This study investigates the depositional history of the Late Eocene sedimentary record in the northwest of the Thrace Basin in a sequence stratigraphic approach and estimates the contribution of regional tectonics, basin physiography and eustasy. Late Eocene sedimentary succession was analyzed in two third-order sequences based on two major data sets / seismic reflection and well data sets. Depositional Sequence-1, represented by progradational stacking patterns, comprises the coarse-grained Hamitabat turbidite system. The base of the Sequence-1 was defined as the base of channel fill deposits in the northern shelf setting and the base of slope fan deposits in the slope setting. This boundary separates Lower-Middle and Upper Eocene sediments. In the slope setting, the Hamitabat turbidite system was analyzed in three major depocenters / Western, Northwestern and Northeastern depocenters respectively. Hamitabat turbidite system was controlled by the interaction of regional tectonics, basin physiography and eustatic fluctuations in the Late Eocene. This study highlighted the role of the regional variables / tectonic influence and basin morphology on the submarine canyon formation. The facies distribution was controlled by the high subsidence rate of sea-floor dominantly instead of eustasy. Depositional Sequence-2, represented by mostly retrogradational stacking patterns, is a clastic-carbonate mixed system. Depositional Sequence-2 was subdivided into three higher-order sequences. The lower sequence boundaries were induced by the rapid relative sea-level rise. The upper boundary of the Depositional Sequence-2 was defined as the termination of clastic-carbonate mixed system and a candidate for the Eocene-Oligocene contact.

The purpose of this study is to investigate the Upper Tournaisian substage within the Carboniferous carbonate deposits of the Aladag Unit in the Hadim region (Central Taurides) based on foraminiferal diversity and to study the meter scale cyclicity in order to explain the sequence stratigraphic evolution of the carbonate succession. In this study, a 27.01 m thick stratigraphic section consisting of limestones and shales was measured and 89 samples, collected along this section, were analyzed. Micropaleontological analyses are based on benthic foraminifera. According to the benthic foraminiferal assemblages, two biozones were identified as Zone Ut1 and Zone Ut2 within the Upper Tournaisian. Zone Ut1 is characterized by a poor foraminiferal assemblage while the Zone Ut2 consists of a diverse Upper Tournaisian foraminiferal fauna. In order to construct a sequence stratigraphic framework and appreciate depositional environmental changes, microfacies studies were carried out. Seven microfacies types were recognized and depending on the stacking patterns of these microfacies types, two fundamental types of cycles, A and B, were identified. Through the measured section, twenty-five shallowing-upward meter scale cycles and two sequence boundaries were determined. Quantitative analysis of benthic foraminifera was used to demonstrate the biological response to cyclicity. Since foraminifers are very sensitive to sea level changes, the abundance of benthic foraminifera displays a good response to sedimentary cyclicity. In order to apply a worldwide sequence stratigraphic correlation, the sequence boundaries and the meter scale cycles of this study were compared with those described in South China and Western European platform and the Moscow Syneclise. An Early Tournaisian transgression was followed by a major fall in relative sea level during the Late Tournaisian. Two sequence boundaries recognized in the measured section correspond to global sea level falls in the Late Tournaisian.

The Thrace Basin located in northwest Turkey displays attractive prospective traps for hydrocarbon and has received much attention from the petroleum industry. Despite the extensive exploration efforts, there are only few studies which address the fault kinematics and deformation mechanism of the region in connection with structural development. In this study, 3D raw seismic data set collected around Temrez High near Babaeski fault zone will be processed and interpreted along with the available borehole data to reveal the subsurface structure of the region that will contribute towards understanding the Neogene tectonic evolution of the central Thrace basin, origin of the transcurrent tectonics and possible role of the North Anatolian Fault Zone.

Interpretation of 900 km of a closely spaced grid of high-resolution seismic profiles over the northwestern margin of South Caspian Basin (SCB) allows recognition and study of six late Pleistocene - Holocene depositional sequences. Sequence stratigraphy analysis of sedimentary strata from 117,000 years B.P. to present led to the identification of a highstand systems tract, two transgressive systems tracts and six lowstand systems tracts. Each systems tract is characterized by specific seismic facies. Diverse depositional processes on the northwestern margin of the SCB are suggested by the thirteen seismic facies patterns recognized in the study area. Two distinct progradational complexes were interpreted within Sequence III and Sequences IV and V in the northeastern and northwestern parts of the study area, respectively. Stratigraphic interpretation of the sequences provided important information on parameters that control depositional architectures, such as lake level fluctuations, tectonic dynamics, and sediment supply. High sedimentation rates combined with a series of high-frequency and high-amplitude lake-level fluctuations, abrupt changes at the shelf edge, abnormally high formation pressure, and high tectonic activity during Quaternary time resulted in the development of a variety of complex geologic drilling hazards. I distinguished three types of hazards as a result of this study: mud volcanoes, sediment instability, and shallow gas. The 2D high-resolution seismic dataset from the northwestern margin of the SCB allowed more detailed seismic sequence stratigraphic analysis in the study area than has previously been attempted. In particular, it has a clear application in deciphering sediment supply and relative lake level changes as well as tectonic relationship of the northwestern shelf margin of the SCB. Results of this work led us towards better understanding of recent depositional history, improved our knowledge of the nature of the basin tectonics, climate history and styles of and controls on sedimentation processes within a sequence stratigraphic framework during the late Pleistocene-Holocene time.

Approximately 720 square miles of digital 3-dimensional seismic data covering the eastern Mississippi Canyon area, Gulf of Mexico, continental shelf was used to examine the structural and stratigraphic evolution of the geology in the study area. The analysis focused on salt tectonics and sequence stratigraphy to develop a geologic model for the study area and its potential impact on engineering and geologic hazards. Salt in the study area was found to be established structural end-members derived from shallow-emplaced salt sheets. The transition from regional to local salt tectonics was identified through structural deformation of the stratigraphic section on the seismic data and occurred no later than ~450,000 years ago. From ~450,000 years to present, slope depositional processes have become the dominant geologic process in the study area. Six stratigraphic sequences (I-VI) were identified in the study area and found to correlate with sequences previously defined for the Eastern Mississippi Fan. Condensed sections were the key to the correlation. The sequence stratigraphy for the Eastern Mississippi Fan can be extended ~28 miles west, adding another ~720 square miles to the interpreted Fan. A previously defined channel within the Eastern Fan was identified in the study area and extended the channel ~28 miles west. Previous work on the Eastern Fan identified the source of the Fan to be the Mobile River; however, extending the channel west suggests the sediment source to be from the Mississippi River, not the Mobile River. Further evidence for this was found in ponded turbidites whose source has been previously established as the Mississippi River. Ages of the stratigraphic sequences were compared to changes in eustatic sea level. The formation stratigraphic sequences appear decoupled from sea level change with ?pseudo-highstands? forming condensed sections during pronounced Pleistocene sea level lowstands. Miocene and Pleistocene depositional analogues suggest the location of the shifting Mississippi River Pleistocene depocenter is a more dominant influence on sequence formation. Thus, the application of traditional sequence interpretation with respect to sea level change should be reconsidered to also account for the shifting depocenter for both the study area as well as the broader Eastern Mississippi Fan.

The Black Shale Basin of West Texas covers an area in excess of 21,000 square miles and includes the region from Terrell and Pecos Counties eastward to Menard and Kimble Counties. It extends from Real, Edwards, and Val Verde northward beyond Glasscock and Upton Counties. This basin includes such local basins as the "Midland Basin," and "Val Verde Basin," of Frank E. Lewis, the "Sheffield Channel," and the "Kerr Basin." Reasons are given for the belief that the black shale sediments in this basin were derived from rocks south of this area. The shale ranges in age from Bend (lower Pennsylvanian) through Clear Fork (middle Permian). The shale of the Midland Basin has been divided into three distinct zones. Pre-Cretaceous erosion has removed the offlapping Permian shale in the extreme southern portion of the area leaving Pennsylvanian directly beneath the Trinity. The problem of stratigraphy is complicated by gradation and lack of diagnostic fossils. There is a great divergence of opinion as to correlative formational units derived from a study of the well cuttings. / text

High rates of Neogene sediment influx to the offshore Canterbury Basin resulted in preservation of a high-resolution record of seismically resolvable sequences (~0.1-0.54 my periods). Subsequent sequence development was strongly influenced by submarine currents. This study focuses on correlating seismically interpreted sequence boundaries and sediment drifts architectures beneath the modern shelf and slope with sediment facies observed in cores from shelf Site U1351 and slope Site U1352 drilled by Integrated Ocean Drilling Program (IODP) Expedition 317. A traveltime-depth conversion was created using sonic and density logs and is compared with two previous traveltime-depth conversions for the sites. Eleven large elongate drifts were interpreted prior to drilling. Two new small-scale plastered slope drifts in the vicinity of the IODP sites, together with sediment waves drilled at Site U1352, have been interpreted as part of this study. Lithologic discontinuity surfaces and transitions together with associated sediment packages form the basis of identifying sequences and sequence boundaries in the cores. Contacts and facies were characterized using shipboard core descriptions, emphasizing grain-size contrasts and the natures of the lower and upper contacts of sediment packages. Lithologic surfaces in cores from sites U1351- (surfaces S1-S8) and U1352- (surfaces S1-S6) correlate with early Pleistocene to recent seismic sequence boundaries U12-U19 and U14-U19, respectively. The limited depths achieved by downhole logging, in particular sonic and density logs, together with poor recovery in the deeper section did not allow correlation of older lithologic surfaces. Slope Site U1352 experienced a complex interplay of along-strike and downslope depositional processes and cores provide information about the principal facies forming sediment waves. The general facies are fine-grained mud rich sediment interbedded decimeter-centimeter thick sand and sandy mud. Core evidence for current activity is reinforced at larger scale by seismic interpretations of sediment waves and drifts. / text

The sediment budget and paleogeography was reconstructed for the Maastrichtian fluvial to coastal plain Lance Formation (>200m thick) that developed coevally with the shoreline/shelf Fox Hills Sandstone (>200m thick) and deep-water Lewis Shale (>750m thick) in a complete source-to-sink system in the Washakie and Great Divide Basins of south central Wyoming. The system initiated during the final Western Interior Seaway (WIS) transgression and the onset of the Laramide Orogeny rapid subsidence (>2km in 1.9 My) that largely outpaced sediment flux into the basin so the system became and remained a deep-water (>500m water depth) basin beyond the Lance-Fox Hills shelf prism. The active tectonic setting and rapid subsidence caused the Lance fluvial and coastal plain deposits to aggrade and accumulate behind the generally rising shoreline trajectory of the Fox Hills Sandstone. The depositional succession is subdivided into 15 clinothem units and the Lance Formation is best exposed in outcrops in clinoforms 10, 11, and 12. Subsurface analysis correlates key stratigraphic surfaces across the basin to define the sediment budget and clinoform architecture. Field analysis along clinoform 12 on the east side of the basin details facies and paleohydraulic dimensions. Sediment partitioning shows the regressive and transgressive systems tracts (RST and TST) form complementary wedges such that the RST thickens basinward and the TST thins basinward, reflecting the preferential storage of sediment. Channels measured in the field and subsurface datasets are similar in thickness (2m-16m) and suggest braided channel morphology with channel belts from 6.2-8.4km. N/NE paleocurrent trends departing from the subsurface dataset and previous studies of the system provide evidence of possible tidal influences in a developed shoreline embayment or an east to west supply from the basement-cored Rawlins and Sierra Madre Uplifts in the east. The fluvial Lance Formation paleogeography associated with the RST and TST is primarily driven both by modest, Late Cretaceous relative sea level changes and sediment supply linked to the tectonic setting and climate. / text

Recent drilling of deep stratigraphy in subsalt offshore Gulf of Mexico has revealed the presence of thick, amalgamated, Cretaceous siliciclastic reservoirs with the potential to become valid exploration targets. Similar to the Lower Tertiary deepwater play, the significant down-dip distance (> 400 km) from the source deltaics, the data gap across the modern structurally complex salt-tectonics-dominated slope and the difficulties of imaging subsalt stratigraphy pose challenges for the construction of meaningful deepwater system models to aid in exploration and appraisal efforts. A 3D seismic dataset in the Mad Dog field at the basinward end of the modern allochthonous salt canopy and outboard of the Sigsbee Escarpment offers the opportunity to study the nature of the deep stratigraphy at central positions in the basin. The nature of the Cretaceous sedimentary system has been investigated through detailed structural and seismic geomorphologic mapping. An early syndepositional contractional event has been identified and temporally associated with Mesozoic emplacement of a deep salt sheet. These events are masked by the major Neogene-age phase of fold amplification that dominates the present-day subsalt structural framework. Ponded-basin deepwater sedimentation processes control early phases of deposition in the Cretaceous Mad Dog area and sediment-gravity flows are deposited as complexes of low sinuosity amalgamated channelized deposits in roughly-confined sediment pathways. Ponded fills show internal lateral accretion architectures that grow sigmoid in nature as the migrating systems interact with the approaching minibasin margins making evident the structural control on sediment architecture. Later phases of deposition are characterized by slightly sinuous feeder channels with multiple lobe development at their terminus. Variable directions of sediment source pathways indicate a linear-sourced slope apron depositional model for these systems. In addition to the more structured morphologic elements, there were also pervasive mass-transport processes active, presumably triggered by Mesozoic halokinesis. Data in sparse deep wells in the GoM that penetrate the Cretaceous suggest that the Late Cretaceous deepwater depositional system was composed of coarse-grained high density gravity flows. The geometries seen in seismic beneath the Mad Dog area support the existence of such a basinwardly extensive deepwater fan systems developed during the Cretaceous, and the low sinuosity channel geometries and small length:width ratio and amalgamated nature of fan lobes suggest that these systems may have indeed been high-density in nature. / text

The SACROC unit is an isolated carbonate platform style of reservoir that typifies a peak icehouse system. Icehouse carbonate platforms are one of the least well understood and documented carbonate reservoir styles due to the reservoir heterogeneities they embody. The current study is an attempt to recognize carbonate rock types defined based on rock fabrics by integrating log and core based petrophysical analysis in high-frequency cycle (HFC) scale sequence stratigraphic framework and to improve our ability to understand static and dynamic petrophysical properties of these reservoir rock types, and there by, improve our understanding of heterogeneity in the middle early to late early Canyon (Canyon 2) high frequency sequence (HFS) in the Northern Platform of the SACROC Unit. Based on core descriptions, four different sub-tidal depositional facies were defined in the Canyon 2 HFS. Identified depositional facies were grouped into three different reservoir rock types in respect to their rock fabrics in order for the HFC scale petrophysical reservoir rock type characteristic analysis. Composed of succession of the identified reservoir rocks, twenty different HFCs were determined within the HFC scale sequence stratigraphic framework. The overall trend in the HFCs demonstrate systematic coarsening upward cycles with high reservoir quality at the cycle tops and low reservoir quality at the cycle bottoms. It was observed in terms of systems tracts described within the cycle scale frame work that the overall stacking pattern for high stand systems tracts (HST) and transgressive systems tracts (TST) is aggradational. And, the reservoir rocks representing the HST are more porous and permeable than those of TST. In addition to that, it was detected that the diagenetic overprint on the HST reservoir rocks is more than that of the TST. According to the overall petrophysical observations, the grain-dominated packstone deposited during HST was interpreted as the best reservoir rock. Upon well log analysis on the identified reservoir rocks, some specific log responses were attributed to the identified reservoir rocks as their characteristic log signatures. / text