and santon downham reveals that episodic aeolian activity has taken place during the last 7000 years five sand depositional phases on breckland dunes are identified c 6500 c 1600 1100 c 500 c 400 335 and from c 200 30 years before present between c 2120 1840 years ago and within the period 1100 300 years ago quiescent periods allowed the development of fen peat and soils local controlling factors on aeolian activity in breckland appear to be related to anthropogenic activities and livestock sheep and rabbits reducing vegetation cover and decreased precipitation and sea levels which led to lowering of water tables breckland aeolian activity when compared to the national and sub continental holocene aeolian activity record shows a high level of concordance the underlying forcing factor for late holocene dune activity in the uk and elsewhere in europe appears to be climatic instability in the north atlantic associated with both the little ice age and previous similar events which led to increased storminess climatic variability and lower temperatures

evidence of late glacial paleoseismicity from submarine landslide deposits within lac dasserat northwestern quebec canada abstract an integrated seismo and chronostratigraphic investigation at lac dasserat northwestern quebec identified 74 separate failures within eight event horizons horizons e and b and h and g have strong or moderately strong multi landslide signatures respectively composed of 11 23 failures while horizons f d c and a have minor landslide signatures consisting of a single or pair of deposit s cores collected at six sites recovered glacial lake ojibway varve deposits that are interbedded with the event horizons the correlation of the varves to the regional timiskaming varve series allowed varve ages or ranges of varve ages to be determined for the event horizons horizons h g e and b are interpreted to be evidence of paleoearthquakes with differing levels of interpretative confidence based on the relative strength of the multi landslide signatures the correlation to other disturbed deposits of similar age in the region and the lack or possibility of alternative aseismic mechanisms the four interpreted paleoearthquakes occurred between 9770 200 and 8470 200 cal yr bp when glacial lake ojibway was impounded behind the laurentide ice sheet during deglaciation they probably represent an elevated period of seismicity at deglaciation that was driven by crustal unloading

lake sediments record cycles of sediment flux driven by large earthquakes on the alpine fault new zealand large earthquakes in mountain regions commonly trigger extensive landsliding and are important drivers of erosion but the contribution of this landsliding to long term erosion rates and seismic hazard remains poorly understood here we show that lake sediments record postseismic landscape response as a sequence of turbidites that can be used to quantify erosion related to large moment magnitude m w 7 6 earthquakes on the alpine fault new zealand alpine fault earthquakes caused a threefold increase in sediment flux over the 50 yr duration of each postseismic landscape response this represents considerable delayed hazard following earthquake induced strong ground motion earthquakes were responsible for 27 of the sediment flux from the lake catchment over the past 1100 yr leading us to conclude that alpine fault earthquakes are one of the most important drivers of erosion in the range front of the southern alps

reconstructing 4000 years of mass movement and tsunami history in a deep peri alpine lake lake geneva france switzerland the study of mass movements in lake sediments provides insights into past natural hazards at historic and prehistoric timescales sediments from the deep basin of lake geneva reveal a succession of six large scale volumes of 22 x 10 6 to 250 x 10 6 m 3 mass transport deposits associated with five mass movement events within 2600 years 4000 cal bp to 563 ad the mass transport deposits result from i lateral slope failures mass transport deposit b at 3895 225 cal bp and mass transport deposits a and c at 3683 128 cal bp and ii rhone delta collapses mass transport deposits d to g dated at 2650 150 cal bp 2185 85 cal bp 1920 120 cal bp and 563 ad respectively mass transport deposits a and c were most probably triggered by an earthquake whereas the rhone delta collapses were likely to be due to sediment overload with a rockfall as the external trigger mass transport deposit g the tauredunum event in 563 ad known from historical records an earthquake mass transport deposit e or unknown external triggers mass transport deposits d and f independent of their origin and trigger mechanisms numerical simulations show that all of these recorded mass transport deposits are large enough to have generated at least metre scale tsunamis during mass movement initiation since the tauredunum event in 563 ad two small scale volumes of 1 to 2x10 6 m 3 mass transport deposits h and i are present in the seismic record both of which are associated with small lateral slope failures mass transport deposits h and i might be related to earthquakes in lausanne geneva possibly 1322 ad and aigle 1584 ad respectively the sedimentary record of the deep basin of lake geneva in combination with the historical record show that during the past 3695 years at least six tsunamis were generated by mass movements indicating that the tsunami hazard in the lake geneva region should not be neglected although such events are not frequent with a recurrence time of 0 0016 yr 1

the late holocene coastal dunefield at vejers denmark characteristics sand budget and depositional dynamics abstract the coastal dunefield at vejers west coast of jutland which is now stabilized by vegetation covers an area of approximately 120 km 2 and occurs in a very high energy wind regime along the coastline a narrow belt of 5 15 m high dune ridges occur the dune ridges are gradually replaced inland by 10 20 m high parabolic or irregular dune forms in the central part of the dunefield a large aeolian sand plain ca 50 km 2 occurs at the windward side of a large and up to 20 m high parabolic dune the 3d structure of the dunefield deposits have been studied by geomorphological analysis sedimentological facies analysis of borings trenches and natural exposures and most importantly by georadar mapping the aeolian deposits which overlie a middle to late holocene barrier spit depositional system can be divided into a lower unit that drapes the underlying barrier system topography and an upper unit that includes the present dunes the boundary between the two aeolian units is a well developed phragmites peat the lower aeolian unit is composed of two aeolian subunits separated by an organic rich horizon also the upper unit is composite and composed of a basal aeolian sand cover and overlying dune or sand plain deposits the dune deposits locally are composed of up to four depositional subunits separated by immature soils the base of the lower aeolian unit formed around 300 a d whereas the phragmites peat at the base of the upper aeolian unit has been dated to ca 1000 a d from historical sources we know that the present dunefield primarily formed between 1550 and 1850 a d the sand content in the upper unit is estimated to 550 10 6 m 3 which yields sand transport rates between 25 m 3 m width 1 yr 1 accumulation in 1000 years and 83 m 3 m width 1 yr 1 accumulation in 300 years the sand in the dunefield originated from beach deposits a large but pulsating supply of sand was supplied to the beaches by southwards running coastal currents the composition of the vejers dunefield deposits indicate that periods of dunefield growth alternated with periods of dunefield stabilization during the last ca 1700 years the final and most important phase of dunefield growth took place during the little ice age this period was characterized by an overall cold and stormy climate and a relative low sea level and resulted in an increased availability of sand in the shorezone and a high influx of sand into the dunefield short periods of decreased storminess are recorded by the immature soils dunefield growth prior to 1000 a d was also linked to cold and stormy climatic intervals

changes in distal sedimentation regime of the rhone delta system controlled by subaquatic channels lake geneva switzerland france abstract seismic reflection profiles combined with sediment cores reveal centennial changes in the proximal and distal sedimentation regime in the rhone river delta system lake geneva which is dominated by sublacustrine channels from detailed analyses of the thickness distribution of depositional units and the occurrence of turbidites at least two shifts of the primarily active sublacustrine channels are inferred for the past 1500 years the first northward shift is dated at 1480 20 cal ad and was likely linked to a centennial flood in the swiss rhone valley that occurred in 1469 ad and acted either as a direct cause or as a preconditioning factor favoring the shifting a shift back southward in 1720 90 cal ad may have been caused either by long term human impact related to the first embankment constructions on the rhone river or by a natural event such as the 1755 ad brig earthquake or the centennial flood of 1640 ad another important change in the sedimentation regime occurs in 1775 125 cal ad when the onset of rhone turbidite deposition is recorded in the distal sediments this relative progradation of the rhone turbidites is certainly due to the disconnection of the vieux rhone branch before 1826 and the subsequent first rhone river correction starting in 1863 that led to the present single active rhone subaquatic channel

evolution of a large baltic beach ridge plain neudarss ne germany a continuous record of sea level and wind field variation since the homeric minimum

prehistoric earthquake history revealed by lacustrine slump deposits five strong paleoseismic events were recorded in the past 15 k y in a series of slump deposits in the subsurface of lake lucerne central switzerland revealing for the first time the paleoseismic history of one of the most seismically active areas in central europe although many slump deposits in marine and lacustrine environments were previously attributed to historic earthquakes the lack of detailed three dimensional stratigraphic correlation in combination with accurate dating hampered the use of multiple slump deposits as paleoseismic indicators this study investigated the fingerprint of the well described a d 1601 earthquake i vii viii mw 6 2 in the sediments of lake lucerne the earthquake triggered numerous synchronous slumps and megaturbidites within different subbasins of the lake producing a characteristic pattern that can be used to assign a seismic triggering mechanism to prehistoric slump events for each seismic event horizon the slump synchronicity was established by seismic stratigraphic correlation between individual slump deposits through a quasi three dimensional high resolution seismic survey grid four prehistoric events dated by accelerator mass spectrometry 14c measurements and tephrochronology on a series of long gravity cores occurred at 2420 9770 13 910 and 14 560 calendar yr ago these recurrence times are essential factors for assessing seismic hazard in the area the seismic hazard for lakeshore communities is additionally amplified by slump induced tsunami and seiche waves numerical modeling of such tsunami waves revealed wave heights to 3 m indicating tsunami risk in lacustrine environments

the thermal and radiation exposure history of lunar meteorites we have measured the natural and induced thermoluminescence tl of seven lunar meteorites in order to examine their crystallization irradiation and recent thermal histories lunar meteorites have induced tl properties similar to apollo samples of the same provenance highland or mare indicating similar crystallization and metamorphic histories macalplne hills 88104 5 has experienced the greatest degree of impact regolith processing among the highland dominated meteorites the basaltic breccia que 94281 is dominated by mare component but may also contain a significant highland component for the mare dominated meteorites eet 87521 may have a significant highland impact melt component while asuka 881757 and y 793169 have been heavily shocked the thermal history of y 793169 included slow cooling either during impact processing or during its initial crystallization our natural tl data indicate that most lunar meteorites have apparently been irradiated in space a few thousand years with most less than 15 000 a elephant moraine 87521 has the lowest irradiation exposure time being less than 1 000 a either the natural tl of alha81005 asuka 881757 and y 82192 was only partially reset by lunar ejection or these meteorites were in small perihelia orbits less than or equal to 0 7 au

induced thermoluminescence as a method for dating recent volcanism eastern snake river plain idaho usa the induced thermoluminescence properties of 24 samples of basalts from volcanoes in the eastern snake river plain idaho were measured as part of an investigation into the possibility of using this technique for dating purposes the volcanic flows sampled ranged in age from 2200 years to 400 000 years the tl sensitivity values obtained i e maximum induced tl normalized to that of the dhajala meteorite where dhajala 1000 ranged from 1 6 0 3 to 226 15 and showed a correlation between log tl and age with an r2 value of 0 47 thus tl sensitivity values correlate with age in the manner expected although there is a high level of scatter we discuss various mechanisms for the correlation and scatter particularly 1 the role of primary igneous processes and secondary solid state processes 2 composition of the plagioclase feldspar 3 weathering the induced tl signal from feldspars the mineral responsible for the tl is strongly dependent on their composition and correcting for this improved the correlation r2 0 7 variations in primary feldspar are affecting the data but we find no evidence that weathering of the samples is important further work is required to explore the remaining causes for the scatter and the tl age trend however it is clear from the present study that induced tl has the potential for dating volcanism on the 2200 to 400 000 year time frame this dating method if successful would be well suited to spacecraft use since it requires low mass and low power instruments with a low data demand

the induced thermoluminescence and thermal history of plagioclase feldspars feldspars are a common component in igneous and metamorphic rocks most feldspars exhibit luminescence and this has proved useful in a number of mineralogical applications in this paper we concentrate on the thermoluminescence tl properties of feldspar or the luminescence produced when a sample of feldspar is heated we determined the induced tl properties of four feldspars of various compositions in their natural states and after heating and we compared the tl data with structural changes as determined by x ray diffraction the major tl peak at 120 240 c in the tl glow curve a plot of light intensity against temperature varies significantly among feldspar bearing samples meteorites and lunar samples with slow cooling histories of 10 c my as determined by independent methods have induced tl peak temperatures of 120 c while samples with fast cooling histories 100 c my have induced tl peak temperatures of 220 c this variation in tl peak temperature can be reproduced by heating the present feldspar samples meteorites and lunar samples prior to the tl measurement most of the present samples in their natural state had tl peak temperatures of 120 c heating below 750 c in the laboratory caused no change in tl peak temperatures or the structural disorder of the feldspar while heating 750 c caused tl peak temperatures to move to 220 c and disordered the feldspar structure we suggest that induced tl peak temperature in feldspar is influenced by the degree of al si ordering in the feldspar thus induced tl peak temperature can be used as an indicator of cooling rate for igneous and metamorphic rocks

flood and earthquake disturbance of 210pb geochronology lake anterne nw alps dating recent lake sediment records yielding disturbed 210pb profiles has been a problem of wide interest in palaeoclimatic and palaeoseismic studies over the last few centuries when applied to an alpine lake sedimentary record a high resolution sedimentological study reveals that the 210pb profile is disturbed by the occurrence of single event deposits triggered by two different mechanisms flood events deposits and gravity reworking removing disturbed layers from the 210pb profile yields a logarithmic depth activity relationship using a simple 210pb decay model cfcs provides an assessment of mean accumulation rate of continuous sedimentation as opposed to event linked sedimentation the correlation of the thickest four gravity reworked deposits with historically known earthquakes permits both validation and refinement of the age depth relationship this refinement highlights variations in accumulation rate consistent with post little ice age climatic variations

a workflow for the rapid assessment of the landslide tsunami hazard in peri alpine lakes although lake tsunamis constitute a rare peril they have repeatedly occurred in peri alpine lakes in the past there are several documented historical examples of landslide triggered tsunamis in swiss lakes how ever fundamental information and workflows to rapidly quantify the lacustrine tsunami hazard for multiple lakes are missing so far the fact that the shorelines of major peri alpine lakes are densely populated underlines the need for a hazard assessment detailed assessments require high resolution geophysical geotechnical and sedimentological data and considerable computation time due to the involved data acquisition and calculation efforts such assessments are mainly conducted as detailed case studies for single lakes we present a workflow for a rapid first order estimation of the landslide triggered tsunami hazard along the shores of peri alpine lakes a crucial step is the identification of potential tsunami sources unstable slopes are mapped automatically based on parameters that are derived from past studies such parameters include the bathymetry and derived parameters and type characteristics and thickness of the sediments wave amplitudes are estimated with exist ing predictive equations based on the constructed maps of potentially unstable slopes the results may be used for focusing more detailed lake specific tsunami hazard assessments in respective areas

textural and rheological evolution of basalt flowing down a lava channel the muliwai a pele lava channel was emplaced during the final stage of mauna ulu s 1969 1974 eruption kilauea hawaii the event was fountain fed and lasted for around 50 h during which time a channelized flow system developed in which a 6 km channel fed a zone of dispersed flow that extended a further 2 6 km the channel was surrounded by initial rubble levees of a a capped by overflow units of limited extent we sampled the uppermost overflow unit every 250 m down the entire channel length collecting and analyzing 27 air quenched samples bulk chemistry density and textural analyses were carried out on the sample interior and glass chemistry and microlite crystallization analyses were completed on the quenched crust thermal and rheological parameters cooling crystallization rate viscosity and yield strength were also calculated results show that all parameters experience a change around 4 5 km from the vent at this point there is a lava surface transition from pahoehoe to a a lava density microlite content viscosity and yield strength all increase down channel but vesicle content and lava temperature decrease cooling rates were 6 7 c km with crystallization rates increasing from 0 03 c km proximally to 0 14 c km distally modeling of the channel was carried out using the flowgo thermo rheological model and allowed fits for temperature microlite content and channel width when run using a three phase viscosity model based on a temperature dependent viscosity relation derived for this lava the down flow velocity profile suggests an initial velocity of 27 m s declining to 1 m s at the end of the channel down channel lava underwent cooling that induced crystallization causing both the lava viscosity and yield strength to increase moreover lava underwent degassing and a subsequent vesicularity decrease this aided in increasing viscosity with the subsequent increase in shearing promoting a transition to a a

remobilized cordon caulle 2011 tephra deposits in north patagonian watersheds resedimentation at deltaic environments and its implications abstract the argentinean side of the andean north patagonia is drained by several fluvio lacustrine systems flowing eastwards from their headwaters at the andes mountains towards large glacial lakes these watersheds are recurrently affected by the deposition of tephra erupted from the many active andean volcanos located in the southern volcanic zone this research focusses on two fluvial systems pireco and totoral pt located in nahuel huapi national park which were severely impacted by the cordon caulle 2011 eruption cc2011 we investigate particularly the resedimentation of pyroclastic materials on their lacustrine deltas and its potential implications considering 1 the deltas morphology and 2 mass wasting processes developing at the delta fronts original tephra fall deposits were registered at nahuel huapi national park in 2011 based on the isopach map we performed a gis based volume estimation of the deposit for the studied watersheds delta plain progradation from 2011 to 2017 was analyzed from satellite images we studied the temporal evolution of the subaqueous morphology and mass wasting processes at the delta fronts using high resolution bathymetric grids registered in 2011 2014 and 2017 during june 2011 the studied watersheds received a tephra input of 72 x 106m3 the significant progradation experienced by both deltas especially during the first month of the eruption was favored by 1 abundant precipitation at the watersheds concomitant to heavy tephra deposition and 2 the pre existing subaqueous morphology characterized by a wide shallow terrace bordering pt delta plains about six years after the beginning of cc2011 6 of the tephra fallen over the entire basins had been resedimented at the delta environments terrace and delta front totalizing 3 x 106t evidence of pre eruption and or co eruptive mass wasting processes occurring at pt delta fronts was found on november 2011 up to 30 m thick pyroclastic deposits were accumulated at pt delta fronts since november 2011 burying mass wasting features at the upper delta fronts a suspended sediment collector installed at the prodelta in 2012 detected hyperpycnal currents transporting pyroclastic materials these currents probably explain the development of mass movements at high depths such as the one that displaced and filled up the bottom sediment trap this frontally confined landslide initiated at a depth of 60 m and involved tephra and organic materials deposited at the lower part of totoral delta front because of their recent deposition and loose consolidation we propose that fresh tephra deposits at pt delta fronts could become particularly unstable and represent a potential hazard to failure especially if a strong earthquake affects the study area in the next years a landslide induced tsunami wave generated at these deltas would impact rural settlements located along the coasts of brazo rincon and probably reach the coastal city of villa la angostura

thermoluminescence measurements on shock metamorphosed sandstone and dolomite from meteor crater arizona 1 shock dependence of thermoluminescence properties the thermoluminescence tl properties of shocked coconino sandstone and kaibab dolomite from meteor crater arizona have been studied equivalent dose ed a measure of stored tl decreases with increasing shock decreasing tl sensitivity but becomes shock independent at high shock grades the minimum shock grade at which ed becomes shock independent the shock threshold for resetting preimpact tl to a negligible level falls within petrographic shock class 2 as defined by kieffer and corresponds to an equilibrated state at about 10 gpa and 700 c shocked coconino fragments suitable for evaluation of the formation age of the crater using tl are those shocked in excess of the resetting threshold the average postimpact temperature of the crater floor about 190 c based on the il of samples heated during burial is consistent with impact energy estimates for the crater

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

on the architecture of intra formational mass transport deposits insights from the carbonate slopes of great bahama bank and the apulian carbonate platform abstract large sub tropical carbonate platforms shed huge volumes of sediment onto their adjacent slopes resulting carbonate successions are comprised of gravity flow beds turbidites debrites which are occasionally reworked into mass transport deposits mtds by the failure of inconsistently lithified portions of slope strata despite their significance in the depositional record the internal architecture of mtds along relatively tectonically stable and sediment producing carbonate platforms is poorly understood in comparison with counterparts in active compressional tectonic settings this study compares carbonate slope derived mtds imaged in seismic reflection data with those observed in outcrop the internal architecture of mtds from two case studies is presented the seismically imaged mtds in miocene recent carbonate slope deposits from the bahamas and mtds off the cretaceous apulian carbonate margin exposed in outcrops of the ionian basin albania understanding the large scale kilometers to tens of kilometers internal architecture of mtds in seismic is crucial for identification of these structures in outcrop in turn only outcrop studies allow the detailed analysis of the reworking style within these massive sediment bodies at a smaller scale meters to kilometers the internal architecture of the studied carbonate mtds testifies to the existence of an along slope continuum of deformation structures characterized by vertical partitioning into distinct mass flows during single mass transport events mass wasting processes are inferred from strain partitioning structures recording along slope and slope parallel architectural heterogeneities three deformation domains are recognized extensional headwall domain translational body domain and contractional toe domain confined mtds are limited by steep and deep lateral margins and frontal ramps that mark the boundaries between failed deposits and undisturbed strata vertical strain partitioning is pronounced in the toe domain upward intensification of deformation within mtds is common and corresponds to a top down reorganization of failed strata during downslope transport intra formational mtds along carbonate slopes that are lacking exotics such as the ones studied here differ from extra formational mtds occurring in compressional tectonic settings that form sedimentary melanges ductile layer deformation structures are predominant in carbonate mtds as opposed to block in matrix fabrics in sedimentary melanges the development of shear surfaces rather than ductile shear zones in the body and toe domains presents predictive in modern environments and diagnostic criteria in fossil examples of mass wasting events along carbonate slopes

dating volcanic and related sediments by luminescence methods a review abstract applications of luminescence dating of geological materials have undergone extensive development and refinement since 1974 when wintle first attempted to date volcanic lava using thermoluminescence tl today luminescence techniques are potentially highly useful methods for dating volcanic and related materials and events over timescales ranging from 10 2 to 10 6 years while luminescence approaches generally do not possess the precision afforded by techniques such as 40 ar 39 ar and 14 c methods they offer a useful alternative approach with advantages in terms of age range and scope of material although the application of luminescence methods has in some cases been successfully described a comprehensive study outlining and defining protocols for routine luminescence dating of volcanic materials has not been forthcoming this review surveys previous attempts to develop luminescence techniques to date volcanic products and discusses the state of knowledge of the luminescence behaviour of the four principal materials currently used for luminescence dating of volcanic events particular attention is paid to the red luminescence emissions primarily because of previous successes in using red thermoluminescence rtl of quartz and feldspar for dating volcanic products for which the upper age limit may extend beyond a million years proposals are made for future research directions these include technological developments in the measurement of optically stimulated red luminescence the systematic characterization of rtl and optically stimulated red luminescence as key luminescence parameters in volcanic quartz feldspar glass and polymineral sample fractions and optimization of luminescence dating methods to define a comprehensive protocol for routine dating of volcanic materials

subaquatic slope instabilities the aftermath of river correction and artificial dumps in lake biel switzerland river engineering projects are developing rapidly across the globe drasti cally modifying water courses and sediment transfer investigation of the impact of engineering works focuses usually on short term impacts thus a longer term perspective is still missing on the effects that such projects have the jura water corrections the largest river engineering project ever undertaken in switzerland radically modified the hydrological system of lake biel in the 19th and 20th century the deviation of the aare river into lake biel more than 140 years ago in 1878 thus represents an ideal case study to investigate the long term sedimentological impacts of such large scale river rerouting sediment cores along with new high resolution bathymetric and seismic reflection datasets were acquired in lake biel to document the consequences of the jura water corrections on the sedimentation history of lake biel numerous subaquatic mass transport structures were detected on all of the slopes of the lake notably a relatively large mass transport complex 0 86 km2 was observed on the eastern shore along the path of the aare river intrusion the large amount of sediment delivered by the aare river since its deviation into the lake likely caused sediment overloading resulting in subaquatic mass transport alternatively the dumping since 1963 in a subaquatic landfill of material excavated during the second phase of river engineering when the channels flowing into and out of lake biel were widened and deepened might have triggered the lar gest mass transport dated to 1964 or 1965 additional potential triggers include two nearby small earthquakes in 1964 and 1965 mw 3 9 and 3 2 respectively the data for this study indicate that relatively large mass transports have become recurrent in lake biel following the deviation ofthe aare river thus modifying hazard frequency for the neighbouring communities and infrastructure

dawn the vesta hed connection and the geologic context for eucrites diogenites and howardites the dawn mission has provided new evidence strengthening the identification of asteroid vesta as the parent body of the howardite eucrite and diogenite hed meteorites the evidence includes vesta s petrologic complexity detailed spectroscopic characteristics unique space weathering diagnostic geochemical abundances and neutron absorption characteristics chronology of surface units and impact history occurrence of exogenous carbonaceous chondritic materials in the regolith and dimensions of the core all of which are consistent with hed observations and constraints global mapping of the distributions of hed lithologies by dawn cameras and spectrometers provides the missing geologic context for these meteorites thereby allowing tests of petrogenetic models and increasing their scientific value

lake dwellers occupation gap in lake geneva france switzerland possibly explained by an earthquake mass movement tsunami event during early bronze age abstract high resolution seismic and sediment core data from the grand lac basin of lake geneva reveal traces of repeated slope instabilities with one main slide evolved mass flow minimum volume 0 13 km 3 that originated from the northern lateral slope of the lake near the city of lausanne radiocarbon dating of organic remains sampled from the top of the main deposit gives an age interval of 1865 1608 bc this date coincides with the age interval for a mass movement event described in the petit lac basin of lake geneva 1872 1622 bc because multiple mass movements took place at the same time in different parts of the lake we consider the most likely trigger mechanism to be a strong earthquake mw 6 that occurred in the period between 1872 and 1608 bc based on numerical simulations we show the major deposit near lausanne would have generated a tsunami with local wave heights of up to 6 m the combined effects of the earthquake and the following tsunami provide a possible explanation for a gap in lake dwellers occupation along the shores of lake geneva revealed by dendrochronological dating of two palafitte archaeological sites

development and age structure of holocene coastal sand dunes at horn head near dunfanaghy co donegal ireland two areas of holocene coastal sand dunes on the western side of the horn head peninsula extend from low ground immediately inland of their respective source beaches onto flanking higher ground 100 m od stratigraphic investigations supported by 14c dating of buried organic rich horizons and shells demonstrate several phases of sand accumulation in the pollaguill croaghadara system in contrast to the larger tramore anloge hill system where the available evidence points to relatively recent dune emplacement a broadly synchronous phase of dune development occurred during the thirteenth to fourteenth centuries ad and is viewed as part of a regional northwestern europe dune building episode resulting from climatic deterio ration earlier phases pre 3300 2800 14c years bp of aeolian sand deposition at pollaguill croaghadara have no apparent equivalents at tramore anloge hill and repeated fluvial incision and sand reworking during the last 2000 14c years is also evident at the former site dated organi

negatively skewed aeolian sands from a humid tropical coastal dunefield northern australia abstract this paper describes the nature and environmental significance of variations in textural parameters within a large coastal dunefield in tropical northern australia grain size parameters of modern beaches and foredunes are very similar but are distinct from those of parabolic dune and sandplain environments on average beach and foredune sands have a normal grain size distribution but parabolic dune sands are predominantly negatively skewed negative skewness is interpreted as primarily reflecting sorting of dune sediments by winnowing at dune crests and by avalanching on slip faces a general relationship between mean size and skewness is supported with finer sediments showing increased negative skewness positive skewness can therefore not be used as a diagnostic property of aeolian sediments

model simulations of tsunamis generated by the storegga slides abstract a mathematical model based on the hydrodynamic shallow water equations is developed for numerical simulation of water waves generated by the submarine storegga slides on the norwegian continental slope the equations are solved numerically by a finite difference technique computations of wave amplification effects reveal run up heights for the second storegga slide between 3 and 5 m in exposed areas along the eastern coast of greenland iceland and scotland and the western coast of norway the calculated run up heights agree remarkably well with possible tsunami wave heights deduced from geological evidences along the eastern coast of scotland the generated wave heights are strongly dependent on the acceleration of the slide the effects of shear stress at the interface between the water and the slide body has turned out to be important

palaeoflood activity and climate change over the last 1400 years recorded by lake sediments in the north west european alps a high resolution sedimentological and geochemical study of a high altitude proglacial lake lake blanc aiguilles rouges 2352m a s l revealed 195 turbidites 190 of which are related to flood events over the last 1400 years we used the coarsest sediment fraction of each turbidite as a proxy for the intensity of each flood event because most flood events at this locality are triggered by localized summer convective precipitation events the reconstructed sedimentary record reveals changes in the frequency and intensity of such events over the last millennium comparisons with other temperature palaeohydrological and glacier reconstructions in the region suggest that the most intense events occurred during the warmest periods i e during the medieval climate anomaly ad 800 1300 and the current period of global warming on a multi decadal time scale almost all the flood frequency peaks seem to correspond to warmer periods whereas multi centennial variations in flood frequency appear to follow the regional precipitation pattern consequently this new alpine flood record provides further evidence of a link between climate warming and an increase in the frequency and intensity of flooding on a multidecadal time scale whereas the centennial variability in flood frequencies is related to regional precipitation patterns

attempts at dating ancient volcanoes using the red tl of quartz abstract the suitability of the red tl peak of quartz for long range dating is tested by application to some volcanic events of the french massif central see map fig 1 having assumed ages in the range 14 150 ka the samples are sediments heated by lava flows and pyroclastic products in most cases the results fit with the geological evidence no direct comparison can yet be made with other dating methods on the other hand for two events having ages of 2 and 14 ma the growth curve using the additive dose technique had an abnormal shape which could not be reproduced with a sample zeroed in the laboratory this effect which is not yet properly understood may prevent the use of the tl regeneration technique for evaluation of the palaeodose for very old samples

the record of historic earthquakes in lake sediments of central switzerland deformation structures in lake sediments in central switzerland can be attributed to strong historic earthquakes the type and spatial distribution of the deformation structures reflect the historically documented macroseismic intensities thus providing a useful calibration tool for paleoseismic investigations in prehistoric lake sediments the swiss historical earthquake catalogue shows four moderate to strong earthquakes with moment magnitudes of mw 5 7 to mw 6 9 and epicentral intensities of i0 vii to i0 ix that affected the area of central switzerland during the last 1000 years these are the 1964 alpnach 1774 altdorf 1601 unterwalden and 1356 basel earthquakes in order to understand the effect of these earthquakes on lacustrine sediments four lakes in central switzerland sarner see lungerer see baldegger see and seelisberg seeli were investigated using high resolution seismic data and sediment cores the sediments consist of organicand carbonate rich clayey to sandy silts that display fine bedding on the centimeter to millimeter scale the sediments are dated by historic climate and environmental records 137 cs activity and radiocarbon ages deformation structures occur within distinct zones and include large scale slumps and rockfalls as well as small scale features like disturbed and contorted lamination and liquefaction structures these deformations are attributed to three of the abovementioned earthquakes the spatial distribution of deformation structures in the different lakes clearly reflects the historical macroseismic dataset lake sediments are only affected if they are situated within an area that underwent groundshaking not smaller than intensity vi to vii we estimate earthquake size by relating the epicentral distance of the farthest liquefaction structure to earthquake magnitude this relationship is in agreement with earthquake size estimations based on the historical dataset d 2004 elsevier b v all rights reserved

complexity of holocene climate as reconstructed from a greenland ice core glaciochemical time series developed from summit greenland indicate that the chemical composition of the atmosphere was dynamic during the holocene epoch concentrations of sea salt and terrestrial dusts increased in summit snow during the periods 0 to 600 2400 to 3100 5000 to 6100 7800 to 8800 and more than 11 300 years ago the most recent increase and also the most abrupt coincides with the little ice age these changes imply that either the north polar vortex expanded or the meridional air flow intensified during these periods and that temperatures in the mid to high northern latitudes were potentially the coldest since the younger dryas event

the use of glass for dating volcanic ash by thermoluminescence the development of a new physical dating method for late pleistocene tephrochronometry is described here tests of laboratory procedures applied to glass from independently dated samples show that the thermoluminescence tl additive dose dating method can yield accurate ages for both proximal and distal tephra from a few hundred years to at least 400 ka the technique involves purification of 4 to 11 m glass by heavy liquid centrifugation pre tl readout heating at 50 75 c for 8 days and careful regression analysis of tl growth curves several unknown age tephra are dated directly by this method for the first time these include five ash beds from summer lake oregon 67 200 ka a sheep creek valley ash from alaska 81 9 ka an ash from nevada 200 50 ka correlated to the wadsworth tephra an unknown ash 210 30 ka from rye patch dam in nevada previously correlated to the 400 to 600 ka dibekulewe tephra and ash 9m from washtucna in eastern washington 250 30 ka

regional intensity attenuation models for france and the estimation of magnitude and location of historical earthquakes summary intensity assignments for 33 calibration earthquakes were used to develop intensity attenuation models for the alps armorican provence pyrenees and rhine regions of france intensity decreases withmost rapidly in the french alps provence and pyrenees regions and least rapidly in the armorican and rhine regions the comparable armorican and rhine region attenuation models are aggregated into a french stable continental region model and the com parable provence and pyrenees region models are aggregated into a southern france model we analyse msk intensity assignments using the technique of bakun wentworth which provides an objective method for estimating epicentral location and intensity magnitude m i m i for the 1356 october 18 earthquake in the french stable continental region is 6 6 for a location near basle switzerland and moment magnitude m is 5 9 7 2 at the 95 per cent 2 confidence level m i for the 1909 june 11 trevaresse lambesc earthquake near marseilles in the southern france region is 5 5 and m is 4 9 6 0 at the 95 per cent confidence level bootstrap resampling techniques are used to calculate objective reproducible 67 per cent and 95 per cent confidence regions for the locations of historical earthquakes these confidence re gions for location provide an attractive alternative to the macroseismic epicentre and qualitative location uncertainties used heretofore

metamorphism of eucrite meteorites studied quantitatively using induced thermoluminescence eucrite meteorites1 are especially important in studies of the early solar system because they are the simplest and most ancient products of a process that was widespread in the inner solar system2 3 basaltic volcanism they are also the meteorites for which there is least doubt of an asteroidal origin4 5 after volcanism the eucrites experienced a period of metamorphism6 either inside the asteroid as it cooled from igneous temperatures7 or on the surface of the asteroid as a result of impact heating8 induced thermoluminescence studies provide a new and quantitative means of determining relative metamorphic intensities for these meteorites using this technique we show that the eucrites constitute a continuous metamorphic series and not as commonly assumed two groups of metamorphosed and non metamorphosed meteorites9 these studies are the first application of the induced thermoluminescence technique to igneous rocks and we suggest that the method may well have application to other basalts

holocene coastal change and geoarchaeology at howick northumberland uk the recent discovery of one of the earliest mesolithic occupation sites in northern britain at howick on the northumberland coast in association with multiperiod archaeological evidence nearby highlights the importance of uk coastal settings as focii of human occupation through the holocene environmental evidence from a nearby river valley 8 15 m of sediment ranging in age from about 12 000 cal bp to the present records local and regional environmental change twenty four radiocarbon dates based on plant macrofossils provide a strong chronological framework calcareous microfossil assemblages foraminifera ostracods have been recovered from the fine grained sediments recording a change from marine through to brackish and eventually freshwater conditions between about 8200 and 6500 cal bp a preliminary pollen study of the core has permitted a reconstruction of the regional vegetation as it responded to climatic amelioration and human influence upon the landscape radiocarbon dating and sedimentological evidence indicates a major hiatus between approximately 11 000 and 8000 years bp including the period of mesolithic occupation represented by a 30 cm layer of coarse sands and sandstone pebbles probably the result of a significant high energy event dated to about 8300 cal bp although not a typical tsunami deposit the age and context suggests that this may be associated with the storegga slide event already well documented along the eastern coast of scotland the sedimentary and biological remains at howick record environmental change over much of the holocene and are compared with other environmental change records from the region to provide an environmental framework for the archaeology of this coastline

lacustrine turbidites as a tool for quantitative earthquake reconstruction new evidence for a variable rupture mode in south central chile understanding the long term earthquake recurrence pattern at subduction zones requires continuous paleoseismic records with excellent temporal and spatial resolution and stable threshold conditions south central chilean lakes are typically characterized by laminated sediments providing a quasi annual resolution our sedimentary data show that lacustrine turbidite sequences accurately reflect the historical record of large interplate earthquakes among others the 2010 and 1960 events furthermore we found that a turbidite s spatial extent and thickness are a function of the local seismic intensity and can be used for reconstructing paleo intensities consequently our multilake turbidite record aids in pinpointing magnitudes rupture locations and extent of past subduction earthquakes in south central chile comparison of the lacustrine turbidite records with historical reports a paleotsunami subsidence record and a marine megaturbidite record demonstrates that the valdivia segment is characterized by a variable rupture mode over the last 900 years including i full ruptures mw 9 5 1960 1575 1319 9 1127 44 ii ruptures covering half of the valdivia segment mw 9 1837 and iii partial ruptures of much smaller coseismic slip and extent mw 7 5 8 1737 1466 4 also distant or smaller local earthquakes can leave a specific sedimentary imprint which may resolve subtle differences in seismic intensity values for instance the 2010 event at the maule segment produced higher seismic intensities toward southeastern localities compared to previous megathrust ruptures of similar size and extent near concepci n

1400 years of extreme precipitation patterns over the mediterranean french alps and possible forcing mechanisms investigation of lake allos sediments revealed 160 graded layers interpreted as flood deposits over the last 1400 yr comparisons with records of historic floods support the interpretation of flood deposits and suggest that most recorded flood events are the result of intense meso scale precipitation events as there is no evidence for any major changes in erosion processes in the catchment since the medieval warm period mwp we interpret the allos record in terms of repeated intense precipitation events over the last millennium with a low flood frequency during the mwp and more frequent and more intense events during the little ice age this interpretation is consistent with the pattern of increasingly humid conditions in the northwestern mediterranean region this long term trend is superimposed on high frequency oscillations that correlate with solar activity and autumnal north atlantic oscillation nao finally a comparison of flood records across the northwestern mediterranean region showed that intense precipitation events in allos east of the rhone valley were out of phase with events in the cevennes west of the rhone but in phase with events in eastern spain supported by meteorological analyses this suggests an oscillation in atmospheric circulation patterns over the northwestern mediterranean

assessment of temporal changes in coastal sand dune environments using the log hyperbolic grain size method three cores 9 m long recovered from late holocene coastal sand dunes in northumberland north eastern england were examined stratigraphically and dated by the infrared stimulated luminescence irsl method to the time period between the medieval warm period mwp 900 1200 ad and little ice age lia 1550 1800 ad grain size variability and caco 3 content were determined at 10 mm intervals throughout parts of the cores the sahara computer program was used to plot the log hyperbolic distribution lhd of grain size spectra from different stratigraphic levels and estimate the lhd s statistical components core samples plot variously in the depositional and erosional domains of the hyperbolic chi vs xi shape triangle which describes components of sediment sorting depositional and erosional phases discriminated within the lhd s shape triangle cannot readily be resolved from core stratigraphies or correlated between cores irsl dates from single cores show a clustering about the period 1430 1540 between the dated horizons dunes accreted at 0 02 0 05 m year 1 enabling the timing of excursions in and to be estimated these excursions which can be resolved to the subannual level between the dated horizons may be related to deposition by episodic storms or storm surges in the north sea region which is supported by historical documentary evidence this innovative use of the lhd method and its derived statistics can be used successfully to describe temporal trends in coastal depositional environments and identify likely storm events in dune sediment records

signatures of slope failures and river delta collapses in a perialpine lake lake lucerne switzerland historical reports from the 17th century document two destructive tsunamis with runups exceeding 5 m affecting proximal basins of lake lucerne switzerland one event in ad 1601 is coeval with a strong nearby earthquake mw ca 5 9 which caused extensive slope failures in many parts of the lake the second event in ad 1687 is associated with an apparently spontaneous partial collapse of the muota river delta this study combines high resolution bathymetry reflection seismic and lithological data in order to document the sedimentary and morphological signatures of the two subaqueous mass movements that probably generated the observed tsunamis such mass movements are significant as a common sedimentation process and as natural hazard in fjord type lakes and similar environments the deposits covering large parts of the basins with thicknesses reaching 10 m consist of two subunits a lower massflow deposit contains variably deformed sediments from the source areas its emplacement affected pre existing sediments incorporating thin sediment slices into the deposit and increasing its volume deep reaching deformation near this is an accepted article that has been peer reviewed and approved for publication in the sedimentology but has yet to undergo copy editing and proof correction

thermoluminescence and the shock and reheating history of meteorites iv the induced tl properties of type 4 6 ordinary chondrites abstract the induced thermoluminescence tl properties of 121 equilibrated ordinary chondrites have been measured the samples were 74 h and 47 l chondrites of which 33 h and 32 l were from antarctica the distribution of tl sensitivities for non antarctic l chondrites differs from that of non antarctic h chondrites consistent with a greater proportion of the former class suffering post metamorphic shock data on the effect of laboratory annealing on tl sensitivity and step wise ar release measurements enable the meteorites to be sorted into three shock related temperature groups

giant earthquakes in south central chile revealed by holocene mass wasting events in lake puyehue abstract very high resolution reflection seismic profiling 3 5 khz revealed nine holocene mass wasting events in lake puyehue south central chile these events are made up of numerous coeval mass wasting deposits and some homogenites which are radiocarbon dated the two youngest mass wasting events could be attributed to the giant ad 1960 and ad 1575 valdivia earthquakes the most extensive event took place around 1660 cal yr bp evaluation of all possible slope failure processes led us to infer that giant earthquakes roughly comparable to the ad 1960 valdivia earthquake mw 9 5 are the most likely trigger mechanisms of all mass wasting events in lake puyehue these occurred with a mean recurrence rate of 1000 yr although relatively aperiodically ranging between 500 and 2000 yr quantitative comparison of mass wasting events related to historically reported earthquakes ad 1960 and ad 1575 showed significant differences although these earthquakes are assumed to have had a comparable strength a lowered background sedimentation rate could be responsible for this variable earthquake recording which highlights the importance of a thorough assessment of the depositional history before using lacustrine records for quantitative paleoseismic analysis

a new windstorm proxy from lake sediments a comparison of geological and meteorological data from western germany for the period 1965 2001 1 the feasibility of detecting windstorm layers in lake sediments is explored by comparing quartz grain size data from a freeze core obtained from the schalkenmehrener maar eifel region western germany to recent meteorological wind data the schalkenmehrener maar is appropriate for such a calibration study because the morphological settings of the lake allow the conservation of windstorm layers in particular there is no fluvial sediment inflow and long term wind measurements are available from nearby stations the age model for the uppermost 30 cm of the sediment core is based on measurements of 137cs and 210pb concentrations an ultra high resolution grain size analysis is performed digitally on thin sections and reveals distinct 1 mm thick layers with increased quartz grain content and sharp gaussian grain size distributions which are shifted to larger grain sizes compared to the normal lake sediment in order to compare the occurrence of these layers with meteorological wind data a windstorm index is developed combining data from meteorological stations in the eifel region and reanalyses from the european centre for medium range weather forecast a statistical evaluation of matches between the windstorm index and the core s silt fraction data indicates that the sediment layers very likely coincide with the major windstorm events in the eifel region during the last decades six historical storm are identified this pilot study identifies the main requirements and proposes a novel methodological approach for using sediment data from lakes with similar settings as the schalkenmehrener maar as a new proxy to reconstruct the windstorm record of the geological past

lake sediment based paleoseismology limitations and perspectives from the swiss alps abstract in regions with moderate seismicity and large intervals between strong earthquakes paleoseismological archives that exceed the historical and instrumental timescale are needed to establish reliable estimates of earthquake recurrence for long return periods in several regions lake sediments have shown to be suitable for paleoseismological studies by causally linking characteristic sedimentological features to historic earthquakes studies on single lakes however do neither allow determining the paleoepicentre nor the paleomagnitude for the potential paleoearthquakes here we compile using shaking induced mass movements and micro deformations summarized as sedimentary event deposits seds the sedimentary paleoseismic record of 11 lakes from switzerland over the last 10 000 years the large dating uncertainty attributed to such deposits up to 250 years does not allow us to conclusively test for one large earthquake hypothesis when comparing the different lake records and therefore represents one of the major limitations of this approach instead using a new approach of exploring the normalized frequency of occurrence averaged over a larger area the compiled dataset reveals striking periods of enhanced occurrence of seds in the studied lakes during several phases of the past 10 000 years centered at 9700 6500 and during the last 4000 cal yr bp moreover we use a calibrated intensity attenuation relation in order to model scenarios of possible epicentral areas and ranges of magnitudes of paleoearthquakes we differentiate two cases i a single earthquake scenario if seds occur simultaneously in various studied lakes or ii a multi earthquake scenario if seds in the studied lakes cluster within a time interval the modelled scenarios allow us to propose maximally possible magnitudes of large paleoearthquakes constituting an important input for seismic hazard assessment in the swiss alps

optically stimulated luminescence dating of late holocene raised strandplain sequences adjacent to lakes michigan and superior upper peninsula michigan usa this study evaluates the accuracy of optically stimulated luminescence to date well preserved strandline sequences at manistique thompson bay lake michigan and tahquamenon and grand traverse bays lake superior that span the past 4500 yr the single aliquot regeneration sar method is applied to produce absolute ages for littoral and eolian sediments sar ages are compared against ams and conventional 14 c ages on swale organics modern littoral and eolian sediments yield sar ages b100 yr indicating near if not complete solar resetting of luminescence prior to deposition beach ridges that yield sar ages b2000 yr show general agreement with corresponding 14 c ages on swale organics significant variability in 14 c ages n2000 cal yr b p complicates comparison to sar ages at all sites however a sar age of 4280 f 390 yr uic913 on ridge77 at tahquamenon bay is consistent with regional regression from the high lake level of the nipissing ii phase ca 4500 cal yr b p sar ages indicate a decrease in ridge formation rate after 1500 yr ago likely reflecting separation of lake superior from lakes huron and michigan this study shows that sar is a credible alternative to 14 c methods for dating littoral and eolian landforms in great lakes and other coastal strandplains where 14 c methods prove problematic

presidential address presented 2000 august 28 chicago illinois usa the eucrite vesta story many lines of evidence indicate that meteorites are derived from the asteroid belt but in general identifying any meteorite class with a particular asteroid has been problematical one exception is asteroid 4 vesta where a strong case can be made that it is the ultimate source of the howardite eucrite diogenite hed family of basaltic achondrites visible and near infrared reflectance spectra first suggested a connection between vesta and the basaltic achondrites experimental petrology demonstrated that the eucrites the relatively unaltered and unmixed basaltic achondrites were the product of approximately a 10 melt studies of siderophile element partitioning suggested that this melt was the residue of an asteroidal scale magma ocean mass balance considerations point to a parent body that had its surface excavated but remains intact modern telescopic spectroscopy has identified kilometer scale vestoids between vesta and the 3 1 orbit orbit resonance with jupiter dynamical simulations of impact into vesta demonstrate the plausibility of ejecting relatively unshocked material at velocities consistent with these astronomical observations hubble space telescope images show a 460 km diameter impact basin at the south pole of vesta it seems that nature has provided multiple free sample return missions to a unique asteroid major challenges are to establish the geologic context of the hed meteorites on the surface of vesta and to connect the remaining meteorites to specific asteroids

the generating mechanisms of the august 17 1999 izmit bay turkey tsunami regional tectonic and local mass instabilities causes abstract the m w 7 4 earthquake that affected the northwestern part of turkey on august 17 1999 and in particular the gulf of izmit had dramatic consequences also as regards tsunami generation the main cause of the earthquake was a dextral strike slip rupture that took place along different segments of the western part of the north anatolian fault wnaf the rupture process involved not only a number of distinct strike slip fault segments but also dip slip ancillary faults connecting the main transcurrent segments the general picture was further complicated by the occurrence of subsidence and liquefaction phenomena especially along the coasts of the izmit bay and in the sapanca lake tsunami effects were observed and measured during post event surveys in several places along both the northern and the southern coasts of the bay the run up heights in most places were reported to lie in the interval 1 3 m but in the small town of degirmendere where a local slump occurred carrying underwater buildings and gardens of the waterfront sector eyewitnesses reported water waves higher than 15 m the purpose of this work is to investigate on the causes of the tsunami by means of numerical simulations of the water waves we show that the tsunami was a complex event consisting at least of the combination of a regional event due to tectonic causes and of a local event associated with the mass failure as to the first we are able to demonstrate that the observed tsunami cannot be explained only in terms of the sea bottom dislocation produced by the main right lateral dislocation but that the prominent contribution comes from the displacement associated with the secondary shallow normal faults furthermore the large waves and effects seen in degirmendere can be explained as the consequence of the slump by means of a stability analysis based on an original method making use of the limit equilibrium concept we show that the slump was highly stable before the earthquake and that it was triggered by seismic waves simulation of the tsunami induced by the slump was carried out by a two step numerical code that computes the landslide motion first and then the generated water wave propagation it is shown that the computed local tsunami matches the experimental data

time dependent recurrence of strong earthquake shaking near plate boundaries a lake sediment perspective abstract accurate probabilistic seismic hazard analysis requires a good knowledge of the recurrence parameters of the strongest earthquakes in a region due to the typical short temporal span of instrumental and historical data it is often unclear whether one should adopt a time dependent or time independent poissonian recurrence model the choice of which has large repercussions on the probability estimates for new strong events the rapidly growing discipline of lacustrine paleoseismology aims at producing long continuous records of strong seismic shaking which integrate the activity of all significant seismic sources in a region and allow a reliable determination of recurrence patterns the typical continuous sedimentation regime in lakes can lead to complete sensitive paleoseismic records and a reduced temporal uncertainty in recurrence intervals here i present a worldwide compilation of published long lacustrine paleoseismic records grouped per tectonic domain and statistically explore the variability of their recurrence intervals expressed by the coefficient of variation cov a cov 1 indicates a time independent process whereas cov 1 may be related to changes in the sensitivity of the lacustrine paleoseismograph or to real earthquake clustering due to e g stress transfer between neighboring faults the most useful lacustrine paleoseismic records can be retrieved in high seismicity settings where many paleoseismic events can be recorded in a relatively short time span i e

evidence for the long term sedimentary environment in an antarctic subglacial lake lakes beneath the antarctic ice sheet are of fundamental scientific interest for their ability to contain unique records of ice sheet history and microbial life in their sediments however no records of subglacial lake sedimentation have yet been acquired from beneath the interior of the ice sheet and understanding of sediment pathways processes and structure in subglacial lake environments remains uncertain here we present an analysis of seismic data from subglacial lake ellsworth showing that the lake bed comprises very fine grained sediments deposited in a low energy environment with low water and sediment fluxes minimum sediment thickness is 6 m the result of prolonged low sedimentation rates based on the few available analogues we speculate this sediment age range is a minimum of 150 ka and possibly 1 ma sediment mass movements have occurred but they are rare and have been buried by subsequent sedimentation we present a new conceptual model of subglacial lake sedimentation allowing a framework for evaluating processes in subglacial lake environments and for determining future lake access locations and interpreting subglacial lake samples

two twentieth century mlh 7 5 earthquakes recorded in annually laminated lake sediments from sary chelek western tian shan kyrgyzstan central asia is highly vulnerable to large earthquakes yet existing records of past seismic activity in this area are still insufficient to reliably assess regional earthquake hazard on longer timescales within this study the sediments of sary chelek a mountain lake in the western kyrgyz tian shan were investigated to explore its potential as a natural paleoseismic archive the lacustrine deposits are characterized by a succession of annually laminated varved sediments overlying event deposits that consist of large scale turbidites and distorted lake sediments similar to earthquake related deposits described from other lake sediment records microscopic sediment analysis furthermore revealed distorted varves in the laminated sequence that closely resemble earthquake related soft sediment deformation structures varve counting and radiometric dating determine the formation of the distorted varves and the emplacement of the large scale event deposits to the early 1990s and mid 1940s respectively this is in good temporal agreement with the occurrence of two large earthquakes that struck western kyrgyzstan in ad 1992 and ad 1946 these results and particularly the precise age control of the sary chelek sediment record highlight its potential for establishing a long and precisely dated record of regional earthquake activity

a thermoluminescence study of experimentally shock loaded oligoclase and bytownite the thermoluminescence tl of samples of terrestrial oligoclase and bytownite shock loaded to 10 5 45 gpa have been measured the tl sensitivities of both feldspars decreased 10 fold after shock loading to 25 32 gpa and for the oligoclase 25 fold after shock loading to greater pressures the shock induced changes for oligoclase are very similar to those of the kernouve meteorite in which the tl phosphor is oligoclase after similar shock loading the data indicate that ordinary chondrites of shock facies d f have suffered shock pressures over 25 gpa consistent with petrographic estimates petrographic studies on the shocked samples suggest that the lowering of tl sensitivity is caused by maskelynization and at the highest pressures melting the oligoclase samples shocked above 34 gpa showed changes in their glow curve shapes similar to those produced by annealing amelia albite and a type 3 4 ordinary chondrite above 700 c the dominant peak moves from 132 8 c to 230 12 c changes in the glow carve shape for bytownite resembled those produced by annealing certain shergottites in addition to a major peak at 138 3 c a peak appeared at 178 8 c for albite the changes were shown to be associated with small degrees of disordering and we suggest that shock induced disordering or some process closely associated with the onset of disordering is occurring in the trace amounts of feldspar that survive maskelynization after shock loading to pressures 34 gpa