contact diagenesis the effect of an intrusion on reservoir quality in the triassic sherwood sandstone group northern ireland abstract intrusion of a dolerite sill into clay bearing arkosic triassic sherwood group sandstones with moderate porosity 22 and high but anisotropic permeability mode 500 md led to the progressive transformation of precursor diagenetic minerals in the host rock locally pore filling mg rich smectite saponite quartz and dolomite existing in the rock following earlier burial diagenesis reacted to produce grain coating flakes of talc at the lowest contact temperatures 130 180 c based on equilibrium reaction path and thermal history calculations at higher temperatures 200 230 c talc reacted with calcite to produce an actinolitic amphibole close to the intrusion at temperatures of 250 c bundles of acicular needles of actinolite protruding into open pores were produced by a second reaction involving saponite hematite and calcite framework feldspar minerals mainly k feldspars played little or no part in the reactions because there were no k al rich minerals produced by contact diagenesis and because the detrital feldspar grains are essentially unaltered thus while equilibrium may have been approached on the intrapore scale 10 m it was not achieved between grains e g detrital feldspars pore water and clays in the pores total porosity has been unaffected by the intrusion and consequent mineral reactions because reactions involved recrystallization of original pore filling minerals despite the contact diagenetic changes in the rock the permeability of the sandstone remained largely unaffected by intrusion

alteration of basalt hyaloclastite at the off axis sea cliff hydrothermal field gorda ridge abstract the sea cliff hydrothermal field on the northern segment of the gorda ridge is situated along a rift bounding normal fault about 2 6 km east of the neovolcanic zone and approximately 300 m above the spreading axis the structural setting of this hydrothermal field differs from that of most other active seafloor hydrothermal sites investigated to date which are typically situated in the neovolcanic zone mineralization occurs in basaltic talus covering a large normal fault scarp hydrothermal crusts cover much of the seafloor in the area of the active hydrothermal field these crusts form by extensive alteration of basaltic hyaloclastite in a zone of mixing between ascending hydrothermal fluid and entrained seawater the initial stage of alteration is magnesian metasomatism of both crystalline basalt and basaltic glass converting the rock to mg rich smectite and smectite chlorite further alteration removes nearly all cations and ultimately leads to silicification preservation of basaltic texture in the silicified rocks provides evidence that even such sparingly soluble elements as a1 and ti have been removed oxygen isotopic ratios of the altered rocks constrain initial alteration to temperatures near 220 c close to the maximum measured vent temperatures of 247 c silicification proceeded to much lower temperatures and most amorphous silica deposition occurred at temperatures below 100 c sulfur strontium and lead isotopic data all indicate a predominantly basaltic source with important contributions from seawater but no significant contribution from sedimentary sources comparison with ophiolite hosted massive sulfide deposits shows that the structural setting alteration sequence and depositional environment are all similar and suggests that mineralization and replacement of basaltic breccia in the sea cliff hydrothermal field likely occur in the subsurface beneath a capping layer of silicified hyaloclastite

petroleum in basement rocks basement reservoirs are a special type of important oil reservoirs that until recently have generally been neglected as targets for exploration most basement reservoirs occur either on platforms or in intermontane basins they are rare in foredeep basins the basement reservoirs always occur on highs or uplifts within the basin and have been subjected to long periods of weathering and erosion younger sediments presumably source beds directly overlie basement providing opportunity for entrapment of oil in the basement rock almost all basement reservoirs occur below a regional unconformity all source beds of basement reservoirs lie above the reservoir rock but all source beds lying above the reservoir rock do not necessarily form basement reservoirs although most source beds lie above an unconformity some lie below it and form a so called second crop unconformities play an important role in basement reservoirs as they are the passageway for oil migration provide conditions for long distance migration and connect source and reservoir rocks which may lie on opposite sides of the unconformity and at great distances from each other the unconformity surface provides evidence that basement rocks have undergone weathering erosion solution and leaching for so long a time that porosity and permeability have increased greatly and the accumulation of petroleum was facilitated oil may accumulate in any igneous metamorphic or sedimentary rocks with secondary fissures dissolved interstices and caverns or in sandstone and carbonate rocks with primary porosity carbonates form the best basement reservoirs because being hard and brittle they not only develop secondary fissures but are readily dissolved by ground water so that original pores are enlarged and new porosity produced basement reservoirs are characterized by thick reservoir rocks porosity and permeability are irregular production from basement reservoirs is usually high and reserves are large

alteration of crystalline basement rocks by hydrocarbon bearing fluids moinian of ross shire scotland abstract moinian proterozoic gneisses in easter ross shire scotland exhibit pronounced alteration where they have been subjected to the flow of hydrocarbon bearing fluids from an adjacent devonian sedimentary basin comparison of the petrography of altered and unaltered gneiss indicates that element redistribution accompanied the alteration process the alteration involved creation of secondary porosity by dissolution of primary minerals in the gneiss chloritization of biotite and precipitation of authigenic orthoclase cross cutting veinlets include bitumen authigenic quartz orthoclase albite monazite and titanium oxides attesting to redistribution of all the major components of the gneiss evidence for bitumen being coeval with albite quartz and an association of high porosity with bitumen indicate that hydrocarbon bearing fluids were present during the alteration process bitumen also penetrated beyond the visible alteration zone and accreted around radioelement bearing accessory minerals organic geochemical data indicate that there is a local source for the bitumen in the devonian sequence bitumen veining also occurs within the devonian sequence fluid inclusion data from quartz associated with bitumen in the gneiss and the devonian indicate minimum trapping temperatures of 120 140 and 100 120 c respectively the alteration was probably a result of a fluid flow episode relating to fault movement during basin subsidence

volcano tectonic implications of 3 d velocity structures derived from joint active and passive source tomography of the island of hawaii 1 we present a velocity model of the onshore and offshore regions around the southern part of the island of hawaii including southern mauna kea southeastern hualalai and the active volcanoes of mauna loa and kilauea and loihi seamount the velocity model was inverted from about 200 000 first arrival traveltime picks of earthquakes and air gun shots recorded at the hawaiian volcano observatory hvo reconstructed volcanic structures of the island provide us with an improved understanding of the volcano tectonic evolution of hawaiian volcanoes and their interactions the summits and upper rift zones of the active volcanoes are characterized by high velocity materials correlated with intrusive magma cumulates these high velocity materials often do not extend the full lengths of the rift zones suggesting that rift zone intrusions may be spatially limited seismicity tends to be localized seaward of the most active intrusive bodies low velocity materials beneath parts of the active rift zones of kilauea and mauna loa suggest discontinuous rift zone intrusives possibly due to the presence of a preexisting volcanic edifice e g along mauna loa beneath kilauea s southwest rift zone or alternatively removal of high velocity materials by large scale landsliding e g along mauna loa s western flank both locations also show increased seismicity that may result from edifice interactions or reactivation of buried faults new high velocity regions are recognized and suggest the presence of buried and in some cases previously unknown rift zones within the northwest flank of mauna loa and the south flanks of mauna loa hualalai and mauna kea

volcanic spreading at kilauea 1976 1996 the rift system traversing about 80 km of the subaerial surface of kilauea volcano has extended continuously since the m 7 2 flank earthquake of november 1975 widening across the summit has amounted to more than 250 cm decelerating after 1975 from about 25 to 4 cm yr 1 since 1983 concurrently the summit has subsided more than 200 cm even as the adjacent south flank has risen more than 50 cm the axes of the upper zones about 10 km from the summit subsided before 1983 at average rates of 9 and 4 cm yr 1 respectively and at rates of 4 and 3 cm yr 1 since the middle southwest rift zone is also subsiding and at the other end of kilauea s subaerial rift system subsidence along the lower east rift zone has averaged 1 2 cm yr 1 deformation of kilauea s south flank has been continuous although subject as well to displacements caused by major rift zone seismic swarms whereas horizontal strains across the subaerial south flank seem to have been generally compressive after 1975 they have been extensional since about 1980 or 1981 interrupted only by the east rift zone dike intrusion of 1983 because the magnitudes of these contractions and extensions are much less than the extension across the rift system the subaerial south flank is apparently sliding seaward on its basal decollement more than it is accumulating horizontal strains within the overlying volcanic pile kilauea suffers from gravitational spreading made even more unstable by accumulation of magma along the rift system at depths in excess of about 4 5 km in the presence hot rock incapable of withstanding deviatoric stresses this seismicly quiescent zone decouples the south flank from the rest of hawaii s volcanic edifice the rift zones at lesser depths exhibit a more brittle and therefore sporadic extensional behavior judging from the modern extension record of the summit which both predates the m 7 2 earthquake of 1975 and has outlived its 10 year period of aftershocks kilauea will continue to spread along its rift system as its south flank slips seaward to accommodate the accretion of magma and its relatively dense olivine rich differentiate

the use of jadammina macrescens brady and balticammina pseudomacrescens bronnimann lutze and whittaker protozoa foraminiferida as sea level indicators in studies of foraminiferal distributions in saltmarshes in new england and atlantic canada balticammina pseudomacrescens and jadammina macrescens have formerly been grouped as trochammina macrescens this study recognises them as distinct species and shows that they have significantly different distributions on the surface of saltmarshes in maine here relative abundances of j macrescens correlate with tidal elevation r2 0 55 p 0 00 whereas those of b pseudomacrescens do not r2 0 03 p 0 34 therefore j macrescens is a better sea level indicator in maine marshes than b pseudomacrescens in menunketesuck river marsh connecticut a clear vertical zonation of saltmarsh foraminifera is absent which hinders interpretation of fossil data this study shows that in maine separating b pseudomacrescens and j macrescens in counts of fossil data facilitates the detection of transgressional and regressional events in the biostratigraphical record and hence the reconstruction of local sea level histories regional variability between northern and southern new england saltmarshes necessitates the establishment of local reference sets of modern analogue data to aid palaeoecological interpretations

relative sea level rise and climate change over the last 1500 years we constructed a detailed relative sea level rise curve for the last 1500 years using a novel approach i e charting the rate of relative sea level rise using microfaunal and geochemical data from a coastal salt marsh sequence clinton ct usa the composition of benthic foraminiferal assemblages and the iron abundance in peats were used to describe shifts in marsh environment through time quantitatively the resulting sea level rise curve with age control from 14c dating and the onset of anthropogenic metal pollution shows strong increases in the rate of relative sea level rise during modern global warming since the late nineteenth century but not during the little climate optimum ad 1000 1300 there was virtually no rise in sea level during the little ice age ad 1400 1700 most of the relative sea level rise over the last 1200 years in clinton appears to have occurred during two warm episodes that jointly lasted less than 600 years changes from slow to fast rates of relative sea level rise apparently occurred over periods of only a few decades we suggest that changes in ocean circulation could contribute to the sudden increases in the rate of relative sea level rise along the northeastern usa seaboard relative sea level rise in that area is currently faster than the worldwide average which may result partially from an ocean surface effect caused by hydrodynamics our data show no unequivocal correlation between warm periods on a decaal to centennial time scale and accelerated sea level rise one period of acclerated sea level rise may have occurred between about ad 1200 and 1450 which was the transition for the little climate optimum to the little ice age i e a period of cooling at least in northwestern europe local changes in tidal range might also have contributed to this apparent increase in the rate of relative sea level however the second period of accelerated sea level rise occurred during the period of modern global warming that started at the end of the last century

the roles of elevation and salinity as primary controls on living foraminiferal distributions cowpen marsh tees estuary uk abstract benthic foraminiferal assemblages in subrecent deposits are commonly used to reconstruct past sea level interpretations are generally made by comparison with either modern dead or total live plus dead assemblages in both cases there will have been post mortem changes that have differentially affected preservation it is therefore important to establish the primary ecological controls by analysis of the living assemblages we have determined the spatial and temporal variability of intertidal benthic foraminifera in the surface 0 1 cm sediments from a time series survey of 31 sampling stations at cowpen marsh for a period of 12 months we counted 112 067 live foraminifera assigned to 28 species the fauna was dominated by two agglutinated species jadammina macrescens and trochammina inflata on the high and middle marshes and three calcareous species elphidium williamsoni haynesina germanica and quinqueloculina spp on the low marsh and tidal flat the standing crop of the whole intertidal zone including the high middle low marsh and tidal flat habitats and the individual species varied both temporally and spatially the standing crop of the intertidal zone as a whole was greatest in the summer months and showed a positive correlation with elevation the standing crops of the high and middle marshes showed similar temporal variation with peaks in summer and autumn and a trough in winter the low marsh showed numerous peaks and troughs of standing crop during the year whereas the tidal flat showed a single peak in summer the standing crops of jadammina macrescens and trochammina inflata on the high and middle marshes peaked from april to may and august to october with troughs in winter these agglutinated species showed a strong correlation with elevation haynesina germanica peaked in may to august and november to january on the low marsh whereas on the tidal flat there was a single peak in july the standing crops of e williamsoni on the low marsh and tidal flat were relatively high in june and may and july respectively quinqueloculina spp peaked in may to july on the low marsh and july on the tidal flat the species was also found in the middle marsh from july to may and high marsh from september to november haynesina germanica showed a strong negative correlation with elevation whereas the other two dominant calcareous species demonstrated weak negative correlations with both elevation and salinity reconstructing former sea level depends primarily on the recognition of high and middle marsh assemblages and in this study these are shown to be strongly controlled by elevation rather than salinity caution may be needed in interpreting low marsh and tidal flat data as salinity plays a more important role here

giant blocks in the south kona landslide hawaii a large field of blocky sea floor hills up to 10 km long and 500 m high are gigantic slide blocks derived from the west flank of mauna loa volcano on the island of hawaii these megablocks are embedded in the toe of the south kona landslide which extends 80 km seaward from the present coastline to depths of nearly 5 km a 10 15 km wide belt of numerous smaller 1 3 km long slide blocks separates the area of giant blocks from two submarine benches at depths of 2600 and 3700 m depth that terminate seaward 20 to 30 km from the shoreline similar giant blocks are found on several other major submarine hawaiian landslides including those north of oahu and molokai but the south kona blocks are the first to be examined in detail using high resolution bathymetry dredging and submersible diving dredging of two of the giant blocks brought up pillowed tholeiitic lava observations from the u s navy submersible sea cliff on the asymmetrically steep eastern flank of one block 10 km long and 300 m high revealed a succession of fractured massive basalt laminar lava flows hyaloclastite and pillow lavas chemical analyses of dredged lava identified 19 units that overlap compositionally with lavas from the south rift zone ridge of mauna loa sulfur content indicates that most of the lavas were erupted in subaerial and shallow submarine

mauna loa s submarine western flank landsliding deep volcanic spreading and hydrothermal alteration four new remotely operated vehicle dives carried out by monterey bay aquarium research institute mbari reveal a heterogeneous distribution of lithologies and compositions along a transect across the submarine west flank of mauna loa from the outer scarp of the frontal bench to the upper flank the frontal bench is composed predominantly of volcaniclastic sediments ranging from very fine grained monomictic hyaloclastites to coarse grained compositionally mixed volcaniclastic breccias the predominance of subaerially derived clasts suggests accumulations of landslide deposits probably emplaced along a regional shear plane preserved in cataclastic breccias with local foliations and grain trails repeated packages of inversely graded strata are interpreted to reflect thrust imbrication of the resulting volcaniclastic apron during volcanic spreading of mauna loa s western flank similar to that now documented along k lauea s south flank many of the rocks from the bench show evidence for alteration ranging from low grade burial diagenesis to higher grade hydrothermal alteration including phases never before observed in submarine hawaiian rocks including epidote talc sphene and corrensite alteration is concentrated in deformed zones denoting pathways for fluid flow into or out of the volcanic edifice formed at depth the altered rocks were subsequently transported along low angle thrust faults into the bench and exposed along high angle fractures and faults the upper submarine flanks are draped by subaerially erupted submarine emplaced pillow lavas and interbedded hyaloclastites generated by shoreline crossing lava flows basalt glasses indicate mauna loa origin but imply earlier compositions than present day lavas consistent with ar ar ages suggesting eruption 0 28 0 10 ma late stage detachment of a nearshore slump produced the lika 2 debris avalanche that broke through the frontal bench perhaps portending the evolution of the active hilina slump now present on k lauea volcano s south flank

significant role of structural fractures in renqiu buried hill oil field in eastern china renqiu oil field is in a buried hill of sinian late precambrian rocks located in the jizhong depression of the western bohai bay basin in eastern china the main reservoir consists of sinian dolomite the buried hill is a fault block bounded on the west side by a large growth fault that trends north northeast and has throws of up to 1 km 3 300 ft the source rocks for the oil are tertiary sediments that overlie the sinian dolomite structural fractures are the main factor forming the reservoir of the buried hill oil field three dominant structural trends northeast north northeast and northwest form the regional fracture system the fractures are best developed along the north northeast fault zones and at the intersections of other structural trends because the regional stress field altered during the late mesozoic the mechanical properties of north northeast fault zones were changed from compressional shear to extensional shear consequently the enlargement of the structural fractures provided good channels for the circulation of meteoric water the north northeast growth fault controlled the structural development of the fault block the block was raised and eroded before the tertiary sediments were dep sited so the sinian dolomite was exposed and underwent a long period of weathering and leaching during the eocene the jizhong depression subsided but deposition faulting and relative uplift of the block occurred simultaneously as the block was gradually submerged at the same time several horizontal and vertical karst zones were formed along the fracture system by the circulating water the eocene source rocks lapped onto the block therefore the buried hill with many developed karst fractures was surrounded by a great thickness of source rocks as the growth fault developed the height of the fault block increased from 400 m 1 300 ft before the oligocene to 1 300 m 4 300 ft after as petroleum was generated it migrated immediately along the growth fault into the karst fracture system of the buried hill the karst fracture block reservoir has 800 m 2 625 ft of oil bearing closure and has good interconnected porosity between the leached fracture zones renqiu buried hill oil field offers a high yield

the spatial and vertical distribution of living stained benthic foraminifera from a tropical intertidal environment north queensland australia we investigated the distribution of living stained benthic foraminifera across a tropical intertidal shoreline adjacent to cocoa creek queensland australia for the purpose of better understanding the nature of test production and ultimately fossil assemblage development within such environments short cores up to 1 m were collected during the wet and dry season along an elevational gradient comprising non vegetated intertidal mudflat and higher intertidal mangrove forest environments the distribution of stained specimens can be broadly delineated into assemblages characterising upper mangrove 2 64 2 91 m above lowest astronomical tide lat and low mangrove mudflat 1 62 2 18 m above lat environments agglutinated species were generally limited to upper mangrove stations calcareous species occurred within all of the intertidal environments examined but differ in their composition between upper and lower intertidal settings upper mangrove faunas were characterised by the agglutinated species arenoparrella mexicana haplophragmoides wilberti miliammina fusca miliammina obliqua and trochammina inflata and the calcareous species helenina anderseni live stained assemblages at lower intertidal elevations were dominated by the calcareous species ammonia aoteana as well as rosalina spp elphidium oceanicum triloculina oblonga ammonia pustulosa and shackoinella globosa absolute densities of stained specimens were lowest within the low mangrove sediments 6 8 specimens per cm2 but higher within the upper mangrove 25 249 specimens per cm2 and mudflat 8 77 specimens per cm2 abundances within mudflat sediments varied seasonally being significantly larger in the wet season whereas those within mangrove zone sediments changed little through the year stained foraminifera were found to a maximum depth of 50 cm at cocoa creek extending to the greatest depth at the upper mangrove stations and were generally shallowest beneath the lower mangroves all stations had over 50 of their foraminiferal standing crop below the upper 1 cm although at most stations 10 of living specimens occurred within this layer comparison of this data with dead assemblages suggests that 1 abundances of stained specimens averaged over two sampling events reasonably approximate aggregate in situ test production and 2 a clear enrichment of infaunal species occurs within the mangrove the latter effect was less conspicuous on the mudflat due to high rates of mixing and assemblage time averaging which obscure the signal of test production within the dead assemblages in both cases the validity and stratigraphic resolution of surface assemblages for sea level and other palaeoenvironmental reconstructions is questionable

surface distributions of salt marsh foraminifera from connecticut usa modern analogues for high resolution sea level studies abstract salt marsh foraminifera are routinely used as sea level indicators since their vertical distribution is closely linked with elevation relative to the tidal frame the precise nature of these relationships is variable in time and space and the accuracy of sea level reconstructions depends upon the selection of appropriate modern analogues that reliably reflect past fauna environment associations the marshes of connecticut usa are sites of ongoing research seeking to produce high resolution records of sea level change yet little published data regarding their modern foraminiferal distributions exist this paper presents new surface foraminiferal data from three connecticut salt marshes and evaluates their suitability as modern analogues for past sea level changes the results indicate that significant intra and inter site variability between these marshes and those of neighbouring states exists as a consequence of this the extrapolation of fauna environment relationships developed from marshes with different hydrographic physiographic vegetative or climatic characteristics may produce erroneous reconstructions even when adjusted for variations in tidal range these errors are potentially greatest if single indicator species are used since the relative abundance of individual taxa does not vary consistently with elevation even in high marsh environments from the same site whilst cluster analysis demonstrates that foraminiferal assemblages from connecticut are vertically zoned with respect to mean high water mhw the composition elevation and height range of these zones is variable between sites this spatial heterogeneity results in reconstructions of relatively low and variable precision that restricts their utility in high resolution sea level research new studies seeking to distil decimetre scale changes in relative sea level will need to employ quantitative methods capable of combining multi site information to develop fauna environment relationships that capture this spatial variability reconstructions will be most precise when employing local foraminiferal distributions but may require the collection of additional modern analogue samples from other regions when the extant foraminiferal population of a site differs in composition from its sub fossil counterpart

emplacement mechanisms of the south kona slide complex hawaii island sampling and observations by remotely operated vehicle kaiko emplacement of a giant submarine slide complex offshore of south kona hawaii island was investigated in 2001 by visual observation and in situ sampling on the bench scarp and a megablock during two dives utilizing the remotely operated vehicle rov kaiko and its mother ship r v kairei topography of the bench scarp and megablocks were defined in 3 d perspective using high resolution digital bathymetric data acquired during the cruise compositions of 34 rock samples provide constraints on the landslide source regions and emplacement mechanisms the bench scarp consists mainly of highly fractured vesiculated and oxidized a a lavas that slumped from the subaerial flank of ancestral mauna loa the megablock contains three units block facies matrix facies and draped sediment the block facies contains hyaloclastite interbedded with massive lava which slid from the shallow submarine flank of ancestral mauna loa as indicated by glassy groundmass of the hyaloclastite low oxidation state and low sulfur content the matrix facies which directly overlies the block facies and is similar to a lahar deposit is thought to have been deposited from the water column immediately after the south kona slide event the draped sediment is a thin high density turbidite layer that may be a distal facies of the alika 2 debris avalanche deposit its composition overlaps with rocks from subaerial mauna loa the deposits generated by the south kona slide vary from debris avalanche deposit to turbidite spatial distribution of the deposits is consistent with deposits related to large landslides adjacent to other hawaiian volcanoes and the canary islands

fluid inclusion evidence of petroleum migration through a buried metamorphic dome in the pannonian basin hungary some of the petroleum currently produced in the pannonian basin in hungary stems from buried metamorphic basement domes that form structural highs between neogene sedimentary sub basins in the bekes sedimentary sub basin the source rocks of the petroleum are known to be of middle to late miocene age whereas at least part of the petroleum in the adjacent szeghalom basement dome appears to be of lower miocene age or even older virtually nothing is known about the compositions distribution sources and migration history of this older petroleum although such variables are crucial to future exploration strategies this study addresses the first two of these gaps in knowledge by providing a basic characterization of the older petroleum trapped as fluid inclusions in fracture hosted quartz crystals within the szeghalom dome szd fluid inclusion samples from 9 wells at depths of 1900 to 2200 m were analysed by visible and cie calibrated uv microscopy microthermometry laser raman and 1 h nmr spectroscopy two major types of early miocene oils were found distributed over 5 distinct temporal generations an earlier immature brown oil succeeded by a light gas condensate the early petroleum was undersaturated with respect to methane gas and it migrated through the fracture network at temperatures between about 160 to 130 c entraining blebs of bitumen and flushed by weakly saline water the later gas condensate migration consisted of a heterogeneous mixture of volatile oil methane rich gas weakly saline water at slightly lower temperatures between 135 and 120 c the temperature evolution was caused by cooling of the metamorphic wall rocks during basement uplift culminating in middle miocene exhumation the various hydrocarbons are unevenly distributed across the szeghalom dome showing that pre middle miocene fluid migration through the fracture network was compartmentalized at the km scale 2007 elsevier b v all rights reserved

incorporating temporal and spatial variability of salt marsh foraminifera into sea level reconstructions abstract foraminifera from salt marsh environments have been used extensively in quantitative relative sea level reconstructions due to their strong relationship with tidal level however the influence of temporal and spatial variability of salt marsh foraminifera on quantitative reconstructions remains unconstrained here we conducted a monitoring study of foraminifera from four intertidal monitoring stations in new jersey from high marsh environments over three years that included several extreme weather temperature precipitation and storm surge events we sampled four replicates from each station seasonally four times per year for a total of 188 samples the dead foraminiferal assemblages were separated into four site specific assemblages after accounting for systematic trends in changes in foraminifera over time among stations the distribution of foraminiferal assemblages across monitoring stations explained 87 of the remaining variation while 13 can be explained by temporal and or spatial variability among the replicate samples we applied a bayesian transfer function to estimate the elevation of the four monitoring stations all samples from each station predicted an elevation estimate within a 95 uncertainty interval consistent with the observed elevation of that station combining samples into replicate and seasonal aggregate datasets decreased elevation estimate uncertainty with the greatest decrease in aggregate datasets from fall and winter information about the temporal and spatial variability of modern foraminiferal distributions was formally incorporated into the bayesian transfer function through informative foraminifera variability priors and was applied to a common era relative sea level record in new jersey the average difference in paleomarsh elevation estimates and uncertainties using an informative vs uninformative prior was minimal

subsurface biodegradation of crude oil in a fractured basement reservoir shropshire uk subsurface biodegradation of crude oil in current oil reservoirs is well established but there are few examples of ancient subsurface degradation biomarker compositions of viscous and solid oil residues bitumen in fractured precambrian and other basement rocks below the carboniferous cover in shropshire uk show that they are variably biodegraded high levels of 25 norhopanes imply that degradation occurred in the subsurface lower levels of 25 norhopanes occur in active seepages liquid oil trapped in fluid inclusions in mineral veins in the fractured basement confirms that the oil was emplaced fresh before subsurface degradation a triassic age for the veins implies a 200 myr history of hydrocarbon migration in the basement rocks the data record microbial biodegradation of hydrocarbons in a fractured basement reservoir and add to evidence in modern basement aquifers for microbial activity in deep fracture systems buried basement highs may be especially favourable to colonization through channelling fluid flow to shallow depths and relatively low temperatures and are therefore an important habitat within the deep biosphere

reassessing transfer function performance in sea level reconstruction based on benthic salt marsh foraminifera from the atlantic coast of ne north america abstract the need to increase the number and distribution of sea level records spanning the last few hundred years has led to particular interest in developing high precision geologically based sea level reconstructions that capture decimetre and multi decadal scale changes transfer functions for tide level are statistical tools that quantify the vertical relationship between inter tidal microfossils and elevation within the tidal frame and their use in sea level reconstruction is growing in popularity whilst a range of sampling strategies dataset qualities and underlying statistical models have been used in transfer function development all variants share the common requirement of accurately extracting precise species elevation relationships from surface data and reliably applying these to fossil assemblages to infer past conditions we present surface foraminiferal data from six transects sampled at three sites spanning a large latitudinal range extending from newfoundland canada to north carolina usa these data demonstrate that significant spatial differences exist within the high marsh foraminiferal assemblages commonly used to reconstruct past relative sea level rsl we standardise these data to account for inter site differences in tidal range using several variants of the standardised water level index swli of horton et al 1999b and show that the best performance is achieved by using the highest occurrence of foraminifera as the upper tidal datum level the standardised surface foraminiferal data are used to develop a suite of foraminiferal transfer functions for tide level which are then applied to fossil assemblages from two sediment cores to reconstruct palaeomarsh surface elevation we highlight the manner in which species elevation relationships are extracted and modified during transfer function development and the impacts that choices in dataset composition and transfer function type have on the resulting reconstructions our results graphically illustrate the importance of these choices and the impacts of temporal and spatial variability in foraminiferal distributions none of which are adequately represented or discernible from the standard summary statistics of performance that commonly accompany transfer function reconstructions we conclude that a more explicit treatment of the transfer function development process is required to support the growing body of precise rsl reconstructions that are now appearing in the literature to that end we make the following four recommendations for a framework to assist in transfer function development that will allow better record inter comparison and minimise the potential for producing precise but ultimately inaccurate reconstructions 1 sampling for surface data should focus on capturing complete species response curves rather than simply compiling modern analogues for fossil material 2 the similarity between the surface assemblages used to produce transfer functions and the fossil assemblages to which they are applied should be better quantified using a range of statistical approaches and must accompany any reconstruction 3 where modern analogues are lacking in local surface assemblages data from additional sites should be added with selection based on fulfilling the requirements of the previous two recommendations the manner in which individual species optima are combined to produce a composite optimum and the extent to which this provides a reasonable representation of the surface data should also be documented 4 the application of wa pls component 2 and higher cannot be justified solely on the grounds of increased performance measures e g r2jack and rmsep and if applied the pattern of optima updates should be used to highlight species that may distort reconstructions

alteration history of mount epomeo green tuff and a related polymictic breccia ischia island italy evidence for debris avalanche this paper presents mineralogical chemical and textural data for the mount epomeo green tuff and an associated polymictic breccia on ischia island italy with the purpose of defining the alteration history of the two units and the emplacement origin of the polymictic breccia our results indicate that the green tuff trachytic ignimbrite experienced three alteration events that produced the following mineral assemblages 1 phillipsite randomly interstratified r0 illite smectite i s fe illite and smectite in situ green tuff 2 chabazite phillipsite r0 i s and fe illite proximal facies green tuff at scarrupata di barano and 3 analcime authigenic k feldspar fe illite r0 i s and smectite clasts of green tuff in polymictic breccia phillipsite chabazite and r0 i s within the in situ and proximal facies green tuff indicate low temperature alteration t 70 c alteration within a mostly closed chemical system these data suggest that the polymictic breccia represents a debris avalanche deposit created by a catastrophic volcanic collapse which was associated with low temperature hydrothermal alteration and thus structural weakening of the volcano the debris avalanche that produced the polymictic breccia on ischia may be related to nearby massive debris avalanche deposits recently discovered offshore of southern ischia the young age of the polymictic breccia 5 7 8 6 ka and the possibility of its catastrophic emplacement indicate an additional volcanic hazard for ischia island

the ninole basalt implications for the structural evolution of mauna loa volcano hawaii lava flows of the ninole basalt the oldest rocks exposed on the south side of the island of hawaii provide age and compositional constraints on the evolution of mauna loa volcano and the southeastward age progression of hawaiian volcanism although the tholeiitic ninole basalt differs from historic lavas of mauna loa volcano in most major element contents e g variably lower k na si higher al fe ti ca ree and other relatively immobile minor elements are similar to historic and prehistoric mauna loa lavas and the present major element differences are mainly due to incipient weathering in the tropical environment new k ar whole rock ages from relatively fresh roadcut samples suggest that the age of the ninole basalt is approximately 0 1 0 2 ma although resolution is poor because of low contents of k and radiogenic ar originally considered the remnants of a separate volcano the ninole hills are here interpreted as faulted remnants of the old south flank of mauna loa deep canyons in the ninole hills eroded after massive landslide failure of flanks of the southwest rift zone have been preserved from burial by younger lava due to westward migration of the rift zone landslide induced depressurization of the southwest rift zone may also have induced phreatomagmatic eruptions that could have deposited widespread basaltic ash that overlies the ninole basalt subaerial presence of the ninole basalt documents that the southern part of hawaii island had grown to much of its present size above sea level by 0 1 0 2 ma and places significant limits on subsequent enlargement of the south flank of mauna loa

rapid deformation of the south flank of kilauea volcano hawaii the south flank of kilauea volcano has experienced two large magnitude m 7 2 and m 6 1 earthquakes in the past two decades global positioning system measurements conducted between 1990 and 1993 reveal seaward displacements of kilauea9s central south flank at rates of up to about 10 centimeters per year in contrast the northern side of the volcano and the distal ends of the south flank did not displace significantly the observations can be explained by slip on a low angle fault beneath the south flank combined with dilation deep within kilauea9s rift system both at rates of at least 15 centimeters per year

rapid deformation of kilauea volcano global positioning system measurements between 1990 and 1996 campaign global positioning system gps measurements from 1990 to 1996 are used to calculate surface displacement rates on kilauea volcano hawaii the gps data show that the south flank of the volcano which has generated several large earthquakes in the past 3 decades is displacing at up to 8 cm yr to the south southeast the summit and rift zones are subsiding with maximum subsidence rates of 8 cm yr observed a few kilometers south of the summit caldera elastic dislocation modeling of the gps data suggests that the active sources of deformation include deep rift opening along the upper east and east rift zone fault slip along a subhorizontal fault near the base of the volcano and deflation near the summit caldera a nonlinear optimization algorithm was used to explore the parameter space and to find the best fitting source geometry there is a broad range of model geometries that fit the data reasonably well however certain models can be ruled out including those that have shallow rift opening or shallow fault slip some offshore aseismic slip on a fault plane that dips between 258 north northwest and 88 south southeast is required best fitting slip and rift opening rates are 23 28 cm yr although rates as low as 10 cm yr are permitted by the data

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

submarine growth and internal structure of ocean island volcanoes based on submarine observations of mauna loa volcano hawaii a recent model for the submarine growth of hawaiian volcanoes indicates that these volcanoes are composed mainly of fragmental lava debris formed as lavas enter the ocean this model has major implications for locating earthquake hypocenters and for the landslide hazard potential of these and other ocean island volcanoes observations from submersible dives and analyses of volcanic glasses collected from the western submarine flank of mauna loa indicate that subaerially erupted pillow lavas are abundant at depths of 950 to 1900 m below sea level fragmental lava is an important component of ocean island volcanoes as witnessed during the most recent eruption of kilauea volcano but probably is the dominant lithology only in the upper 1 km of the submarine section a submarine dike complex was discovered 17 km west of the assumed axis of mauna loa9s southwest rift which indicates that its intrusive complex is much broader than previously suspected 20 km vs 8 km the great width of this dike complex may be a consequence of crustal unloading following the south kona landslide or a normal feature of hawaiian rift zones that was previously unrecognized

slope failure and volcanic spreading along the submarine south flank of kilauea volcano hawaii 1 new multichannel reflection data and high resolution bathymetry over the submarine slopes of kilauea volcano provide evidence for current and prior landsliding suggesting a dynamic interplay among slope failure regrowth and volcanic spreading disrupted strata along the upper reaches of kilauea s flank denote a coherent slump correlated with the active hilina slump the slump comprises mostly slope sediments underlain by a detachment 3 5 km deep extension and subsidence along the upper flank is compensated by uplift and folding of the slump toe which surfaces about midway down the submarine flank uplift of strata forming papa u seamount and offset of surface features along the western boundary of kilauea indicate that the slump has been displaced 3 km in a south southeast direction this trajectory matches coseismic and continuous ground displacements for the hilina slump block on land and contrasts with the southeast vergence of the rest of the creeping south flank to the northeast slope sediments are thinned and disrupted within a recessed region of the central flank demonstrating catastrophic slope failure in the recent past debris from the collapsed flank was shed into the moat in front of kilauea building an extensive apron seaward sliding of kilauea s flank offscraped these deposits to build an extensive frontal bench a broad basin formed behind the bench and above the embayed flank uplift and back tilting of young basin fill indicate recent and possibly ongoing bench growth the hilina slump now impinges upon the frontal bench this buttress may tend to reduce the likelihood of future catastrophic detachment

the giant submarine alika debris slide mauna loa hawaii probably represent multiple subsidence events before during and after the debris avalanches lower slopes of the slide contain distinctive lobate terraced deposits that are interpreted as having been emplaced more slowly prior to the debris avalanches estimated thicknesses of 50 200 m suggest volumes of 200 600 km 3 for the two lobes the combined volume of the entire slide and slump terrane is probably 1500 2000 km 3 the slide deposits predate a 13 ka coral reef and probably postdate the block faulted ninole basalt roughly dated as a few hundred thousand years old the alika slide or a similar deposit recognized on gloria images further north along the hawaiian ridge probably triggered a giant wave that washed 325 m high on lanai at about 100 ka slumping on mauna loa has been most intense adjacent to the large arcuate bend in its southwest rift zone as the rift zone migrated westward away from the growing kilauea volcano slumping events were probably triggered by seismic activity accompanying dike injection along the rift zone such massive slumps landslides and distal submarine turbidity flows appear to be widespread on the flanks of hawaiian volcanoes

ups and downs on spreading flanks of ocean island volcanoes evidence from mauna loa and kīlauea submarine flank deposits of hawaiian volcanoes are widely recognized to have formed largely by gravitationally driven volcano spreading and associated landsliding observations from submersibles show that prominent benches at middepths on flanks of mauna loa and k lauea consist of volcaniclastic debris derived by landsliding from nearby shallow submarine and subaerial flanks of the same edifice massive slide breccias from the mature subaerial tholeiitic shield of mauna loa underlie the frontal scarp of its south kona bench in contrast coarse volcaniclastic sediments derived largely from submarine erupted preshield alkalic and transitional basalts of ancestral k lauea underlie its hilina bench both midslope benches record the same general processes of slope failure followed by modest compression during continued volcano spreading even though they record development during different stages of edifice growth the dive results suggest that volcaniclastic rocks at the north end of the kona bench interpreted by others as distal sediments from older volcanoes that were offscraped uplifted and accreted to the island by far traveled thrusts alternatively are a largely coherent stratigraphic assemblage deposited in a basin behind the south kona bench

hyaloclastites and the slope stability of hawaiian volcanoes insights from the hawaiian scientific drilling project s 3 km drill core abstract core samples recovered during the hawaiian scientific drilling project hsdp drilling project reveal that the upper 1 km of the submarine flank of mauna kea is comprised mainly of hyaloclastites progressive very low temperature alteration of these hyaloclastites has been accompanied by systematic transformations in physical properties of these deposits hyaloclastite deposits which directly underlie ca 1 km of subaerially emplaced lavas are very poorly consolidated but over a depth interval of ca 500 m compaction and especially precipitation of zeolitic pore filling cements associated with palagonitization of sideromelane have eliminated porosity as well as promoted the consolidation of these hyaloclastites the latter is reflected in unconfined compressive strengths which increase from mean values respectively of 2 5 and 4 6 mpa in weakly consolidated smectite rich hyaloclastites from the incipient 1080 to 1335 mbsl and smectitic 1405 1573 mbsl alteration zones to a mean value of 10 0 mpa in the more highly consolidated hyaloclastites of the palagonitic zone of alteration from 1573 mbsl to the bottom of the drill hole conversely overlying intercalated and underlying lava flows are generally much less altered and have mean compressive strengths which are 1 to 2 orders of magnitude greater then hyaloclastites at equivalent depths the shear strengths of the hyaloclastites also increase with depth and grade of alteration but are uniformly and substantially lower in the lavas those hyaloclastites exhibiting the highest grade of alteration i e palagonitic also exhibit the highest measured strengths and thus the alteration of hyaloclastites appears to strengthen as opposed to weaken the flanks of the edifice however the contrast in strength between hyaloclastites and lavas may be a primary factor in localizing destabilization and the zones of weak and poorly consolidated hyaloclastites may facilitate slumping by servings as hosts for shallow detachment surfaces on the unsupported flanks of these volcanoes

deep seated abiogenic origin of petroleum from geological assessment to physical theory the theory of the abyssal abiogenic origin of petroleum is a significant part of the modern scientific theories dealing with the formation of hydrocarbons these theories include the identification of natural hydrocarbon systems the physical processes leading to their terrestrial concentration and the dynamic processes controlling the migration of that material into geological reservoirs of petroleum the theory of the abyssal abiogenic origin of petroleum recognizes that natural gas and petroleum are primordial materials of deep origin which have migrated into the earth s crust experimental results and geological investigations presented in this article convincingly confirm the main postulates of the theory and allow us to reexamine the structure size and locality distributions of the world s hydrocarbon reserves

fractured basement play development on the uk and norwegian rifted margins fractured crystalline basement reservoirs basement on the uk continental shelf ukcs and the norwegian continental shelf ncs have been underexplored over the last 12 years hurricane energy has deliberately set out to explore basement potential by exploring and appraising the rona ridge west of shetland and the rona ridge lancaster field is now being progressed towards being the first uk basement field development the norwegian basement play is also recognized as a potentially material resource through serendipitous oil discoveries with the 16 1 15 well drilled in 2011 being the first successful full scale basement test on the ncs building on this success the 2018 rolvsnes appraisal well 16 1 28 s has demonstrated the significant basement potential of the extensive utsira high and confirmed the materiality of a norwegian basement play the rona ridge and utsira basement discoveries are used as a comparison with two other yet to be evaluated prospective basement plays on the ncs with the objective of establishing technical subject areas where future ukcs and ncs collaboration would aid in accelerating understanding of the ukcs ncs basement play

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

volcanic spreading on mauna loa volcano hawaii evidence from accretion alteration and exhumation of volcaniclastic sediments a transect of submersible dives across the submarine west flank of mauna loa volcano yields compelling evidence for volcanic spreading and associated hydrothermal circulation during volcano growth a frontal bench at the toe of the flank formerly thought to be a downdropped block of mauna loa contains a mix of volcaniclastic lithologies including distally derived siltstone mudstone and hyaloclastite the bench is overlain by bedded gravels and subaerially erupted pillow flows derived from local shoreline crossing lava flows the volcaniclastic strata in the bench were offscraped uplifted and accreted to the edge of the flank as it plowed seaward into the surrounding moat the accreted strata underwent significant diagenesis through deep burial and circulation of hydrothermal fluids expelled from porous sediments beneath the volcano timing constraints for bench growth and breakup suggest that catastrophic failure of the subaerial edifice ca 250 200 ka triggered volcanic spreading by reducing stresses resisting basal sliding and rift zone inflation increased eruptive activity and westward migration of mauna loa9s southwest rift zone gradually rebuilt the massive flank arresting slip prior to detachment of the alika 2 debris avalanche ca 120 ka

formation of uranium thorium rich bitumen nodules in the lockne impact structure sweden a mechanism for carbon concentration at impact sites the ordovician lockne impact structure is located in central sweden the target lithology consisted of limestone and black unconsolidated shale overlaying a precambrian crystalline basement the precambrian basement is uranium rich and the black shale is both uranium and organic rich this circumstance makes lockne a good candidate for testing the occurrence of u th rich bitumen nodules in an impact structure setting u th rich bitumen nodules are formed through irradiation hence the increase in the complexity of organic matter by a radioactive uranium and thorium rich mineral phase u th rich bitumen nodules were detected in crystalline impact breccia and resurge deposits from the impact structure but samples of non impact affected rocks from outside the impact structure do not contain any u th rich bitumen nodules this implies that in the lockne impact structure the nodules are associated with impact related processes u th rich bitumen nodules occur throughout the geological record and are not restricted to an impact structure setting but our studies at lockne show that this process of irradiation can readily occur in impact structures where fracturing of rocks and a post impact hydrothermal system enhances fluid circulation the irradiation of organic matter by radioactive minerals has previously been proposed as a process for concentration of carbon on the early earth impact structures are suggested as sites for prebiotic chemistry and primitive evolution and irradiation by radioactive minerals could be an important mechanism for carbon concentration at impact sites

hydrocarbon downward accumulation from an upper oil source to the oil reservoir below in an extensional basin a case study of chezhen depression in the bohai bay basin abstract there is a disputable theory that hydrocarbon can be injected into the reservoir and migrate downward in an oil reservoir with an upper oil source which is still questioned now however although some examples are previously found questions still remain about the theory regarding oil sources oil migration pathways and migration forces that related to downward hydrocarbon migration for this reason the chezhen graben in the bohai bay basin is selected to study all the problems above geo chemical evidence show that lower es3 source rock t6 in seismic profiles has a close genetic relationship with the underlying es4 t7 in seismic profiles and ordovician oil therefore the upper source lower reservoir type can be formed inside the lower gentle slopes and sag zones and inside the cambrian and permian reservoirs the fluid inclusion experiment shows that the lower es3 source rock underwent 3 over pressure evolution stages meanwhile there is a huge pressure difference between the lower es3 source rock and underlying es4 reservoirs which is the migration force of downward migration in the lower areas of gentle slopes and sags the early generated and early ended faults are terminated at the source rock of es3 member and can be re opened under the over pressure influence of the source rock and regional tensile stress then they become the pathways of the so called downward migration the distance of downward migration can be calculated through the accumulation dynamic which is obtained by hydrocarbon pressure subtracting the reservoir hydrostatic pressure pressure attenuation and displacement pressure the research result on downward migration process is of great significance to broaden the hydrocarbon exploration fields

quantitative vertical zonation of salt marsh foraminifera for reconstructing former sea level an example from new jersey usa we present a quantitative technique to reconstruct sea level from assemblages of salt marsh foraminifera using partitioning around medoids pam and linear discriminant functions ldf the modern distribution of foraminifera was described from 62 surface samples at three salt marshes in southern new jersey pam objectively estimated the number and composition of assemblages present at each site and showed that foraminifera adhered to the concept of elevation dependent ecological zones making them appropriate sea level indicators application of pam to a combined dataset identified five distinctive biozones occupying defined elevation ranges which were similar to those identified elsewhere on the u s mid atlantic coast biozone a had high abundances of jadammina macrescens and trochammina inflata biozone b was dominated by miliammina fusca biozone c was associated with arenoparrella mexicana biozone d was dominated by tiphotrocha comprimata and biozone e was dominated by haplophragmoides manilaensis foraminiferal assemblages from transitional and high salt marsh environments occupied the narrowest elevational range and are the most precise sea level indicators recognition of biozones in sequences of salt marsh sediment using ldfs provides a probabilistic means to reconstruct sea level we collected a core to investigate the practical application of this approach ldfs indicated the faunal origin of 38 core samples and in cross validation tests were accurate in 54 of 56 cases we compared reconstructions from ldfs and a transfer function the transfer function provides smaller error terms and can reconstruct smaller rsl changes but ldfs are well suited to rsl reconstructions focused on larger changes and using varied assemblages agreement between these techniques suggests that the approach we describe can be used as an independent means to reconstruct sea level or importantly to check the ecological plausibility of results from other techniques

foraminifera as an indicator of overwash deposits barrier island sediment supply and barrier island evolution folly island south carolina abstract micropaleontological analysis of four vibracores from back barrier marshes of folly island south carolina detected intervals of storm deposited sediment individual washover intervals were not detectable from lithology alone but only in conjunction with associated foraminifera washovers contained more modern offshore and oligo miocene genera and total calcareous foraminifera than background marsh samples the presence of tertiary foraminifera in the back barrier cores from folly island supports the hypothesis that much of the sediment for barrier island migration is derived from offshore foraminiferal analyses of back barrier cores were also used to calculate relative bioturbation rates by the method of officer and lynch officer c b lynch d r 1983 mixing sedimentation rates and age dating for sediment cores mar geol 46 261 278 eqs 10 14 in all cores the current depositional environment correlated well with the expected mixing parameter g the highest mixing parameter greatest signal attenuation was recorded in a core from a low marsh creek side environment whereas the lowest mixing parameter least smearing of signal was recorded in a high marsh core

the nature and age of basement host rocks and fissure fills in the lancaster field fractured reservoir west of shetland hosting up to 3 3 billion barrels of oil in place the upfaulted precambrian crystalline rocks of the lancaster field offshore west of shetland give key insights into how fractured hydrocarbon reservoirs can form in such old rocks the neoarchean c 2700 2740 ma charnockitic basement is cut by deeply penetrating oil mineral and sediment filled fissure systems seen in geophysical and production logs and thin sections of core mineral textures and fluid inclusion geothermometry suggest that a low temperature supplementary material analytical methods and isotopic compositions and ages are available at https doi org 10 6084 m9 figshare c 4763237 thematic collection this article is part of the geology of fractured reservoirs collection available at https www lyellcollection org cc the geology of fractured reservoirs

north kona slump submarine flank failure during the early tholeiitic shield stage of hualalai volcano abstract the north kona slump is an elliptical region about 20 by 60 km 1000 km 2 area of multiple geometrically intricate benches and scarps mostly at water depths of 2000 4500 m on the west flank of hualalai volcano two dives up steep scarps in the slump area were made in september 2001 using the rov kaiko of the japan marine science and technology center jamstec as part of a collaborative japan usa project to improve understanding of the submarine flanks of hawaiian volcanoes both dives at water depths of 2700 4000 m encountered pillow lavas draping the scarp and bench slopes intact to only slightly broken pillow lobes and cylinders that are downward elongate dominate on the steepest mid sections of scarps while more equant and spherical pillow shapes are common near the tops and bases of scarps and locally protrude through cover of muddy sediment on bench flats notably absent are subaerially erupted hualalai lava flows interbedded hyaloclastite pillow breccia and or coastal sandy sediment that might have accumulated downslope from an active coastline the general structure of the north kona flank is interpreted as an intricate assemblage of downdropped lenticular blocks bounded by steeply dipping normal faults the undisturbed pillow lava drape indicates that slumping occurred during shield stage tholeiitic volcanism all analyzed samples of the pillow lava drape are tholeiite similar to published analyses from the submarine northwest rift zone of hual lai relatively low sulfur 330 600 ppm and water 0 18 0 47 wt contents of glass rinds suggest that the eruptive sources were in shallow water perhaps 500 1000 m depth in contrast saturation pressures calculated from carbon dioxide concentrations 100 190 ppm indicate deeper equilibration at or near sample sites at water depths of 3900 to 2800 m either vents close to the sample sites erupted mixtures of undegassed and degassed magmas or volatiles were resorbed from vesicles during flowage downslope after eruption in shallow water the glass volatile compositions suggest that the tholeiitic lavas that drape the slump blocks were erupted either 1 early during shield stage tholeiitic volcanism prior to emergence of a large subaerial edifice or alternatively 2 from submarine radial vents during subaerial shield building because no radial vents have been documented on land or underwater for the unbuttressed flanks of any hawaii volcano alternative 1 is favored in comparison to other well documented hawaiian slumps and landslides north kona structures suggest a more incipient slump event with smaller down slope motions and lateral displacements

migration of biogenic hydrocarbons into granites a review of hydrocarbons in british plutons abstract the occurrence of hydrocarbons bitumens senso lato in granite plutons and other basement rocks is not per se evidence of an abiogenic origin for the hydrocarbons on the contrary plutons are thermal foci and often highly fractured and therefore are hosts to the migration of fluids from outside the plutons including water and biogenic hydrocarbons hydrocarbons are associated with several british granites in all cases they can be attributed to biogenic sedimentary source rocks the occurrences are particularly related to hydrothermal mineralized veins in granites including the cornish hercynian granites the mountsorrel granodiorite and the weardale granite

utility of salt marsh foraminifera testate amoebae and bulk sediment δ13c values as sea level indicators in newfoundland canada abstract we investigated the utility of foraminifera testate amoebae and bulk sediment 13 c measurements for reconstructing holocene relative sea level from sequences of salt marsh sediment in newfoundland canada modern surface sediment was collected along transects from low to supra tidal elevations in eastern at placentia and western at hynes brook and big river newfoundland consistent with previous work low diversity assemblages of foraminifera display an almost binary division into a higher salt marsh assemblage dominated by jadammina macrescens and balticammina pseudomacrescens and a lower salt marsh assemblage comprised of miliammina fusca this pattern and composition resembles those identified at other high latitude sites with cool climates and confirms that foraminifera are sea level indicators the lowest occurrence of testate amoebae was at approximately mean higher high water the composition of high salt marsh testate amoebae assemblages centropyxis cassis type trinema spp tracheleuglypha dentata type and euglypha spp in newfoundland was similar to elsewhere in the north atlantic but preservation bias favors removal of species with idiosomic tests over those with xenosomic tests the mixed high salt marsh plant community in newfoundland results in bulk surface sediment 13 c values that are typical of c 3 plants making them indistinguishable from freshwater sediment therefore we propose that the utility of this proxy for reconstructing rsl in eastern north america is restricted to the coastline between chesapeake bay and southern nova scotia using a simple multi proxy approach to establish that samples in three radiocarbon dated sediment cores formed between the lowest occurrence of testate amoebae and the highest occurrence of foraminifera we generated three example late holocene sea level index points at hynes brook

overthrusting and sediment accretion along kilauea s mobile south flank hawaii evidence for volcanic spreading from marine seismic reflection data a large intermittently active submarine landslide known as the hilina slump has been interpreted along the south flank of kilauea volcano seaward dipping faults on land mark its headwall and an offshore bench may define its uplifted toe geodetic data show that the entire south flank is also moving seaward by a process referred to as volcanic spreading this provides an alternative explanation for the bench i e overthrusting along the edge of the sliding flank the latter interpretation is consistent with new seismic reflection data across the submarine flank a prominent reflection near the top of the oceanic plate suggests the decollement upon which the mobile flank slides landward dipping reflections rise from this horizon and bound packages of bedded strata faulted and imbricated within the bench the absence of correlative seaward dipping faults and rotated strata on the upper flank suggests that the bench is not coupled to a slump moreover kinematic reconstructions of the bench indicate that it has accommodated 15 24 km of displacement this value is consistent with estimates for rift zone extension but too high for shortening at the toe of a slump we interpret the bench to result from overthrusting and accretion of volcaniclastic sediments to the edge of the mobile flank and suggest that morphologic benches develop preferentially where landslide debris has accumulated near the base of the volcano and can be accreted to its sliding edifice

a submarine perspective of the honolulu volcanics oahu lavas and volcaniclastic deposits were observed and collected from 4 submarine cones that are part of the honolulu volcanics on oahu hawaii the locations of these and a few additional but unsampled vents demonstrate that nearly all the vents are located on or very close to the shoreline of oahu with the most distal vent just 12 km offshore the clastic samples and outcrops range from coarse breccias to cross bedded ash deposits and show that explosive volcanism at depths between about 350 and 590 m depth played a part in forming these volcanic cones the eruptive styles appear to be dominantly effusive to strombolian at greater depths but apparently include violent phreatomagmatic explosive activity at the shallower sites along the submarine southwest extension of the koko rift the compositions of the recovered samples are broadly similar to the strongly alkalic subaerial honolulu volcanics lavas but the submarine lavas erupted further from the koolau caldera have slightly more radiogenic sr isotopic ratios and trace element patterns that are distinct from either the subaerial honolulu volcanics or the submarine north arch lavas these patterns are characterized by moderate to strong positive sr and p anomalies and moderate to strong negative cs rb u th zr and hf anomalies most samples have strong negative k and moderate negative ti anomalies as do all subaerial honolulu volcanics and north arch samples but one group of samples from the koko rift lack this chemical signature the data are consistent with more garnet in the source region for the off shore samples than for either the on shore honolulu volcanics lavas new ar ar ages show that eruptions at the submarine vents and diamond head occurred between about 0 5 ma and 0 1 ma with the youngest ages from the koko rift these ages are in general agreement with most published ages for the formation and suggest that some much younger ages reported previously from the koko rift are probably erroneously young d 2005 elsevier b v all rights reserved

microfossil measures of rapid sea level rise timing of response of two microfossil groups to a sudden tidal flooding experiment in cascadia comparisons of pre earthquake and post earthquake microfossils in tidal sequences are accurate means to measure coastal subsidence during past subduction earthquakes but the amount of subsidence is uncertain because the response times of fossil taxa to coseismic relative sea level rsl rise are unknown we measured the response of diatoms and foraminifera to restoration of a salt marsh in southern oregon usa tidal flooding following dike removal caused an rsl rise of 1 m as might occur by coseismic subsidence during momentum magnitude m w 8 1 8 8 earthquakes on this section of the cascadia subduction zone less than two weeks after dike removal diatoms colonized low marsh and tidal flats in large numbers showing that they can record seismically induced subsidence soon after earthquakes in contrast low marsh foraminifera took at least 11 months to appear in sizeable numbers where subsidence measured with diatoms and foraminifera differs their different response times may provide an estimate of postseismic vertical deformation in the months following past megathrust earthquakes

buried hill play jizhong subbasin bohai bay basin a review and future prospectivity as one of the six subbasins in the lacustrine bohai bay basin the jizhong subbasin is characterized by a dominance of the petroleum reserves located in buried hill traps of paleozoic and proterozoic marine carbonates particularly the latter this paper documents the revitalization of exploration of the buried hill play and discusses other play fairways not previously considered through use of case studies discovery of the largest field renqiu field in 1975 led to the establishment of the buried hill play in this play oil derived from the paleogene lacustrine source rocks charged into and accumulated in the underlying proterozoic marine carbonate reservoirs a number of buried hill fields were discovered within a time span of ca 10 yr in the subbasin with more and more large buried hill structures at depths of less than 5000 m 16 400 ft being drilled the annual reserve addition showed a rapid decline until 2006 the application of new technologies including reprocessing of merged three dimensional seismic data improved logging and testing techniques together with innovative exploration ideas made it possible to revitalize the buried hill play the exploration success lies with the focus change from targeting the conventional shallow to moderately buried hills to the unconventional buried hill pools which include deeply buried hilltop hillslope and intrahill pools case studies of one conventional buried hill field renqiu field and three unconventional buried hill fields chang 3 wengu 3 and niudong 1 fields together with modern geological investigations indicate that there still exists significant exploration potential for the buried hill play in the jizhong subbasin the potential largely lies with the unconventional buried hills the baxian wuqing and baoding depressions are favorable fairways for the deeply buried hill pools represented by the niudong 1 field the wenan slope is the favorable fairway for the intrahill pools represented by the chang 3 and wengu 3 fields

oil and gas production from basement reservoirs examples from indonesia usa and venezuela abstract basement rocks are important oil and gas reservoirs in various areas of the world such reservoirs include fractured or weathered granites quartzites or metamorphics in south america basement reservoirs occur in venezuela and brazil in north africa basement oil and gas production occurs in morocco libya algeria and egypt significant basement reservoirs occur in the west siberia basin as well as in china in the usa basement derived oil production occurs in a number of areas including california wilmington and edison fields kansas el dorado and orth fields and texas apco field in southeast asia basement reservoirs are the main contributor of oil production in vietnam in indonesia to date oil and gas production from basement rocks has been minimal however the recent large gas discovery in pre tertiary fractured granites in southern sumatra has led to a focusing of exploration in indonesia for basement reservoirs

volatiles in glasses from mauna loa volcano hawai i implications for magma degassing and contamination and growth of hawaiian volcanoes glasses from mauna loa pillow basalts recent subaerial vents and inclusions in olivine were analyzed for s cl f and major elements by electron microprobe select submarine glasses were also analyzed for h2o and co2 by infrared spectroscopy the compositional variation of these tholeiitic glasses is dominantly controlled by crystal fractionation and they indicate quenching temperatures of 1 115 1 196 c submarine rift zone glasses have higher volatile abundances except f than nearly all other submarine and subaerial glasses with the maximum concentrations increasing with water depth the overwhelming dominance of degassed glasses on the submarine flanks of mauna loa implies that much of volcano s recent submarine growth involved subaerially erupted lava that reached great water depths up to 3 1 km via lava tubes anomalously high f and cl in some submarine glasses and glass inclusions indicate contamination possibly by fumarolic deposits in ephemeral rift zone magma chambers the relatively high co2 but variable h2o k2o and s k2o in some submarine rift zone glasses indicates pre eruptive mixing between degassed and undegassed magma within mauna loa s rift system volatile compositions for mauna loa magmas are similar to other active hawaiian volcanoes in s and f but are less cl rich than l ihi glasses however cl k2o ratios are similar mauna loa and l ihi magmas have comparable but lower h2o than those from kilauea thus kilauea s source may be more h2o rich the dissimilar volatile distribution in glasses from active hawaiian volcanoes is inconsistent with predictions for a simple concentrically zoned plume model

relative sea level trends in new york city during the past 1500 years new york city nyc is threatened by 21st century relative sea level rsl rise because it will experience a trend that exceeds the global mean and has high concentrations of low lying infrastructure and socioeconomic activity to provide a long term context for anticipated trends we reconstructed rsl change during the past 1500 years using a core of salt marsh sediment from pelham bay in the bronx foraminifera and bulk sediment 13c values were used as sea level indicators the history of sediment accumulation was established by radiocarbon dating and recognition of pollution and land use trends of known age in down core elemental isotopic and pollen profiles the reconstruction was generated within a bayesian hierarchical model to accommodate multiple proxies and to provide a unified statistical framework for quantifying uncertainty we show that rsl in nyc rose by 1 70 m since 575 ce including 0 38 m since 1850 ce the rate of rsl rise increased markedly at 1812 1913 ce from 1 0 to 2 5 mm y

growth structure instability and collapse of canarian volcanoes and comparisons with hawaiian volcanoes recent onshore and offshore investigations in the canarian archipelago especially in the western islands of la palma and el hierro have greatly improved the understanding of the genesis and evolution of these islands and allow interesting comparisons with other hotspot induced oceanic island volcanoes especially the hawaiian archipelago genesis induced by hotspot activity and consequently shield and post erosional stages of growth allow the definition of similar main stratigraphic units the canarian and hawaiian volcanoes show common constructional and structural features such as rift zones progressive volcano instability and multiple gravitational collapses however the canaries present some important geological differences from the prototypical hotspot volcanoes of the hawaiian islands particularly the absence of significant subsidence the canarian volcanoes remain emergent until completely mass wasted by gravitational collapses and erosion volcanic formations over 20 million years are observable in outcrop in the canaries including the seamount stages of growth in several of the islands

a low relief shield volcano origin for the south kaua i swell 1 the south kaua i swell sks is a 110 km x 80 km ovoid bathymetric feature that stands 2 km high and abuts the southern flank of the island of kaua i the origin of the sks was investigated using multibeam bathymetry and acoustic backscatter gravity data radiometric ages and geochemistry of rock samples most of the sks rock samples are tholeiitic in composition with ages of 3 9 5 4 ma indicating they were derived from shield volcanism the ages and compositions of the sks rocks partially overlap with those of the nearby ni ihau kaua i and west ka ena volcano complexes the sks was originally described as a landslide however this interpretation is problematic given the ovoid shape of sks its relatively smooth flat to convex surface and the lack of an obvious source region that could accommodate what would be one of earth s most voluminous 6 x 103 km3 landslides the morphology size and the surrounding gravity anomaly are more consistent with the sks being a low relief shield volcano which was partially covered with a small volume of landside debris from south kaua i and later with some secondary volcanic seamounts a shield origin would imply that hawaiian and possibly other hotspot shield volcanoes can take on a wider variety of forms than is commonly thought ranging from tall island building shields to smaller edifices such as ka ena ridge and mahukona to even lower relief volcanoes represented by the sks and possibly the south west o ahu volcanic field

physics of crustal fracturing and chert dike formation triggered by asteroid impact 3 26 ga barberton greenstone belt south africa archean asteroid impacts reflected in the presence of spherule beds in the 3 2 3 5 ga barberton greenstone belt bgb south africa generated extreme seismic waves spherule bed s2 provides a field example it locally lies at the contact between the onverwacht and fig tree groups in the bgb which formed as a result of the impact of asteroid possibly 50 km diameter scaling calculations indicate that very strong seismic waves traveled several crater diameters from the impact site where they widely damaged onverwacht rocks over much of the bgb lithified sediments near the top of the onverwacht group failed with opening mode fractures the underlying volcanic sequence then failed with normal faults and opening mode fractures surficial unlithified sediments liquefied and behaved as a fluid these liquefied sediments and some impact produced spherules filled near surface fractures today represented by swarms of chert dikes strong impact related tsunamis then swept the seafloor p waves and rayleigh waves from the impact greatly exceeded the amplitudes of typical earthquake waves the duration of extreme shaking was also far longer probably hundreds of seconds than that from strong earthquakes dynamic strains of 10 3 occurred from the surface and downward throughout the lithosphere shaking weakened the onverwacht volcanic edifice and the surface layers locally moved downhill from gravity accommodated by faults and open mode fractures coast parallel opening mode fractures on the fore arc coast of chile formed as a result of megathrust events are the closest modern analogs it is even conceivable that dynamic stresses throughout the lithosphere initiated subduction beneath the onverwacht rocks

sea level change during the last 2500 years in new jersey usa relative sea level changes during the last w2500 years in new jersey usa were reconstructed to test if late holocene sea level was stable or included persistent and distinctive phases of variability foraminifera and bulk sediment d 13 c values were combined to reconstruct paleomarsh elevation with decimeter precision from sequences of salt marsh sediment at two sites using a multi proxy approach the additional paleoenvironmental information provided by bulk sediment d 13 c values reduced vertical uncertainty in the sea level reconstruction by about one third of that estimated from foraminifera alone using a transfer function the history of sediment deposition was constrained by a composite chronology an ageedepth model developed for each core enabled reconstruction of sea level with multi decadal resolution following correction for land level change 1 4 mm yr four successive and sustained multi centennial sea level trends were objectively identified and quantified 95 confidence interval using error in variables change point analysis to account for age and sea level uncertainties from at least 500 bc to 250 ad sea level fell at 0 11 mm yr the second period saw sea level rise at 0 62 mm yr from 250 ad to 733 ad between 733 ad and 1850 ad sea level fell at 0 12 mm yr the reconstructed rate of sea level rise since w1850 ad was 3 1 mm yr and represents the most rapid period of change for at least 2500 years this trend began between 1830 ad and 1873 ad since this change point reconstructed sea level rise is in agreement with regional tide gauge records and exceeds the global average estimate for the 20th century these positive and negative departures from background rates demonstrate that the late holocene sea level was not stable in new jersey

structure of the mobile south flank of kilauea volcano hawaii how do huge landslides occur in hawaii we can begin to address this question by examining an incipient landslide structure on the mobile south flank of kilauea volcano between 1970 and 1989 this part of the south flank moved in a southeast direction seaward by 4 m on its eastern end and by 10 m on its western end parallel to the western boundary of a large oifshore topographic bench we show that abrupt decreases in cumulative flank movement correspond to abrupt decreases in hypocenter concentration most of the earthquakes occur in a 7 to 10 km deep band beneath the south flank and relative relocation of a subset of these events shows that they are derived from a single horizontal plane which appears to be a decollement focal mechanisms for this deep seismicity are dominated by thrust fault mechanisms with the overlying block moving seaward a comparison of south flank bathymetry with decollement structures on other volcanoes suggests that the distal end of this decollement coincides with the distal end of the offshore topographic bench 30 50 km from shore and 5 km below sea level the fault system forming the hilina pali is connected with this decollement so that slip on the hilina pali s normal faults coincides with slip of the decollement and with reverse faulting of the distal end of the bench this interpretation is supported by studies of the events associated with the m7 2 kalapana earthquake in 1975 when the hilina pali is connected to the outer bench with a decollement inferred from seismicity a wedge 8 km thick adjacent to kilauea s magma system and 1 2 km thick along the edge of the outer bench an area over 3000 km2 is defined the thickness adjacent to the magma system decreases eastward along kilauea s east rift zone and southwestward from kilauea caldera whereas the thickness of the lip of the outer bench decreases only eastward geologic observations and geophysical studies of the subaerial flank reveal an extensive magma system beneath the koae fault system as well as beneath kilauea caldera and its east rift zone we infer that the boundary of the proximal end of the mobile flank is the southern boundary of this magma system and that this boundary coincides with the southern boundaries of both the koae fault system and kilauea s east rift zone

new insights into landslide processes around volcanic islands from remotely operated vehicle rov observations offshore montserrat submarine landslide deposits have been mapped around many volcanic islands but interpretations of their structure composition and emplacement are hindered by the challenges of investigating deposits directly here we report on detailed observations of four landslide deposits around montserrat collected by remotely operated vehicles integrating direct imagery and sampling with sediment core and geophysical data these complementary approaches enable a more comprehensive view of large scale mass wasting processes around island arc volcanoes than has been achievable previously the most recent landslide occurred at 11 5 14 ka deposit 1 1 7 km3 and formed a radially spreading hummocky deposit that is morphologically similar to many subaerial debris avalanche deposits hummocks comprise angular lava and hydrothermally altered fragments implying a deep seated central subaerial collapse inferred to have removed a major proportion of lavas from an eruptive period that now has little representation in the subaerial volcanic record a larger landslide deposit 2 10 km3 occurred at 130 ka and transported intact fragments of the volcanic edifice up to 900 m across and over 100 m high these fragments were rafted within the landslide and are best exposed near the margins of the deposit the largest block preserves a primary stratigraphy of subaerial volcanic breccias of which the lower parts are encased in hemipelagic mud eroded from the seafloor landslide deposits south of montserrat deposits 3 and 5 indicate the wide variety of debris avalanche source lithologies around volcanic islands deposit 5 originated on the shallow submerged shelf rather than the terrestrial volcanic edifice and is dominated by carbonate debris

the smectite to chlorite transition in a fossil seamount hydrothermal system the basement complex of la palma canary islands the hydrothermal metamorphism of a sequence of pliocene aged seamount extrusive and volcanoclastic rocks on la palma includes a relatively complete low p t facies series encompassing the zeolite prehnite pumpellyite and greenschist facies the observed mineral zonations imply metamorphic gradients of 200 300 c km 1 the transition from smectite to chlorite in the la palma seamount series is characterized by discontinuous steps between discrete smectite corrensite and chlorite which occur ubiquitously as vesicles and to a much lesser extent vein in fillings trioctahedral smectites mg fe mg 0 4 0 75 occur with palagonite and na ca zeolites such as analcime and a thompsonite natrolite solid solution corrensite mg fe mg 0 5 0 65 first appears at stratigraphic depths closely corresponding to the disappearance of analcime and first appearance of pumpellyite discrete chlorite mg fe mg 0 4 0 6 becomes the dominant layer silicate mineral coincident with the appearance of epidote and andraditic garnet within the stratigraphic section there is some overlap in the distribution of the three discrete layer silicate phases although random interstratifications of these phases have not been observed although smectite occurs as both low and high charge forms the la palma corrensite is a compositionally restricted 1 1 mixture of low charge trioctahedral smectite and chlorite electron microprobe analyses of coarse grained corrensite yield structural formulae close to ideal values based on 50 negative charge recalculations calcium average 0 20 cations formula unit is the dominant interlayer cation with lesser mg k and na the absence of randomly interlayered chlorite smectite in the la palma seamount series may reflect high time integrated fluid fluxes through the seamount sequence this is consistent with the ubiquity of high variance metamorphic mineral assemblages and the general absence of relict igneous minerals in these samples

microfossils from coastal environments as indicators of paleo earthquakes tsunamis and storms abstract coastal risk assessment and hazard mitigation require datasets on centennial and millennial temporal scales to capture natural variability and multiple occurrences of the largest but least frequent events coastal sediments from low energy depositional environments archive geologic evidence of paleo earthquakes tsunamis and storms many of the best reconstructions of these events are derived from changes in microfossil diatoms foraminifera and pollen assemblages in this review we explain how microfossils are used to reconstruct records of paleoearthquakes by quantifying the amount of coseismic and interseismic vertical land movements along tectonically active coastlines examples from the united states alaska and the pacific northwest japan and chile show that microfossil based transfer functions may provide continuous records of vertical land movement during earthquake deformation cycles we discuss how microfossil habitat preferences and taphonomic character are used to constrain sediment provenance e g beach nearshore or offshore sources and identify overwash deposits and how this information can be used to reconstruct the recurrence of tsunamis and storms analysis of overwash deposits from thailand and malaysia indicates the ability of microfossils to resolve individual waves within tsunami sediments and an example from the sendai coastal plain in japan uses foraminifera to ascribe a beach to nearshore provenance for the 2011 tohoku tsunami deposit finally we present recent examples from the gulf of mexico on the use of foraminifera to estimate the volume and distance of transport of storm overwash from hurricanes

prodigious submarine landslides on the hawaiian ridge the extensive area covered by major submarine mass wasting deposits on or near the hawaiian ridge has been delimited by systematic mapping of the hawaiian exclusive economic zone using the side looking sonar system gloria these surveys show that slumps and debris avalanche deposits are exposed over about 100 000 km2 of the ridge and adjacent seafloor from kauai to hawaii covering an area more than 5 times the land area of the islands some of the individual debris avalanches are more than 200 km long and about 5000 km3 in volume ranking them among the largest on earth the slope failures that produce these deposits begin early in the history of individual volcanoes when they are small submarine seamounts culminate near the end of subaerial shield building and apparently continue long after dormancy consequently landslide debris is an important element in the internal structure of the volcanoes the dynamic behavior of the volcanoes can be modulated by slope failure and the structural features of the landslides are related to elements of the volcanoes including rift zones and fault systems the landslides are of two general types slumps and debris avalanches the slumps are slow moving wide up to 110 km and thick about 10 km with transverse blocky ridges and steep toes the debris avalanches are fast moving long up to 230 km compared to width and thinner 0 05 2 km they commonly have a well defined amphitheater at their head and hummocky terrain in the lower part oceanic disturbance caused by rapid emplacement of debris avalanches may have produced high level wave deposits such as the 365 m elevation hulopoe gravel on lanai that are found on several islands most present day submarine canyons were originally carved subaerially in the upper parts of debris avalanches subaerial canyon cutting was apparently promoted by the recently steepened and stripped slopes of the landslide amphitheaters

stratigraphic constraints on the timing and emplacement of the alika 2 giant hawaiian submarine landslide abstract previous work has found evidence for giant tsunami waves that impacted the coasts of lanai molokai and other southern hawaiian islands tentatively dated at 100 and 200 ka by u series methods on uplifted coral clasts seafloor imaging and related work off hawaii island has suggested the alika phase 2 debris avalanche as the source of the 100 ka giant wave deposits although its precise age has been elusive more recently a basaltic sand bed in odp site 842 300 km west of hawaii estimated at 100 20 ka has been suggested to correlate with this or another large hawaiian landslide our approach to the timing and linkage of giant submarine landslides and paleo tsunami deposits is a detailed stratigraphic survey of pelagic deposits proximal to the landslide feature beginning with a suite of seven piston gravity and box cores collected in the vicinity of the alika 2 slide we used u series dating techniques including excess 230 th and 210 pb profiling high resolution paleomagnetic stratigraphy including continuous u channel analysis 18 o stratigraphy visual and x ray sediment lithology and the petrology and geochemistry of the included turbidites and ash layers minimum ages for the alika phase 2a slide from detailed investigation of two of the cores are 112 15 ka and 125 24 ka 2 based on excess 230 th dating a less precise age for the alika phase 1 and or south kona slide is 242 80 ka 2 consistent with previous geological estimates oxygen isotope analyses of entrained planktonic foraminifera better constrain the alika phase 2a maximum age at 127 5 ka which corresponds to the beginning of the stage 5e interglacial period it is proposed that triggering of these giant landslides may be related to climate change when wetter periods increase the possibility of groundwater intrusion and consequent phreatomagmatic eruptions of shallow magma chambers our study indicates the contemporaneity of the alika giant submarine landslides and distal deposits from enormous turbidity currents as well as coral clasts reported to be tsunami deposits on lanai and molokai through direct dating and compositional analysis of the landslide deposits

basement exploration west of shetlands progress in opening a new play on the ukcs abstract commercial production of hydrocarbon from fractured crystalline basement is well documented with petroleum basins across the globe hosting fractured basement fields the uk is an anomaly within this global phenomenon as despite numerous serendipitous discoveries of basement oil in the north sea and the west of shetlands there is currently no commercial field on the united kingdom continental shelf ukcs that is reliant on oil production from fractured basement recognizing that this situation presented an exploration niche hurricane energy plc hurricane was formed to focus on ukcs basement exploration and concentrated its efforts in acquiring exploration acreage in the west of shetlands in 2009 hurricane drilled the first well designed to explore the basement play on the ukcs leading to the lancaster discovery with a contingent resource range 1c 3c of 62 456 million barrels of oil equivalent mmboe the lancaster discovery is presented to summarize the challenges and processes that have been applied in the exploration and evaluation of the west of shetlands basement play conclusions from this work indicate that basement hydrocarbon resource potential is of such significance that it may represent a strategic resource for the uk with over 1154 mmboe of 2c and mean unrisked prospective resources so far identified

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

relative sea level change in newfoundland canada during the past 3000 years abstract several processes contributing to coastal relative sea level rsl change in the north atlantic ocean are observed and or predicted to have distinctive spatial expressions that vary by latitude to expand the latitudinal range of rsl records spanning the past 3000 years and the likelihood of recognizing the characteristic fingerprints of these processes we reconstructed rsl at two sites big river and placentia in newfoundland from salt marsh sediment bayesian transfer functions established the height of former sea level from preserved assemblages of foraminifera and testate amoebae age depth models constrained by radiocarbon dates and chronohorizons estimated the timing of sediment deposition during the past 3000 years rsl rose by 3 0 m at big river and by 1 5 m at placentia a locally calibrated geotechnical model showed that post depositional lowering through sediment compaction was minimal to isolate and quantify contributions to rsl from global regional linear regional non linear and local scale processes we decomposed the new reconstructions and those in an expanded global database using a spatio temporal statistical model the global component confirms that 20th century sea level rise occurred at the fastest century scale rate in over 3000 years p 0 999 distinguishing the contributions from local and regional non linear processes is made challenging by a sparse network of reconstructions however only a small contribution from local scale processes is necessary to reconcile rsl reconstructions and modeled rsl trends we identified three latitudinally organized groups of sites that share coherent regional non linear trends and indicate that dynamic redistribution of ocean mass by currents and or winds was likely an important driver of sea level change in the north atlantic ocean during the past 3000 years

40ar 39ar geochronology of submarine mauna loa volcano hawaii 1 new geochronologic constraints refine the growth history of mauna loa volcano and enhance interpretations of the petrologic geochemical and isotopic evolution of hawaiian magmatism we report results of 40ar 39ar incremental heating experiments on low k tholeiitic lavas from the 1 6 km high kahuku landslide scarp cutting mauna loa s submarine southwest rift zone and from lavas in a deeper section of the rift obtaining precise40ar 39ar ages from young tholeiitic lavas containing only 0 2 0 3 wt k2o is challenging due to their extremely low radiogenic 40ar contents analyses of groundmass from 45 lavas yield 14 new age determinations 31 success rate with plateau and isochron ages that agree with stratigraphic constraints lavas collected from a 1250 m thick section in the landslide scarp headwall were all erupted around 470 10 ka implying an extraordinary period of accumulation of 25 mm yr possibly correlating with the peak of the shield building stage this rate is three times higher than the estimated vertical lava accumulation rate for shield building at mauna kea 8 6 3 1 mm yr based on results from the hawaii scientific drilling project between 470 and 273 ka the lava accumulation rate along the southwest rift zone decreased dramatically to 1 mm yr we propose that the marked reduction in lava accumulation rate does not mark the onset of post shield volcanism as previously suggested but rather indicates the upward migration of the magma system as mauna loa evolved from a submarine stage of growth to one that is predominantly subaerial thereby cutting off supply to the distal rift zone prior to 250 ka lavas with loihi like isotopic signatures were erupted along with lavas having typical mauna loa values implying greater heterogeneity in the plume source earlier in mauna loa s growth in addition to refining accumulation rates and the isotopic evolution of the lavas erupted along the southwest rift zone our new40ar 39ar results constrain the eruption of the ninole basalts from 227 to 108 ka and provide maximum estimates on the timing of the ka lae and south kona landslides

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