bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interplay of tectonics and sea‐level changes in basin evolution: an example from the intracratonic Amadeus Basin, central Australia
Authors: Lindsay JOHN F. , Korsch R. J. 
Published: November 2007

Abstract The Amadeus Basin, a broad intracratonic depression (800 times 300 km) in central Australia, contains a complex Late Proterozoic to mid‐Palaeozoic depositional succession which locally reaches 14 km in thickness. The application of sequence stratigraphy to this succession has provided an effective framework in which to evaluate its evolution. Analysis of major depositional sequences shows that the Amadeus Basin evolved in three stages. Stage 1 began at about 900 Myr with extensional thinning of the crust and formation of half‐grabens. Thermal recovery following extension was well advanced when a second less intense crustal extension (stage 2) occurred towards the end of the Late Proterozoic. Stage 2 thermal recovery was followed by a major compressional event (stage 3) in which major southward‐directed thrust sheets caused progressive downward flexing of the northern margin of the basin, and sediment was shed from the thrust sheets into the downwarps forming a foreland basin. This event shortened the basin by 50–100 km and effectively concluded sedimentation.The two stages of crustal extension and thermal recovery produced large‐scale apparent sea‐level effects upon which eustatic sea‐level cycles are superimposed. Since the style of sedimentation and major sequence boundaries were controlled to a large degree by basin dynamics, depositional patterns within the Amadeus and associated basin are, to a large degree, predictable. This suggests that an understanding of major variables associated with basin dynamics and their relationship to depositional sequences may allow the development of generalized depositional models on a basinal scale.The Amadeus Basin is only one of a number of broad, shallow, intracratonic depressions that appeared on the Australian craton during the Late Proterozoic. The development of these basins almost certainly relates to the breakup of a Proterozoic supercontinent and in large part, basin dynamics appears to be tied to this global tectonic event. Onlap and apparent sea‐level curves derived from the sequence analysis appear to be composite curves resulting from both basin dynamics and eustatic sea‐level effects. It thus appears likely that sequence stratigraphy could be used as a basis for inter‐regional correlation; a possibility that has considerable significance in Archaean and Proterozoic basins.
Simple equations of sedimentation: applications to sequence stratigraphy
Authors: Cant DOUGLAS J. 
Published: November 2007

Abstract An equation to relate the thickness of sediment deposited (ΔSed), eustatic sea‐level change (ΔE), and subsidence (ΔSub), to changes in depth of water (ΔD) is: ΔSub +ΔE‐ΔSed =ΔD.Using existing sea‐level curves, the equation shows that some transgressive‐regressive sequences in a foreland basin and a composite seismic facies sequence on a passive margin cannot result solely from eustatic variation. In each case, the space created by subsidence is greater than that provided by eustatic rise. However, eustatic variation could have triggered sequence development if superimposed on a basin with relatively constant values of the other parameters. Short‐period sea‐level fluctuations with high rates of change, exceeding 70–100 m Myr‐1 for periods less than 2–3 Myr, affect the stratigraphy and sedimentology more than longer period, higher amplitude variations.Clinoforms are generated because of lateral variations in sedimentation rate compared to the rate of creation of accommodation space. These variations may result from differing sedimentation rates, subsidence rates, or rates of eustatic change, superimposed on a basin with lateral sediment supply. Clinoform slopes and curvatures are interpre table in terms of these variables as well as the type of sediment supplied and the energy distribution in the basin.These equations put some well‐known geological principles on a simple quantitative basis. They force precision in definition of variables, and may lead to further development of quantitative techniques in stratigraphy and sedimentology.
Mesozoic sedimentation rates in the Western Canada Basin as indicators of the time and place of tectonic activity
Authors: Chamberlain V. E. , Lambert R. ST J. , McKerrow W. S. 
Published: November 2007

Abstract The Mesozoic stratigraphy of the westernmost part of the Western Canada Basin is used to estimate sedimentation and relative crustal subsidence rates in the region between 49oN and 60oN, immediately to the east of the disturbed belt. Average rates of subsidence varied from zero to 120 m/Myr, with prominent maxima occurring three times during the Mesozoic. The first occurred during the Tithonian, when rates rose to 100 m/Myr; the second during the Albian to early Santonian, when rates rose to 120 m/Myr in the north and to 70 m/Myr in the south, with subsidence occurring earlier in the north than in the south. The third period of rapid subsidence occurred during the Campanian and Maastrichtian, with rates rising to 120 m/Myr in the southern part of the basin. During non‐peak periods, average rates of subsidence ranged from 3.5 m/Myr to 35 m/Myr in the Triassic, from zero to 20 m/Myr in the Jurassic and from zero to 30 m/Myr in the Cretaceous.Tectonic loading of the lithosphere is considered to be the most probable cause for all three of these periods of rapid subsidence. The three separate episodes are correlated with the separate arrivals of accreted terranes; the first in north‐east Oregon and central west Idaho during the Late Jurassic, the second in the central Yukon during the late Early Cretaceous and the third in south‐east British Columbia during the Late Cretaceous.
The interaction of eustacy and tectonism from provenance studies of the Eocene Hecho Group Turbidite Complex (South‐Central Pyrenees, Spain)
Authors: Fontana DANIELA , Zuffa GIAN GASPARE , Garzanti EDUARDO 
Published: November 2007

Abstract Using a detailed petrographical procedure conceived for arenites rich in carbonate clasts, the influence of tectonism and eustacy on silicate/carbonate cycles of the Eocene Hecho Turbidite Complex has been tested, and the palaeogeography of the source/basin system outlined.Both extrabasinal and intrabasinal sources of sediments were active during basin filling. The extrabasinal source terrains, located in the southern sector of the basin, were made of the Pyrenean crystalline basement (granites, gneisses and phyllites) overlain mainly by carbonate rocks (Cretaceous limestones and dolostones, minor chert and siltstones). The intrabasinal sources, represented by foramol shelf carbonate factories, provided penecontemporaneous carbonate bioclasts, intraclasts and peloidal grains.Foreland thrusting in the South‐Central Pyrenees has acted as the major control on the composition and architecture of the Hecho Turbidite Complex. Strong uplift of old silicate and carbonate source terrains during southward thrust propagation was responsible for erosion, swamping and/or reduction of shelfal areas, and gave rise to siliciclastic and carbonate basinal sequences (silicate arenites and calclithites) during lowstand stages. Conversely, hybrid arenites (mixture of extrabasinal and intrabasinal grains) originated from resedimentation of marginal shelf sediments produced in carbonate factories active during the initial phase of sea‐level rise. Hybrid arenites with minor intrabasinal content also formed during one stage of relative sea‐level fall from the erosion of previously accumulated highstand complexes.During resedimentation processes, hybrid sands underwent marked hydraulic selection documented by deposits depleted in carbonate grains in the channel area, and by thin‐bedded turbidites rich in platy‐skeletal fragments, low‐density peloids and void‐rich bioclasts down‐basin.
Half‐graben basin filling models: new constraints on continental extensional basin development
Authors: Schlische Roy W. 
Published: November 2007

AbstractThree end‐member models of half‐graben development (detachment fault, domino‐style, and fault growth) evolve differently through time and produce different basin‐filling patterns. The detachment fault model incorporates a basin‐bounding fault that soles into a subhorizontal detachment fault; the change in the rate of increase in the volume of the basin during uniform fault displacement is zero. Younger strata consistently pinch out against older synrift strata rather than pre‐rift rocks. Both basin‐bounding faults and the intervening fault blocks rotate during extension in the domino fault block model; a consequence of this rotation is that the change in the rate of increase of the volume of the basin is negative during uniform extension. Basin fill commonly forms a fanning wedge during fluvial sedimentation, whereas lacustrine strata tend to pinch out against older synrift strata. In the fault growth models, basins grow both wider and longer through time as the basin‐bounding faults lengthen and displacement accumulates; the change in the rate of increase in basin volume is positive. Fluvial strata progressively onlap pre‐rift rocks of the hanging wall block, whereas lacustrine strata pinch out against older fluvial strata at the centre of the basin but onlap pre‐rift rocks along the lateral edges. These fundamental differences may be useful in discriminating among the three end‐member models. The transition from fluvial to lacustrine deposition and hanging wall onlap relationships observed in numerous continental extensional basins are best explained by the fault growth models.
Tectonic loading, sedimentation, and sea‐level changes in the foreland basin of north‐west Alberta and north‐east British Columbia, Canada
Authors: Underschultz J. R. 
Published: November 2007

AbstractBy calculating mass accumulation rates for foreland basin sediments, the changing capacity of the basin can be monitored through time. It has often been assumed that there was a direct link between foreland basin sedimentation and tectonic deformation and lithospheric loading in the adjacent orogenic belt. The results of this study suggest that tectonic deformation is most likely associated with the changing capacity of the basin and the rate at which sediments accumulate within it, However, there appears to be no relation between tectonic deformation and the lithology of sediment which accumulates in the foreland basin. Instead, eustatic sea‐level fluctuations appear to have significant control, through their impact on water depth, on the lithology of sediments accumulating in the foreland basin. These relations are evidenced by mass accumulation rates calculated for foreland basin strata in north‐west Alberta and north‐east British Columbia, Canada.
Tectonic brines and sedimentary basins: further applications of fission track analysis in understanding Karoo Basin evolution (South Africa)
Authors: Duane Michael J. , Brown Roderick W. 
Published: November 2007

AbstractFission track analyses of detrital components in the Permo‐Triassic Karoo Basin (South Africa), highlight the potency of tectono‐magmatically driven fluids to penetrate wide and far in foreland basins. The data, together with the data published on Karoo tectonics and magmatism, support a model which requires that fluids were driven north out of the Cape‐Karoo orogen during the Cape Orogeny (270–200 Ma). Later fluids were redistributed and aquifers rejuvenated during (and after) the final break‐up of Gondwana (<200 Ma). The fission track data indicate that thermal annealing of fission tracks in zircon occurs non‐uniformly between individual zircon grains. This model is in agreement with recent models applied to deformed foreland basins and implicates tectonic fluids in U metallogenesis.
Tectonic development of the Drummond Basin, eastern Australia: backarc extension and inversion in a Late Palaeozoic active margin setting
Authors: Johnson S. E. , Henderson R. A. 
Published: November 2007

AbstractDetailed seismic reflection data combined with regional magnetic, gravity and geological data indicate that the Drummond Basin originated as a backare extensional basin associated with Late Devonian and Early Carboniferous active margin tectonism in the northern New England Fold Belt. Seismic reflection data have been used to generate a two‐way time map of seismic basement, providing a clear view of the basinal geometry and structural development. Broadscale structural asymmetry of the basin implies that simple shear along a deep, upper‐crustal detachment provided the extensional mechanism and generated an inter‐related set of listric normal faults and associated transfer faults, as well as steeply‐dipping planat normal faults. The orientation of normal faults near the basin margins appears to have been controlled by regional basement structural trends. Transfer‐fault trends were approximarely orthogonal to the line of plate convergence as assessed from the orientation of coeval are, forcare and subduction complex stratorectonic elements. Three distinct phases of infill are represented in the basinal stratigraphic succession. The first consists largely of volcanics and volcaniclastics, indicating that effusive magmatism and extension were closely associated in space and time. The second is quartzose and of basement derivation, but was not derived from footwall blocks at the faulted basinal margins to the east and north. Uplifted hanging‐wall crust beyond the western basinal margin, a product of west‐directed simple shear detachment, was the likely source terrain. The final infill phase consisted of volcaniclastics considered to have been derived from a coeval volcanic are to the east. Major faults at the basin margins provided conduits for magmatism during extensional basin development, and long after the basinal history was complete. During the Late Carboniferous and mid‐Triassic, the basin was affected by two discrete episodes of compressional deformation. This led to inversion with the development of folds, and reverse and wrench faults now seen at the surface.
Purana basins of peninsular India: a review
Authors: Kale Vivek S. , Phansalkar V. G. 
Published: November 2007

AbstractSeven supracratonic, Proterozoic basins, occupying more than a fifth of the Precambrian exposures in the Indian Peninsula, comprise the Purana basins. A comprehensive review of the current status of knowledge of these voluminous orthoquartzite‐carbonate‐shale suites in the context of their contemporary lithostratigraphy, depositional environments and structural disposition is presented. Stromatolite biostratigraphy and available geochronological data are compared, to discern their age limits.These basins contain perhaps one of the most elaborate records of Middle to Late Proterozoic (Riphean‐Vendian) sedimentation preserved in an unmetamorphosed and only slightly deformed state. Further sedimentological and structural studies could lead to a better understanding of the Proterozoic craton‐margin processes. Their close association with the Middle Proterozoic Mobile Belt of peninsular India is that of two contrasting tectonic regimes, contemporaneously adjoining each other. The existing lithostratigraphic classifications of many of these sequences may not stand the test of process ‐ response considerations as demonstrated by the recent revisions in the stratigraphy of the Cuddapah and Bhima basins. The prolific stromatolitic, micro‐organic and trace‐fossil communities preserved in them require much more detailed, but cautious study, and may yield information on the Riphean‐Vendian biota. However, these studies must be undertaken in association with elaborate geochronological determinations which are sparse at present.Inadequacy of the existing knowledge of these basins is highlighted, with the view of inviting the attention of the geological community to these unique basins from peninsular India.
Structure of the Central North Aegean Trough: an active strike‐slip deformation zone
Authors: Roussos Nicolas , Lyssimachou Triantafyllos 
Published: November 2007

AbstractDetailed interpretation of marine seismic data shows the presence of an extending, active, dextral strike‐slip fault zone at the south edge of the Mount Athos Peninsula. The zone is over 100 km long and has both transtensional and transpressive features observable on the seismic lines. We suggest that dextral strike‐slip displacement along the zone is on the order of 5–7 km. The structure and fault patterns of Recent deformation in the Central North Aegean Trough is typical of strike‐slip tectonism.
Application of a dual‐lithology, depth‐dependent diffusion equation in stratigraphic simulation
Authors: Rivenæs Jan C. 
Published: November 2007

ABSTRACTA process‐based dynamic‐slope approach is incorporated in a two‐dimensional (2D) stratigraphic basin simulation software. It is based on the classical topographical diffusion concept, but in contrast to previous models it predicts down‐slope sorting of two grain‐size classes (here sand and mud). The effect of compaction is included in the mass balance, as well as arbitrary depth‐dependent transport coefficients (difrusivities). Each lithology will have its own transport‐coefficient function, which can be tuned to predict realistic lithology dispersion (e.g. trapping of sand in shallow‐marine environments). The set of partial‐differential equations is solved numerically by using a fully implicit finite difference method, applying a Newton iteration scheme on the non‐linear equations.Simulations show that the mass balance due to compactional effects is taken care of. A case from a technically quiescent margin demonstrates, as commonly observed in nature, that the sand fraction increases on the alluvial plain when accommodation space is limited. In the marine part, sand‐rich coarsening‐upward sequences form during progradation, while a condensed and partly erosional maximum flooding surface (MFS) forms during transgression. The MFS is associated with very shaly lithology, a feature that is observed both in field work and on geophysical well logs. If compaction and isostasy modelling are included in this case, the overall architecture is altered. The deposits become proximal, and the timing of maximum regression, etc. is modified. Alternatively, if the time span of simulation is doubled, the result is lower slope angles and increased penetration distance of the sediment wedge into the ljasin. Thus, it is demonstrated that a process‐based dynamic‐slope approach with lithology sorting is a rich alternative to more geometrically based models when the formation of large‐scale stratigraphic architecture is investigated.
Volcanism and sedimentation in part of a Late Archaean rift: the Hartbeesfontein basin, Transvaal, South Africa
Authors: Karpeta W. P. 
Published: November 2007

AbstractThe Hartbeesfontein basin is one basin within the Late Archaean rift system of South Africa. This rift system has been recently compared to the Basin and Range province in western North America and may therefore be an ensialic extensional back‐arc basin. Structurally, the Hartbeesfontein basin is a half‐graben structure bounded to the south‐east by a major, normal, listric fault and to the north‐east and south‐west by strike‐slip (transfer?) fault zones. It is infilled by over 2000 m of diamictites, shales, lavas and chemical sediments. Initial basin formation appears to be accompanied by phreatomagmatic volcanic activity caused by the interaction between basic tholeiitic magmas rising along fractures and groundwater. Volcaniclastic debris from these eruptions was incorporated into laharic debris flows and deposited on basin marginal alluvial fans. At the same time a deep, permanent lake formed within the basin in which silts and muds accumulated. Major fissure eruptions of basic, tholeiitic lavas followed, their eruptive centres being apparently located along the strike‐slip (transfer?) fault /ones. Initially, these fissure eruptions had high rates of magma discharge accompanied by intense fire fountaining that resulted in the rapid accumulation of aa type flows. Later lava discharge rates decreased and more quiescent pahoehoe type flows were erupted. Localized centres of acid volcanism within the basic lava pile were located along the south‐western strike‐slip fault zone. These acid volcanic rocks are interpreted as co‐ignimbrite lag breccias and pyroclastic flow deposits and tuffs produced by the repeated formation and collapse of Plinian eruption columns. Towards the top of the basic lava pile, two breaks in volcanism permitted the formation of dolomitic playa lakes. Sedimentation in these lakes was terminated by further basic lava flows. At the top of the basin fill sequence is a thick, bedded chert interpreted as a magadiitic, alkaline playa lake fed by silica‐rich hot springs located along the south‐eastern edge of the basin. Quartzites and conglomerates deposited by braided rivers unconformably overlie the basin‐fill sequence and probably represent a through flowing river system signifying termination of the Hartbeesfontein basin as a separate basin. The Hartbeesfontein basin and its fill demonstrate that a close relationship exists between fissure volcanism, sedimentation and basin evolution and that the strike‐slip, transfer faults acted as the loci of volcanic activity.
Structural evolution of African basins: stratigraphic synthesis
Authors: Sahagian DORK L. 
Published: November 2007

AbstractThe structural and stratigraphic character of African interior sedimentary basins is highly variable, indicating contrasting basin‐forming mechanisms and subsequent subsidence histories. A stratigraphic database has been compiled for African interior depositional basins for the purpose of better understanding basin thermal and structural development. Data are recorded in the form of stratal age, lithology, thickness and elevation of top with respect to present sea level. The data are obtained from published structure contour maps, well sections, and outcrop geology and elevation. There are various degrees of data coverage of the basins, proportional to the amount of water and oil drilling activity. Consequently, there is excellent coverage of North African basins such as the Algerian basin and the Sirte basin, while there is little known about the subsurface of the Congo basin. The stratigraphic data are used to reconstruct the depositional history of the basins, while backstripping leads to the quantification of the thermo‐tectonic component of basin subsidence. The nature of basement subsidence can provide constraints on lithospheric flexural rigidity. In addition, the depositional and thermo‐tectonic history of each basin bears upon the mechanisms of basin formation and subsidence. Virtually all types of basins are represented in interior Africa, including thrust‐loaded basins (Algerian), passive‐margin rift basins (Algerian, Sirte), modern active rift basins (East African), ancient rift basins (Benue, Abu Gabra), basins caused by uplift of their margins (Congo, Chad, Illumeden) and even basins that may be related to thermal subsidence of hot‐spot domes (Algerian, Sirte).