the role of calcining and basal fluidization in the long runout of carbonate slides an example from the heart mountain slide block wyoming and montana u s a abstract in order to understand the movement of large rock masses or allochthons on low angle surfaces we have studied the 3400 km2 heart mountain slide block of northwestern wyoming and southwestern montana the heart mountain slide block was initiated on a 2 gradient with its toe thrust a minimum of 45 km across an early eocene landscape the slide block moved on a basal layer that ranges in thickness from a few tens of centimeters to several meters this basal layer commonly has a concrete like appearance of rounded mixed lithology grains in a fine grained carbonate matrix and in some locations it has features similar to sedimentary deposits including both normal and inverse grading flow banding turbidite like structures and clastic dikes containing pieces of carbonized wood nowhere did we observe crosscutting relationships in the basal layer or overlying clastic dikes as would be expected from incremental or noncatastrophic emplacement results from cathodoluminescence and 18o 13c and 8

the river orontes in syria and turkey downstream variation of fluvial archives in different crustal blocks the geomorphology and quaternary history of the river orontes in western syria and south central turkey have been studied using a combination of methods field survey differential gps satellite imagery analysis of sediments to determine provenance flow direction and fluvial environment incorporation of evidence from fossils for both palaeoenvironments and biostratigraphy uranium series dating of calcrete cement reconciliation of palaeolithic archaeological contents and uplift modelling based on terrace height distribution the results underline the contrasting nature of different reaches of the orontes in part reflecting different crustal blocks with different histories of landscape evolution upstream from homs the orontes has a system of calcreted terraces that form a staircase extending to 200 m above the river new u series dating provides an age constraint within the lower part of the sequence that suggests underestimation of terrace ages in previous reviews this upper valley is separated from another terraced reach in the middle orontes by a gorge cut through the late miocene early pliocene homs basalt the middle orontes terraces have long been recognized as a source of mammalian fossils and palaeolithic artefacts particularly from latamneh near the downstream end of the reach this terraced section of the valley ends at a fault scarp marking the edge of the subsiding ghab basin a segment of the dead sea fault zone which has been filled to a depth of 1 km by dominantly lacustrine sediments of pliocene quaternary age review of the fauna from latamneh suggests that its age is 1 2 0 9 ma significantly older than previously supposed and commensurate with less uplift in this reach than both the upper and lower orontes two localities near the downstream end of the ghab have provided molluscan and ostracod assemblages that record somewhat saline environments perhaps caused by desiccation within the former lacustrine basin although they include fluvial elements the ghab is separated from another subsiding and formerly lacustrine depocentre the amik basin of hatay province turkey by a second gorge implicit of uplift this time cut through palaeogene limestone the ne sw oriented lowermost reach of the orontes is again terraced with a third and most dramatic gorge through the northern edge of the ziyaret dagi mountains which are known to have experienced rapid uplift probably again enhanced by movement on an active fault indeed a conclusion of the research in which these various reaches are compared is that the crust in the hatay region is significantly more dynamic than that further upstream where uplift has been less rapid and less continuous

particle interaction in fjord suspended sediment abstract glacial flour enters the surface layer of howe sound a fjord in southwestern british columbia as a sediment plume which moves quickly down inlet while gradually mixing with the sea water flocculation occurs in the lower brackish waters of the surface layer although mixing and diffusion are the dominant processes for sediment to enter the marine water once in the underlying marine water zooplankton pelletization and biologic agglomeration of inorganic floccules predominate this generates a response in the order of days between the two layers in terms of sedimentation of particulate matter most particles settling in the fjord environment fall as 1 sand and silt grains containing attached clay particles 2 clay clasts possibly related to river mudballs 3 mineral bearing fecal pellets from pelagic zooplankton 4 large grain inorganic and colloidal floccules and 5 inorganic biogenic agglomerates analysis of sediment trap data has led to the following conclusions 1 water turbidity cannot be used to infer the downward flux of particles 2 size distributions of sediment deposited on the sea bed are a function of non lognormal size distributions from particles composing sub laminae

thermoluminescence properties of a deglacial marine sequence from cumberland sound arctic canada sedimentologic and geochronologic implications abstract thermoluminescence tl analysis of glacial marine and postglacial sediments in core 85027 029 from cumberland sound baffin island shows that the tl signal can be used to differentiate glacial marine sediments deposited extremely close 4 to 10 5 yrs

role of the palaeogene recent sinistral el kabir lineament and the associated transtensional neogene recent el kabir basin northern syria in distributed deformation between the african and eurasian plates

earthquake clustering in the eastern mediterranean during historical times most coastal sectors which show evidence of holocene coseismic uplift in greece and the eastern mediterranean were raised during a short period called here the early byzantine tectonic paroxysm ebtp between the middle of the fourth and the middle of the sixth century a d the areas uplifted at that time include cephalonia and zante in the ionian islands lechaion and the perachora peninsula in the gulf of corinth the pelion coast of thessaly antikythira and the whole of western crete a coastal sector near alanya in southern turkey and the entire levant coast from hatay turkey to syria and the lebanon the amount of the ebtp uplift was generally between 0 5 m and 1 0 m but reached a maximum of about 9 m in southwestern crete in several areas zante pelion coast antikythira western crete alanya the ebtp uplifted shoreline is the only evidence of holocene emergence in other areas however a similar uplift occurred earlier in the holocene levant coast or more recently cephalonia evidence of preseismic subsidence prior to the ebtp uplift has been reported from thessaly antikythira and crete in both the latter islands the ebtp uplift was preceded by a series of about 10 coseismic small subsidence movements each measuring some tens of centimeters which took place in the preceding 3000 years no evidence was observed of postseismic vertical displacements

dendroarchaeology of the mid first millennium ad in constantinople abstract the 1st millennium ad was a time of great transition in europe and the mediterranean at the heart of the byzantine empire constantinople modern day istanbul was a pivotal trade hub for the aegean region establishing a precise and accurate dating framework for the development of this remarkable city and a chronological reference for this critical time period for the mediterranean region is of great importance to a wide range of scholars here we present a new 213 year tree ring record from 89 oak samples placed in time by dendrochronology and supported by radiocarbon analysis and historical documentation it represents the middle of the first millennium ad in constantinople the tree ring series are derived from pilings recovered from the extraordinary excavations of the so called theodosian harbor at yenikapi istanbul along with timbers from other sites and buildings around the city including one of the most famous sites on the istanbul sky line hagia sophia they provide potential for new insight into a time period in which earthquakes the justinianic plague and even a possible tsunami struck the city and during which dramatic changes in climate have been recorded in other paleoenvironmental proxies the chronology is the first published tree ring series from the aegean region to cover the event years of ad 536 7 and 542 which are characterized by anomalous growth in other tree ring series from around the world but interestingly these event years are not evident in this tree ring sequence

thermoluminescence properties of fiord sediments from engelskbukta western spitsbergen svalbard a new tool for deciphering depositional environment this study explored the relationship between high arctic fiord depositional environments and the natural thermoluminescence tl signal of sediments the energy and duration of light exposure during transportation and deposition controls the tl level of silicate mineral grains in the sediment the tl signal of sediments rapidly decreases within c 0 5 km of a glacier sediment source the highest tl levels are from tills and ice proximal glacial marine sediments which receive little or no light exposure during transportation and deposition intermediate and consistent tl levels are recorded for ice distal glacialmarine muds c 0 5 5 0 km from the glacier front reflecting slower sedimentation rates the lowest tl levels are for littoral and sublittoral sediments which receive extended light exposure with shoaling the granulometry of the sediments is fairly homogeneous and is not diagnostic of a sedimentary environment with most samples dominated by silt and clay littoral and ice proximal samples exhibit peak abundances in sand these results suggest that the relative tl signal of sediments is sensitive to a depositional environment particularly for environments proximal within 0 5 km to a glacier terminus and in shallow water less than 15 m deep

fluctuations in the thermoluminescence signal of suspended sediment in an alpine glacial meltwater stream abstract analysis of the thermoluminescence tl signal from suspended sediment samples from the dora di ferret river in northern italy reveals two scenarios for entrainment transport and bleaching of the tl signal in clear weather a simple diurnal fluctuation in luminescence intensity is apparent but the correlation with sediment concentration in the stream is very low storm events in contrast cause large amounts of unbleached sediment to be mobilised and entrained in the flow producing a significant positive correlation between tl intensity and sediment concentration such storm events may be identified by an initial dip in the intensity of the tl signal believed to be due to zeroed grains on the surface of valley slopes being washed off the slopes followed by a major rise in signal as erosion starts to incorporate previously unbleached sediment into the flow

active thrusting offshore mount lebanon source of the tsunamigenic a d 551 beirut tripoli earthquake on 9 july a d 551 a large earthquake followed by a tsunami destroyed most of the coastal cities of phoenicia modern day lebanon tripoli is reported to have drowned and berytus beirut did not recover for nearly 1300 yr afterwards geophysical data from the shalimar survey unveil the source of this event which may have had a moment magnitude mw of 7 5 and was arguably one of the most devastating historical submarine earthquakes in the eastern mediterranean rupture of the offshore hitherto unknown 100 150 km long active east dipping mount lebanon thrust deep towed sonar swaths along the base of prominent bathymetric escarpments reveal fresh west facing seismic scarps that cut the sediment smoothed seafloor the mount lebanon thrust trace comes closest 8 km to the coast between beirut and enfeh where as 13 14c calibrated ages indicate a shoreline fringing vermetid bench suddenly emerged by 80 cm in the sixth century a d at tabarja the regular vertical separation 1 m of higher fossil benches suggests uplift by three more earthquakes of comparable size since the holocene sea level reached a maximum ca 7 6 ka implying a 1500 1750 yr recurrence time unabated thrusting on the mount lebanon thrust likely drove the growth of mount lebanon since the late miocene

limitations of infra red stimulated luminescence in dating high arctic marine sediments abstract the accuracy of infra red stimulated luminescence irsl dating was evaluated for modern late glacial 11 to 13 ka and older 70 10 ka and 125 10 ka nearshore marine sediments from west spitsbergen despite the increased sensitivity of the irsl signal to solar reduction compared with thermoluminescence the irsl signal of these sediments was not totally reset resulting in overestimates of a few 1000 to 10 000 years subtraction of residuals determined after 10 or 60 minutes of filtered light exposure wavelengths

extending the geochronometry of arctic lake cores beyond the radiocarbon limit by using thermoluminescence reconstructing detailed paleoclimatic paleoenvironmental histories from pleistocene sediments in the arctic is an ongoing challenge because of the difficulty of measuring accurate timescales beyond the range of radiocarbon 14c dating important archives of such histories are arctic lakes that exist outside the known extent of the last major glaciations to develop reliable geochronometry of sediment cores from arctic and other lakes we applied thermoluminescence tl sediment dating methods to 24 samples 8 reported earlier but some reanalyzed here selected from cores from squirrel and joe lakes in northwestern alaska a sequence of 23 14c ages from the upper parts of these cores permitted tests of the zeroing assumption of tl dating that all fine silt grains were exposed to daylight before final burial we performed multiple tl tests on most samples to isolate stable tl signals and measured tl emissions spectra to help characterize samples tl ages generally agree with the 30 kyr age depth trend derived from 14c dating and extend the timescale apparently to 180 ka for squirrel lake and to at least 60 ka for joe lake an anomalously old tl result from squirrel lake is attributed to failure of the tl zeroing assumption within that sediment horizon in the lower joe lake core we assign a timing of 45 ka to 50 ka for the beginning of an apparently climatic warming interval these results identify and quantify the main tl sources of tl age inaccuracy and the preferred tl protocols for accurate tl sediment dating in northern high latitude lake deposits they also provide the first direct chronology beyond the 14c dating range for these lakes

the kinematics of central southern turkey and northwest syria revisited central southern turkey nw syria and adjacent offshore areas in the ne mediterranean region form the boundary zone between the turkish african and arabian plates a great deal of new information has emerged in recent years regarding senses and rates of active crustal deformation in this region but this material has not hitherto been well integrated so the interpretations of key localities by different teams remain contradictory we have reviewed and synthesised this evidence combining it with new investigations targeted at key areas of uncertainty this work has led to the inference of previously unrecognised active faults and has clarified the roles of other structures within the framework of plate motions provided by gps studies roughly one third of the relative motion between the turkish and arabian plates is accommodated on the misis kyrenia fault zone which links to the study region from the kyrenia mountain range of northern cyprus much of this motion passes nne then eastward around the northern limit of the amanos mountains as previously thought but some of it splays northeastward to link into newly recognised normal faulting within the amanos mountains the remaining two thirds of the relative motion is accommodated along the karasu valley some of this component steps leftward across the amik basin before passing southward onto the northern dead sea fault zone dsfz but much of it continues southwestward past the city of antakya then into offshore structures ultimately linking to the subduction zone bounding the turkish and african plates to the southwest of cyprus however some of this offshore motion continues southward west of the syrian coast before linking onshore into the southern dsfz this component of the relative motion is indeed the main reason why the slip rate on the northern dsfz measured geodetically is so much lower than that on its southern counterpart in some parts of this region notably in the karasu valley it is now clear how the expected relative plate motion has been accommodated on active faults during much of the quaternary rather than constant slip rates on individual faults quite complex changes in the partitioning of this motion on timescales of hundreds of thousands of years are indicated however in other parts of the region it remains unclear whether additional major active faults remain unrecognised or whether significant relative motions are accommodated by distributed deformation or on the many smaller scale structures present

new evidence of holocene coastal uplift in the strophades islets w hellenic arc greece abstract the strophades islets ionian sea correspond to a 2 km thick evaporitic diapir formed due to compression along the western part of the aegean arc in the last 5 ma field observations and radiometric dating indicate that the only clear evidence of holocene vertical movement in these islets is an approximately 2 m vertical displacement which occurred about 1560 years ago while the traces of the 10 cm uplift of a 1997 earthquake and possibly of other earthquakes which have produced minor uplifts are not preserved a mean uplift rate of 0 8 mm yr for the last 2500 years and possibly of 0 1 mm yr since the last interglacial are inferred this indicates a high contrast between strong deformation over the long term and small uplift during the holocene and possibly also since the last interglacial in agreement with results of seismological and tectonophysical studies

luminescence dating and its application to key pre late devensian sites in scotland abstract relatively few sites have been identified in scotland that contain records that predate the peak of the late devensian glaciation ca 18 ka bp where such records have been identified they have assumed a key role in developing our understanding of climate change in scotland radiocarbon dating has been the primary chronological tool applied to these sites but the reliability of age determinations in excess of 30 ka is questionable in this paper we describe the results of a programme which applies luminescence dating methods to eight key pre late devensian sites in scotland methods were developed and tested to enable the identification of samples for which luminescence dating was only able to provide an upper limit on the age because of the limited light exposure that the sample experienced at deposition these new approaches were applied to four sites where independent age control was available this meant that the choice of sediments from test sites was restricted to those sediments which were formed in the last 40 000 years and hence were amenable to radiocarbon dating the luminescence age estimates for the control sites and the pre late devensian sites are discussed within the context of any existing chronological control on a site by site basis

the structural relationship between the east anatolian and dead sea fault zones in southeastern turkey abstract the complex structural relationship between the east anatolian and dead sea fault zones is examined mostly based on field observations in southeastern turkey where the two fault zones are close together several faults previously poorly documented can be traced to connect either to the east anatolian fault zone or to the dead sea fault zone one of these faults connects the dead sea fault zone to the east to the amanos fault to the west the amanos fault a n trending normal fault is a part of the east anatolian fault zone since it is apparently a left step fault between the main and southern strands of the east anatolian fault zone the dead sea fault zone also is connected to the east anatolian fault zone northeast of the town of narli and or northeast of the hazar lake therefore we suggest that the two fault zones can be considered as one broad fault system in southeastern turkey although they are well recognized as two different fault zones this fault system is responsible for several complex neogene structural features of the western part of the southeastern turkey one of these is the hatay graben which can be divided into southern central and northern parts the graben contains down to the west normal faults in its southern part the central part of the graben is a divergent strike slip basin and the northern part is a half graben

zeroing of the tl signal in sediment undergoing fluvioglacial transport an example from austerdalen western norway abstract study of levels of natural tl in sediment undergoing fluvial transport in austerdalen norway shows that bleaching does occur but does not follow a regular pattern this is attributed to the incorporation of older unbleached material into the sediment load as a result of riverbank erosion levels of residual tl are high enough to raise doubts about the accuracy of fine grain tl dating of fluvioglacial sediments which have experienced only a short distance of transport

mis 5a and mis 3 relatively high sea level stands on the hatay samandag coast eastern mediterranean turkey abstract the coastal belt of hatay samandag in the east mediterranean is marked by the intersection of the african arabian and eurasian anatolian platelet plates where several quaternary shorelines related to relative sea level changes can be seen above the current sea level in this study the most common and best preserved high sea level markers of the marine isotope stage mis 5 and mis 3 shorelines were dated for the first time using the mollusc based electron spin resonance esr method as a result of this research the age of the late mis 5 and mis 3 sea level highstands in the eastern mediterranean the elevation of the corresponding shoreline at samandag coast and the vertical component of the late quaternary tectonic movements which has an impact on shoreline were determined the shorelines at 48 43 m elevations between cevlik and samandag at 58 6 m in tekebasi and at 21 m at keldag have been dated to approximately 72 ka and therefore are correlated with mis 5a the shoreline at 40 39 m elevations between cevlik and samandag has been dated to approximately 53 ka and therefore is correlated with mis 3 according to the position of the mis 5a shorelines the uplift rate over the last 72 ka was 0 88 mm y between cevlik and samandag 1 08 mm y in tekebasi and 0 56 mm y in keldag yielding a 0 84 mm y average this rather fast uplift appears to be related to the vertical component of the strike slip active faults in the samandag antakya fault zone

thermoluminescence dating applied to glaciolacustrine sediments from central british columbia glaciolacustrine and lacustrine sediments are important indicators of deglacial interglacial and nonglacial intervals within the quaternary of canada yet there are no techniques for measuring their absolute deposition ages beyond the last 50 000 years in an attempt to develop an absolute dating tool for such sediments we applied the partial bleach thermoluminescence tl dating technique to glaciolacustrine sediments of known age from central british columbia samples were selected to represent both ice proximal and ice distal deposition and different modes of sedimentation the results show clearly that both tl procedures and sedimentation processes as reflected in the particle size and sedimentary structures of the samples critically affected the accuracy of tl apparent ages specifically care was required to isolate the effects of laboratory overbleaching apparent glow curve shifts and inappropriate regression analysis clay dominant layers lacking silt or sand interlayers produced expected

kinematics and deformation of central and southwestern greece from historical triangulation data and implications for the active tectonics of the aegean abstract changes in the coordinates of 38 stations 32 of which were common to three historical triangulation surveys 1889 1905 1927 1930 and 1950 1970 in central greece were computed based on conventional adjustment techniques and the assumption of a nearly fixed baseline length some of the calculated coordinate changes are significant against the a posteriori network adjustment errors and are likely to indicate tectonic motions consistent with those deduced from geological and geophysical data and other geodetic studies comparison of the first survey network with gps data more explicitly the historical geodetic data confirm the rotational character of the deformation in the area but they show that the strain pattern is likely to have changed after 1930 between 1890 and 1930 strain was changing smoothly as if no strain discontinuities existed while the peloponnesus was under contraction from the northeast probably reflecting accommodation of strain from the arc significant left lateral shear in the gulf of corinth and n s extension in the whole of the study area were observed only after 1930 estimates of strain are consistent with those deduced from comparison of historical triangulation and gps data corrected for the scale error that exists in the terrestrial geodetic data in greece and estimates of strain from seismological data the change in the kinematic pattern after 1930 seems to be confirmed by changes in the shear strain computed directly from changes in observed angles between stations and from changes in the seismicity rates such changes although not unusual in the geological record are not easy to explain but may reflect elastic rebound effects in area with an extremely complicated tectonic fabric or hysteresis in the accommodation of e w compression from the arc by n s stretching

applications and limitations of thermoluminescence to date quaternary sediments abstract the thermoluminescence tl method dates sediment by quantifying time dependent dosimetric properties of mineral grains sunlight exposure of the sediment during transportation and deposition or heating resets the tl clock to time zero after burial of the mineral grains ionizing radiation from the decay of radioisotopes imparts a tl signal this accumulated tl signal is proportional to the equivalent dose ed which is a measure of radiation exposure during the burial period a tl age estimate is determined from the ratio of the ed to the environmental radiation dose rate the calculation of an ed is influenced by the susceptibility of sediments to optical bleaching the emission spectra of minerals and possible long and short term fading there are three basic methods for determining an ed regeneration total and partial bleach the regeneration technique may yield under estimates because of sensitivity changes with laboratory bleaching the latter two techniques are most useful for well and partially light bleached sediments respectively a number of sediments can be dated by the tl method eolian and a variety of terrestrial sediments yield apparently accurate tl age estimates though there are possible complications associated with pedogenesis it appears that some fluvial sediment can be accurately dated by tl but little is known about the efficiency of optical bleaching for fluvial depositional systems till and glacier proximal deposits are inadequately light bleached to be dated by tl sediments deposited distal from the glacier margin which are at least partially bleached are preferred for dating future research is needed to understand better the relationship between sedimentary environments and the extent of light bleaching also studies should concentrate on dating feldspar extracts from well dated sequences to more fully ascertain the temporal limitations of the method only by understanding the interplay of sedimentology tl dosimetry and environmental radiation can the tl method be effectively applied to the myriad of depositional environments spanning the late to middle pleistocene

environmental assessment from the sedimentary record of high latitude fiords the sedimentary record of fiords at high latitude where global change may be occurring earliest and will be greatest has the potential for assessment of environmental change at both low resolution the scale of millennia and high resolution decadal to less than daily unlike the lacustrine record which has been used very successfully in these studies the sedimentary processes and thus the sedimentary deposits of fiords differ 1 in the role of salt water in inhibiting mixing and promoting flocculation and through the role of sea ice 2 in the exchange of mass and energy with the much larger ocean beyond and 3 in the role of benthic biota in the sedimentary environment the work reviewed in this paper shows that fiord sediments are being used to assess sedimentary and oceanic processes as well as glacial periglacial and geomorphic history and that they are important proxies for long term climate and hydrology recommendations for advancing this work include long term monitoring of conditions in fiords and their drainage basins so that the transfer relations can be more solidly constructed from the proxy of fiord sediment integration of results from fiords in opposite polar latitudes and among proxies especially from lacustrine and ice core records will produce valuable insights assessment of the range of conditions in fiords from the most polar to temperate regions is important to building models of their processes and understanding of the paleoenvironmental signals that can be interpreted from each type

limitations of thermoluminescence to date waterlain sediments from glaciated fiord environments of western spitsbergen svalbard abstract a fundamental problem in the tl dating of waterlain sediments particularly in the arctic is the accurate determination of the level of solar resetting prior to deposition this study determined the effect of wavelength on the solar resetting of the tl signal and concomitant effects on the accuracy of tl age estimates for late glacial and modern glacial and nearshore marine sediments from fiords on spitsbergen the reduction in tl level decreases with filtering of wavelengths above 400 nm modern and late weichselian tills have tl levels at saturation probably received no light exposure prior to deposition and thus cannot be dated by tl glacial marine sediments deposited within 0 5 km of a glacier terminus yielded tl age estimates 10 times the known age presumably because these sediments received limited light exposure prior to deposition modern sublittoral sediments and fiord muds yielded tl apparent ages between

interpretation of holocene sea level tendency and intertidal sedimentation in the tees estuary using sediment luminescence techniques a viability study it is demonstrated that detailed examination of the photo and thermoluminescence pl tl of holocene intertidal sediments can reveal important information regarding their depositional history in the context of sea level tendency and storm surge activity the technique is particularly applicable to thick deposits of relatively uniform composition and is demonstrated with a 1 7 m core of marine to brackish water silty clay taken from cowpen marsh in the tees estuary north east england this sedimentary unit is intercalated with an upper and a lower terrestrial peat bed which have been radiocarbon dated to 5250 45 and 7065 45 14c years bp respectively an investigation of the mineral composition and diatom assemblage of the silty clay facies reveals a marked hiatus in deposition towards the top of the minerogenic unit analysis of the luminescence profiles of the sediment illustrates that below this hiatus sedimentation was slow and continuous with approximately 1 0 m of sediment being deposited in 1800 400 years whilst above sedimentation was rapid with 0 7 m of sediment being deposited in 0 200 years it is shown that variations in the luminescence of the sediments can be interpreted in terms of the onset of a positive sea level tendency period coupled with the occurrence of a low frequency extreme water level event

holocene raised beaches along the northern coast of the beagle channel tierra del fuego argentina abstract raised beaches developed during holocene times along the northern beagle channel coast these deposits contain a rich marine fauna especially shelled organisms such as mollusks four holocene marine sites along the northern coast of the beagle channel have been analysed from west to east they are bahia ensenada playa larga bahia brown and cutalataca airfield they were studied in relation to relative altitude sediment type faunal composition and radiocarbon dates the area is characterized by several discontinuous terraces with elevations varying from about 1 5 to 10 m above sea level their possible origin 1 due to tectonic uplifting in comparison with raised beaches of the northern part of tierra del fuego and 2 resulting from glacio isostatic recovery taking into account the ice retreat is discussed seventeen species of mollusks eight bivalves nine gastropods were collected from the study sites all of them are living species from the beagle channel and have been interpreted as representative of holocene paleocommunities in this channel these species show no evidence of substantial climatic changes during the holocene although minor temperature fluctuations cannot be ruled out yet

a model for sedimentation by tidewater glaciers sampling of sediment from the fjord floor in front of tidewater glaciers in glacier bay alaska has provided information about processes in this restricted glacimarine dreimanis 1979 setting sediment sampling in conjunction with oceanographic and glacial dynamics data has also enabled the discrimination of sediment types and their facies associations deposits are strongly controlled by sea water characteristics position and sediment discharge of melt water streams iceberg calving and rate of glacierfront retreat five distinct facies associations have been found to reflect glacier fjord regimes the facies associations and ice fjord conditions responsible for them form the basis for constructing a preliminary model for glacimarine sedimentation by tidewater glaciers the model can be used to predict i rapid retreat of an actively calving ice front ii slow retreat or stabilization of a calving ice front at a channel constriction iii stabilization of a melting very rarely calving ice front when the glacier base is near tidewater elevation and iv large outwash delta progradation into a fjord when the ice front retreats onto land this model can be used to interpret facies associations found in a stratigraphic record

the effect of light intensity and spectra on the reduction of thermoluminescence of near shore sediments from spitsbergen svalbard implications for dating quaternary water lain sequences the thermoluminescence tl properties of silicate mineral grains have been used as geochronometers for water lain sediments this study provides new insight into the limitations of tl the technique by quantifying the effects of incident wavelength and light intensity on the resetting of the tl signal the tl residual level increases as wavelengths between 440 and 540 nm are blocked and remains unchanged after ca 4 hours these residual levels were maintained even after 24 hours of continuous exposure the light intensity threshold for reduction in the tl signal is quite low 10 of full light exposure or 1 104joules m2 however during the late glacial on svalbard and possibly in other aqueous glacial environments the concentration of suspended sediment was sufficiently high to reduce the ambient light intensities to below these levels resulting in elevated residual levels that are difficult to duplicate in the laboratory the available thermoluminescence techniques are unsuitable for unequivocally dating water lain sediments because of the natural spatial and temporal variations in the solar reduction in the tl signal in turbid aqueous environments

thermoluminescence dating tests for lacustrine glaciomarine and floodplain sediments from western washington and british columbia to help further develop reliable procedures for accurate thermoluminescence tl dating of quaternary waterlaid sediments we tested tl dating procedures on sediment types rarely examined six glaciolacustrine samples three samples of glaciomarine drift and eight samples of floodplain deposits we used the partial bleach r beta gamma technique applied to fine silt polymineral grains results from our younger known age glaciolacustrine sediments confirm earlier observations that only the clayey laminae are generally suitable for tl dating a clayey lamina older than ca 140 150 ka produced no age underestimation and this result ca 300 ka suggests that such older lake sediments are probably suitable for tl dating two proximal samples of glaciomarine drift produced large tl age overestimates whereas the single distal glaciomarine drift sample yielded an expected age 177 38 ka suggesting that follow up studies are warranted our results for eight flood plain samples confirm that zeroing of li

crustal block movements from holocene shorelines crete and antikythira greece abstract marks of several shorelines left by sea level stands during the last 4000 yrs occur along the coasts of the islands of crete and antikythira in this area recent movements of the earth s crust were identified by using a systematic survey based on multidisciplinary analyses strengthened by 60 radiometric datings between 4000 and 1700 yr b p a block of lithosphere a about 150 km long fig 10 which included antikythira and the levka mountains in crete underwent a series of ten rapid subsidences from 10 to 25 cm each time without noticeable tilting these movements ended about 1 530 40 yr b p a further block of lithosphere b approximately 200 km long was then uplifted about 10 m and inclined northeastwards in a single event block b includes block a and extends 50 km further eastwards beyond the ida mountains as far as the iraklion sedimentary basin the tectonic movements were preceded by vertically reversed displacements of short duration on at least three occasions if the a block subsidences can be ascribed to gravitational forces then the b block uplift suggests a cause that originated at depth crustal consumption and elastic rebound to the east of the ierapetra graben the sitian peninsula appears to belong to a block of lithosphere c affected by a northeast tilting and separated by an active fault from the crustal block of khrisi koufonisi

holocene raised shorelines on the hatay coasts turkey palaeoecological and tectonic implications abstract the marks of two emerged shorelines superimposed erosional notches and in situ bioconstructed rims with the vermetid dendropoma on both sides of the orontes delta near the border between turkey and syria are interpreted as representing the occurrence of two rapid uplifts during the late holocene rather than representing eustatic fluctuations of climatic origin as claimed by previous authors in other areas of the eastern mediterranean the upper shoreline which has an elevation of about 2 0 m south of the delta and which increases from 2 5 m to 3 0 m between 2 and 8 km north of the delta has been radiocarbon dated four dates to between 5170 190 and 2595 100 yrs b p the lower shoreline indicating a former relative sea level situated consistently at about 0 7 to 0 8 m has yielded seven dates between 2910 95 and 1345 70 yrs b p the latter age being that of fossil oyster shells collected in growth position on a quay of the ancient harbour of seleucia pieria if the possible contamination of some oyster shells is taken into account the two uplift movements may be dated at around 2500 100 yrs b p for the upper shoreline and to historical times for the lower shoreline probably in july 551 a d when devastating earthquake damage was reported from all the levant regions the age of the second uplift movement falls within the possible time span of a major tectonic event the early byzantine tectonic paroxysm ebtp which about 1500 yrs b p caused sudden relative sea level changes in various areas of the eastern mediterranean antikythira western crete and alanya area the lebanon northern cyprus etc in the hatay region the effect of the ebtp has been a reactivation of local fault lines probably in connection with movements on the east anatolian fault system this has contributed a new jerk to the long term trend of uplift in this coastal area

osl ages on glaciofluvial sediment in northern lower michigan constrain expansion of the laurentide ice sheet abstract we report new ages on glaciofluvial outwash sediment from a large upland in northern lower michigan the grayling fingers the fingers are cored with 150 m of outwash which is often overlain by the informal blue lake till of marine isotope stage mis 2 they are part of an even larger interlobate upland comprised of sandy drift known locally as the high plains the ages determined using optically stimulated luminescence osl methods indicate that subaerial deposition of this outwash occurred between 25 7 and 29 0 ka probably associated with a stable mis 2 ice margin with mean ages of ca 27 ka these dates establish a maximum limiting age of ca 27 ka for the mis 2 late wisconsin advance into central northern lower michigan we suggest that widespread ice sheet stabilization at the margins of the northern lower peninsula during this advance and later during its episodic retreat partly explains the thick assemblages of coarse textured drift there our work also supports the general assumption of a highly lobate ice margin during the mis 2 advance in the great lakes region with the fingers an interlobate upland remaining ice free until ca 27 ka

pleistocene geomorphological and sedimentary development of the akaki river catchment northeastern troodos massif in relation to tectonic uplift versus climatic change the uplift of the troodos ophiolite is reflected in the development of the akaki river catchment in the northeast troodos massif four main stages f1 f4 of geomorphological terrace development and related deposits are recognised using satellite imagery and field observations the geomorphological terraces have been tectonically uplifted during the pleistocene so that they dip northwards from the troodos mountains until they merge with the mesaoria plain lithology e g hard diabase versus soft extrusive rock has exerted an important control on the geomorphology of the akaki river channel the f1 terraces and related deposits are well preserved in the lower reaches of the catchment the f2 terraces are more widely preserved but with few preserved deposits the f3 erosional surfaces e g strath terraces and related deposits are widespread up into the higher reaches of the catchment the f4 to recent geomorphological surfaces and deposits are confined to near the modern river channel the f1 to f3 aged deposits each include very high energy mass flow deposits and somewhat lower energy traction flow deposits with minimal sand preservation stages of fluvial aggradation were followed by soil development e g terra rossa the f1 to f4 aged terraces and related deposits mainly formed in response to a combination of very long term tectonic uplift and climatic related change long term and short term tectonic uplift was the dominant driver related to the updoming of the troodos ophiolite especially during the earlier time period f1 and f2 whereas climate related effects appear to have dominated more recently f3 and f4 sedimentary aggradation is likely to have predominated during interglacial periods while interglacial glacial transitions when climate fluctuated are seen as times of increased incision previous correlations of the f1 f4 fluvial deposits with similar deposits elsewhere in cyprus including coastal marine carbonate deposits suggest that the f1 and f2 deposits are likely to be of middle pleistocene age and the f3 f4 deposits of late pleistocene to holocene age