evidence for an earthquake and tsunami about 3100 3400 yr ago and other catastrophic saltwater inundations recorded in a coastal lagoon new zealand abstract okupe lagoon is 2 02 masl brackish and ponded behind two boulder banks at the northern end of kapiti island new zealand the sediments of the lagoon provide a record of late holocene environmental changes such as tectonic uplift catastrophic saltwater inundation and vegetation change five main events were identified over a 5300 yr record with a sixth representing a re evaluation of previous work an uplift event of 1 5 3 0 m and an associated tsunami are recorded and are inferred to have been caused by a local fault rupture possibly the northern extension of the wairau fault about 3360 40 yr bp two additional tsunami generated by ruptures of either the ohariu or wellington faults 1290 and 1220 ad respectively and either the wellington or alpine faults 1450 ad have been tentatively proposed two catastrophic saltwater inundations csis have also been identified one possibly a tsunami generated by either the wairarapa fault 500 ad or taupo eruption 190 ad the other about 4780 150 yr bp may relate to a local fault rupture however further work is needed to determine whether these are tsunami or storm surge related and they are therefore designated csis the sixth event is the 1855 tsunami recorded from a raised shore platform to the west of okupe lagoon

comparison of imbrie kipp transfer function and modern analog temperature estimates using sediment trap and core top foraminiferal faunas we evaluate the reliability of statistical estimates of sea surface temperature sst derived from planktonic foraminiferal faunas using the modem analog method and the imbrie kipp method global core top faunas provide a calibration data set while modem sediment trap faunas are used for validation linear regression of core top predicted sst against atlas sst generated slopes close to one for both methods however the imbrie kipp transfer function temperature estimates had an intercept 1 3oc warmer than modem analog estimates and 1 7oc warmer than recorded atlas sst the rms error for the core top data set using the modem analog method 1 5oc was smaller than that of the imbrie kipp method 1 9oc sst errors for the sediment trap faunas were not statistically different from those of the core top data set regardless of method developing imbrie kipp transfer functions for limited regions reduced the rms variability but introduced residual structure not present in the global imbrie kipp transfer function dissolution simulations with the sediment trap sample which generated the warmest sst residual for both methods suggests that the loss of delicate warm water foraminifera from midlatitude sediments may be the cause of this thermal error we conclude that 1 the fauna structure of sediment trap and core top assemblages are similar 2 both methods estimate sst reliably for modem foraminifera flux assemblages but the modem analog method exhibits less bias and 3 both methods are relatively robust to samples with low communality but sensitive to selective faunal dissolution

analysis of hydraulic and tracer response tests within moderately fractured rock based on a transition probability geostatistical approach 1 a transition probability and markov chain geostatistical approach is applied to synthesize the discrete permeability structure of moderately fractured rock the approach can infuse either hard or subjective categorical information that is consistent with geological interpretations the methodology is tested using data collected from the moderately fractured rock mfr experiment area of the underground research laboratory url in southeastern manitoba canada attributes pertaining to fracture location frequency and orientation along an array of boreholes intersecting the mfr experiment area taken together with results from hydraulic response tests within packed off intervals along the boreholes are used to produce conditional stochastic realizations of hydraulic conductivity and effective porosity using the generated hydraulic conductivity and porosity realizations we compare predicted tracer concentrations to the results of measured breakthrough data in a stochastic framework the results show that solute migration behavior in moderately fractured rock can be successfully characterized and reasonably predicted upon careful error analysis of the results obtained from the various medium realizations synthesized from the conditional categorical descriptions of the fractured crystalline rock

foraminiferal assemblages response to anthropogenic influence and parallel to decadal sea level changes over the last 70 years in lake kugushi fukui prefecture southwest japan abstract foraminiferal assemblages in lake kugushi in the sea of japan coast of southwest japan responded to both human activity and sea level changes over the last 70 years human modifications in and around this lake were mainly related to the dredging and widening of the urami river in 1935 and to shore protection projects that removed aquatic plants around the lake in the middle 1970s about 60 of the natural shoreline was replaced by artificial ones marine foraminifera migrated into the southern part of the lake after the modifications of 1935 brackish foraminifera preferring phytodetritus became dominant from the middle 1970s while the original assemblage preferring low salinity and probably land derived organic matter decreased the sea level rise over the last 70 years is clearly indicated by two kinds of foraminiferal assemblages the appearance of marine species in the 1950s and 1970s and the development of a brackish assemblage preferring eutrophic water from the 1980s onward the latter is an assemblage dominated by trochammina hadai which is common in coastal lagoons with a well developed halocline and highly eutrophied argillaceous substrates based on the different response of these foraminiferal assemblages to sea level rise the most recent sea level rise is driven by a mechanism unlike those in the 1970s and 1950s the thermal expansion of seawater will lead to coastal lagoons that will be more stagnant and eutrophic with little exchange of coastal marine water

vertical saltmarsh accretion and its relationship to sea level in the severn estuary u k an investigation using foraminifera as tidal indicators saltmarsh vertical accretion has been used as a proxy for sea level rise in previous studies on the assumption that accretion is in quasi equilibrium with sea level rise this assumption requires verification in each case as accretion may lag or exceed sea level rise leading to under or over estimates of sea level rise respectively verification may be provided by biostratigraphic analysis where biological remains in saltmarsh sediments may be related to former tide levels foraminifera are well suited as studies of modern saltmarshes have demonstrated distinct tidal relationships which may be used to calibrate downcore temporal foraminifera sequences it is hypothesized that depending on the relationship between sea level rise and accretion quasi equilibrium submergence and emergence foraminifera sequences may be recognized these are explored here in a severn estuary u k saltmarsh where an emergence foraminifera sequence is identified suggesting that previous sea level rise rates for the severn estuary based on saltmarsh accretion rates may be over estimates wider consequences of this may include over estimation of regional crustal subsidence rates required to accommodate artificially high sea level rise rates saltmarsh accretion rates are clearly not a suitable proxy for sea level rise in all cases and as such each saltmarsh requires biostratigraphic evaluation to establish sea level rise accretion relationships preferably independent sea level index points slips should be used over saltmarsh accretion rates in constructing sea level histories

microfossil analysis of sediments representing the 1964 earthquake exposed at girdwood flats alaska usa abstract diatom pollen foraminifera and thecamoebian assemblages from an outcrop of peat and silt at girdwood flats in the upper turnagain arm of the cook inlet alaska record four phases of relative land and sea level changes the first phase is the development of freshwater swamp above high marsh sediments during relative land uplift caused by strain accumulation along the locked portion of the alaska aleutian subduction zone in second phase the top 2 cm of the peat all microfossil groups record pre seismic relative sea level rise relative land subsidence the third phase is rapid land subsidence 1 7 m during the earthquake of march 1964 that initiated intertidal silt accumulation above the peat the final phase is the colonisation of mudflat by salt marsh communities during post seismic land uplift the microfossil data compare favourably with sequences from washington oregon and british columbia that record late holocene submergence events caused by earthquakes the comparable changes in microfossil assemblages record the different phases of relative land and sea level changes and the magnitude of land subsidence caused by each earthquake expressed relative to the tidal range at the site these results raise the question whether preseismic sea level rise represents any kind of warning of large earthquakes

sea surface temperatures of the southwest pacific ocean during the last glacial maximum the southwest pacific ocean covers a broad range of surface water conditions ranging from warm salty water in the subtropical east australian current to fresher cold water in the circumpolar current using a new database of planktonic foraminifera assemblages ausmat f2 we demonstrate that the modern analog technique can be used to accurately reconstruct the magnitude of sea surfacetemperature sst in this region we apply this technique to data from 29 deep sea cores along a meridional transect of the southwest pacific ocean to estimate the magnitude of sst cooling during the last glacial maximum we find minimal cooling in the tropics 0 2 c moderate cooling in the subtropical midlatitudes 2 6 c and maximum cooling to the southeast of new zealand 6 10 c the magnitude of cooling at the sea surface from the tropics to the temperate latitudes is found to generally be less than cooling at the surface of adjacent land masses

multiproxy approach for holocene paleoenvironmental reconstructions from microorganisms testate amoebae and foraminifera and sediment analyses the infilling of the loire valley in nantes france foraminifera and testate amoebae are jointly used with sediment characteristics sediment size calcium carbonate c h n and s proportions and clay mineralogy to reconstruct the holocene sediment infilling of the loire estuary nantes france the results reveal the infilling of the loire valley during the holocene deposited on the hercynian substratum the first deposits are made of gravels with rare associated fauna this corresponds to the gravel lag usually present as basal deposits in the river course the clay mineralogy indicates an erosion of the substratum then from 8850 to 5850 cal yr bp estuarine fauna settled in a laminated sediment that alternates between clay and sand the smectite associated with kaolinite and illite suggests increased input from the sevre nantaise river the fauna progressively shifts from estuarine to marine indicating a rise in the sea level from 5850 cal yr bp the pace of the sea level rise slowed and channels migrated implying intense erosion after 2100 cal yr bp the fauna was dominated by testate amoebae indicating a continentalization of the environment the top samples reflect recent human activity and urbanization

mid to late holocene relative sea level change in poole harbour southern england a foraminiferal transfer function for mean tide level mtl is used in combination with ams radiocarbon dated material to construct a record of relative sea level rsl change from poole harbour southern britain these new data based on multiple cores from duplicate sites indicate four phases of change during the last 5000 cal calendar yr i rising rsl between ca 4700 cal yr bp and ca 2400 cal yr bp ii stable to falling rsl from ca 2400 cal yr bp until ca 1200 cal yr bp iii a brief rise in rsl from ca 1200 cal yr bp to ca 900 cal yr bp followed by a period of stability iv a recent increase in the rate of rsl rise from ca 400 200 cal yr bp until the present day in addition they suggest that the region has experienced long term crustal subsidence at a rate of 0 5 mm c 14 yr 1 although this can account for the overall rise in mtl observed during the past 2500 yr it fails to explain the changes in the rate of rise during this period this implies that the phases of rsl change recorded in the marshes of poole harbour reflect tidal range variations or eustatic fluctuations in sea level copyright 2001 john wiley sons ltd

foraminiferal record of the 2010 2011 canterbury earthquake sequence new zealand and possible predecessors abstract this study documents changes in elevation plant zones and foraminiferal faunas along a transect through salt marsh taken 14 months prior to and 12 and 33 months after the feb 2011 canterbury earthquake which devastated the city of christchurch new zealand the saltmarsh subsided 0 1 m relative to the adjacent sand spit due to shaking induced lateral spread over the 33 month period the lower 0 3 m elevation of the rush zone died away and a pine tree plantation on the sand spit terrace 0 3 0 5 m above highest astronomical tide hat in 2009 also died and was removed the foraminiferal faunal composition changed only slowly following the earthquake except in the highest stations here their landward extent had migrated 0 45 m upwards by the end of 2013 and the foraminifera based elevation estimates modern analogue technique mat indicated a total subsidence of 0 36 0 62 m similar to that indicated by lidar surveys elevation estimates based on the dead foraminiferal faunas in replicate salt marsh cores 10 m apart indicate a subsidence event of 0 15 0 2 m at 45 cm downcore this was probably a result of shaking induced lateral spread of the marsh into the river channel during a late 19th century earthquake most probably the 1869 christchurch earthquake a second possible co seismic subsidence event is indicated at 80 cm downcore but the mat elevational estimates are less reliable because of the low density foraminiferal faunas a sudden relative fall in sea level or uplift of land of 0 2 0 25 m is indicated by mat elevation estimates at 60 cm downcore as there is no known supporting evidence for a tectonic uplift event we infer the most likely explanation is that this event spans an erosional time break 500 yrs although we did not recognise its significance at the time the foraminiferal record in our 2009 salt marsh core indicated that christchurch had previously experienced significant co seismic shaking on at least one and maybe more occasions within the last 1000 yrs

modern foraminifera δ13c and bulk geochemistry of central oregon tidal marshes and their application in paleoseismology we assessed the utility of 13c and bulk geochemistry total organic content and c n to reconstruct relative sea level changes on the cascadia subduction zone through comparison with an established sea level indicator benthic foraminifera four modern transects collected from three tidal environments at siletz bay oregon usa produced three elevation dependent groups in both the foraminiferal and 13c bulk geochemistry datasets foraminiferal samples from the tidal flat and low marsh are identified by miliammina fusca abundances of 45 middle and high marsh by m fusca abundances of 25 the 13c values from the groups defined with 13c bulk geochemistry analyses decrease with an increasing elevation 24 1 1 7 in the tidal flat and low marsh 27 3 1 4 in the middle and high marsh and 29 6 0 8 in the highest marsh samples we applied the modern foraminiferal and 13c distributions to a core that contained a stratigraphic contact marking the great cascadia earthquake of ad 1700 both techniques gave similar values for coseismic subsidence across the contact 0 88 0 39 m and 0 71 0 56 m suggesting that 13c has potential for identifying amounts of relative sea level change due to tectonics

distribution of modern salt marsh foraminifera in the albemarle pamlico estuarine system of north carolina usa implications for sea level research abstract we described the distributions of foraminifera from ten physiographically distinct salt marshes in the albemarle pamlico estuarine system north carolina using 193 surface samples we defined elevation dependent ecological zones at individual sites using cluster analysis and detrended correspondence analysis additionally seven principal biozones of salt marsh foraminifera were identified that have distinctive spatial distributions reflecting a pattern of salinity regimes caused by the current configuration of barrier island inlets high salinity sites along the southern outer banks are associated with sub tidal calcareous assemblages low marshes dominated by miliammina fusca and high marsh environments defined by haplophragmoides wilberti trochammina inflata and arenoparrella mexicana in contrast lower salinity marshes have ammobaculites spp in sub tidal settings miliammina fusca dominated low marshes and high marsh settings characterized by jadammina macrescens spatial variation of foraminiferal populations and the potential for biozones to migrate in response to changing inlet configuration and salinity suggests that datasets of modern salt marsh foraminifera from multiple environments would be appropriate for reconstructing holocene relative sea level in north carolina

micropaleontological evidence of large earthquakes in the past 7200 years in southern hawke s bay new zealand abstract foraminiferal and diatom assemblages in 11 cores 3 7 5 m deep of holocene sediment from brackish marine ahuriri inlet in southern hawke s bay new zealand provide a record of 8 5 m of subsidence followed by 1 5 m of uplift in the last 7200 cal years in a region overlying the subduction zone between the australian and pacific plates modern analogue technique was used to estimate paleotidal elevation of the 97 richest foraminiferal assemblages the most precise estimates are for high tidal salt marsh assemblages cored in marginal settings in the north and south of the former inlet the least precise estimates are from low tidal and subtidal assemblages from cores in the middle of the inlet these paleoelevation estimates combined with sediment thicknesses age determinations from tephrostratigraphy and radiocarbon dates the new zealand holocene sea level curve and estimates of compaction identify the holocene land elevation changes and earthquake displacement events in each core the following major earthquake related displacements are inferred ca 7000 cal yr bp 0 6 m displacement ca 5800 cal yr bp 0 5 m ca 4200 cal yr bp ca 1 5 m ca 3000 cal yr bp 1 4 to 1 8 m ca 1600 cal yr bp ca 1 7 m ca 600 cal yr bp ca 1 m 1931ad napier earthquake 1 5 m further smaller events involving regional subsidence or earthquake shake compaction are indicated during the 7000 3000 yr bp interval but cannot be identified precisely the six possibly subduction interface subsidence events in the last 7000 years have had a return time of 1000 1400 years identified displacement events have a range of sedimentary expressions from an eroded and burrowed hiatus surface to an abrupt lithologic switch from mud to sand or peat to shelly mud or in some places no change in sediment character whatsoever

reconstructing relative sea level change using uk salt marsh foraminifera abstract the position of past sea levels can be reconstructed using a series of sea level index points that possess information on age location altitude and a quantified vertical relationship with a former tidal frame the indicative meaning whilst these points fix the altitude of relative sea level at one instant in time they provide no information on its variation between them here a foraminiferal transfer function is used to reconstruct changes in water depth from fossil assemblages preserved within salt marsh sediments the transfer function performs reliably in the high marsh zone where agglutinated foraminiferal species are dominant in lower marsh environments where calcareous species are prevalent postmortem test dissolution alters the fossil assemblages and leaves them without modern analogues to circumvent this problem a new transfer function based on agglutinated foraminifera and utilising preserved test linings is developed this new transfer function significantly reduces the number of samples without modern analogues but at the expense of diminished sensitivity in the low marsh environment additionally the transfer function is used to establish a series of sea level index points that place observed lateral shifts in depositional environment into a vertical and temporal context the combination of age altitude and high resolution water level reconstructions offers the potential to obtain more detailed and reliable records of relative sea level change from salt marsh sediments

uk intertidal foraminiferal distributions implications for sea level studies foraminiferal assemblages have been collected from ten intertidal study areas situated on the east south and west coasts of the uk the assemblages display a vertical zonation which indicates that the distribution of foraminifera in these intertidal environments is usually the direct function of altitude with the duration and frequency of intertidal exposure the most important factors multivariate analyses separate foraminiferal assemblages into two faunal zones a high and middle marsh zone consisting of differing abundances of jadammina macrescens trochammina inflata and miliammina fusca and a low marsh and tidal flat zone dominated by calcareous foraminiferal species notably elphidium williamsoni haynesina germanica and quinqueloculina spp these faunal zones are similar to those in other mid latitude cool temperate intertidal environments although there are spatial and temporal variations between areas the altitudinal ranges of the faunal zones are employed to identify the vertical relationship of the local environment in which the assemblage accumulated to a reference tide level

techniques for estimation of tidal elevation and con nement salinity histories of sheltered harbours and estuaries using benthic foraminifera examples from new zealand techniques for estimating tidal elevation and con nement proxy for salinity using modern benthic foraminiferal census data from new zealand harbours and lower salinity estuaries are described and assessed for their utility for reconstructing the depositional settings of late holocene sequences we describe a simple modern analogue technique for estimating tidal or subtidal elevation of holocene fossil faunas utilizing the modern data set most applicable to the holocene setting sheltered tidal harbours and inlets or lower salinity estuaries canonical correspondence analysis was used to extract a synthetic con nement gradient from for aminiferal census data in transects down ve new zealand estuaries this gradient was used to develop a new zealand con nement index that can be computed for new zealand modern and holocene estuarine and harbour samples based on their foraminiferal composition the value of the method for estimating holocene elevational and con nement palaeosalinity histories was

contemporary distribution of benthic foraminiferal assemblages in coastal wetlands of south eastern australia abstract benthic foraminifera identified from the upper intertidal zone of coastal mangrove and saltmarsh wetlands of south eastern australia exhibit spatial zonation that varies with elevation and corresponds to position in the tidal frame this study describes relationships between benthic foraminiferal assemblages and environmental variables such as wetland elevation pore water salinity substrate organic matter content and sediment grainsize agglutinated taxa dominated higher in the tidal frame whereas calcareous taxa increased in both relative abundance and diversity lower in the tidal frame species composition varied within and between study sites reflecting local differences in other environmental variables three major spatial clusters were identified in the upper intertidal zone from a dataset consisting of 111 contemporary samples a high to mid elevation assemblage consisting of differing abundances of entzia macrescens and trochammina inflata a mid elevation assemblage comprised of arenoparrella mexicana in association with trochammina inflata and quinqueloculina seminula and mid to low elevation assemblage characterised by cribroelphidium excavatum quinqueloculina seminula ammobaculites spp and miliammina fusca multivariate analysis correlated foraminiferal assemblages with environmental variables showing that foraminiferal distribution in the region is constrained primarily by wetland elevation but also by pore water salinity foraminiferal assemblages derived from cluster analysis correlated with vegetation zones implying that both foraminifera and vegetation are influenced by elevation and salinity this paper seeks to demonstrate that the consistency in spatial zonation of assemblages provides greater confidence that contemporary distribution of foraminiferal assemblages can assist with the interpretation of past depositional conditions and palaeo environmental reconstructions providing insights into the evolution of coastal wetlands of south eastern australia over the holocene

salt marsh foraminifera from the great marshes massachusetts environmental controls abstract by using sites in the great marshes at barnstable massachusetts usa this study examines the effects of a set of environmental parameters on the foraminiferal distribution the studied parameters are elevation above mean high water salinity of the porewater various sediment characteristics vegetation and food source relations between the environmental parameters and foraminiferal properties frequencies densities and diversities are quantified with correlation coefficients for the first time siphotrochammina lobata and balticammina pseudomacrescens are documented in the new england region the following species show a significant correlation with one or more of the studied parameters and are designated as key species haplophragmoides manilaensis jadammina macrescens balticammina pseudomacrescens miliammina fusca and tiphotrocha comprimata based on cluster analysis and the presence absence or dominance of the key species characteristic associations are distinguished the distribution of three associations is indicative of specific marsh environments the marsh fringe the middle marsh and the marsh edge these three marsh units are separated by their own salinity regime flooding and sediment characteristics the marsh fringe is typified by the h manilaensis association and experiences freshwater input seepage surface runoff and rainwater and only slight marine influence resulting in low salinity values 2 5 20 the width of the marsh fringe is variable dependent on the amount of seepage which in turn is controlled by the permeability of the basement and the peat the j macrescens association characterizes the middle marsh where salinities are controlled by infiltration of sea and rainwater and by evaporation salinity values are higher than 20 while temporarily salinity can reach extreme high values during periods without flooding and high evaporation rates e g 44 the fully marine m fusca association occupies the daily flooded marsh edge where the salinities have the same values as cape cod bay water ca 28 unlike many other salt marshes the distribution of foraminiferal assemblages in the great marshes does not show a vertical zonation with respect to mean high water this shows that a worldwide applicable model for paleoenvironmental studies in salt marshes based on foraminifera is not feasible each salt marsh has its own characteristics regional factors such as climate play an important role in the salinity regime while the local upland characteristics determine if seepage takes place thus each marsh has its own foraminiferal fingerprint showing the opportunistic behaviour of the salt marsh agglutinants a surface study is an indispensable first step in assessing the value of foraminifera as paleo ecological indicators

an earthquake history derived from stratigraphic and microfossil evidence of relative sea level change at coos bay southern coastal oregon much of the uncertainty in determining the number and magnitude of past great earthquakes in the cascadia subduction zone of western north america stems from difficulties in using estuarine stratigraphy to infer the size and rate of late holocene relative sea level changes a sequence of interbedded peaty and muddy intertidal sediment beneath a small protected tidal marsh in a narrow inlet of coos bay oregon records ten rapid to instantaneous rises in relative sea level each rise is marked by a contact that records an upward transition from peaty to muddy sediment but only two contacts dating from about 1700 and 2300 yr ago show the site wide extent and abrupt changes in lithology and foraminiferal and diatom assemblages that can be used to infer at least half a meter of sudden coseismic subsidence although the characteristics of a third gradual contact do not differ from those of some contacts produced by nonseismic processes regional correlation with other similar sequences and high precision 14 c dating suggest that the third contact records a great plate boundary earthquake about 300 yr ago a fourth contact formed too slowly to have been caused by coseismic subsidence because lithologic and microfossil data are not sufficient to distinguish a coseismic from a nonseismic origin for the other six peat mud contacts we cannot determine earthquake recurrence intervals at this site similar uncertainties in great earthquake recurrence and magnitude prevail at similar sites elsewhere in the cascadia subduction zone except those with sequences showing changes in fossils indicative of 1 m of sudden subsidence sand sheets deposited by tsunamis or liquefaction features

foraminiferal evidence for the amount of coseismic subsidence during a late holocene earthquake on vancouver island west coast of canada abstract foraminiferal data from two sites 6 km apart on the shores of an inlet near tofino on the west coast of vancouver island british columbia allow estimates to be made of the amount of coseismic subsidence during a large earthquake 100 400 years ago the sampled sediment succession at the two sites is similar peat representing a former marsh surface is abruptly overlain by intertidal mud grading upward into peat of the present marsh at one of the sites a layer of sand interpreted to be a tsunami deposit locally separates the buried peat from the overlying intertidal mud the abrupt peat mud contact records sudden crustal subsidence during the earthquake the paleoelevation of each fossil sample was estimated by comparing its foraminiferal assemblage with modern assemblages of known elevation the modern assemblages were obtained from surface samples collected along transects across the marsh near the fossil sample sites comparisons were made statistically using transfer functions estimates of coseismic subsidence based on differences in paleoelevations just above and below the top of the buried peat range from 20 cm to 1 m with the most likely value in the 55 70 cm range post seismic crustal rebound began soon after the earthquake and may have been largely complete a few decades later

evidence for past subduction earthquakes at a plate boundary with widespread upper plate faulting southern hikurangi margin new zealand abstract at the southern hikurangi margin new zealand we use salt marsh stratigraphy sedimentology micropaleontology and radiocarbon dating to document evidence of two earthquakes producing coseismic subsidence and in one case a tsunami over the past 1000 yrs the earthquake at 520 470 yrs before present b p produced 0 25 0 1 m of subsidence at big lagoon the earthquake at 880 800 yrs b p produced 0 45 0 1 m of subsidence at big lagoon and was accompanied by a tsunami that inundated 360 m inland with a probable height of 3 3 m distinguishing the effects of upper plate faulting from plate interface earthquakes is a significant challenge at this margin we use correlation with regional upper plate paleoearthquake chronologies and elastic dislocation modeling to determine that the most likely cause of the subsidence and tsunami events is subduction interface rupture although the older event may have been a synchronous subduction interface and upper plate fault rupture the southern hikurangi margin has had no significant m 6 5 documented subduction interface earthquakes in historic times and previous assumptions that this margin segment is prone to rupture in large to great earthquakes were based on seismic and geodetic evidence of strong contemporary plate coupling this is the first geologic evidence to confirm that the southern hikurangi margin ruptures in large earthquakes the relatively short time interval between the two subduction earthquakes 350 yrs is shorter than in current seismic hazard models online material historical accounts description of vertical deformation core names foraminifera census and abundance diatom census modern analog samples map of cores collected stratigraphic correlation diagram for all cores and detailed core logs

the use of foraminifera as indicators of tidal effects in estuarine deposits estuaries are classified according to the degree of mixing of freshwater and seawater into three categories stratified partially mixed and well mixed these generally relate to microtidal mesotidal and macrotidal conditions respectively with increase in tidal influence there is an increase in transport of foraminiferal tests both as bed load and especially in suspension the latter group are generally very small 200 m and include many open marine species when they are sedimented they lead to high diversity assemblages in environments where the diversity of the living assemblages is low the abundance of these exotic tests shows a progressive increase with increased tidal strength thus the presence of size sorting with small mean size diversity range and proportion of exotic individuals can be used as criteria for the recognition of tidal effects in ancient estuarine deposits

environmental control on a land sea transitional setting integrated sedimentological geochemical and faunal approaches because of their location at the interface between sea and emerged lands so called transitional environments are characterized by strong spatial and temporal variability in terms of sedimentological physicochemical and geochemical parameters an increasing number of studies put forward the use of bioindicators as a tool for environmental monitoring however the sensitivity to these environmental parameters is commonly tested separately even though it is known that interactions are numerous within this complex ecosystem an integrated methodological study was conducted in lake varano italy on the basis of 45 spatially distributed samples throughout the area and selected environmental parameters trace elements organic matter clay mineral assemblages grain size of sediment and water characteristics four factors are identified the lake varano ecosystem is predominantly influenced by terrigenous inputs first order factor the clastic fractions of the sediments supply a large range of trace elements occasionally in relatively high concentrations under such circumstances despite occasionally exceeding of threshold limits the trace element pollution can generally be ruled out the organic content combined with depth is the second key factor in lake varano the organic content is high and may lead to seasonal eutrophication as a third order factor although only analyzed once oxygen orp salinity and ph gradients show that foraminiferal diversity is positively influenced by more saline conditions the fourth order factor is the sediment size to conclude this paper illustrates the interest in and need to conduct a detailed integrated sedimentological study of a site prior to any examination of its ecological status possible occurrences of sources of pollution

holocene subsidence at the transition between strike slip and subduction on the pacific australian plate boundary marlborough sounds new zealand abstract this paper provides the first solid evidence in support of a century old hypothesis that the mountainous marlborough sounds region in central new zealand is subsiding more recent hypotheses suggest that this may be a result of southward migration of a slab of subducted pacific plate causing flexural downwarping of the overlying crust in the vicinity of the transition between subduction and strike slip on the pacific australian plate boundary the proxy evidence for gradual holocene subsidence comes from micropaleontological study of seven intertidal sediment cores from the inner marlborough sounds at havelock mahau sound and shakespeare bay quantitative estimates using modern analogue technique of former tidal elevations based on fossil foraminiferal faunas provide evidence of tectonic not compaction related subsidence in all cores estimates of subsidence rates for individual cores vary within the range 0 2 2 4 m ka 1 the wide variation within subsidence rate estimates are related to a combination of the accuracy limits of radiocarbon dates elevation estimates and particularly our poor knowledge of the new zealand holocene sea level curve the most consistent subsidence rate at all three sites for the mid late holocene last 6 7 ka is 0 7 0 8 m ka 1 this rate is consistent with the average subsidence rate in the adjacent 4 km thick wanganui sedimentary basin for the last 5 myr subsidence is inferred to have migrated southwards from the wanganui basin to impinge on the inner marlborough sounds in just the last 100 200 ka

hypersaline benthic foraminifera from the shuaiba lagoon eastern red sea saudi arabia their environmental controls and usefulness in sea level reconstruction abstract the shuaiba lagoon is a fossil back reef hypersaline small basin located 80 km south of jeddah city on the eastern red sea coast saudi arabia the surface sediments of the lagoon were investigated for their benthic foraminiferal content in order to correlate in general with environmental factors such as temperature salinity ph sediment grain size organic matter and in particular with tidal elevations to develop a training set for predicting sea level changes in the lagoon hierarchical cluster analysis divided the benthic foraminifera in the shuaiba lagoon into four distinct faunal assemblages quinqueloculina cf q limbata assemblage 1 and monalysidium acicularis assemblage 2 assemblages dominated the intertidal high subtidal areas 0 3 to 0 5 m lat the peneroplis planatus sorites orbiculus assemblage 3 occurred abundantly at all subtidal elevations 0 to 1 m lat whereas the quinqueloculina costata spiroloculina communis elphidium striatopunctatum assemblage 4 dominated the lowest elevations

mud volcanoes of the orinoco delta eastern venezuela abstract mud volcanoes along the northwest margin of the orinoco delta are part of a regional belt of soft sediment deformation and diapirism that formed in response to rapid foredeep sedimentation and subsequent tectonic compression along the caribbean south american plate boundary field studies of five mud volcanoes show that such structures consist of a central mound covered by active and inactive vents inactive vents and mud flows are densely vegetated whereas active vents are sparsely vegetated four out of the five mud volcanoes studied are currently active orinoco mud flows consist of mud and clayey silt matrix surrounding lithic clasts of varying composition preliminary analysis suggests that the mud volcano sediment is derived from underlying miocene and pliocene strata hydrocarbon seeps are associated with several of the active mud volcanoes orinoco mud volcanoes overlie the crest of a mud diapir cored anticline located along the axis of the eastern venezuelan basin faulting along the flank of the pedernales mud volcano suggests that fluidized sediment and hydrocarbons migrate to the surface along faults produced by tensional stresses along the crest of the anticline orinoco mud volcanoes highlight the proximity of this major delta to an active plate margin and the importance of tectonic influences on its development evaluation of the orinoco delta mud volcanoes and those elsewhere indicates that these features are important indicators of compressional tectonism along deformation fronts of plate margins

a new sea level curve from nova scotia evidence for a rapid acceleration of sea level rise in the late mid holocene a new late holocene sea level curve is presented from the atlantic coast of nova scotia contrary to earlier data from the same area this curve starts at 4400 sidereal years before present bp and shows a rapid acceleration between 4400 and 3800 bp which coincides with a similar acceleration already reported from the northumberland strait nova scotia and an oscillation observed in south carolina comparing the two nova scotia curves suggests that the acceleration lasts just over 1000 years and has a vertical extent of 10 m one puzzling fact is that the 10 m vertical extent in nova scotia is 8 m more than the same event measured in south carolina and it cannot be accounted for simply by postglacial isostatic depression since that occurs on a much longer time scale a closer examination of most of the sea level curves from northeastern north america reveals that either the record is missing from this interval or it is inconsistent we suggest that this acceleration is part of a global response that c

the distribution of contemporary intertidal foraminifera at cowpen marsh tees estuary uk implications for studies of holocene sea level changes abstract foraminiferal assemblages were collected at 2 weekly intervals over a period of 12 months from the intertidal zone of cowpen marsh statistical analyses indicate that the foraminiferal distributions for this site are controlled predominantly by altitude furthermore the contemporary foraminiferal assemblages from cowpen marsh broadly reflect vertical floral zones based on vascular plants cluster analysis separates foraminiferal assemblages into four zones two high and middle marsh zones consisting of differing abundances of jadammina macrescens and trochammina inflata a low marsh zone dominated by jadammina macrescens and miliammina fusca and a mudflat zone dominated by calcareous foraminiferal species notably elphidium williamsoni haynesina germanica and quinqueloculina spp the altitudinal ranges of the faunal zones are employed to identify the vertical relationship of the local environment in which the assemblage accumulated to a reference tide level

foraminiferal biofacies eco succession and holocene sealevels port pirie south australia abstract at port pirie on the eastern coast of northern spencer gulf south australia 10 cores taken along a 3 km transect recovered a succession of holocene marine sediments facies representing shallow subtidal posidonia seagrass and intertidal sandflat mangrove and back storm ridge coastal lagoon environments are recognized on the basis of lithological characteristics and their preserved foraminifera an assemblage dominated by nubecularia lucifuga peneroplis planatus and discorbis dimidiatus signifies sediments of shallow subtidal posidonia seagrass meadows subtle changes in the numerical distribution of these species upcore are used to infer the change from subtidal to intertidal sandflat facies elphidium crispum and elphidium macelliforme become more numerous across this transition the mangrove facies is characterized by trochammina inflata this species is present significantly in only one seaward core where modern mangrove woodland continues to grow today and no equivalent biofacies are recognized in other cores the lagoonal sediments preserve a rich assemblage of species of euryhaline foraminifera together with those of the mangrove woodland they exhibit an ecological succession which can be related to decreasing intervals of tidal inundation and increasing salinity helenina anderseni with subordinate ammonia beccarii and elphidium cf articulatum are the pioneer species in the euryhaline setting giving way to trichohyalus tropicus and miliolinella schauinslandi late stages of hypersaline sedimentation are characterized by triloculina inflata triloculina oblonga in the mangroves h anderseni a beccarii and elphidium cf articulatum are replaced by trochammina inflata as the dominant species in turn as further sediment aggradation leads to ever shorter intervals of tidal inundation at the landward side of the mangrove woodland trochammina inflata is overtaken by ammobaculites barwonensis quantitative foraminiferal biofacies analysis confirms and refines the sedimentological interpretation of intertidal sediment facies from macro observations of the core materials it provides independent estimates of the elevation of key facies boundaries in cores and confirmation of a general relative fall in sealevel in northern spencer gulf over the past 7000 yr

using foraminiferal transfer functions to produce high resolution sea level records from salt marsh deposits maine usa quantitative analyses of foraminiferal distributions along the coast of maine are used to provide transfer functions for reconstruction of sea level changes from fossil foraminiferal assemblages the indicative meaning of fossil assemblages is most accurately predicted by a training set that incorporates live and dead foraminifera and that uses flooding duration not height as the predictor variable sea level records are produced for two sites in maine usa a middle marsh site in scarboro and a high marsh site in machiasport these records offer temporal resolution of five to seven years and span the past century they are compared with instrumental data from a nearby tidal station to assess their accuracy strong correlations are found between the geologic records and the observational data in particular between the foraminiferal record from machiasport and the tide gauge record from eastport r2 0 83 p 0 005 thus a foraminifera based transfer function approach offers great potential for reso