Download or read book A Revised Seismic Stratigraphic Framework for the Early Mesozoic Crayfish Group Onshore Otway Basin Victoria Implications for Understanding the Development of Depositional Environments Within a Continental Rift Basin written by David Leopold Briguglio and published by . This book was released on 2015 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this study was to construct a new stratigraphic framework for the Victorian section of the onshore Otway Basin, while answering unresolved questions about the basin's early rift history. These include the order in which individual depocentres were formed, the timing of deposition of laterally varying stratigraphic packages, which units were confined to individual rift depocentres and how the transition between depositional environments was controlled by rift related tectonism. The approach first involved the integration of stratigraphic correlations, petrophysical interpretation, drill-core descriptions and biostratigraphy with seismic facies analysis. This resulted in the identification of at least two new lithostratigraphic members and the construction of a new stratigraphic framework for the sediments. Structural analysis was then undertaken by building a 3D structural model which was used to calculate cumulative displacement rate across depocentre bounding faults and sediment accumulation rates within the main depocentres. This analysis suggests that changes in rates of fault activity were the primary control on temporal shifts in depositional environments. The results were then enhanced by building a series of continental sequence stratigraphy models for each depocentre. These demonstrated that a series of age correlatable regional tectonic events controlled common variations in the vertical stacking order of stratigraphy in all the depocentres. Sequence stratigraphy interpretation also allowed detailed palaeogeography mapping which in turn led to the construction of a high-resolution volumetric model of the Crayfish Group members. This resulted in a revised chronostratigraphic framework for the onshore Otway Basin, which provided a basis for explaining the relationship between fluvio-lacustrine sedimentation and tectonism during the early history of intercontinental rift systems. Finally, the resulting geological model was used to evaluate its consequences on the thermal history and source rock maturation of the basin. This was done by building a series of 1D and 3D thermal models. These models allowed investigation of the potential for both conventional and unconventional petroleum systems and carbon capture and storage potential. They demonstrate that the highest quality source rocks in the system are mature for hydrocarbon generation but are restricted to a series of ancient lacustrine environments within the central Otway Basin. They also demonstrate that highest quality reservoirs are buried deeply enough and are hot enough to store carbon dioxide in its supercritical phase within many of the existing drilled structural culminations.
Download or read book The Stratigraphy and Structrural History of the Mesozoic and Cenozoic of the Central Nova Scotian Slope Eastern Canada written by Jennifer Leigh Young and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The continental shelf and slope of Nova Scotia is underlain by a number of interconnected rift sub-basins that collectively form the Scotian Basin. Petroleum exploration companies have been moderately successful on the shelf region of the basin, close to Sable Island, where several significant hydrocarbon discoveries have lead to the development of the Sable Project. This success has sparked interest in exploration of the adjacent frontier slope region within water depths between 200 and 2500m. However, the Scotian Slope Basin has been the focus of only limited regional geologic studies. Present accounts of the slope are largely extrapolated from shelf descriptions and/or modeled after play types and depositional systems typically associated with deep water exploration in other Atlantic margin areas. A discrete study area was defined for this project within the central slope region approximately 125 kilometres southwest of Sable Island. The area is approximately 120 square kilometres and contains five of the ten Scotian Slope exploration wells, three shelf wells and 4 500 kilometres of 2D seismic data. -- Scotian Basin development commenced in the Late Triassic - Early Jurassic with rifting of the Pangean Supercontinent and opening of the Atlantic Ocean. Red bed and evaporate deposition characterized the rift phase, while the drift phase was characterized by clastic progradational with periods of carbonate deposition. A prominent carbonate bank developed in the western part of the basin during the Late Jurassic, the eastern extent of which was limited by a Late Jurassic - Early Cretaceous Sable Delta. As relative sea level rose throughout the Late Cretaceous and Tertiary major transgressive sequences were deposited. This overall transgression was punctuated by major sea level drops resulting in the deposition of regressive lowstand sequences partially comprising turbidite deposits. -- Seismic stratigraphic analysis of the study area identified ten major sequence boundaries on the basis of reflection character and termination patterns. The sequence boundaries divide the Mesozoic through Cenozoic Scotian Slope Basin fill into nine depositional sequences. There are major changes in depositional style and thickness distribution patterns of the depositional sequence through time. Depositional patterns are closely linked to the tectonic, structural and halotectonic evolution of the basin. -- Five fault families were defined within the study on the basis of their regionality, duration of movement and depths of detachment; the Slope Basin-Bounding Fault Family, the Basement-Involved Fault Family, the Listric Growth Fault Family, the Major and Minor Sedimentary Fault Family and the Halokinetically Induced Fault Family. The existence of a sixth fault family, the Transfer Fault Family, is implied by local structural and stratigraphic architecture, however, the signature of this potential transfer fault is not clear enough on the available seismic data to allow for confident mapping. -- The complete spectrum of salt structures typical of passive margins has been identified and mapped within the study area. Five halotectonic structural associations with variable areal distributions have been identified. These associations are: the Trough and Swell Association, the Intra-Salt Detachment Association, the Diapiric Association, the Secondary Weld Association, and the Allochthonous Salt Association. -- The integration of seismic stratigraphic, structural and halotectonic analysis of the study area allowed for several conclusions regarding implications of a potential Scotian Slope petroleum system to be proposed. Considering all the elements and processes necessary for working hydrocarbon system, the most likely plays within the mapped study area consist of: 1) a reservoir of Cretaceous to Tertiary turbidite channel, levee or lobe sands, 2) a source rock most likely within the Kimmeridgian Verrill Canyon Formation (possible contribution from Jurassic Mohican Formation or Late Triassic to Early Jurassic early Syn-rift and/or Post-rift Lacustrine deposits, 3) a seal of Verrill Canyon Formation, Dawson Canyon or Banquereau shale or allochthonous salt, and 4) structural, tectonic and/or halokinetic traps ranging from Triassic to Cretaceous in age. -- Failure to discover hydrocarbons in recent slope explorations wells may point to the limitations of seismic resolution to predict reservoirs within the late Jurassic-Early Cretaceous successions. It also shows that drilling on the Scotian Slope is high risk exploration; more regional and better correlation of seismic with lithologies encountered in the wells are needed.
Download or read book The structural and stratigraphic evolution of the Celtic Sea Basin offshore Ireland written by Philip Rowell and published by . This book was released on 1993 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Formation and Applications of the Sedimentary Record in Arc Collision Zones written by Amy E. Draut and published by Geological Society of America. This book was released on 2008-01-01 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Inspired by a GSA Penrose Conference held in 2005 (cosponsored by the International Association of Sedimentologists and the British Sedimentological Research Group), the 17 papers in this volume explore sedimentary environments in arc collision zones and their utility in recording the evolution of modern and ancient convergent margins. The first set of papers in the collection focuses on formation and evolution of the sedimentary record in arc settings and arc collision zones, concentrating on modern intra-oceanic examples. Papers include studies of flexural modeling and factors that affect development of siliciclastic and carbonate deposits around modern arcs. The second half of the volume presents new applications of arc sedimentary records. These relate primarily to constraining tectonic events in the evolution of arc systems, but also concern the links among tectonic uplift, collision, and geomorphic and climatic feedback mechanisms in arc collision zones."--Publisher's website.
Download or read book Stratigraphic Framework of Cambrian and Ordovician Rocks in the Central Appalachian Basin from Morrow County Ohio to Pendleton County West Virginia written by Robert T. Ryder and published by . This book was released on 1992 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Eustasy High Frequency Sea Level Cycles and Habitat Heterogeneity written by Mu Ramkumar and published by Elsevier. This book was released on 2017-02-17 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: Eustatic High-Frequency Sea Level Cycles and Habitat Heterogeneity: Basinal-Regional-Global Implications presents the current understanding and future directions of the research on Cretaceous sea level cycles in a single source. This reference work is for beginners, graduates, and postgraduates who are interested in the subject and intend to venture into serious research. This hybrid text/reference is for beginners, academics, and professionals who intend to document sea level dynamics on long and short time scales and resultant habitat and paleobiodiversity changes. - Presents new and important regional geological knowledge with regard to the sedimentary basins of India - Provides a one-stop-shop on high-frequency sea level cycles and fluctuations, and the impact created by tectonics and climatic cycles - Contains reviews on the current status, case studies, and a look at future trends
Download or read book The Exmouth Plateau written by N. F. Exon and published by National Gallery of Australia. This book was released on 1980 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Structure Stratigraphy and Petroleum Potential of the Portland Trough Otway Basin Victoria written by C. J. Lavin and published by . This book was released on 1995 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Impact of Shelf Margin Geometry and Tectonics on Shelf to sink Sediment Dynamics and Resultant Basin Fill Architectures written by Migdalys Beatriz Salazar and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation focuses on understanding the relative importance of external (eustacy) versus local tectonic and sedimentary processes in controlling continental-margin depositional architectures and their implications for sediment distribution. The emphasis of this study is the interpretation of clinoform geometries and stratigraphic relationships observed on 3D and 2D seismic reflection data in the Taranaki Basin, which is characterized by a variety of clinoform architectures on its Pliocene-Recent margin (Giant Foresets Formation). I combined seismic stratigraphic interpretations and biostratigraphic studies using a dataset that consists of 1,700 km2 of 3D seismic lines, 4,000 km of 2D regional seismic lines, and data from six wells. The study was divided into three sections. First, three major stages of clinoform evolution were identified based on their architectural and geomorphological characteristics. Isochron maps were generated to identify correlations between stratigraphy and paleostructures, and seismic attribute maps were elaborated to identify and characterize geological features and depositional elements. In the second phase of the study, 2D stratigraphic forward modeling techniques were applied in an effort to quantitatively determine the relative importance of the mechanisms acting in the basin (eustacy, tectonism and sediment supply). Finally, a similar approach was applied using clinoform morphologies in the eastern Trinidad margin where the tectonic configuration of the basin was completely different to the one in the Taranaki Basin. The objective was to compare the results in a region with different a tectonic setting to validate the applicability of the methodology in other basins worldwide. The results of this research indicate that the methodology that was developed for the quantitative analysis of clinoform architectures in the Taranaki Basin is applicable to other basins worldwide and that the work flow provides a more comprehensive understanding of the factors that influence continental margin development. Generic observations of this research showed that (1) underlying structures in the shelf and slope area can play an important role in influencing the location and morphology of the shelf edge area and controlling sediment distribution; (2) high sediment supply, along with accommodation, play a key role in the construction of high-relief clinoforms and earlier dispersal of sediments into deep water; and (3) lateral variations associated with high sediment discharge sources (e.g. paleo Orinoco shelf-edge delta) can generate important changes in continental-scale clinoform architectures alongstrike in continental margins influence sediment distribution patterns in the deep-water component of the basin.
Download or read book Geomechanics and Geology written by J.P. Turner and published by Geological Society of London. This book was released on 2017-09-19 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: Geomechanics investigates the origin, magnitude and deformational consequences of stresses in the crust. In recent years awareness of geomechanical processes has been heightened by societal debates on fracking, human-induced seismicity, natural geohazards and safety issues with respect to petroleum exploration drilling, carbon sequestration and radioactive waste disposal. This volume explores the common ground linking geomechanics with inter alia economic and petroleum geology, structural geology, petrophysics, seismology, geotechnics, reservoir engineering and production technology. Geomechanics is a rapidly developing field that brings together a broad range of subsurface professionals seeking to use their expertise to solve current challenges in applied and fundamental geoscience. A rich diversity of case studies herein showcase applications of geomechanics to hydrocarbon exploration and field development, natural and artificial geohazards, reservoir stimulation, contemporary tectonics and subsurface fluid flow. These papers provide a representative snapshot of the exciting state of geomechanics and establish it firmly as a flourishing subdiscipline of geology that merits broadest exposure across the academic and corporate geosciences.
Download or read book Stratigraphic Framework New Siliciclastic Depositional Model and Provenance Analysis in the Virgilian Gzhelian Cisco Group Eastern Shelf of the Permian Basin written by Fritz Charles Palacios Albujar and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Cisco Group records several 4th-order regressive-transgressive (R-T) sequences of mixed siliciclastic and carbonate systems in the Eastern Shelf of the Permian Basin. These sequences formed during the Late Pennsylvanian to Early Permian in the context of relief generation in the Marathon-Ouachita orogenic belt and the climax of the Late Paleozoic Icehouse. Sandstones and limestones within each R-T sequence are significant hydrocarbon reservoirs in the basin. Therefore, with a particular interest in understanding the controls of sandstone distribution, this study examines the variation of mixed siliciclastic and carbonate facies along the dip and strike directions in the Virgilian (Gzhelian) interval of the Cisco Group. With the support of 5,000 well-logs and 952 ft. (290 m) of core, a stratigraphic framework was constructed, and a new depositional model for the siliciclastic deltaic systems was proposed. The framework reveals three periods of shelf evolution influenced by sea-level changes, tectonic subsidence, and a transition to a cool-dry climate during the Virgilian period. A new depositional model for the Virgilian Cisco Group deltas is presented in the Eastern Shelf, consisting of eight facies associations that indicate a significant tidal influence. A compound clinoform geometry characterizes these tide-dominated deltas, and the presence of carbonates adds complexity to the model. In addition to the sedimentological study, this research includes new 1345 U-Pb detrital-zircon ages and biostratigraphic analysis. These analyses provide new insights into provenance and sediment dispersal during the Virgilian period. The detrital zircon ages and palynological samples reveal a predominant provenance from Peri-Gondwanan terranes. Overgrowth in zircons indicates contributions from the Acatlán complex in Mexico and recycled zircons from the Goiás magmatic arc in Brazil. Provenance variations are observed along the Eastern Shelf, with slight variations in zircon presence and age groups. The palynological analysis supports reworking sediments from uplifted wedge-top blocks with Atokan strata. A better understanding of the controls on the architecture and distribution of reservoirs in the Cisco Group supports hydrocarbon exploration and production in the Eastern Shelf and the search for potential aquifers and carbon storage
Download or read book Seismic Sequence Stratigraphy During the Cretaceous Through the Early Paleogene in the Northern Scotian Basin Laurentian Subbasin Offshore Nova Scotia and Newfoundland Canada written by Ika Sulistyaningrum and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis uses seismic-sequence-stratigraphic analysis to show the stratigraphic development of the northern Nova Scotia passive margin (the Laurentian Subbasin) during the Cretaceous through Paleogene. It documents the interplay of several variables on margin evolution including changes in relative sea-level, sediment supply, and tectonic activity including thermoflexural subsidence and salt movement. Salt structures, basement-involved deformation, and sparse well control impede the interpretation of stratigraphic patterns in the study area. Despite these difficulties, I have identified eight candidate sequence boundaries using seismic-reflection terminations: (1) top-lap and truncation below a discontinuity, and (2) on-lap and down-lap above a discontinuity. Study of the sequence stratigraphy in the Laurentian Subbasin reveals two significant unconformities, the Jurassic-Cretaceous (Avalon) unconformity and the Cretaceous-Paleogene (KP) unconformity, and seven sequences: three Cretaceous sequences (Sequences 1, 2, and 3) and four Paleogene sequences (Sequences 4, 5, 6 and 7). Change in relative sea level and sediment-supply directions during the Cretaceous are not well documented. Salt tectonics and thermoflexural subsidence created the accommodation space for the Early Cretaceous sequences. System tracts controlled by relative sea-level change show that sediment supply was from the northwest and depocenters migrated from northeast to southeast during the Paleogene. Comparison of the Baltimore Canyon Trough with the Laurentian Subbasin shows that these basins in the passive margin of eastern North America have similarities and differences. The similarity includes the presence of clinoform geometries above the KP boundary indicating aggradational-progradational stratigraphic patterns. The differences include the major Jurassic-Cretaceous (JK) unconformity, the presence of salt structures, and the presence of Paleogene sequences. In the Scotian Basin, the JK unconformity is a major angular unconformity (Avalon unconformity) separating gently dipping Cretaceous rocks above from folded Jurassic rocks below. However, the JK unconformity in the Baltimore Canyon Trough generally is a paraconformity separating subparallel beds above and below the unconformity.
Download or read book Revised Stratigraphic Framework for the Cutoff Formation and Implications for Deepwater Systems Modified by Large scale Inflections in Slope Angle Below the Shelf Break written by Greg Hurd and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Near times of ocean anoxic events or the peaks of long-term transgressions, carbonate margins may be drowned below a backstepping platform, and preserved as a submarine edifice which demonstrates hundreds-of-meters of vertical relief above the basin floor and forms a large-scale inflection (LSI) in slope angle. This study uses outcrops in the Guadalupe Mountains Region of West Texas, a robust suite of subsurface data from the northern Delaware Basin, and previously published literature in order to illustrate how LSIs influence patterns of sediment dispersal and accumulation in carbonate systems. Outcrops of the Lower Upper Permian Cutoff Formation reveal that processes of channelization, bypass, and slope failure associated with a drowned carbonate margin (LSI) contributed to a dramatic thickening of carbonate, shale, and sandstone strata in the basinward direction. Correlation of this unit to the equivalent shelf system reveals that bedrock channels incising the LSI served as conduits for turbidity currents throughout the transgression and much of the ensuing highstand of a 2-4 m.y. composite sequence (PCS9). In the latest highstand, an increase in the production of carbonate mud by the active shelf system contributed to the complete filling of bedrock channels and the accumulation of carbonate mud-dominated mass-transport deposits basinward of the LSI. Correlation of this shelf-to-slope framework to basinal strata of the Bone Spring and Avalon trends in the subsurface reveals a landward shift in the locus of deposition downdip of the LSI across the northern Delaware Basin which was concomitant with the transition to patterns of sediment dispersal dominated by mass-transport events. Strata associated with turbidite systems accumulate mainly near the center of the basin, and demonstrate basinward-stepping geometries along shallow slope gradients downdip of the LSI, while demonstrating aggradational geometries along steep slopes. Strata associated with mass-transport deposits accumulate near the LSI on both shallow and steep slopes. Previous studies in other basins have documented LSIs which exhibit dimensions and stratal patterns comparable to the relict platform margin in the Delaware Basin. Insights developed from this study can help to improve exploration activities in the Delaware Basin, and other basins with analogous deepwater systems.
Download or read book Petroleum Geology Inventory of Australia s Offshore Frontier Basins written by Jennifer Totterdell and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Oil and gas discoveries in Australia's offshore basins are concentrated on the North West Shelf (Northern Carnarvon, Browse and Bonaparte basins) and Bass Strait (Gippsland, Otway and Bass basins). While discoveries have been made in a few regions outside these areas (e.g. Perth Basin), a large proportion of Australia's offshore basins remain exploration frontiers. However, the decline in oil production from the North West Shelf and Bass Strait basins since 2000 has led to an increasing exploration interest in the frontier basins. In order to improve our knowledge of the offshore frontiers and encourage exploration to these areas, from 2003-2011, Geoscience Australia was funded by the Australian Government to undertake a series of pre-competitive data acquisition and analyses programs in frontier basins around the Australian margin. This Record presents a comprehensive inventory of the geology, petroleum systems, exploration status and data coverage for 35 frontier basins, sub-basins and provinces, that draws on the results of those pre-competitive data programs, as well as exploration results and the geoscience literature. The Record also provides an assessment of the critical science and exploration questions and issues for each area. The results of each basin assessment are summarised in a prospectivity ranking. The availability of data and level of knowledge in each area is reflected in a confidence rating for that ranking. While the prospectivity of some areas is widely acknowledged to be high (e.g. Ceduna Sub-basin), the perception of prospectivity in many basins is negatively affected by the amount or quality of data available; in these basins, the acquisition of new data or targeted research could make a significant difference to the understanding of petroleum potential and likelihood of success. Therefore, recommendations for future work that could assist in addressing key knowledge or data gaps are included in each basin assessment." -- Online abstract.
Download or read book The Influence of Bottom Currents on the Sedimentary Evolution of the Alboran Sea During the Pliocene and Quaternary written by Carmen Juan Valenzuela and published by . This book was released on 2016 with total page 351 pages. Available in PDF, EPUB and Kindle. Book excerpt: "An interdisciplinary study of the geomorphology, sedimentology, stratigraphy and physical oceanography of the deep-sea environments of the Alboran Sea (south-western Mediterranean Sea) has been carried out with the purpose of evidencing and understanding the role of bottom currents in the sedimentary evolution of the Spanish and Moroccan continental margins and adjacent basins during the Pliocene and Quaternary. This study was conducted using swath bathymetry data, more than 1900 profiles consisting of parametric, single- and multi-channel seismic records, scientific and commercial wells, sediment cores, and hydrographic data comprising: Conductivity, Temperature and Depth (CTD) profiles, Acoustic Doppler Current (ADCP) profiles, and EK60 echograms. Here, for the first time, a morphosedimentary scenario with a wide spectrum of depositional (plastered, sheeted, channel-related, mounded confined, elongated and separated drifts) and erosional (terraces, escarpments, moats, channels and furrows) contourite features are described in the Alboran Sea, from the shelf break to the basin floor. Hydrographic data offers new insights into the distribution of the Mediterranean water masses, and reveals that the bottom circulation of the Western Intermediate Water (WIW) and the Levantine Intermediate Water (LIW) interact with the Spanish slope, and the Western Mediterranean Deep Water (WMDW) with the Moroccan slope, Spanish base- of-slope and deep basins. The integration of distinct datasets and approaches allow a new sedimentary model to be proposed for the Alboran Sea that underlines the significance of bottom current processes in shaping deep-sea morphology. This model suggests that the bottom circulation of water masses governs physiography that the interface positions of water-masses with contrasting densities sculpt terraces at a regional scale, and that morphological obstacles play an essential role in the local control of processes and water- mass distribution. An analysis of the seismic stratigraphy from the Pliocene and Quaternary sequences has enabled to update and rename the stratigraphic boundaries and establish a new seismic stratigraphy for the Alboran Sea, after relocating the base of the Quaternary from 1.8 to 2.6Ma. Additionally, the seismic analysis involves the presentation and discussion for the first time of the evidence for contourite features reaching the scale of the Alboran Basin. Contourite drifts (plastered, sheeted, elongated separated and confined mounded drifts) and erosive features (terraces, escarpments, moats, channels, furrows) were developed under the continuous influence of Mediterranean water masses after the opening of the Strait of Gibraltar ( -5.33Ma). At least two primary factors have controlled the contourite features in this sea: i) tectonics, which has governed the relocation of the main Mediterranean flow pathways and their circulation patterns; and ii) climate, which has influenced both water-mass conditions (depth and density contrast of the interfaces) and hinterland sediment sources, conditioning the morphoseismic expression and growth pattern of drifts and terrace formation (dimensions). The distribution of contourite features through time and space allows to propose three main scenarios for ocean circulation since the opening of the Strait of Gibraltar: i) Atlantic Zanclean flooding; ii) the Pliocene sea, with two different stages for the dense circulation and characterised by poorly-defined and unstable interfaces for the Atlantic Waters (AW), light and dense Mediterranean waters and the presence of a strong countercurrent in the Western Basin; and iii) the Quaternary sea, characterised by tabular Mediterranean water masses with multiple current dynamics, increasingly important density contrasts, and climate shifts causing major vertical and horizontal displacement of the interfaces. These stages reflect variability in the bottom current regimes and related alongslope efficiency in terms of transport, deposition and erosion. The detailed seismic analysis of the units making up the Pliocene and Quaternary sequences allows for the first time, to make an in-depth analysis of the contourite features, turbidite systems and mass-movement deposits, and map them through time. These maps are enormously helpful when it comes to understanding the sedimentary architecture of the Spanish and Moroccan continental margins and basins, as well as for decoding the palaeoceanographic processes from a geological perspective. Two main contourite depositional systems are defined: the Intermediate Mediterranean Contourite System (IMCS), formed under the action of the Light Mediterranean Waters (LMW) on the Spanish margin, and the Deep Mediterranean Contourite System (DMCS), formed under the action of the Dense Mediterranean Waters (DMW) mainly on the Moroccan margin and basins. The characterisation of the terraces as contourite features that form under the combination of two water masses, has also led to the definition of the Atlantic Contourite System (ACS). The occurrence of several contourite depositional systems has led to the suggestion of a new term, not heretofore considered in the literature: Multiple Contourite Depositional System (MCDS), which refers to the set of different CDSs that occurs in the same area and evolving under the action of multiple water masses. In addition, twenty turbidite systems have been characterised, revealing that they are responsible for the different sedimentary architecture of the Spanish margin, where they coexist with contourites, as on the Moroccan margin the turbidite systems are less well developed. The mass-movement deposits are mainly related to the reworking of the contourites draping the highs. Mainly contourites but also turbidites, allowed to define from a geological perspective the basic oceanographic processes and to determine their occurrence, relative magnitude and energy, and time of action. This PhD thesis also explains the uneven development of the turbidite systems in the Alboran Sea, which is interpreted to be conditioned by the interaction of alongslope with downslope processes. Several morphological and sedimentary signatures produced by the interaction between both processes have been identified in the Pliocene and Quaternary records, as well as on the present-day seafloor of the Alboran Sea. The interaction scenarios move between two-end-members: from bottom currents dominating gravity flows to gravity flows dominating contour currents. In between these extreme cases, the alternation and mutual influence of both processes can occur. Two different conceptual models of interaction are proposed for the Spanish and Moroccan margins. i) On the Spanish margin, the alongslope and downslope interaction is especially complex and varied, with both regional and local effects on the turbidite systems. This is because here the turbidite systems are influenced at different water depths by Atlantic and Mediterranean water masses and their interfaces, with current flows that change across- and downslope. ii) On the Moroccan margin, the vigorous action of the WMDW primarily inhibits the formation of canyons and associated deposits. The findings of this PhD thesis suggest that the relevance of bottom-water processes in deep sea must be reevaluated. It is concluded that understanding the influence of bottom currents is not only essential for reconstructing present and past water mass circulation, but also for recognising sea floor morphologies and decoding the sedimentary stacking pattern and evolution of deposits, as well as global climate and periods of eustatic variation."--TDX.
Download or read book Petroleum Atlas of Victoria Australia written by Victoria. Minerals and Petroleum Victoria. Petroleum Development Branch. Basin Studies Group and published by . This book was released on 2001 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geology of Victoria written by John G. Douglas and published by . This book was released on 1993 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt:
