bluuebunny/crossref_metadata_2025_split huggingface dataset:
INTERNAL ARCHITECTURE OF A CHANNEL-LEVEE COMPLEX, CERRO TORO FORMATION, SOUTHERN CHILE
Authors: DEVRIES MICHAEL B. , LINDHOLM ROSANNE M. 
Published: April 2012

ABSTRACT
Well tests have demonstrated that levee/overbank deposits in the Gulf of Mexico intraslope basins can be economically productive reservoirs with good flow rates. However, very little has been published on the internal reservoir geometry of deep-water levee deposits or on potential sources of reservoir heterogeneity on the interwell-scale. Depositional features that can affect estimates of hydrocarbon volume, production strategy, and reserves are best observed and explained from outcrop. Unfortunately, levee/overbank outcrops weather easily due to an abundance of shale and are typically poorly exposed. An exception is the Cerro Toro Formation of southern Chile.
A single channel-levee complex in the Cerro Silla syncline was studied in detail. Four main depositional facies are identified in the levee. These are blanket beds, lenticular beds, crevasse-fill, and mass movement facies. The major facies in the levee is composed of blanket beds that consist of thin-bedded sandstones and silty shales that are laterally continuous across the length of the outcrops. The change in thickness of the sandstone blanket beds was measured across the length of one outcrop. Thicker sandstone blanket beds (&gt; 2”) thin at a higher initial rate than thinner blanket sandstone beds (≤ 2”) and are also more likely to pinch out entirely. Lenticular sandstone beds are common in the proximal levee outcrops and locally have a high sandstone to mudstone ratio but are prone to be laterally discontinuous over distances of a few hundred feet. The most laterally discontinuous sandstones occur as thick, relatively coarse-grained beds within the crevasses. Crevasse-fill deposits can potentially be recognized in core as thick-bedded sandstone that occurs above a debris flow or slump deposit. Erosional surfaces and mass movement deposits are most common in the proximal and lower portions of the levee. Erosional surfaces are draped by blanket beds and less common onlapping lenticular sandstone beds. Recognition of these types of erosional surfaces in seismic data or in core may be difficult because they are below seismic resolution and lack a diagnostic lithofacies fill.
UTILIZATION OF 3-D SEISMIC IN VISUALIZING AND REINTERPRETING AN UNSTABLE SHELF AREA AND ITS RELATIONSHIP TO TURBIDITE DEPOSITION DOWNDIP, OFFSHORE NIGERIA
Authors: KEAN ALLAN 
Published: April 2012

Mobil’s largest 3D seismic survey undertaken to date lies offshore in the eastern portion of the Niger Delta. The geologic section of interest is located between 1.5–2.5 seconds. The seismic data quality is very good in the zone of interest. Previous interpretations of the area, based on 2D seismic defined the gross structural picture, and significant oil/gas fields were discovered based on these interpretations.
Seismically, the 3D coverage facilitated interpretation of all the data through the acquisition of closely spaced lines. The closely spaced seismic profiles used in conjunction with time slice views allowed for improved integration and visualization of the entire data set. Areas of instability were identified where large blocks of sediments appear to have been rotated and transported out and away from their original depositional locations. Areas where shelfal sand deposits become unstable are potential source areas for turbidile deposition. Missing section, up to several thousand feet in the Unam wells, is interpreted to have been transported (or redeposited) downdip, in west-east and north-south directions, from its original depositional location. Turbidite sands, interpreted as having been deposited as part of a channel-levee system in a Lowstand Systems Tract, were drilled approximately 20 km downdip. The genetic relationship of these younger turbidite sands to the older, shallow water beach sands was in question.
Upon first look analysis of the 3D seismic volume, a different structural interpretation was envisioned, than previously existed. The new structural setting was one of contrattional overprinting on the extensional framework. A shale diapir became a shale mass. In cross-section, a rollover structure was determined to be related to a concave-convex-concave fault bend and lateral contractional stresses. Both the Eku and Unam field areas fit into this newly visualized tectonic framework.
RELATING DEPOSITIONAL FACIES TO SEISMIC-SCALE STRATAL GEOMETRIES, UPPER JURASSIC GREAT VALLEY SEQUENCE, CALIFORNIA
Authors: LYONS KEVIN T. 
Published: April 2012

Abstract
Stratal patterns identified from low-altitude aerial photographs have been integrated with the results of depositional facies mapping to document the two-dimensional lithologic heterogeneity of the Upper Jurassic Great Valley Sequence of the northern Sacramento Valley, California. This turbidite complex comprises the following depositional elements: (1) debris flow units, (2) channels and channel complexes, (3) channel-overbank systems, and (4) depositional lobe successions.
Vertical facies associations indicate that early phases of deposition within the turbidite complex were strongly influenced by local and regional tectonic instability. The Paskenta fault zone appears to have exerted a significant control on sedimentation patterns during this time. The resulting disorganized association of facies consists of (1) thick, amalgamated debris flow deposits, (2) broad, shallow, conglomerate and sandstone-filled channels, and thick intervals of mud-rich strata.
Upper portions of the turbidite complex are characterized by a more orderly association of facies consisting of laterally continuous coarse-grained intervals separated by thick successions of thin-bedded strata. Coarse-grained depositional elements include (1) isolated, conglomerate-filled channels, (2) associations of coarse-grained channelized and fine-grained unchannelized units interpreted as channel complexes, and (3) intervals of tabular sandstone units interpreted as depositional lobe successions.
Fine-grained channel-overbank intervals contain widely scattered sandstone-filled channels and sand-rich overbank deposits, but consist primarily of monotonous successions of mud-rich interchannel deposits. Taken together the observed facies associations suggest that the Great Valley turbidite complex was deposited in a lower slope to base of slope setting.
SEQUENCE STRATIGRAPHY OF NEOGENE STRATA IN OFFSHORE NIGERIA
Authors: Pacht Jory A. , Bowen Bruce E. , Hall David J. , Rosen Rachel , Shaffer Bernard L. , Choudhury Abu 
Published: April 2012

Abstract
The Dahomey Basin, located along the western portion of the Nigerian continental margin, is underlain by continental and transitional crust. It exhibits stable to moderately unstable progradation and is characterized by a well-developed shelf-slope break. Systems tracts are similar to those described for other stable progradational margins. In contrast, the Niger Delta Complex, located off the central and eastern portions of the Nigerian coast, exhibits highly unstable progradation. The shelf-slope break is commonly not well-developed. Instead, a ramp, characterized by relatively uniform dip, is present. Large growth faults cut the ramp and define the shelf margin. Systems tracts are similar to those in deep-water Neogene strata of the offshore Gulf of Mexico.
The basin floor fan and slope fan depositional systems comprise the lower lowstand systems tract. Basin-floor fans in both areas are defined by a prominent reflection along their upper boundary. This reflection downlaps along the sequence boundary or abuts against the down thrown side of a growth fault surface. The slope fan contains channel-fill complexes characterized by chaotic bedding and less common large channel-fills, which exhibit concave-upward reflections. Most slope-f an strata exhibit discontinuous lo semi-continuous subparallel reflections. In the Dahomey Basin, slope fan deposits commonly pinch out at or near the shelf margin. In contrast, contemporaneous shallow-water facies are developed in the Niger Delta Complex. Deposition occurred from multiple point sources.
Large amplitude anomalies in the upper lowstand (prograding wedge) suggest thick sheet sands are present in the Niger Delta Complex. These sands occur in both shallow-water (interpreted as delta front facies) and deep-water environments (interpreted as shingled turbidites). Water depths are constrained in areas in which well control is present by benthic foraminifera. Transgressive and highstand systems tracts are commonly very thin.
Different exploration strategies are appropriate for each systems tract off both the western and central portions of the Nigerian Coast. The best plays off the central portion of the Nigerian coast are probably structural traps and combination structural and stratigraphic traps (this includes updip pinchouts), whereas hydrocarbons may occur in smaller pure structural to pure stratigraphic traps along the west coast of Nigeria.
INTERPRETING FORMATION MICROSCANNER LOG IMAGES OF GULF OF MEXICO PLIOCENE TURBIDITES BY COMPARISON WITH PENNSYLVANIAN TURBIDITE OUTCROPS, ARKANSAS
Authors: SLATT ROGER M. , JORDAN DOUGLAS W. , DAVIS ROBERT J. 
Published: April 2012

Abstract
Sedimentair features observed in canyon-fill and basin floor turbidites in the Pennsylvanian Jackfork Formation, Ouachita Mountains of Arkansas have been compared with what we interpret as identical features observed on Formation MicroScanner (mark of Schlumberger) images from offshore Louisiana Pliocene turbidites.
Small-scale features displayed in outcrop and on the Formation MicroScanner images include slumps, erosional surfaces, thin sand-shale interbeds, mud-lined depressions/scours, isolated sandstone clasts in shaley debris flow beds, remnant bedding in various stages of disruption owing to flowage, and load structures. On a larger scale, thin-and thick-bedded sandstone-shale intervals are recognized, which are probably laterally continuous for some distance.
Based upon the outcrop criteria, recognition of these features on Formation MicroScanner images can lead to an improved interpretation of the images with respect to Gulf of Mexico (and elsewhere) deep-water deposilional processes, facies and their three-dimensional geometry, relative reservoir quality, and lateral and vertical continuity of beds. This improved interpretation can be valuable in resolving reservoir iramagement, development drilling, and exploration issues.
A SEQUENCE STRATIGRAPHIC ANALYSIS OF THE LOWER MIOCENE, WEST AND EAST CAMERON AREAS, GULF OF MEXICO
Authors: Wagner John B. , Kofron Bruce M. , Morin Ronald W. , Ford David W. , Mathur Vinod R. , Mauro Richard T. 
Published: April 2012

ABSTRACT
A sequence stratigraphic analysis of the nearshore West Cameron and East Cameron blocks, central Gulf of Mexico, was developed for Lower Miocene age strata. Interpretation of each depositional sequence included delineation of paleoshelf/slope breaks, isopach, seismic facies, and paleogeography maps. Sequence development and sedimentation patterns were influenced by two prominent structural styles, growth faulting and salt/shale deformation. Two depositional sequences A and B, were identified and interpreted to consist of depositional environments ranging from submarine fan to coastal and shallow marine deltaics.
Sequence A is the oldest Lower Miocene sequence and is divided into two depositional packages, a lowstand portion and a condensed interval. Because the paleo-shelf break was landward of our study area, there is an absence of well-developed shelfal facies in this sequence, and the condensed interval represents the distal transgressive and highstand portion of the sequence. The lowstand portion suggests a north to northwest source direction and has a maximum thickness of 2200 feet. The axis of maximum thickness, derived from isochron mapping, integrated with paleogeographic interpretation, indicates that the thickness or aggradation is related to mass-wasting processes and channel systems characteristic of submarine fan environments. The influence of pre-existing topography and basin configuration on sequence development and stratal architecture is evident where the axes of maximum thickness are separated by thin intervals of little to no deposition, related to a paleostructural high.
Sequence B is better developed than Sequence A because of its location within the axis of the depocenter and can be subdivided into the following depositional environments: well-developed prograding submarine fan and slope deposits (associated primarily with falling sea-level) that are capped updip by an erosional surface associated with a marine transgression; an overall transgressive unit composed of localized regressive deltaic deposits; and aggradational fluvial/deltaic and shallow marine sediments associated with a continued rise in sea-level. Sequence B has a maximum thickness of 3200 feet and, like Sequence A, this aggradation within the basin is attributed to mass-wasting and channel development within a slope envronment. The variation in location of thickness trends, combined with evidence of erosional channels from different source directions, indicates the migration of sediment supply through time from a more westerly to a more northerly direction.
SEQUENCE STRATIGRAPHY OF NEOGENE TURBIDITE SYSTEMS, NORTHERN GREEN CANYON AND EWING BANK, NORTHERN GULF OF MEXICO
Authors: Weimer Paul , Varnai Peter , Acosta Zurilma M. , Budhijanto Fadjar M. , Martinez Rafael E. , Navarro Alonso F. , Rowan Mark G. , Mcbride Barry C. , Villamil Tomas 
Published: April 2012

ABSTRACT
The Ncogene turbidite systems of Green Canyon and Ewing Bank lease areas in the northern Gulf of Mexico are amajor exploration play. The regional sequence stratigraphy for this area has been interpreted to help define the potential areas for future exploration. Data base consists of 6300 miles of 2-D multifold seismic data well log data for 175, wells, and biostratigraphy from 180 wells.
Four main intervals have been identified, which reflect different kinds of turbidite systems based upon lithologies and seismic facies. Exploration concepts must be different in each of the four intervals because of the different nature of the turbidite systems. Paleoecology data indicate that deposition of these turbidite systems occurred in bathyal water depths. Lower Pliocene sediments (5.5 to 3.0 Ma) include the 5.5, 4.2 and 3.8 sequence boundaries. The interval consists of sandrich turbidite systems. The upper Pliocene interval (3.0 to 1.4 Ma) comprises the 3.0, 2.6, 2.4, 1.9 sequence boundaries. The interval is thin in the eastern portion of the area and becomes thicker to the west. Sands develop only in the western portion of the area. The interval corresponds to when the Mississippi River avulsed to farther in the western Gulf of Mexico and sediment supply decreased significantly.
The lower Pleistocene interval (1.4 to 0.7 Ma) includes the 1.4, 1.1 and 0.8 Ma sequence boundaries. The interval is predominantly shale-rich with localized sands developing in channel-levee systems and unchannelized sands. The upper Pleistocene interval (0.7 Ma to Present) consists of shale-dominated turbidite systems. Notable submarine canyons develop in this interval to the east.
DELINEATION OF AN OIL AND GAS FIELD WITHIN A TURBIDITE SYSTEM: BREDASDORP BASIN, SOUTH AFRICA
Authors: WINTERS S.J. , KUHLMANN S. 
Published: April 2012

ABSTRACT
A sequence stratigraphic approach applied to the central Bredasdorp basin has delineated a eustatic third-order Aptian sequence in which several hydrocarbon discoveries have been made to date. The sequence consists of a lowstand sequence set within which higher-order sequences are developed, a transgressive systems tract with a thick marine condensed section, and a progradational highstand systems tract. The fourth-order simple sequences within the lowstand sequence set are associated with basin floor fans which have been deposiited retrogradationally within the confines of a fault-controlled erosional valley. The basin floor fans are characterized by stacked deep-marine channel deposits and form combination traps through stratigraphic pinch-outs and local inversion tectonics.
The channel-fill sandstones comprise the primary reservoirs and are characterized by high amplitude seismic anomalies. Mapping of these anomalies, facilitated by a 3-D seismic survey, forms a critical part of the interpretation process as the amplitude variations signify changes in sandstone thickness, porosity, net-to-gross ratios, and fluid content Seismic modelling has been applied in an attempt to calibrate these amplitude responses.
Appraisal drilling has confirmed the sequence stratigraphic model of two retrogradationally stacked basin floor fans which contain significant oil and gas accumulations.
TECTONIC CONTROLS ON THE SEQUENCE STRATIGRAPHY OF UPPER JURASSIC FAN SYSTEMS IN THE BARROW-DAMPIER RIFT, NORTHWEST SHELF, AUSTRALIA
Authors: WULFF KEIRAN , BARBER PETER 
Published: April 2012

ABSTRACT
Upper Jurassic syn-rift strata in the Barrow-Dampier Rift can be subdivided into at least nine depositional sequences. Sequence boundary development is closely related to major tectonically-induced changes in basin architecture associated with progressive continental breakup of Eastern Gondwana. Episodic crustal extension and transtension in the Barrow-Dampier Rift created a series of terraces along the posterior peri-rift margin. Rapid changes in the rate of creation of accommodation space related to syndepositional tectonism, in association with changes in sediment supply and eustatic sea level fluctuations, influenced the type and geometry of submarine fan complexes which subsequently developed within each depositional sequence.
Deposition of Callovian to Oxfordian sequences occurred whilst the Barrow and Dampier sub-basins were two distinct structural entities separated by a complex intra-basinal arch. In this context, early Callovian to Oxfordian basin-floor sand cycles were locally confined to the rift margins and peri-rift terraces, forming mixed channel lobe and fan mound forms. Kimmeridgian to Tithonian depositional sequences, however, are more widespread. These followed marked submergence of the intra-basinal arch, allowing widening of the sub-basins into one tectonic entity, giving rise to deposition of thick detached non-channellized lobes. In the Dampier Sub-basin where a more complete and thicker Kimmeridgian to Tithonian interval exists, identified sequences demonstrate an apparent synchroneity with the world-wide global eustasy curve, especially with third-order cycles. This may be a function of the effect of the breakup of Eastern Gondwana on accommodation space and eustasy on a global scale.
SPATIAL AND TEMPORAL VARIATIONS IN THE FACIES ASSOCIATIONS OF DEPOSITIONAL SEQUENCES ON THE SLOPE: EXAMPLES FROM THE MIOCENE-PLEISTOCENE OF THE GULF OF MEXICO
Authors: YEILDING CINDY A. , APPS GILLIAN M. 
Published: April 2012

ABSTRACT
There is a systematic spatial and temporal distribution of facies associations within deepwater depositional systems of the northern Gulf of Mexico. The building blocks that make up deepwater depositional sequences include turbidite, debris flow, slump, and pelagic deposits. These building blocks combine in a variable, yet systematic and predictive, assemblage of facies. Through time, a deepwater depositional sequence stacks in an overall fining-upward succession of higher-energy to lower-energy deposits.
Sequence mapping illustrates an overall evolution of the deposy stem from updip to downdip. The active slope deposystem is characterized by a progradational shelf margin, which is often extensively slumped or bypassed. The upper slope is dominated by bypass, erosional channel systems, and/or small-scale leveed-channel systems. The middle and lower slope is prone to deposition of debris flows, lobate (unconfined flow) turbidite sand bodies, and larger-scale leveed-channel systems. In general, the best sand development is observed in the middle and lower slope, directly downdip of the major delta system. Outside of the areas of active deposition, slope sedimentation is minimal, and the time-equivalent section is represented primarily by condensed strata.
The base of each depositional sequence is interpreted to represent the fall of relative sea level, and highest energy processes. These processes include shelf margin failure, bypass, erosional channels, which feed sediments into downdip lobate bodies. In the middle and lower slope, high net sand leveed channels also appear to supply sediment to downdip lobate bodies. Sediments of the upper part of the lowstand are focused in the upper slope and shelf margin, with deltas and smaller scale, low net sand leveed channels. Downdip, the equivalent section is characterized primarily by hemipelagic sedimentation. The final stages of the depositional sequence are the transgressive, condensed section and highstand systems tract This interval represents the most time, and slowest sedimentation rates (primarily muds and marls) in the deep-water deposystem.
Advanced Visualization Techniques in the Geosciences
Authors: Loftin R. Bowen , Harding Chris , Chen Dave , Lin Ching-Rong , Ugray Adrian , Gordon Peter , Nesbitt Keith , Chuter Chris , Acosta Mark 
Published: April 2012

Abstract
This paper describes the development of applications for the interactive investigation of three-dimensional seismic data and geological surfaces interpreted from that data (using a projective workbench, or the CAVE™). This approach enables geoscientists to more fully exploit threedimensional seismic data by providing them with a truly three-dimensional display of data that can be shared (locally or remotely) with others. In addition, the threedimensional interactivity of this technology can support more productive interpretation of the seismic data and more efficient verification of the resulting interpretations. The result is an enhanced process for characterizing a hydrocarbon reservoir.