surface eddy momentum flux and velocity variances in the southern ocean from geosat altimetry abstract satellite altimetry has previously been used to map the magnitude of the surface eddy variability of the global oceans but the direction of the time variable velocities have been more difficult to determine here a technique is presented for resolving both magnitude and direction of residual surface geostrophic velocities at geosat altimeter crossover points providing a two year time series with a temporal resolution of 17 days and horizontal resolution of around 100 km the time series of residual velocity components are then used to determine surface eddy statistics in the southern ocean and to investigate the role of transient eddies in the southern ocean momentum balance the surface eddy statistics from geosat crossover points show a complex spatial distribution in the surface reynolds stresses u 2 v 2 u v in contrast to the assumptions of isotropic variability in previous analyses of altimeter data velocity variance ellipses are found to be distinctly anisotropic in many regions

estimating groundwater exchange with lakes 1 the stable isotope mass balance method groundwater inflow and outflow contributions to the hydrologic budget of lakes can be determined using a stable isotope 18o 16o mass balance method the stable isotope method provides a way of integrating the spatial and temporal complexities of the flow field around a lake thereby offering an appealing alternative to the traditional time and labor intensive methods using seepage meters and an extensive piezometer network in this paper the method is applied to a lake in northern wisconsin demonstrating that it can be successfully applied to lakes in the upper midwest where thousands of similar lakes exist inflow and outflow rates calculated for the wisconsin lake using the isotope mass balance method are 29 and 54 cm yr respectively which compare well to estimates derived independently using a three dimensional groundwater flow and solute transport model of 20 and 50 cm yr such a favorable comparison lends confidence to the use of the stable isotope method to estimate groundwater exchange with lakes in addition utilization of stable isotopes in studies of groundwater lake systems lends insight into mixing processes occurring in the unsaturated zone and in the aquifer surrounding the lake and verifies assumed flow paths based on head measurements in piezometers

discontinuity surfaces clinoforms and facies architecture in a wave dominated shoreface shelf parasequence abstract detailed outcrop analysis of a wave dominated shoreface shelf parasequence exposed in the book cliffs utah reveals minor stratigraphic discontinuities which define clinoforms two types of discontinuity are recognized each with a distinctive lithologic character and geometry nondepositional discontinuities are marked by an abrupt decrease in the thickness and amalgamation of storm generated event beds and are interpreted to record hiatuses in sedimentation these discontinuities define clinoforms with a concave upward geometry that dip gently 0 02 0 58 over distances of 800 6000 m down depositional dip erosional discontinuities are marked by an abrupt increase in event bed amalgamation grain size and sand content and are interpreted as enhanced storm wave scours these discontinuities define more steeply dipping 0 22 0 95 concave upward clinoforms that extend over 100 1600 m down depositional dip and 500 1500 m along depositional strike the distribution and amalgamation of minor stratigraphic discontinuities defines linear zones of distinctive facies architecture that are oriented parallel to the paleoshoreline trend using the simple assumption that the shoreface shelf equilibrium profile remained approximately constant for each type of discontinuity throughout shoreface migration the bruun rule intra parasequence facies architecture can be speculatively interpreted in terms of shoreline trajectory which reflects the balance between sediment supply and accommodation the resulting interpretations support the notion that shoreline trajectory exerts a strong control on intra parasequence facies architecture and preservation of the shoreface shelf profile

clinoforms and clinoform systems review and dynamic classification scheme for shorelines subaqueous deltas shelf edges and continental margins abstract clinoforms are inclined and normally basinward dipping horizons developed over a range of spatial and temporal scales in both siliciclastic and carbonatic systems the study of clinoform successions underpins sequence stratigraphy and all efforts to reconstruct the relative partitioning of reservoir seal and source rocks along shoreline to basin floor profiles here we review clinoform research and propose a more systematic description and classification of clinoforms this is a crucial step to improve predictions of facies and lithology distribution within shoreline to continental shelf and abyssal plain successions together with the genesis drivers and dynamics of their constituent sedimentary units four basic clinoform types are here distinguished in delta shorelines lacustrine and marine environments on the basis of their overall spatial and temporal scale morphology outbuilding dynamic and geodynamic and depositional setting 1 2 delta scale clinoforms which in turns are sub divided into shoreline and delta scale subaqueous clinoforms 3 shelf edge clinoforms and 4 continental margin clinoforms delta scale clinoform sets are tens of metres high and typically represent 1 103 kyr with progradation rates ranging from 1 000 100 000 m kyr for shorelines and subaerial deltas to 100 20 000 m kyr for subaqueous deltas shelf edge clinoform sets are hundreds of metres high and are nucleated and accreted in 0 1 20 myr usual progradation rates of 1 100 m kyr by successive cross shelf transits of delta scale clinoforms continental margin clinoform sets are thousands of metres high hallmark key geodynamic crustal boundaries e g continent ocean transition and slowly prograde basinwards in ca 5 100 myr with typical rates of 0 1 10 m kyr as a consequence of the very different progradation rates and of the difficulty of large scale clinothems to backstep during transgressions shorelines are the most dynamic clinoforms with regards to position continental margins the least and shelf edges are intermediate shortly after a transgression therefore the four clinoform types may prograde synchronously along shoreline to abyssal plain transects forming compound clinoform systems during the subsequent regressive cycle however due to the dissimilarity in progradation rates different clinoform types will normally merge progressively with each other giving rise to hybrid clinoforms e g shelf edge deltas and fewer depositional breaks in slope are distinguished along a single shoreline to abyssal plain transect overall all clinoform systems are the result of the dynamic evolution of compound and hybrid clinoforms along a temporal and spatial continuum regulated by the cyclical backstepping of the smaller scale system within natural progradational retrogradational cycles of larger scale clinothem outbuilding all clinothem types may show either an accretionary active or draping passive style depending on the proximity to the sediment source draping clinothems are nearly always composed of condensed fine grained sediments while actively accreting clinothems can be composed of predominantly coarse grained i e reservoir forming or predominantly fine grained i e non reservoir lithotypes a novel hierarchical classification scheme for both recent and ancient clinoforms is here proposed consisting of 12 classes the four basic clinoform types delta scale shoreline delta scale subaqueous shelf edge and continental margin are sub divided into eight accretionary active and draping passive sub types 8 division each accretionary sub type is then sub divided into a sandstone prone and mudstone prone variant 12 division which can be at least tentatively predicted on the basis of the clinoform morphology even in the absence of direct stratigraphic logs

accommodation and sediment supply controls on clastic parasequences a meta analysis this study combines data from many published case studies to undertake a quantitative characterization of clastic parasequences with the aim to determine how accommodation sediment supply and autogenic sediment storage dynamics are recorded in their sedimentary architecture and stacking patterns results of this study are used to critically evaluate the validity of paradigms and models that are routinely used to explain and predict trends in the anatomy and arrangement of parasequences data on 957 parasequences from 62 case studies of clastic shallow water successions were coded in a relational database which includes outcrop and subsurface datasets of ancient and quaternary examples these units cover the preserved records of both river dominated deltas and wave dominated coasts representing shoreline transits over a breadth of timescales likely of both local and regional extent the role of extant accommodation rates of creation of accommodation and rates of sediment supply in determining parasequence architecture is assessed through analysis of relationships between i proxies of these variables at different scales rates of aggradation and progradation facies belt shoreline trajectories systems tract type parasequence set stacking patterns parasequence progradation angle and stratigraphic rise size of feeder rivers and ii parameters that describe the geometry and stacking style of parasequences and associated shallow water sand bodies statistical analyses of database outputs indicate which proxies of accommodation sediment supply and accommodation sediment supply ratio are significant as predictors of parasequence architecture and allow for interpretations of the importance of allogenic and autogenic factors the principal results of this study reveal the following i parasequence thickness varies as a function of water depth accommodation generation and erosional truncation and these variations are also reflected across types of systems tracts and parasequence sets ii the dip length of parasequence sand bodies demonstrates scaling with measures of accommodation sediment supply ratio at multiple scales partly in relation to the possible effect of sediment supply on progradation rates iii in systems tracts stratigraphic trends in parasequence stacking due to autogenic mechanisms or to acceleration or deceleration in relative sea level fluctuations are not revealed quantitatively iv some association is seen between the abundance of deltaic or river dominated parasequences and progradational stacking v positive but modest correlation is observed between measures of river system size and the dip length of shallow marine parasequence sand bodies the resulting insights can be applied to guide sequence stratigraphic interpretations of the rock record and the characterization of sub seismic stratigraphic architectures of subsurface successions

facies analysis of a pliocene river dominated deltaic succession siena basin italy implications for the formation and infilling of terminal distributary channels the recent recognition and description of terminal distributary channels in ancient delta front deposits have led to important progress when it comes to understanding delta construction processes the plan view shapes of both modern and ancient river dominated deltas and sediment dispersal within deltas deltaic deposits fed by terminal distributary channels can be observed in the extensive outcrops approximately up to 300 m wide and 50 to 70 m thick in the central sector of the pliocene siena basin in tuscany italy stratigraphic constraints indicate that the deposition occurred in relatively shallow marine settings was not affected by tidal effects and was influenced only locally by wave action as a consequence these rock exposures provide an opportunity to investigate the facies assemblage of an ancient delta complex which was built up almost exclusively as the result of river related processes the studied deltaic succession is composed of vertically stacked parasequence like units which are invariably characterized by the lack of coarse grained distributary channel deposits at the top and an extensive network of terminal distributary channels that controlled the deltaic deposition these deposits were interpreted previously as deep water turbidites this study provides new elements for the correct distinction between hyperpycnal dominated delta fronts and basinal turbidite deposits the terminal distributary channel facies documented in this study are more complex than those investigated in previous research the channels are often passively filled during abandonment phases and not just due to the aggradation and lateral upstream migration of mouth bars as classically proposed moreover the frequent occurrence of mudstone beds just above the basal channel scours may be indicative of an abandonment phase after the channel incision and before its infilling with subsequent implications for the formational and infilling mechanisms of terminal distributary channels furthermore the channel fills are often the result of alternating depositional and erosional phases leading to a complex stratigraphic arrangement

characteristics and formation of eastern south pacific intermediate water 1 newly gathered hydrographic data from the eastern south pacific is combined with other high quality data mainly woce to reassess the properties and boundaries of the eastern south pacific intermediate water espiw to date the espiw has been only poorly described the espiw core is found off central and northern chile between the coast and 90 w and 20 38 s located at 50 400 m of depth its temperature varies between 11 13 c salinity ranges from 34 1 34 3 and its sigma t lies between 25 75 26 25 kgm 3 espiw spreads with the subtropical gyre circulation and can be traced to at least 150 w formed through the process of subduction southeastward of the wind driven gyre circulation the espiw communicates surface properties of the waters off central chile to tropical latitudes

dynamic temporal patterns of nearshore seepage flux in a headwater adirondack lake abstract although seepage in lakes is known to vary as a function of precipitation and watershed characteristics temporal patterns of seepage flux over daily and weekly time scales have not been extensively studied with a concentrated effort of direct measurement of seepage in nearshore areas in this study seepage was intensively measured with seepage meters over two summers and during snowmelt in lower sylvan pond a small lake in the adirondack mountains region of new york state usa a consistent pattern of slight discharge never exceeding 105 ml m 2 h 1 was observed at three stations along a segment of the shoreline near the inlet stream a distinct temporal pattern of seepage was observed at three stations along another portion of the shoreline seepage discharged 400 ml m 2 h 1 for a portion of the summer in 1998 and then shifted to recharge 2 h 1 for the remainder of the summer a similar temporal pattern was observed again in 1999 but the transition to recharge occurred earlier and higher rates of discharge 610 ml m 2 h 1 and recharge 608 ml m 2 h 1 were recorded additionally seepage at these three stations increased after large rainfall events and a pronounced episodic increase of seepage was measured during snowmelt distinct seepage patterns along portions of the shoreline show that seepage can vary considerably within seasons and suggests a need to consider changes of seepage over time periods of days to weeks as well as among seasons and years this study demonstrates that the resolution of temporal seepage data can be important to the understanding of water fluxes to aquatic ecosystems

sediment supply dominated stratal architectures in a regressively stacked succession of shoreline sand bodies campanian desert member to lower castlegate sandstone interval book cliffs utah colorado usa

characterization of controls on high resolution stratigraphic architecture in wave dominated shoreface shelf parasequences using inverse numerical modeling abstract a new inverse numerical modeling method is used to constrain the environmental parameters e g relative sea level sediment supply and wave climate histories that control stratigraphic architecture in wave dominated shallow marine deposits the method links a process response forward stratigraphic model that simulates wave and storm processes barsim to a combination of inverse methods formulated in a bayesian framework that allows full characterization of uncertainties this method is applied for the first time to a real geologic dataset collected at outcrop from two shoreface shelf parasequences in the aberdeen member blackhawk formation of the book cliffs east central utah usa the environmental parameters that controlled the observed stratigraphic architecture are quantified and key aspects of stratigraphic architecture are successfully predicted from limited data stratigraphic architecture at parasequence stacking and intra parasequence scales was driven principally by relative sea level varying by up to about 55 m and sediment supply varying by up to 70 m2 yr whose interplay determines the shoreline trajectory within zones of distinctive shoreline trajectory variations in wave climate of up to about 3 m in fairweather wave height controlled superimposed variations in sandstone and shale content e g the development of upward coarsening and upward fining bedsets the modeling results closely match the observed stratigraphic architecture but their quality is limited by 1 the formulation and assumptions of the forward modeling algorithms and 2 the observed data distribution and quality which provide poor age constraint

an effect of seiche on groundwater seepage rate into lake biwa japan numerical analyses of seiche and continuous measurements of water level and groundwater seepage rates into lake biwa japan were made to evaluate interactions between surface and subsurface waters an automatic seepage meter was used to obtain continuous groundwater seepage rates analyses of the fluctuations of seepage rate and water level in the lake were done using the fast fourier transform method the finite element method was used for analysis of the seiche in the lake dominant periods of fluctuations of the groundwater seepage rate into lake biwa agree well with those of fluctuations of water levels in the lake the dominant fluctuations of the groundwater seepage rate are caused by the seiche in lake biwa

evaluation of the groundwater capture zone for modelling of nutrient discharge we evaluated a groundwater capture zone through both chemical analysis of groundwater samples and numerical simulation to model the nutrient discharge by groundwater into lake biwa japan solute concentrations in groundwater decrease with depth near the lakeshore the capture zone of the groundwater was estimated by solute concentration to be deeper than 100 m below the surface even though a clay layer exists at a depth of 10 to 20 m numerical simulations of changes in solute concentrations of groundwater seepage have been made using different values for the groundwater capture zone depth calculated concentrations agreed well with observed ones when the depth of the groundwater capture zone is set at 150 m the combination of the chemical and physical evidence helped us to model nutrient discharge by groundwater

high resolution linkage of channel coastal plain and shallow marine facies belts desert member to lower castlegate sandstone stratigraphic interval book cliffs utah colorado usa

sequence stratigraphic significance of sharp based lowstand shoreface deposits kenilworth member book cliffs utah the kenilworth member of the blackhawk formation upper cretaceous campanian is nearly continuously exposed from price to hatch mesa in the book cliffs utah five main depositional environments are recognized coastal plain foreshore and upper shoreface lower shoreface inner shelf and incised valley fill deposits the shelf to shoreface deposits combine to form nine coarsening upward wave to storm dominated parasequences that are 7 32 m thick and that split basinward into smaller coarsening upward successions or bedsets that are 2 18 m thick a maximum of four bedsets occurs within an individual parasequence bedset bounding surfaces are occasionally marked by thoroughly bioturbated iron rich carbonate cemented sandstones within the parasequences in the subsu face similar bedset bounding surfaces may act as permeability barriers or baffles leading to reservoir compartmentalization parasequences 1 6 form an aggradational to progradational parasequence set of the highstand systems tract parasequences 7 and 8 occur as sharp based lowstand shoreface deposits at price river and battleship butte forming the attached lowstand systems tract and parasequence 9 forms the transgressive systems tract the base of each lowstand shoreface is marked by an organic rich lag deposit that consists of granules coarse grained sandstone wood fragments coal intraclasts and shell debris the sharp base basal lag deposit and basinward shift in facies delineate a sequence boundary at the base of each lowstand shoreface deposit the presence of two sharp based lowstand shorefaces suggests that the kenilworth lowstand was punctuated by a stillstand the sharp based lowstand shoref ce sandstones form the bulk of the attached lowstand systems tract and represent one end member in a continuum of lowstand deposits the other end member is the detached lowstand systems tract revising existing sequence stratigraphic models to include both types of lowstand systems tracts is a first step toward improving the accuracy of these models which are often used as prospecting tools in lowstand deltaic environments

along strike variations in stratigraphic architecture of shallow marine reservoir analogues upper cretaceous panther tongue delta and coeval shoreface star point sandstone wasatch plateau central utah u s a abstract along strike variations in sediment supply and process regime may result in different facies distributions preservational biases and stratigraphic architectures in shallow marine strata data from a large c 100 km nearly continuous outcrop belt aligned oblique to depositional strike was integrated with nearby subsurface well data and petrological analysis of distal fine grained deposits to analyze along strike variations in stratigraphic architecture in a single parasequence in the upper cretaceous star point sandstone wasatch plateau central utah usa the parasequence comprises wave dominated shoreface deposits in the southern part of the study area and represents a single episode of shoreline regression and transgression four progradationally stacked bedsets bs1 bs4 in the distal deposits of the parasequence are the expression of minor variations in relative sea level sediment supply and or wave climate the four bedsets can be traced to river dominated deltaic deposits panther tongue in the northern part of the study area we interpret the parasequence on the scale of the wasatch plateau outcrop belt as the record of deposition in a regressive river and wave influenced delta deflected asymmetrically towards the ssw subparallel to the regional paleo shoreline trend and a coeval wave dominated strandplain the lateral transition from river to wave dominated facies is attributed to the localization of a major river acting as a sediment point source in the north with wave induced longshore transport to the south our results imply that characterizing lateral facies distributions and the expression of bedsets is vital for interpreting along strike variability in controlling mechanisms of stratigraphic architecture and that external forcing may be recorded differently along depositional strike

modeling of cretaceous foreland basin parasequences utah with implications for timing of sevier thrusting computer modeling suggests that thrusting order can be discriminated on the basis of foreland basin geometry and parasequence stacking patterns the position of sequential thrust sheets relative to the basin affects the amount and distribution of subsidence source terrain elevation and distance from the shoreline and sediment transport into the basin for this study a forward numerical model was constructed to quantitatively simulate the interaction of geologic processes active in the foreland basin setting including thrusting and orogenic development lithospheric flexure orogenic denudation sediment transport across the coastal plain and nearshore deposition in order to isolate the effects of tectonics and sediment supply on nearshore deposition eustatic sea level is held constant model runs simulate two different thrusting sequences foreland stepping in sequence and hinterland stepping out of sequence when in sequence thrusting is modeled sediment is trapped in intra orogen basins because sediment is prevented from reaching the shoreline the basin is underfilled when out of sequence thrusting is modeled sediment is transported from the orogen to the shoreline episodes of thrusting result in subsidence and marine flooding surfaces and resulting accommodation space allows for parasequence development comparing model output to stratigraphy observed in eastern utah suggests that late cretaceous out of sequence uplift and thrust loading resulted in aggradational and progradational parasequence stacking in the campanian blackhawk formation this result supports the theory that the pavant thrust system was active prior to deposition of the blackhawk formation and that the location of thrust shortening shifted toward the hinterland prior to or during blackhawk formation deposition

the south pacific current the southern hemisphere subtropical front stf is a narrow zone of transition between upper level subtropical waters to the north and subantarctic waters to the south it is found near 40 degrees s across the south atlantic and south indian oceans and is associated with an eastward geostrophic current band the current band in each basin is found at or just north of the surface front except near the eastern boundaries where most of the subtropical waters turn north into the eastern limbs of the subtropical gyres the bands associated with the stf are thus distinct features separated from the strong zonal flows of the antarctic circumpolar current farther south the authors have referred to the current bands in the two respective oceans as the south atlantic current and the south indian ocean current in this paper the authors use the historical database from the south pacific ocean to investigate the geostrophic flow associated with the stf there the stf extends across the southern tasman sea from south of tasmania to southern new zealand and a weak eastward flow appears to be associated with it the transport amounts to only about 3 sv 1sv 10 6 m 3 s 1 little of which passes south of new zealand mixing within the eddy rich tasman sea may account for this weakness while also setting up another more significant front in the northern tasman sea the tasman front it branches off from the east australian current toward the north of new zealand along which moves a flow of about 14 sv after passing north of new zealand a portion of this current flows east to contribute to a current band near 30 degrees s while another portion turns south as the east auckland current and meets with subantarctic waters near chatham rise 44 degrees s thus reestablishing the stf an enhanced eastward current band is associated with the front there one that extends across the remainder of the south pacific and is referred to as the south pacific current in comparison with its counterparts in the other basins which typically begin by carrying 30 sv atlantic to 60 sv indian in the upper 1000 m in their western portions before weakening to 10 15 sv in the east the south pacific current is weak near chatham rise it starts with a transport of approximately 5 sv and it remains near this strength as it shifts gradually north across the basin toward south america the current appears to split into two smaller bands in the region of 115 degrees 85 degrees w while near 28 degrees 5 83 degrees w it begins to turn more strongly north and becomes shallower and weaker potential vorticity distributions indicate that this current acts as an impediment toward the northward spreading of antarctic intermediate water but why the south pacific current east of new zealand should be so much weaker than its counterparts in the other basins is not particularly clear it may be due to the presence of new zealand and other topographic barriers to deep now east of australia to the axis of the subtropical gyre in the south pacific shifting more rapidly southward with depth than those elsewhere thus causing greater reductions in the underlying zonal velocities and to strong poleward eddy heat and salt fluxes in the other two basins leading to smaller cross stf gradients in the pacific

re evaluating the paleogeography of the river dominated and wave influenced ferron notom delta southern central utah an integration of detailed facies architecture and paleocurrent analysis abstract this study re evaluates the paleogeography of a river dominated and wave influenced deltaic system in a single parasequence 6a of the cretaceous ferron sandstone south central utah which was previously interpreted as a typical asymmetric delta the conceptual asymmetric delta model of bhattacharya and giosan 2003 has been widely applied to interpret ancient deltaic systems however reconstructed paleogeographies relying on this conceptual model are commonly not scaled to the architectural elements which could possibly lead to inaccurate interpretations especially when data are relatively sparse the extensively exposed ferron sandstone outcrops provide an opportunity to demonstrate how detailed facies architecture work can be integrated with regional facies relationships to elucidate a properly scaled paleogeography seven facies associations fa are identified in parasequence 6a and are arranged into two distinctively different successions the river dominated succession consists of prodelta distal delta front proximal delta front and terminal distributary channel fa while the wave and storm dominated succession comprises offshore shelf lower shoreface and upper shoreface fa the river dominated succession is muddier and less bioturbated than the wave and storm dominated succession facies architecture analysis shows that the river dominated proximal delta front facies consists of mouth bar and terminal distributary channel elements that are not seen in the wave and storm dominated facies the scales of mouth bars and terminal distributary channels suggest that they are rather small features compared with the river dominated delta lobe which is incompatible with the simple bar elongation asymmetric delta model presented by li et al 2011 instead parasequence 6a is interpreted to be a valley fed river dominated symmetric delta protected from waves by an updrift barrier system which is analogous to the modern mongky river delta on the west coast of madagascar the progressive change in orientation of west directed mouth bars to north directed and east directed lobes around the periphery of the river dominated delta indicates a highly radial lafourche type delta moving away from the protection of the barrier system there is a gradual change from highly river dominated facies to increasingly wave and storm influenced facies toward the southeast due to the entrenched nature of the feeder river associated with an incised valley system the parasequence 6a delta was bifurcation dominated rather than avulsion dominated this study shows that it is critical to integrate detailed facies architecture analysis in order to reconstruct properly scaled paleogeographies and hypothesizes that stable bifurcation dominated deltas should be more common than avulsion dominated deltas in a lowstand delta system due to the entrenched nature of the feeding trunk river which inhibits avulsion

forced regressions in a sequence stratigraphic framework concepts examples and exploration significance sequence stratigraphic concepts suggest that stratal geometries develop and are largely controlled by changes in relative sea level on the shelf lowstand deposits which form during falls and subsequent stillstands of relative sea level can be recognized by the presence of an unconformity at the base the isolated and basinward position relative to the previous shoreline and the abrupt seaward translation of shallow water and shoreline facies into the basin across an unconformity surface this seaward translation of facies and shoreline regression in response to relative sea level lowering is termed a forced regression a forced regression is independent of variations of sediment flux and is in contrast with normal regressions that occur in response to excess sediment flux relative to space available on the shelf i e accommodation forced regressions commonly are associated with a zone of sedimentary bypass subaerial exposure and possible fluvial erosion between the newly formed and preceding shorelines certain shelf sands previously interpreted as offshore or mid shelf sand bodies thus can be reinterpreted as stranded lowstand shorelines associated with forced regressions this alternative interpretation has economic significance insofar as it suggests different subsurface correlations and reservoir geometries with the potential for development of new play types and enhanced recovery in o der fields examples of forced regression can be observed at a variety of scales and ages several such examples include the modern east coulee fan delta and the lower cretaceous viking formation in alberta canada the quaternary rhone delta and the quaternary hudson valley system

late cretaceous subsidence in wyoming quantifying the dynamic component the late cretaceous western interior basin of north america is generally considered to have been a retroarc foreland basin flexural backstripping of the stratigraphic record from 97 2 ma to 73 4 ma along a section perpendicular to the wyoming idaho salient of the sevier belt clearly demonstrates that there were components of subsidence in addition to those driven by the thrust and associated sediment loads the simulation demonstrates that the flexural foredeep is only 180 120 km wide and shows a forebulge located near the subsequent laramide rock springs uplift foredeep strata between the rock springs uplift on the east and the thrust front to the west were mostly involved in the eastward overlapping thrust belt or deeply truncated by inferred rebound after 78 5 ma the difference between the observed decompacted cumulative subsidence and the amount of subsidence that can be explained by simple flexural loading the residual subsidence increases from 800 m in eastern wyoming to 1 8 km near the thrust belt the westward thickening upper cretaceous sediment wedge filled the accommodation space generated by downward tilting to the west of the north american cratonic margin by underplating and mantle flow associated with the shallowly subducted farallon plate

distribution of discontinuous mudstone beds within wave dominated shallow marine deposits star point sandstone and blackhawk formation eastern utah deposits of wave dominated shorelines are typically considered to act as relatively simple hydrocarbon reservoirs and are commonly modeled as tanks of sand however important heterogeneities that can act as barriers to fluid flow occur at the parasequence bedset and bed scales especially in viscous oil or low permeability oil fields heterogeneities at the parasequence and bedset scales have been well studied but discontinuous mudstone beds occurring within the shoreface have received little attention the book cliffs and wasatch plateau are among the best exposed and best studied deposits of wave dominated shallow marine systems in the world two parasequences within these outcrops have been studied in detail to investigate the distributions of intrashoreface shales and to propose models for the controls on their distribution a data set consisting of 30 km 18 6 mi of virtual outcrops derived from oblique helicopter mounted light detection and ranging lidar scanning with supporting stratigraphic sections makes it possible to collect a large quantity of accurate geometric data of depositional elements from inaccessible cliffs nine hundred and twenty one discontinuous mudstone beds were measured these occur as ellipses with long axes oriented normal to the paleoshoreline lengths and widths of these mudstone beds exhibit a lognormal distribution with means of 21 9 and 13 8 m 71 9 and 45 3 ft respectively within the shoreface succession the number of mudstone beds increases downward whereas size does not vary significantly with stratigraphic height an average of 100 m 328 ft cumulative length of shale exists per 100 m 328 ft of horizontal outcrop this increases threefold near both wave dominated deltas and bedset boundaries that reflect minor sea level fluctuations during progradation

dynamics of submarine groundwater discharge and freshwater seawater interface 1 relationships between submarine groundwater discharge sgd and the freshwater saltwater interface are evaluated by continuous measurements of sgd rates conductivity and temperature of sgd and resistivity measurements across the coastal aquifer our measurements show that the processes of sgd differ between the offshore and nearshore environments sgd and submarine fresh groundwater discharge sfgd rates were largest just landward of the saltwater freshwater interface sgd variations landward the saltwater freshwater interface had negative correlations with tidal variations because of the connections of terrestrial groundwater in the land and the ocean sgd in the nearshore can be explained mainly by connections of terrestrial groundwater while offshore sgd rate is controlled mostly by oceanic process such as recirculated saline groundwater discharge

surface circulation and fronts of the south pacific ocean east of 120 w the south pacific surface circulation east of 120 w is studied using satellite tracked drifters from 1979 2004 the major currents of this region are described such as the antarctic circumpolar the south pacific the chile peru and the cape horn currents we suggest the presence of a branch exiting from the acc between 100 120 w and transporting subantarctic surface water toward lower latitudes we also show the existence of an anticyclonic recirculation cell north of 35 s finally based on hydrographic sections we show that in the eastern south pacific the core of the subtropical front corresponds to the 14 c isotherm at 150 m depths and to the 2 7 m of dynamic height relative to 3000 m the subantarctic front is located by maximum temperature gradients in the range 3 8 c at 100 400 m depth

sedimentologic and sequence stratigraphic characteristics of wave dominated deltas wave dominated deltaic strata form prolific hydrocarbon plays in many mature basins across the world examples include the jurassic brent group play in the north sea offshore united kingdom and norway e g husmo et al 2003 eocene jackson group and oligocene frio formation plays texas onshore united states e g fisher et al 1970 galloway and morton 1989 and tertiary plays in the niger delta province offshore nigeria e g evamy et al 1978 the baram delta province offshore brunei e g rijks 1981 and the columbus basin offshore trinidad and tobago e g sydow et al 2003 wave dominated deltas also form key exploration targets in frontier basins e g triassic snadd formation barents sea offshore norway klausen et al 2014 2016 the overall architecture of many wave dominated deltaic reservoirs is determined by their sequence stratigraphic framework together with their structural configuration sequence stratigraphic frameworks contain elements such as shoreface shelf parasequences bounded by flooding surfaces and fluvio estuarine complexes that fill incised coastal valleys developed at sequence boundaries the internal facies distributions and stacking patterns of such elements are ordered which aids prediction of reservoir character and behavior outcrop analogs of wave dominated deltaic reservoirs display aspects of ordered stratigraphic architecture across a range of spatial scales that are equivalent to those observed in core well log and seismic data and can therefore be used to support interpretation of their subsurface counterparts the cretaceous blackhawk formation contains wave dominated deltaic strata that are superbly exposed in the book cliffs of eastcentral utah figure 1a the extensive continuous exposures of the book cliffs outcrop belt have allowed the wave dominated deltas and related deposits to be mapped for tens of kilometers e g young 1955 balsley 1980 and consequently these strata were the birthplace of high resolution sequence stratigraphy using outcrop data van wagoner et al 1990 the blackhawk formation and related

surface water groundwater interaction near shallow circular lakes flow geometry in three dimensions steady flow regimes for three dimensional lake aquifer systems are studied via idealized mathematical models that are extensions of earlier simplified vertical section models of interaction between shallow lakes and underlying aquifers the present models apply to a shallow circular lake at the surface of a rectangular aquifer of finite depth yielding a truly three dimensional representation of the resulting flow system flux boundary conditions are applied at the ends of the aquifer with net vertical recharge or evapotranspiration at the water table the lake is defined by a region with constant head by determining and visualizing solutions to the discretized saturated flow equations a range of possible flow regimes is identified and their topological properties are studied tools for analyzing flow regimes are described including a method for locating and mapping three dimensional dividing surfaces within steady flow fields results show strong similarities between two and three dimensional systems including a large number of flow through recharge and discharge regimes and reverse flow cells flow lines calculated on a vertical plane through the middle of a lake resemble but are not identical to two dimensional streamlines for a range of aquifer flow and recharge conditions estimates of the widths and depths of capture and release zones for various lake aquifer geometries are asymptotic to earlier results for two dimensional systems numerical predictions are compared with analytical results for certain limiting flow regimes

seasonal climatology of hydrographic conditions in the upwelling region off northern chile over 30 years of hydrographic data from the northern chile 18os 24os upwelling region are used to calculate the surface and subsurface seasonal climatology extending 400 km offshore the data are interpolated to a grid with sufficient spatial resolution to preserve cross shelf gradients and then presented as means within four seasons austral winter july september spring october december summer january march and fall april june climatological monthly wind forcing surface temperature and sea level from three coastal stations indicate equatorward upwelling favorable winds throughout the year weakest in the north seasonal maximum alongshore wind stress is in late spring and summer december march major water masses of the region are identified in climatological t s plots and their sources and implied circulation discussed surface fields and vertical transects of temperature and salinity confirm that upwelling occurs year round strongest in summer and weakest in winter bringing relatively fresh water to the surface nearshore surface geostrophic flow nearshore is equatorward throughout the year during summer an anticyclonic circulation feature in the north which extends to at least 200 rn depth is evident in geopotential anomaly and in both temperature and geopotential variance fields subsurface fields indicate generally poleward flow throughout the year strongest in an undercurrent near the coast this undercurrent is strongest in summer and most persistent and organized in the south south of 21os a subsurface oxygen minimum centered at 250 m is strongest at lower latitudes low salinity subsurface water intrudes into the study area near 100 m predominantly in offshore regions strongest during summer and fall and in the southernmost portion of the region the climatological fields are compared to features off baja within the somewhat analogous california current and to measurements from higher latitudes within the chile peru current system

rethinking the incised valley fill paradigm for campanian book cliffs strata utah colorado u s a evidence for discrete parasequence scale shoreface incised channel fills

facies and evolution of the modern brazos delta texas wave versus flood influence abstract in order to better define the facies architecture and processes controlling the evolution of wave dominated deltas a detailed sedimentary and geomorphologic study was undertaken on the brazos delta texas the delta has formed since 1929 when the brazos river was diverted by the u s army corps of engineers the brazos delta is composed primarily of fine grained sediments prodelta clay constitutes more than half of the sediment volume thick sands are restricted to the narrow delta front environment whereas back bar lagoonal clays are a significant component of the delta plain sequence the facies architecture is not representative of the classic strandplain model for wave dominated deltas this is due to the strong influence of floods on deltaic evolution in early 1992 statewide flooding gave rise to a major constructional phase of the delta significant quantities of fine grained sediments were deposited in the prodelta one year after the onset of flooding a channel mouth bar emerged offshore of the river mouth and enabled progradation of the delta similar flood events that occurred during 1941 1957 and 1965 were recorded as ridge trough pairs in the delta headland the brazos delta is therefore fluvially influenced during floods and wave influenced during intervening periods

mean surface circulation and mesoscale turbulent flow characteristics in the eastern south pacific from satellite tracked drifters 1 circulation of the eastern south pacific region 10 34 s 70 100 w was studied using drifting buoy trajectories from 1979 to 2003 three different current regimes were highlighted the south equatorial current flowing westward north of 26 s with surface velocities of 7 8 cm s 1 the south pacific current an eastward current of 2 cm s 1 south of 25 30 s and the chile peru current a northwestward flow of 6 cm s 1 found to the east of 82 w and south of 22 s the velocity variance distribution showed the regional flow to be anisotropic in nature maps of eddy kinetic energy obtained from drifter measurements and satellite altimetry data showed similar patterns with higher energy levels near the south american coast the lagrangian time and length scales of the turbulent flow revealed typical values of 5 9 0 6 days and 40 7 5 4 km in the zonal direction and of 3 5 0 4 days and 29 3 4 km in the meridional direction the estimated diffusivities were 4 9 0 5 107 cm2 s 1 and 2 6 0 3 107 cm2 s 1 in the eastward and northward directions respectively finally we estimated the respective role of horizontal advection and lateral diffusion on the mixed layer heat and salt budgets near the coast the lateral turbulent fluxes in the surface layer were two times larger than the horizontal transports associated with the large scale circulation mean horizontal heat and salt diffusive fluxes were around 25 w m 2 and 50 g m 2 d 1

effect of ground water recharge on configuration of the water table beneath sand dunes and on seepage in lakes in the sandhills of nebraska u s a abstract analysis of water level fluctuations in about 30 observation wells and 5 lakes in the crescent lake national wildlife refuge in the sandhills of nebraska indicates water table configuration beneath sand dunes in this area varies considerably depending on the configuration of the topography of the dunes if the topography of an interlake dunal area is hummocky ground water recharge is focused at topographic lows causing formation of water table mounds these mounds prevent ground water movement from topographically high lakes to adjacent lower lakes if a dune ridge is sharp the opportunity for focused recharge does not exist resulting in water table troughs between lakes lakes aligned in descending altitudes parallel to the principal direction of regional ground water movement generally have seepage from higher lakes toward lower lakes

a theoretical analysis of seepage flow of the confined groundwater into the lake bottom with a gentle slope recently in japan a new interest has been shown to the specific discharge of groundwater from the lake bottom in order to elucidate its influence on the quality and quantity of lake water using conformal mapping techniques the authors describe analytically the steady two dimensional groundwater flow in an idealized confined aquifer which extends infinitely with uniform thickness and constant inclination and is exposed to the lake bottom surface with a gentle slope the techniques enable analytical calculation of the head and stream functions of groundwater in the aquifer and also the distribution of specific discharge at lake bottom surface from the results of calculation it is found that most of the aquifer water flows into the lake through the upper part of the surface of contact between lake and aquifer this analysis may be useful in the evaluation of the role of groundwater seepage in the water balance of large lakes

evaluating along strike variation using thin bedded facies analysis upper cretaceous ferron notom delta utah thin bedded delta front and prodelta facies of the upper cretaceous ferron notom delta complex near hanksville in southern utah usa show significant along strike facies variability primary initiation processes that form these thin beds include surge type turbidity currents hyperpycnal flows and storm surges the relative proportion of sedimentary structures generated by each of these depositional processes events has been calculated from a series of measured sedimentological sections within a single parasequence ps6 1 which is exposed continuously along depositional strike for each measured section sedimentological data including grain size lithology bedding thickness sedimentary structures and ichnological suites have been documented parasequence 6 1 shows a strong along strike variation with a wave dominated environment in the north passing abruptly into a fluvial dominated area then to an environment with varying degrees of fluvial and wave influence southward and back to a wave dominated environment further to the south east the lateral facies variations integrated with palaeocurrent data indicate that parasequence 6 1 is deposited as a storm dominated symmetrical delta with a large river dominated bayhead system linked to an updip fluvial feeder valley this article indicates that it is practical to quantify the relative importance of depositional processes and determine the along strike variation within an ancient delta system using thin bedded facies analysis the wide range of vertical stratification and grading sequences present in these event beds also allows construction of conceptual models of deposition from turbidity currents i e surge type turbidity currents and hyperpycnal flows and storm surges and shows that there are significant interactions and linkages of these often paired processes

eifelian givetian middle devonian high paleolatitude storm and wave dominated shallow marine depositional systems from the bidouw subgroup bokkeveld group of south africa abstract the sedimentology of the eifelian givetian middle devonian bidouw subgroup in the clanwilliam sub basin of south africa has been reassessed four distinct lithofacies associations are recognized a d and are representative of the deposits of offshore os offshore transition zone to distal lower shoreface otz dlsf proximal lower shoreface plsf and upper shoreface beach usf beach paleoenvironments these paleoenvironments are arranged as several t r controlled storm and wave dominated shallow marine depositional systems the presence of storm and wave dominated shallow marine depositional systems in the bidouw subgroup as well as the preceding emsian eifelian early middle devonian ceres subgroup provides an alternative explanation to storm and wave dominated delta and mixed wave and tide dominated delta models that have previously been proposed for the bokkeveld group sequence stratigraphic analysis of the bidouw subgroup suggests that although sedimentation occurred during two large scale second order transgressive events the succession was predominantly regressive third order and fourth order transgressive regressive t r sequences are more numerous with respect to the preceding ceres subgroup suggesting that the driver for t r cyclicity and relative sea level change was more active during the eifelian givetian than in the emsian eifelian of south africa these data are important since relative sea level change and its effects on paleoenvironmental change at high paleolatitudes during the devonian period are poorly known

groundwater lake interactions i accuracy of seepage meter estimates of lake seepage abstract the use of seepage meters to identify nearshore seepage patterns and to quantify seepage in lakes was evaluated with a monte carlo simulation model the model simulated seepage flux as would be derived from seepage meter measurements along a transect extending from the shore of a hypothetical lake to 40 or 100m offshore along the transect simulated seepage velocities decreased exponentially with distance from shore according to patterns measured at narrow lake alta and lake sallie mn to determine statistical parameters needed in the model seepage flux was measured in situ with closely spaced seepage meters at four different sites in narrow lake seepage velocities within a small area of lakebed were log normally distributed and the variance was positively correlated with mean seepage flux the modeling indicated that the most sensitive parameter affecting the accuracy of seepage meter estimates of seepage patterns and average seepage flux along the transect was the variability in the spatial distribution of seepage flux within a small area of lakebed there was little improvement in the accuracy of estimates of seepage patterns or transect flux when more than ten seepage meters were simulated along the transect when the transect was sampled more than twice or when seepage meters along the transect were simulated to follow a stratified rather than a systematic design

geomorphological and sequence stratigraphic variability in wave dominated shoreface shelf parasequences physical stratigraphy within shoreface shelf parasequences contains a detailed but virtually unstudied record of shallow marine processes over a range of historical and geological timescales using high quality outcrop data sets it is possible to reconstruct ancient shoreface shelf morphology from clinoform surfaces and to track the evolving morphology of the ancient shoreface shelf our results suggest that shoreface shelf morphology varied considerably in response to processes that operate over a range of timescales 1 individual clinoform surfaces form as a result of enhanced wave scour and or sediment starvation which may be driven by minor fluctuations in relative sea level sediment supply and or wave climate over short timescales 10 1 10 3 years these external controls cannot be distinguished in vertical facies successions but may potentially be differentiated by the resulting clinoform geometries 2 clinoform geometry and distribution changes systematically within a single parasequence reflecting the cycle in sea level and or sediment supply that produced the parasequence 10 2 10 5 years these changes record steepening of the shoreface shelf profile during early progradation and maintenance of a relatively uniform profile during late progradation modern shorefaces are not representative of this stratigraphic variability 3 clinoform geometries vary greatly between different parasequences as a result of variations in parasequence stacking pattern and relict shelf morphology during shore face progradation 10 5 10 8 years these controls determine the external dimensions of the parasequence

parameterizing parasequences importance of shelf gradient shoreline trajectory sediment supply and autoretreat the basic reservoir flow unit in shallow marine depositional systems is the parasequence since it is bounded top and base by regionally extensive shales that can form barriers to fluid flow as a result it is the key stratigraphic unit requiring parameterization for both exploration and development purposes a database comprising 3385 measurement points from 385 parasequences from 28 locations and 16 different passive margin and foreland basins was compiled from outcrop and subsurface data analysis of the data suggests that a mean value for parasequence thickness is 17 m 56 ft mean parasequence sandstone fraction is 0 60 and mean shoreface sand body thickness is 8 m 26 ft the mean maximum parasequence progradation distance is 23 km 14 mi the results indicate that there are two critical controls that can significantly vary the parameter values stated above 1 stacked shoreline trajectory or systems tract and 2 shelf gradient the analyses indicate that shelf gradient is the most important parameter that has a first order control on parasequence properties shelf gradient in the ancient can be approximated to high gradient or low to moderate gradient categories via analysis of parasequence thickness change versus progradation distance from wells mean parasequence thickness or mean progradation distance from seismic attribute data parasequence progradation distance is to some degree predictable if stacked shoreline trajectory shelf gradient category and mean parasequence thickness are known the data suggest that there are two types of parasequences accommodation dominated and supply dominated parasequences the progradation distance of these parasequences are controlled by delta autoretreat mechanisms modulated by the combination of fifth and fourth order milankovitch scale orbitally forced climate change driven sediment supply cycles interacting with eustatically and tectonically driven accommodation cycles

identifying ordered strata evidence methods and meaning abstract identifying order or pattern in strata on the basis of qualitative interpretation forms the basis for much current sedimentological and sequence stratigraphic analysis order can be usefully defined as some arrangement of facies or unit thickness that has a discernable trend or pattern that is unlikely to occur by chance because it requires some particular systematic process to form coarsening fining thickening or thinning upward trends and arrangement of strata into cycles are examples of order qualitative interpretations of order often demonstrate little more than an implicit assumption of order this paper defines a robust yet simple to apply quantitative method to identify order in strata and to indicate when order cannot be reliably demonstrated the method is based on two calculated metrics the markov metric m derived from analysis of a vertical facies succession and the runs metric r derived from analysis of observed thicknesses of stratal units most importantly both metrics can be compared with equivalent metrics calculated for disordered strata composed of many randomly shuffled versions of the same lithological units probability values can then be calculated from the comparison between observed and randomly shuffled cases and these p values indicate the degree of evidence present for order in the observed strata several test examples using synthetic strata show that the m and r values can define and identify different degrees and types of stratal order and that the metrics are robust for both stationary and non stationary successions with a range of different lengths and numbers of distinct facies analysis of four outcrop examples two siliciclastic and two carbonate demonstrate that ordered facies successions and thickness trends may be less common than typically assumed none of the four examples analyzed show trends in thickness and only the examples from the book cliffs which represent a bedset scale composite of observations show evidence for facies order the examples demonstrate how a quantitative analysis can lead to better understanding of strata either ordered or disordered and can provide better insight into the validity of current stratigraphic interpretations and models absence of order in many of the analyzed 1d vertical successions may also indicate that we need to focus more on longer term trends and analysis of 2d and 3d stratal geometries

mechanisms for forming discontinuity surfaces within shoreface shelf parasequences sea level sediment supply or wave regime abstract a 2d process response model was used to evaluate potential mechanisms involved in the formation of small scale stratigraphic variability that is observed within progradational wave dominated shoreface shelf parasequences model experiments which are based on scenarios that consist of a 25 ky progradational phase suggest that discontinuity surfaces form when either sediment supply or sea level fall rapidly or when wave height regime increases over relatively short time periods 102 104 y during coastal progradation in these cases mean deposition rate near the lower shoreface drops which combined with coastal progradation results in a discontinuity surface both observed and simulated discontinuity surfaces form predominantly in lower shoreface deposits and bound meter scale stratigraphic cycles simulations show that wave regime variability affects the shoreface shelf to a much greater depth than minor sea level change therefore facies shifts along wave climate induced bounding surfaces occur over wider reaches of the shoreface shelf system than sea level induced facies shifts high frequency variability in sediment supply rate results in the formation of discontinuity surfaces across which there are no distinct facies shifts

on the geological significance of clastic parasequences abstract parasequences recognized in clastic sedimentary successions of shallow marine origin are considered by some geologists to be the fundamental building blocks of depositional sequences even though problems in their definition and application have been identified by others who instead advocate their abandonment as formal sequence stratigraphic units to elucidate the geological significance of clastic parasequences and inform the debate on their use in stratigraphy a quantitative characterization of the geometry facies characteristics and timescale of deposition of 1163 parasequences has been undertaken based on a synthesis of data from outcrop and subsurface studies that are available in the scientific literature through a database compilation the attributes of the studied parasequences are analysed with respect to the interpreted geological origin of the units and with consideration of sources of bias and uncertainty particular emphasis is placed on assessing the following i the importance of heuristics and of data types and coverage in the recognition of parasequences ii differences in parasequence characteristics observed across deltaic and shoreface depositional systems and between the quaternary and the ancient rock record iii possible explanations for the range in timescales of deposition of parasequences and iv the role of autogenic dynamics on the development of deltaic parasequences partly based on a comparison with the recent evolution of modern deltas the results demonstrate that parasequence definition and physical correlation suffer from subjectivity and that significant variability exists in the spatio temporal and architectural attributes of clastic parasequences this gives rise to uncertainty that affects the use of parasequences as a framework for comparison of the architecture of packages of strata originating via shoreline regression this uncertainty must be considered when using analogue data for subsurface predictions or when attempting comparative studies of clastic successions

basic building blocks and process variability of a cretaceous delta internal facies architecture reveals a more dynamic interaction of river wave and tidal processes than is indicated by external shape abstract although delta building processes and the resultant facies and facies associations have been studied for over a century there remains a lack of well documented facies architectural studies of ancient deltas in this study architectural element analysis is applied to determine the basic building blocks of a cretaceous delta at the top of the upper turonian wall creek member exposed along the western flanks of the powder river basin wyoming we document the bed scale basic building blocks of this ancient delta and show them in the context of their facies and stratal variability and their hierarchical spatial arrangement within a single deltaic parasequence we also test the idea that external sand body shape may not reflect the internal facies complexity as has recently been suggested in studies of several modern deltas including the burdekin in australia the brazos in the gulf of mexico and the baram trusan in borneo five orders of bounding surfaces separate six facies architectural elements in the prodelta and delta front deposits these elements are prodelta fines pf frontal splay fs channel ch storm sheet ss tidally modulated deposit tm and bar accretion ba seasonal to decadal river floods are thought to represent the main building phases of the delta producing channels bars and frontal splay elements during intervening periods the delta was reworked by waves storms and tides producing tidally modulated and storm sheet elements due to the complex interactions of river effluents with waves storms and tides the delta is interpreted as mixed influenced regional sandstone isolith facies and paleocurrent maps help to reconstruct the paleogeography and show how the various architectural elements varied across the delta front the channels bars frontal splays and tidally modulated elements are found only near the distributary mouth whereas the storm sheets occur extensively away from the distributary mouth the plan view morphology of the studied delta shows a smooth fronted arcuate to cuspate shape which should indicate wave dominance in contrast our analysis of the internal facies architecture shows that the delta was constructed rapidly during major river floods with significant tidal reworking additional outcrop mapping shows that storm wave reworked sands are attached to the flanks of the system previously published delta models predict incorrectly that the tidal reworking of a river flood dominated system should result in a more bird foot shape versus the lobate geometry that is actually mapped our analysis of internal facies versus external shape matches similar observations on several modern deltas and suggests that external shape is a poor indicator of internal facies complexity

temporal variability of exchange between groundwater and surface water based on high frequency direct measurements of seepage at the sediment water interface 1 seepage at the sediment water interface in several lakes a large river and an estuary exhibits substantial temporal variability when measured with temporal resolution of 1 min or less already substantial seepage rates changed by 7 and 16 in response to relatively small rain events at two lakes in the northeastern usa but did not change in response to two larger rain events at a lake in minnesota however seepage at that same minnesota lake changed by 10 each day in response to withdrawals from evapotranspiration seepage increased by more than an order of magnitude when a seiche occurred in the great salt lake utah near the head of a fjord in puget sound washington seepage in the intertidal zone varied greatly from 115 to 217 cm d 1 in response to advancing and retreating tides when the time averaged seepage was upward at 43 cm d 1 at all locations seepage variability increased by one to several orders of magnitude in response to wind and associated waves net seepage remained unchanged by wind unless wind also induced a lake seiche these examples from sites distributed across a broad geographic region indicate that temporal variability in seepage in response to common hydrological events is much larger than previously realized at most locations seepage responded within minutes to changes in surface water stage and within minutes to hours to groundwater recharge associated with rainfall likely implications of this dynamism include effects on water residence time geochemical transformations and ecological conditions at and near the sediment water interface

intra parasequence architecture of an interpreted asymmetrical wave dominated delta although modern wave dominated shorelines exhibit complex geomorphologies their ancient counterparts are typically described in terms of shoreface shelf parasequences with a simple internal architecture this discrepancy can lead to poor discrimination between and incorrect identification of different types of wave dominated shoreline in the stratigraphic record documented in this paper are the variability in facies characteristics high resolution stratigraphic architecture and interpreted palaeo geomorphology within a single parasequence that is interpreted to record the advance of an ancient asymmetrical wave dominated delta the standardville ab1 parasequence of the aberdeen member blackhawk formation is exposed in the book cliffs of central utah usa this parasequence and four others in the aberdeen member record the eastward progradation of north south trending wave dominated shorelines within the standardville ab1 parasequence distal wave dominated shoreface shelf deposits in the eastern part of the study area are overlain across a downlap surface by southward prograding fluvial dominated delta front deposits which have previously been assigned to a separate stranded lowstand parasequence formed by a significant allogenic change in relative sea level high resolution stratigraphic analysis of these deposits reveals that they are instead more likely to record a single episode of shoreline progradation characterized by alternating periods of normal regressive and forced regressive shoreline trajectory because of minor cyclical fluctuations in relative sea level interpreted normal regressive shoreline trajectories within the wave dominated shoreface shelf deposits are marked by aggradational stacking of bedsets bounded by non depositional discontinuity surfaces interpreted forced regressive shoreline trajectories in the same deposits are characterized by shallow incision of fluvial distributary channels and strongly progradational stacking of bedsets bounded by erosional discontinuity surfaces that record enhanced wave base scour fluvial dominated delta front deposits most probably record the regression of a lobate delta parallel to the regional shoreline into an embayment that was sheltered from wave influence wave dominated shoreface shelf and fluvial dominated delta front deposits occur within the same parasequence and their interpretation as the respective updrift and downdrift flanks of a single asymmetrical wave dominated delta that periodically shifted its position provides the most straightforward explanation of the distribution and relative orientation of these two deposit types

mass balance constraints on stratigraphic interpretation of linked alluvial coastal shelfal deposits from source to sink example from cretaceous western interior basin utah and colorado u s a abstract experimental work suggests that the rate of upstream to downstream loss of sediment from an active depositional system to permanent storage exerts a fundamental control on stratigraphic architecture this rate of sediment mass loss is determined by the spatial distribution of tectonic subsidence and rate of sediment supply the character of input sediment grain size distribution and composition is the third parameter that affects stratigraphic architecture we apply this concept in a mass balance framework to linked alluvial coastal shelfal deposits of the upper cretaceous castlegate sandstone blackhawk formation star point sandstone and mancos shale western interior basin utah and colorado usa facies partitioning and sediment budgets are estimated for eight stratigraphic intervals in order to compare temporal dynamics of the sediment routing system from erosional source to depositional sink mapping of each stratigraphic interval and its constituent segments from upsystem to downsystem was achieved along a representative dip oriented 2d cross section over a distance of c 350 km using extensive outcrop exposure and densely spaced subsurface wells the cross section provides time averaged estimates of the spatial distribution of deposition grain size data show that there is limited downsystem fining of any particular facies within the castlegate sandstone but that the proportion of facies changes systematically downsystem to accommodate an overall fining trend therefore it is reasonable as a first approximation to use facies proportions as a textural replacement for grain size sediment supply characteristics for each of the eight stratigraphic intervals are constrained by total facies proportions in each interval for each stratigraphic interval we assess the level of interaction between alluvial and coastal to shelfal segments of the routing system comparison of the downsystem mass balance characteristics of the eight stratigraphic intervals suggests that there were depositional gains and losses of shallow marine shale in the five youngest intervals which can be attributed to along strike sediment transport this result is consistent with increased interaction through time with vigorous wave and tide driven circulation in the seaway as the sediment routing system advanced out of a sheltered embayment in response to decreasing tectonic subsidence in the youngest stratigraphic interval the upstream unconformable base of the castlegate sandstone is marked by a pronounced increase in the sand to gravel grade mass fraction of the fluvially supplied depositional volume this marked increase can be attributed to hinterland unroofing and or cannibalization of wedge top basins leading to import of coarse grained sediment into the castlegate fluvial system our results demonstrate the value of analyzing downsystem sediment loss i e downsystem mass extraction within a mass balance framework as a simple and practical tool to quantify the relationship between accommodation and sediment supply and thus to decode past external forcing mechanisms from stratigraphic architecture

seismic stratigraphic analysis of the middle jurassic krossfjord and fensfjord formations troll oil and gas field northern north sea abstract the syn rift middle jurassic krossfjord and fensfjord formations troll field northern north sea contain a complex distribution of wave and tide dominated deltaic shoreline and shelf depositional environments of varying reservoir potential uncertainty exists in depositional models used to explain the spatial and temporal distribution of these depositional environments and the absence of coeval coastal plain deposits to date the proposed influence of growing rift related structures on stratigraphic architectures and sedimentation patterns in the units has been poorly defined in this study 3d seismic data are integrated with core biostratigraphic and wireline log data to produce a consistent geological interpretation for the formations seismic analysis has identified nine parasequences containing nne ssw striking delta scale clinoforms that prograded westwards over much of the field quantitative analysis highlights an increase in height and dip of clinoforms from proximal to distal locations coincident with an increase in grain size clinoform geometry is sigmoidal with well developed topsets that based on core data lack subaerial deposits these geometrical and sedimentological characteristics suggest that a subaqueous delta depositional system deposited the krossfjord and fensfjord formations in the troll field in the northeast of the field clinoforms exhibit highly variable strike and oblique cross sectional geometries which suggest that sediment was supplied from here and then redistributed through southward directed wave and longshore current activity rift related faulting is recognised to have occurred in the western part of the troll field only during deposition of the youngest fensfjord formation parasequence thus challenging the notion that these units are syn rift seismically imaged clinoforms in the under explored area south of the troll field prograded southward and are interpreted to represent coeval formation of a southward prograding spit that developed landward of the subaqueous delta platform present in the troll field the interpreted long lived subaqueous delta in the troll field constitutes a novel type of shallow marine reservoir

shoreface tongue geometry constrains history of relative sea level fall examples from late cretaceous strata in the book cliffs area utah progradational shoreface tongues preserve a near complete depositional record of relative sea level highstands falls and lowstands two distinct styles of progradational shoreface tongue are examined in an extensive outcrop and subsurface dataset from late cretaceous strata of the book cliffs area utah representing i highstand through attached lowstand progradation and ii highstand through detached lowstand progradation using this dataset key geometrical attributes of the shoreface tongues and their internal facies architecture are identified and quantified that enable the reconstruction of relative sea level fall history for example attached wave dominated lowstand shoreface deposits record a slow 0 2 0 3 mm yr 1 low magnitude 14 m relative sea level fall punctuated by minor rises detached weakly wave influenced lowstand shoreface deposits record a more rapid 0 4 0 5 mm yr 1 high magnitude 45 m relative sea level fall synchronous with a marked change in sediment delivery and depositional process regime at the shoreline

progradational and backstepping shoreface deposits in the ladinian to early norian snadd formation of the barents sea shoreface sandstone deposits within the early carnian part of the snadd formation of the norwegian barents sea can be traced for hundreds of kilometres in the depositional strike direction and for tens of kilometres in the depositional dip direction this study uses three dimensional seismic attribute mapping and two dimensional regional seismic profiles to visualize the seismic facies of these shoreface deposits and to map their internal stratigraphic architecture at a regional scale the shoreface deposits are generally elongate but show variable width from north east to south west which corresponds to a sediment source in the northern part of the basin and a southward decrease in longshore sediment transport the snadd formation presents an example of how large scale progradational shoreface deposits develop the linear nature of its shoreface deposits contrasts with more irregular cuspate wave dominated deltaic shorelines that contain river outlets and instead implies longshore drift as the main sediment source in map view discrete sets of linear features bounded by truncation surfaces scale directly to beach ridge sets in modern counterparts the shoreface deposits studied here are characteristic in terms of scale and basin wide continuity and offer insight into the contrast between shallow marine deposition under stable triassic greenhouse and fluctuating holocene icehouse climates findings presented herein are also important for hydrocarbon exploration in the barents sea because they describe a hitherto poorly understood reservoir play in the triassic interval wherein the most prominent reservoir plays have so far been considered to be found in channelized deposits in net progradational delta plain strata that form the topsets to shelf edge clinoforms the documented presence of widespread wave dominated shoreface deposits also has implications for how the relative importance of different sedimentary processes is considered within the basin during this period

the spatially continuous determination of groundwater flow to surface water bodies application to the connecting channels between lakes huron and erie abstract the hydrogeophysical method to define the hydraulic properties of the sediments beneath a surface water body described by taylor and cherkauer is applied to a specific field site collection of electrical resistivity and seismic data long over 200 km of survey lines in the channels connecting lakes huron and erie has allowed definition of the thickness general composition and hydraulic properties of the sediment column the geophysics provided a measurement of electrical longitudinal conductance of the sediment column at 40 m intervals along the survey line 5000 complete electrical soundings this parameter has been empirically related to the hydraulic leakance ratio of the hydraulic conductivity to the thickness of the unconsolidated materials of the sediment column at discrete calibration points where seepage meters were installed groundwater discharges calculated using the geophysically derived hydraulic properties compare very favorably with those calculated directly from the seepage measurements and others calculated independently from analysis of stream gaging records convergence of three methods on a single answer is taken to indicate the validity of that answer and to confirm the reliability of the hydrogeophysical approach the hydrogeophysical approach offers the advantage of higher resolution of lateral variations in hydraulic properties and relatively low monetary and time expenditures when compared with a drilling program however it cannot be utilized without calibration to direct hydraulic measurements it is best run in conjunction with seepage meters and drilling or existing wells perhaps its greatest usefulness lies in its ability to rapidly and accurately define locations of high potential for interaction between surface water and groundwater

asymmetry in holocene river deltas patterns controls and stratigraphic effects abstract understanding controls on sediment distribution in river deltas is paramount to predicting facies relationships and stratal architecture most classifications of deltas have focused on subaerial plan morphology as a simplistic function of river tide and wave energy new work however is revealing the importance of subaqueous deposits and in particular shore parallel sediment redistribution in the shaping of delta planform delta asymmetry has emerged as an important characteristic reflective of patterns of alongshore sediment dispersal asymmetry has been described from onshore and offshore environments from several different types of modern deltas but aspects of asymmetry have not been fully documented and the degree to which these patterns are recorded in deltaic strata is not yet known this study is a comprehensive literature review of sediment distributions in modern deltas focusing on studies with high resolution geomorphic geophysical and geochronological datasets we reviewed 27 deltas using over 100 papers primarily from the past 15 20 years morphological facies and stratigraphic aspects were analyzed across the entire spectrum of deposits from the delta apex to the most distal muds of the prodelta we define quantifiable indices of asymmetry describing upcurrent vs downcurrent distribution of sediment volume sediment area sediment caliber and distributary channels most deltas are asymmetrical to some degree with respect to one or more of these parameters many deltas are increasingly skewed toward the downcurrent side from proximal to distal sub environments i e delta plain delta front prodelta some deltas are skewed toward the upcurrent side in one sub environment and toward the downcurrent side in another sub environment sand is preferentially deposited on the downcurrent side of most deltas but distributary channels tend to develop toward the upcurrent side the highest sand mud ratios are often on the upcurrent side in the lower delta plain but in the delta front these ratios are highest on the downcurrent side these complex patterns of asymmetry reflect different combinations of controls including discharge partitioning lobe abandonment and localized transgression plume deflection by coastal currents dominance of longshore current direction variable subsidence and other factors these processes may result in upcurrent downcurrent variations in clinoform geometry rates of progradation and stratal lapping relationships asymmetry has multiple aspects manifestations and controls even within a single delta but the long term preservation potential of these patterns likely varies depending on depositional setting and shoreline trajectory studies of ancient deltas will be better informed by recognizing the wide variety of controls on sediment distribution and avoiding the tendency toward a single model of delta asymmetry

enhanced bioturbation on the down drift flank of a turonian asymmetrical delta implications for seaway circulation river nutrients and facies models extant models predict delta front environments down drift of river mouths as unfavourable for organisms because of the physico chemical stresses caused by sediment and fresh water influx this study however finds evidence for near optimal living conditions down drift of contemporaneous mouth bars and distributary channels as well as at the tops of abandoned lobes in part of the asymmetrical notom delta complex of the ferron sandstone turonian south eastern utah usa presented herein is a sedimentological and ichnological model using thirty two detailed measured sections along a 16 km transect through two continuously exposed ca 10 m thick allomembers containing delta front mouth bar and distributary channel facies azimuths from sedimentary structures show south eastward deflection of near shore palaeocurrents relative to the inferred north south shoreline as well as minor reversal of flow two end member trace fossil suites are recognized in delta front sandstones i a stressed suite of low abundance low diversity diminutive traces reflecting mobile deposit feeding resting and locomotion behaviours and ii a comparatively unstressed high abundance moderate diversity suite with a regular heterogeneous distribution of deep vertical or u shaped suspension feeding burrows which in places thoroughly homogenize the sandstones the down drift side of the delta was colonized by suspension feeders during seasonal reversal of the seaway gyre when mud plumes were swept northward or when river derived nutrients were sufficiently concentrated relative to fresh water and sediment input during normal seaway circulation very high sedimentation rates and mud laden wave dampened waters down drift of the river mouths heightened the preservation potential of the pervasively bioturbated facies up drift of the river mouths these bioturbated facies were either not preserved or not developed until the lobe was abandoned this alternative model for delta planform asymmetry contributes to the refinement of facies models for deltaic systems and provides a framework for predicting the distribution of bioturbation enhanced porosity and permeability in lobe deflected deltas

an integrated approach to quantify groundwater transport of phosphorus to narrow lake alberta an integrated approach was used to quantify groundwater phosphorus flux to narrow lake a smallglacial terrain lake in central alberta data from a drilling program major ion concentrations environmental isotopes and computer simulations indicated that the lake gains water through the nearshore region from a small shallow groundwater flow system at deep offshore regions water moves from the lake to the groundwater flow system seepage flux was quantified by water budget darcy s equation with data from wells near the lake darcy s equation with data from minipiezometers in the lake and seepage meters whole lake seepage flux determined from minipiezometer data 30 mm yr i was only lo 25 of the other estimates mean 221 mm yr i range 133 332 mm yr l from seepage meter and water budget data respectively groundwater contributed 30 of the annual water load to the lake the p concentration pi in pore water from lake sediments mean 175 mg m was 8 times higher than groundwater from wells near the lake mean 2 1 mg m 3 thus if well water was used to estimate the p of the seepage water the rate of groundwater p loading to the lake would be underestimated the rate of groundwater p loading to the lake computed from average seepage flux and average pore water p was 39 mg m 2 yr i and groundwater may be the largest single source of p to epilimnetic water in the lake

sequence stratigraphy and marine to nonmarine facies architecture of foreland basin strata book cliffs utah u s a the desert member of the blackhawk formation and the castlegate sandstone in the book cliffs of utah and colorado were analyzed to develop a model of sequence stratigraphy and facies architecture in foreland basins stratal architecture of these rocks is controlled by two regionally extensive surfaces of incision and subaerial exposure interpreted as major sequence boundaries and at least six surfaces of incision and subaerial exposure with more limited lateral extent interpreted as minor sequence boundaries each sequence boundary is a regionally correlatable single surface major sequence boundaries can be traced from marine into proximal alluvial plain environments sequence boundaries have different physical expressions depending upon where in the basin they are observed strata beneath sequence boundaries are unrelated to strata above and time lines cannot be carried across these boundaries flooding surfaces called parasequence or parasequence set boundaries also exert an important control on facies architecture based on parasequence stacking patterns position of sequence boundaries and facies associations the desert member and castlegate sandstone have been divided into sequences with durations of 200 000 to 300 000 yr there are an order of magnitude more sequences in this interval than are predicted by the global sea level chart of haq et al 1988 the major sequences have been divided into the following systems tracts or sequence sets 1 grassy highstand sequence set below the desert sequence boundary named for the grassy member of the blackhawk formation 2 desert lowstand transgressive and highstand systems tracts between the desert and castlegate sequence boundaries 3 castlegate lowstand sequence set resting on the castlegate sequence boundary and 4 castlegate transgressive systems tract parasequence stacking patterns suggest that the grassy highstand sequence set and the desert highstand systems tract were deposited during a relative rise in baselevel the grassy highstand sequence set is punctuated by minor relative falls in baselevel both of these stratal units contain thick

evidence of across shelf transport of fine grained sediments turbidite filled shelf channels in the campanian aberdeen member book cliffs utah usa the shore normal transport of fine grained sediments by shelf turbidity currents has been the focus of intense debate over the last 20 years many have argued that turbidity currents are unlikely to be a major depositional agent on the shelf however sedimentological architectural stratigraphic and palaeogeographic data from the campanian aberdeen member book cliffs eastern utah suggests otherwise and clearly demonstrates that storm generated and river flood generated underflows can transport a significant volume of fine grained sediments across the shelf these across shelf flowing turbidity currents cut large subaqueous channel complexes up to 7 m deep tens of kilometres basinward of their time equivalent shoreface the shelf channels were filled with organic rich siltstones mudstones and very fine to fine grained bouma like sandstone beds including wave modified turbidites hyperpycnites and classical turbidites deposition was above storm wave base palaeocurrent data reveal an overwhelmingly dominant across shelf east south east offshore directed transport trend tectonic activity and or concomitant palaeogeographic reorganization of the basin may favour the generation of these turbidite rich shelf deposits by altering the relative balance of wave versus fluvial energy increased erosion and sediment supply rates because of tectonic uplift of the hinterland may have increased the probability of fluvial dominance along the coastline and hence the possibility of submarine channelization in front of the river mouths additionally the coastline may have become more sheltered from direct wave energy thus allowing the fluvial processes to dominate seasonal increases in rainfall and storm activity may also favour the generation of across shelf underflows on wave dominated shorelines isolated shelf channels and lobes are most likely to be found down dip of fluvial feeder systems in relatively high sediment supply settings these features are also most likely to occur in systems tracts that straddle a sequence boundary especially those which are tectonically generated as these would enhance the potential for altering basin morphology and hence the balance of fluvial and wave energy isolated shelf channels are recognized in older and younger strata in the book cliffs region implying that wave supported gravity flows were a recurrent phenomena in the campanian of utah it is probable that isolated shelf bodies are preserved in other stratigraphic intervals in the cretaceous western interior of north america and other basins worldwide and are currently being overlooked or misidentified shoreface to shelf facies models should be revised to incorporate turbidite rich shelf deposits in some shelf settings

towards a sequence stratigraphic solution set for autogenic processes and allogenic controls upper cretaceous strata book cliffs utah usa upper cretaceous strata exposed in the book cliffs of east central utah are widely used as an archetype for the sequence stratigraphy of marginal marine and shallow marine deposits their stratal architectures are classically interpreted in terms of accommodation controls that were external to the sediment routing system allogenic and that forced the formation of flooding surfaces sequence boundaries and parasequence and parasequence set stacking patterns processes internal to the sediment routing system autogenic and allogenic sediment supply controls provide alternatives that can plausibly explain aspects of the stratal architecture including the following 1 switching of wave dominated delta lobes expressed by the internal architecture of parasequences 2 river avulsion expressed by the internal architecture of multistorey fluvial sandbodies and related deposits 3 avulsion generated clustering of fluvial sandbodies in delta plain strata 4 autoretreat owing to increasing sediment storage on the delta plain as it lengthened during progradation expressed by progradational to aggradational stacking of parasequences 5 sediment supply control on the stacking of and sediment grain size fractionation within parasequence sets the various potential allogenic controls and autogenic processes are combined to form a sequence stratigraphic solution set this approach avoids anchoring of sequence stratigraphic interpretations on a specific control and acknowledges the non unique origin of stratal architectures

high resolution sequence stratigraphy and implications for cretaceous glacioeustasy of the late cretaceous gallup system new mexico u s a

bedset characterization within a wave dominated shallow marine succession an evolutionary model related to sediment imbalances abstract a high resolution analysis of small scale sequence stratigraphic units is presented here in order to bring new information that may help to understand the dynamic evolution of shallow marine systems in the order of thousands to hundreds of thousands of years through an exhaustive architectural analysis several bedsets were identified and described within outcrops of a parasequence in the lower cretaceous pilmatue member of the agrio formation in central neuquen basin the bedsets were mapped with 20 sections in a 12 to 5 km long transect successive bedsets were built by wave dominated shoreface offshore deposits most of them accumulated in a regressive context which were disrupted by minor transgressive episodes that developed the bedset bounding surfaces these bounding surfaces were generated by wave ravinement processes that resulted in thin transgressive lag deposits bedsets thus show a t r sequence architecture bedset sequence architecture also shows sedimentary and architectural differences such as facies distribution thickness and orientation that is attributed to a complex sequence stratigraphic evolution waves and currents dynamics conditioned the system morphology and hence controlled the preserved record within different bedsets the transgressive regressive architecture of the pilmatue bedsets as well as the nature of the bounding surfaces indicate that their evolution could not be attributed to already reported controls such as changes in storminess or high frequency relative sea level cycles these attributes fit better with the concept of climatic variations impacting in the nature of accretion versus retrogradation in that sense resulting interpretations suggest that changes in the wave climate were the main controlling process on its evolution in consideration of that a feasible model related to along strike sediment supply imbalances and shoreline rotation phenomena is proposed as the developer of intra parasequence units at a mid term scale 1 to 100 k y the interpretations made suggest that mid term evolution of shallow marine systems can be strongly controlled by changes in its transport own dynamics and the necessity of the system to heal sediment supply imbalances which result in a complex sequence stratigraphic architecture

high resolution correlation of the upper cretaceous stratigraphy between the book cliffs and the western henry mountains syncline utah u s a abstract exposures of upper cretaceous strata in the book cliffs have played a key role in the formulation of modern sequence stratigraphic concepts and yet correlations with time equivalent strata in nearby regions remain uncertain resulting in an incomplete understanding of regional paleogeography this study presents detailed high resolution correlations of the upper cretaceous stratigraphy between the book cliffs the wasatch plateau and the western henry mountains syncline in utah with emphasis on the campanian interval two newly acquired measured vertical sections at coal canyon near green river in the book cliffs and blind trail in the henry mountains inform the correlations which also incorporate the substantial body of previous research correlations are further constrained by vertical and lateral facies stacking patterns and changes in sediment dispersal directions at discrete stratigraphic horizons derived from paleocurrent measurements much of the campanian succession can be characterized as a single low frequency third order depositional sequence within which are nested numerous high frequency sequences while it is not possible to correlate every high frequency sequence recognized in individual outcrop areas we define four intervals numbered 1 4 in ascending stratigraphic order that we correlate across the entire region interval 1 basal campanian is represented by initially deltaic and later wave dominated shoreface strata of the star point sandstone and equivalent basal muley canyon sandstone interval 2 lower campanian comprises coastal plain facies passing eastward into shallow marine strata of the lower blackhawk formation and equivalent muley canyon sandstone interval 3 lower to mid middle campanian comprises a thick aggradational stack of coastal plain fluvial strata that pass eastward into coastal and shallow marine facies blackhawk formation and equivalent masuk formation interval 4 overlying a major facies dislocation third order sequence boundary comprises amalgamated sheet fluvial deposits of the lower castlegate sandstone and equivalent tarantula mesa sandstone during the early to middle campanian the northern wasatch plateau and western henry mountains regions were along depositional strike with respect to one another the book cliffs near green river were located obliquely down depositional dip from the western henry mountains region during the campanian these new correlations and the improved understanding of paleogeography that derive from them have the potential to inform basin scale stratigraphic interpretations to a greater extent than has been hitherto possible

direct measurements of submarine groundwater discharge sgd over a fractured rock aquifer in flamengo bay brazil abstract measurements of submarine groundwater discharge sgd along the south american coast and over fractured rock aquifers are rare the rate and distribution of sgd was measured using three types of vented benthic chambers on the floor of flamengo bay located at the southeast coast of brazil discharge rates were found up to almost 400 cm day 1 although typically less than 100 cm d 1 large variations in sgd rates were seen over distances of a few meters which are attributed to the geomorphologic features of the fracture rock aquifer underlying a thin blanket of coastal sediments clustering of fractures and the topography of the rock sediment interface might be focusing or dispersing the discharge of groundwater sgd was modulated by the tides with the highest values occurring at times of low tide but the interaction was non linear and the correlation was weak at tidal ranges less than 1 m the effect was masked by devices that integrated the sgd but detected on continuously recording devices

coalesced delta front sheet like sandstone bodies from highly avulsive distributary channels the low accommodation mesa rica sandstone dakota group new mexico u s a