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1
Menier, David, Bernadette Tessier, Jean-Noël Proust, Agnès Baltzer, Philippe Sorrel e Camille Traini. "The Holocene transgression as recorded by incised-valley infilling in a rocky coast context with low sediment supply (southern Brittany, western France)". Bulletin de la Société Géologique de France 181, n.º 2 (1 de março de 2010): 115–28. http://dx.doi.org/10.2113/gssgfbull.181.2.115.
Resumo:
Abstract A combination of morphobathymetric studies, very high-resolution seismics, core sampling and radiocarbon age data is used to investigate the latest stage of the sedimentary infilling of incised valleys in southern Brittany, related to the Holocene transgression. Owing to the bedrock morphology of this highly irregular rocky coast, two main types of valleys are defined by topographic rocky highs parallel to the coastline: 1) wide and rather shallow incised valleys offshore from a topographic sill, 2) narrow and relatively deep valleys between the sill and the coast (ria-type valley). The sedimentary infilling in both types of valleys becomes highly differentiated as the transgression advances onto the coastal area. In the wide valley seaward of the topographic sill, the infilling consists mainly of offshore heterolithic facies while, in the ria-type valley, most of the infill is composed of brackish mudflat deposits and estuarine tidal muddy sands. As the transgression proceeds, the rocky highs are flooded and the whole area is finally covered by the offshore facies. Radiocarbon dating indicates that: 1) the marine ravinement surface is highly diachronous (a few thousand years cross-shore); 2) the top of the offshore facies, coarser and very shelly, represents an episode of condensed sedimentation from about 3000 to 4000 years ago, amalgamating the maximum flooding surface (MFS) and the highstand systems tract (HST). However, we observe a muddy drape, strongly bioturbated in places, in the most proximal areas, overlying the offshore facies. It is thought to represent the modern and most recent stage of sedimentary infilling. This mud cover is made of fine-grained sediments of fluvial and biological origin, and is interpreted as a prograding HST. It reflects an increased influx, partly due to human activities. Finally, the main features of incised valley sedimentary infilling in a rocky coast context with low sediment supply can be characterized by (i) the very strong control of bedrock morphology, (ii) the diachronous character of the transgression, (iii) the late position of the MFS, and (iv), the highly reduced volume of the HST.
2
Farrand, William R., e Jill P. McMahon. "History of the sedimentary infilling of Yarimburgaz Cave, Turkey". Geoarchaeology 12, n.º 6 (setembro de 1997): 537–65. http://dx.doi.org/10.1002/(sici)1520-6548(199709)12:6<537::aid-gea3>3.0.co;2-#.
3
Freiman, S. I., A. M. Nikishin e E. I. Petrov. "Cenozoic clinoform complexes and geological history of the North-Chukchi basin (Chukchi sea, Arctic)". Moscow University Bulletin. Series 4. Geology, n.º 4 (28 de agosto de 2019): 11–19. http://dx.doi.org/10.33623/0579-9406-2019-4-11-19.
Resumo:
New sesmostratigraphic model has been established for the sedimentary cover of the North-Chukchi basin. Based on the model interpretation of the main paleogeographic events within the territory was performed. We identify three stage in the post-rift sedimentary history of the North-Chukchi basin: Late Cretacerous to Paleocene stage when strong progradation of shelf sedimentary packages was occurred, Mid Eocene — Miocene, with gradual infilling of the basin from different sides and Late Miocene to Present stage with present shapes of the shelf and slow clinoform complex aggradation.
4
Odonne, Francis, Daniel Beaufort, Romain Munck, Laure Bourrières e José Darrozes. "Smectite as a marker of telogenetic process along structural heterogeneities of sedimentary basin: case study of the Eocene submarine slide surfaces of the Ainsa Basin". Bulletin de la Société géologique de France 188, n.º 4 (2017): 22. http://dx.doi.org/10.1051/bsgf/2017186.
Resumo:
Fluid circulation in sedimentary basins is responsible for the transformation and cementation of mineral grains during diagenesis. Concretions and pipe chimneys are obvious features resulting from such circulation but some transformations in the matrix of rocks, if less spectacular, may lead to pervasive transformations of the sediments. Inherited slide surfaces in the Eocene Ainsa Basin (Spanish Pyrenees) have been chosen to test this hypothesis. In the Sobrarbe delta, the steady mineralogy of marls indicates homogeneity of the sedimentary source. Enrichment of montmorillonite is only observed close to scar surfaces and in the infilling of the scars. Scanning electron microscope (SEM) observation reveals that smectites are formed by in situ replacement of detrital mafic minerals resulting by transformation of detrital minerals under the action of cold sedimentary fluids, lower than 75 °C. The indications of low temperature conditions and local fluid circulation both support a meteoric origin of the fluids postdating the burial history, probably during an exhumation of the basin associated with the tectonic uplift. The higher smectite contents in the infilling of scars and along the unconformities of slide surfaces reveals enhanced circulation of fluids in under-consolidated sediments and the effective fluid circulation pathways along inherited slide surfaces.
5
Amoussou, Ernest, Henri S. Totin Vodounon, Expédit W. Vissin, Gil Mahé e Marc Lucien Oyédé. "Sedimentary evolution and ecosystem change in Ahémé lake, south-west Benin". Proceedings of the International Association of Hydrological Sciences 377 (16 de abril de 2018): 91–96. http://dx.doi.org/10.5194/piahs-377-91-2018.
Resumo:
Abstract. Tropical moist ecosystems, such as Ahémé lake, south-west Benin, are increasingly marked by water degradation, linked with the activities of increasing riparian populations. The objective of this study is to analyze sedimentary dynamics and its influence on the changing ecosystem of Ahémé lake from 1961–2010. Data used to carry out the study are records of precipitation, flows, turbidity, suspended sediment, mineral elements and bathymetry. Grain size data from the sieving of sediment samples were used to interpret suspended solids distribution in the lake. Linear correlation coefficients were used to assess the degree of dependence between rainfall and runoff inputs to the lake. Lake depth measurements in some areas of the lake serve to determine the rate of infilling. The sorting index was used to highlight the distribution and origin of sediments in the lake. The results show a degradation of the lake Ahémé ecosystem characterized by infilling of its bed, a high correlation (r=0.90) between rainfall and runoff, seasonal change in physicochemical parameters (total suspended sediment decrease by −91 %) and decrease in fish production by 135.8 t yr−1. The highest mean suspended sediment concentrations in lake inputs occur during high water periods (123 mg L−1) compared to low water periods (11.2 mg L−1).
6
Li, Yuan, Wenhui Huang, Bo Jiu, Qilong Sun e Qingsong Che. "Modes of Occurrence and Origin of Minerals in Permian Coals from the Huainan Coalfield, Anhui, China". Minerals 10, n.º 5 (29 de abril de 2020): 399. http://dx.doi.org/10.3390/min10050399.
Resumo:
Minerals in coal provide useful information for not only paleo-environments of peat accumulation, but also for geological evolution during later diagenesis and/or epigenesis. This paper reports new data on coal quality and the mineralogical and geochemical compositions of 17 unaltered (by intrusion) coal samples collected from the Huainan coalfield, providing new insight into the origins and modes of occurrence of the minerals in coal and their geological evolution. The results showed that the studied coal samples were low rank bituminous coal, with low ash yield (11.92–38.31%, average 24.80%) and high volatile content (25.13–43.43%, average 37.29%). Minerals in the coal mainly included kaolinite and quartz; varying proportions of calcite, siderite, ankerite, and pyrite; and traces of chlorite, zircon, strontianite, apatite, and gorceixite. Typical modes of mineral occurrence could be used to determine the formation stage of minerals. The detrital mineral, occurring as sub-angular to rounded discrete fragments or thin layers intimately admixed with organic matter at particular horizons, was of terrigenous origin, deposited during peat accumulation. Cell infillings, as well as nodule siderites and polycrystalline aggregates of pyrite, precipitated during the syngenetic to early diagenetic stages. Cleat infillings, compressed cell infillings, and fracture infillings precipitated in the epigenetic stage. However, the stage of mineral formation of the pore infilling was difficult to determine. Combined with coal quality, mineralogy, and geochemical analysis, the sedimentary environment of Shanxi Formation was affected by seawater, and Fe-rich hydrothermal fluids filled into the No. 3 coal seam in the epigenetic stage. The sedimentary environment of the No. 8 coal seam had widespread reduction and acid conditions due to basin subsidence, and sulfate-rich hydrothermal fluids may have been formed during the peat deposition stage. In contrast, the peat accumulation environment of the Upper Shihezi Formation was oxidized with a low pH condition. Alkaline fluid then flowed into the No. 13-1 coal seam in the epigenetic stage.
7
Beauchamp, Jacques, Alain Izart e Alain Piqué. "Les bassins d'avant-pays de la chaîne hercynienne au Carbonifère inférieur". Canadian Journal of Earth Sciences 28, n.º 12 (1 de dezembro de 1991): 2024–41. http://dx.doi.org/10.1139/e91-183.
Resumo:
The evolution of marine sedimentary basins deformed by the Hercynian Orogeny was studied in Germany, France, Iberia, Northwest Africa, and North America in the Lower Carboniferous. These basins opened along strike–slip faults and were filled with turbidites and shelf deposits until the main compressive phase at the end of Visean and the Namurian. The infilling was interrupted with frequent volcanic episodes and gravity-induced movements. According to sedimentary vergence, these basins were set into two festoons on both sides of an elongated and emergent swell structured during the Devonian and corresponding to the internal zones of the orogen. These basins were filled during a general tectonic compression phase; they correspond to the foreland basins of the Hercynian belt.
8
Cleveringa, P., T. Meijer, R. J. W. van Leeuwen, H. de Wolf, R. Pouwer, T. Lissenberg e A. W. Burger. "The Eemian stratotype locality at Amersfoort in the central Netherlands: a re-evaluation of old and new data". Netherlands Journal of Geosciences 79, n.º 2-3 (agosto de 2000): 197–216. http://dx.doi.org/10.1017/s0016774600023659.
Resumo:
AbstractIn order to obtain a better understanding of the infilling of the Saalian glacial basins during the Eemian, particularly following the recent research in the Amsterdam Basin (Terminal borehole), it was necessary to re-investigate the type locality of the Eemian at Amersfoort. Both published and unpublished data from various biota (diatoms, foraminifers, molluscs, ostracods, pollen) provide new information on the changing sedimentary environments during the Eemian. Although the organic and clastic sediments of the infilling represent nearly all the pollen zones, the sedimentary sequence at Amersfoort is discontinuous: four breaks at least are recognised at the type locality.The successive sedimentary environments and the breaks in the record are linked with the transgression of the Eemian sea, the topographic position at the margin of an ice-pushed ridge, and the changes in hydrodynamic conditions. Local conditions, such as a sandy sea bed, shallow water and a reduced water exchange near the North Sea margin, influenced the salinity of the basin. Rib counts of Cerastoderma edule shells indicate a higher salinity at the end of the Taxus (E4b) and the beginning of the Carpinus (E5) zones than that present in the modern North Sea. Local conditions were responsible for the higher salinity following the climate optimum.During the Abies phase (the later part of regional pollen zone E5), the sea level had already fallen. The change from eu-trophic peat growth (with Alnus and Salix) to an oligotrophic Ericaceae/Sphagnum community at the end of the Eemian resulted from the change from a marine to a fresh-water environment, probably coherent with a deterioration of the climate.
9
Barnett, P. J., J. P. Coakley, J. Terasmae e C. E. Winn. "Chronology and significance of a Holocene sedimentary profile from Clear Creek, Lake Erie shoreline, Ontario". Canadian Journal of Earth Sciences 22, n.º 8 (1 de agosto de 1985): 1133–38. http://dx.doi.org/10.1139/e85-115.
Resumo:
An abandoned channel of Clear Creek, cut approximately 5 m below the present level of Lake Erie, was cored and the infilling sediments were examined. The postglacial history of this channel was reconstructed based on sedimentological, palynological, and chronological studies.The channel was cut initially some 15 m into Wentworth Till during the low-water Early Lake Erie stage. The infilling or aggradation of the channel began about 9500–9000 years BP, probably in response to rising water levels in the Lake Erie basin.This channel was cut off from the main channel shortly afterwards and an oxbow lake formed. By 7000 years BP, complete cutoff of the channel from the main stream system had occurred, allowing peat to accumulate. Eventually trees grew on this site, 4000 years BP.The diversion of glacial Lake Nipissing drainage into the Lake Erie basin may be reflected in the greater abundance of silt laminations in the peat of the upper part of the channel fill between 5975 ± 150 (BGS-899) and 3900 ± 100 (BGS-898) years BP.A rise in water level in the Lake Erie basin possibly over the Clear Creek site is recorded by the "drowning" of the forest shortly after 3900 ± 100 (BGS-898) years BP and the truncation of the Clear Creek site pollen diagram.
10
Horvath, David G., e Jeffrey C. Andrews-Hanna. "The hydrology and climate of Mars during the sedimentary infilling of Gale crater". Earth and Planetary Science Letters 568 (agosto de 2021): 117032. http://dx.doi.org/10.1016/j.epsl.2021.117032.
11
Wysocka, Anna, Andrzej Radwański, Marcin Górka, Maciej Bąbel, Urszula Radwańska e Michał Złotnik. "The Middle Miocene of the Fore-Carpathian Basin (Poland, Ukraine and Moldova)". Acta Geologica Polonica 66, n.º 3 (1 de setembro de 2016): 359–409. http://dx.doi.org/10.1515/agp-2016-0017.
Resumo:
Abstract Studies of Miocene sediments in the Fore-Carpathian Basin, conducted by geologists from the University of Warsaw have provided new insights on the distribution of the facies infilling the basin, particularly in the forebulge and back-bulge zones. The origin of the large-scale sand bodies, evaporitic deposits and large-scale organic buildups is discussed, described and verified. These deposits originated in variable, shallow marine settings, differing in their water chemistry and the dynamics of sedimentary processes, and are unique with regard to the fossil assemblages they yield. Many years of taxonomic, biostratigraphic, palaeoecologic and ecotaphonomic investigations have resulted in the identification of the fossil assemblages of these sediments, their age, sedimentary settings and post-mortem conditions. Detailed studies were focused on corals, polychaetes, most classes of molluscs, crustaceans, echinoderms, and fishes.
12
Tessier, Bernadette, Nicolas Delsinne e Philippe Sorrel. "Holocene sedimentary infilling of a tide-dominated estuarine mouth. The example of the macrotidal Seine estuary (NW France)". Bulletin de la Société Géologique de France 181, n.º 2 (1 de março de 2010): 87–98. http://dx.doi.org/10.2113/gssgfbull.181.2.87.
Resumo:
Abstract The results of a seismo-stratigraphic study performed to study the Holocene sedimentary infilling at the mouth of the Seine River are presented. Combined data comprise very high resolution seismic reflection profiles, vibrocores, up to 4.5 m long, radiocarbon dating and old bathymetric charts. The infill is divided into two main stages: the transgressive systems tract, relative to the early Holocene high rate of sea-level rise, from 9000 to 7000 cal B.P., made of fine-grained, organic-rich, tidal flat to swamp deposits; the highstand systems tract, relative to the middle to late Holocene low rate of sea-level rise, from 7000 to 3000 cal B.P., characterized by the development of the high energy estuarine body above the main axis of the incised valley. Simultaneously, on the southern edge of the valley, a coastal barrier constructed above a bedrock plateau under the dominant action of waves. At 3000 cal B.P., probably in relation to a major climatic deterioration, the destruction of the barrier occurred and the tidal estuarine body expanded finally over the whole incised valley area. The rate of sea-level rise and the bedrock morphology appear to be the two main key-factors that control the sedimentary infilling architecture of this macrotidal, tide-dominated estuarine setting at the pluri-millenium Holocene time scale. Also, rapid climate changes determine part of the infill pattern, especially during the late Holocene sea-level highstand context.
13
Mariani, Guido S., Italo M. Muntoni e Andrea Zerboni. "The Eneolithic/Bronze Age Transition at Tegole di Bovino (Apulia): Geoarchaeological Evidence of Climate Change and Land-Use Shift". Quaternary 3, n.º 2 (16 de maio de 2020): 14. http://dx.doi.org/10.3390/quat3020014.
Resumo:
Human communities at the transition between the Eneolithic period and the Bronze Age had to rapidly adapt to cultural and climatic changes, which influenced the whole Mediterranean. The exact dynamics involved in this crucial passage are still a matter of discussion. As newer studies have highlighted the key role of climatic fluctuations during this period, their relationship with the human occupation of the landscape are yet to be fully explored. We investigated the infilling of negative structures at the archaeological site of Tegole di Bovino (Apulia, Southern Italy) looking at evidence of the interaction between climate changes and human strategies. The archaeological sedimentary deposits, investigated though geoarchaeological and micromorphological techniques, show the presence of natural and anthropogenic infillings inside most structures. Both human intervention and/or natural events occurred in the last phases of occupation of the site and its subsequent abandonment. The transition to unfavorable climatic conditions in the same period was most likely involved in the abandonment of the site. The possible further impact of human communities on the landscape in that period, testified by multiple other archives, might have in turn had a role in the eventual change in land use.
14
Bharti, Rajiv R., Isaac B. Smith, S. K. Mishra, N. Srivastava e Shital H. Shukla. "SHARAD detection of sedimentary infilling within an unnamed crater near Mangala Fossa region, Mars". Icarus 371 (janeiro de 2022): 114713. http://dx.doi.org/10.1016/j.icarus.2021.114713.
15
Suydam, James D., e David R. Gaylord. "Toroda Creek half graben, northeast Washington: Late-stage sedimentary infilling of a synextensional basin". Geological Society of America Bulletin 109, n.º 10 (outubro de 1997): 1333–48. http://dx.doi.org/10.1130/0016-7606(1997)109<1333:tchgnw>2.3.co;2.
16
McClaughry, Jason D., e David R. Gaylord. "Middle Eocene sedimentary and volcanic infilling of an evolving supradetachment basin: White Lake Basin, south-central British Columbia". Canadian Journal of Earth Sciences 42, n.º 1 (1 de janeiro de 2005): 49–66. http://dx.doi.org/10.1139/e04-105.
Resumo:
The middle Eocene White Lake and Skaha formations in the White Lake Basin, British Columbia record the sedimentary and volcanic infilling of a supradetachment basin that developed during the latter stages of Shuswap metamorphic core complex exhumation. The 1.1-km-thick White Lake Formation is characterized by volcanogenic sediment gravity flow, fluvial, and sheetflood facies interbedded with volcanic deposits. Facies relations suggest White Lake strata accumulated on coalesced, west-sloping alluvial fans that drained an active volcanic center. The overlying 0.3-km-thick Skaha Formation records increased tectonism and mass-wasting. Pervasively shattered Skaha avalanche, slide, and sheetflood deposits accumulated on alluvial fans, shed from hanging-wall and footwall sources exposed along the Okanagan Valley fault. Clast compositions of the White Lake and Skaha formations record alluvial and tectonic stripping that locally eliminated hanging-wall blocks. Mylonite clasts in upper Skaha beds imply significant Okanagan Valley fault footwall uplift during the middle Eocene and syntectonic erosion of the Shuswap metamorphic core complex. The syntectonic sedimentary record preserved within the White Lake Basin elucidates the relations and timing between core complex exhumation and extensional tectonism in this region. The White Lake and Skaha formations are the apparent age equivalent of the Klondike Mountain Formation of northern Washington (USA.). White Lake Basin strata, however, are more complexly interstratified, post-depositionally disrupted, and contain a more complete record of core complex unroofing. Variations in the spatial distributions and textural and compositional character of middle Eocene strata in this area underscore the need to exercise care when developing regional-scale sedimentarytectonicvolcanic models.
17
Coello, Juan J., Carolina Castillo e Esther Martı́n González. "Stratigraphy, Chronology, and Paleoenvironmental Reconstruction of the Quaternary Sedimentary Infilling of a Volcanic Tube in Fuerteventura, Canary Islands". Quaternary Research 52, n.º 3 (novembro de 1999): 360–68. http://dx.doi.org/10.1006/qres.1999.2074.
Resumo:
La Cueva del Llano is a volcanic tube of Pleistocene age on Fuerteventura Island, in the Canary Islands. Part of it is infilled with sediments of external origin. These deposits are exceptional in stratigraphic complexity and thickness compared with other known tube infillings, and they comprise nine stratigraphic units deposited in five phases. In Phase I, which has not been dated, sedimentation of cinder from a nearby cone occurred. Phase II began ca. 16,830 ± 900 14C yr B.P., whereas phase IV dates to 9280 ± 370 14C yr B.P. The interpretation of sedimentary features shows that phases III and V correspond to a dry climate, similar to the present one, whereas the climate was much wetter during phases II and IV. This paleoclimatic sequence agrees with those suggested by the study of deposits formed in other sedimentary environments, not only in Fuerteventura but on other islands of the Canary group and the Sud-Maroc region.
18
French, H., e M. Demitroff. "Late-Pleistocene paleohydrography, eolian activity and frozen ground, New Jersey Pine Barrens, eastern USA". Netherlands Journal of Geosciences - Geologie en Mijnbouw 91, n.º 1-2 (setembro de 2012): 25–35. http://dx.doi.org/10.1017/s0016774600000548.
Resumo:
AbstractThe Late Pleistocene surface paleohydrography of the New Jersey Pine Barrens consisted of a series of broad braided alluvial surfaces with meandering paleochannels. This drainage is best explained in terms of impermeable (i.e. frozen) substrate, high sediment load, variable or decreasing discharge, and eolian sedimentary dynamics. Evidence for eolian activity is provided by wind-abraded sand grains, coversand, dunes, ventifacts, deflation hollows and wind-polished boulders. In several places stream avulsion occurred due to channel infilling by locally-derived wind-blown sediment. The braided and meandering river systems that characterise the tundra and polar semi-desert lowlands of the Western Canadian Arctic are described as modern analogs.
19
Alokla, R., I. S. Chuvashova, S. V. Rasskazov e M. V. Danilova. "Microstructures of Clay Minerals from Sedimentary Infilling of Barguzin Valley: Data of Scanning Electron Microscopy". Bulletin of Irkutsk State University. Series Earth Sciences 29 (2019): 24–38. http://dx.doi.org/10.26516/2073-3402.2019.29.24.
20
Łoziński, Maciej, Piotr Ziółkowski e Anna Wysocka. "Tectono-sedimentary analysis using the anisotropy of magnetic susceptibility: a study of the terrestrial and freshwater Neogene of the Orava Basin". Geologica Carpathica 68, n.º 5 (26 de outubro de 2017): 479–500. http://dx.doi.org/10.1515/geoca-2017-0031.
Resumo:
Abstract The Orava Basin is an intramontane depression filled with presumably fine-grained sediments deposited in river, floodplain, swamp and lake settings. The basin infilling constitutes a crucial record of the neoalpine evolution of the Inner/Outer Carpathian boundary area since the Neogene, when the Jurassic-Paleogene basement became consolidated, uplifted and eroded. The combination of sedimentological and structural studies with anisotropy of magnetic susceptibility (AMS) measurements provided an effective tool for recognition of terrestrial environments and deformations of the basin infilling. The lithofacies-oriented sampling and statistical approach to the large dataset of AMS specimens were utilized to define 12 AMS facies based on anisotropy degree (P) and shape (T). The AMS facies allowed a distinction of sedimentary facies ambiguous for classical methods, especially floodplain and lacustrine sediments, as well as revealing their various vulnerabilities to tectonic modification of AMS. A spatial analysis of facies showed that tuffites along with lacustrine and swamp deposits were generally restricted to marginal and southern parts of the basin. Significant deformations were noticed at basin margins and within two intrabasinal tectonic zones, which indicated the tectonic activity of the Pieniny Klippen Belt after the Middle Miocene. The large southern area of the basin recorded consistent N-NE trending compression during basin inversion. This regional tectonic rearrangement resulted in a partial removal of the southernmost basin deposits and shaped the basin’s present-day extent.
21
Lauriol, B., E. Deschamps, L. Carrier, W. Grimm, R. Morlan e B. Talon. "Cave infill and associated biotic remains as indicators of Holocene environment in Gatineau Park (Quebec, Canada)". Canadian Journal of Earth Sciences 40, n.º 6 (1 de junho de 2003): 789–803. http://dx.doi.org/10.1139/e03-015.
Resumo:
A rich sedimentary deposit reaches a depth of more than 4 m in a cave located on the Eardley Escarpment in the Gatineau Park. Analysis shows that the infilling started during the last Ice Age. Following the deglaciation and the Champlain Sea retreat, terrestrial sedimentation began. Radiocarbon dating of wood charcoal indicates that around 9200 ± 110 years BP trees and shrubs were starting to grow on the Eardley Escarpment. A fauna, with boreal affinity, including the Ungava collared lemming (Dicrostonyx hudsonius), was living in vegetation dominated by jack pine. After 8170 ± 60 years BP, the boreal forest was replaced by a mixed forest dominated by white pine, oak, and red maple. The faunal assemblage was enriched at that time by woodland vole (Microtus pinetorum) and Strobilops aenea, a terrestrial mollusk. These two species are presently living in the Carolinian Life Zone south of the Great Lakes. By around 5742 ± 120 years BP these two species had left the site, and the modern fauna was established with mammals, such as the black bear and the white-tailed deer. Holocene infilling of the cave was gravity driven and unassisted, except for an episode just before 8170 ± 60 years BP when a sand layer was deposited by water coming from the surface.
22
Youm, Cheikh Ibrahima, Adama Gueye, Elena García-Villalba, Mbemba F. Doumbouya, Ibrahima-Sory Sow, Elhadji Sow e Juan A. Morales. "Lithofacies and Sediment Sequences of a Microtidal, Wave-Dominated Tropical Estuary in Somone Lagoon (Senegal, West Africa)". Coasts 4, n.º 2 (5 de abril de 2024): 306–22. http://dx.doi.org/10.3390/coasts4020016.
Resumo:
Estuary sedimentary sequences have been the focus of several papers in the last decades; however, the majority these papers were centered in mesotidal and macrotidal estuaries of the middle latitudes. This present paper studies, from a sedimentological point of view, the infilling of a microtidal, wave-dominated tropical estuary, where wide tidal flats, mangroves and sabkhas are developed. Somone Lagoon is a Senegalese protected environment, very rich from an ecological point of view and with a definitive touristic vocation. For this work, 14 piston cores were studied. Additionally, the grain size, calcium carbonate and organic matter contents of 61 sediment samples vertically distributed in these cores were analyzed. The distribution of facies and the vertical sequences of sediments show the influence of the tropical seasonal fluctuations of fluvial sediment supply and evaporation processes. A high degree of bioturbation and an elevated organic content can be interpreted as the result of a high capacity of retention of the organic material into the estuary influenced by the weak tidal currents typical of a microtidal regime. These processes, acting since the last Holocene invasion of sea level, caused an advanced state of infilling of this estuarine system where both flood tidal deltas and bay head deltas prograde above the fine facies of the central domain of the estuary.
23
de Castro, Sandra, e Francisco J. Lobo. "Sedimentary infilling of bedrock-controlled palaeo-embayments off Cape Trafalgar, Strait of Gibraltar (Gulf of Cadiz)". Geo-Marine Letters 38, n.º 1 (15 de maio de 2017): 47–62. http://dx.doi.org/10.1007/s00367-017-0508-4.
24
Bilotte, Michel, Laurent Koess e Elie-Jean Debroas. "Relationships between tectonics and sedimentation on the northeastern margin of the Subpyrenean trough during the late Santonian". Bulletin de la Société Géologique de France 176, n.º 5 (1 de setembro de 2005): 443–55. http://dx.doi.org/10.2113/176.5.443.
Resumo:
Abstract In the eastern part of the Aquitaine Basin and to the south of the Toulouse high, the Subpyrenean trough is a narrow trench oriented N110°E to N130° E. The deposits on the northeastern side of this depression are preserved in the autochthonous Mesozoic cover of the Variscan Mouthoumet Massif, but also in the parautochthonous or allochthonous tectonic units that fringe to the north (Camps – Peyrepertuse slice, fig. 2) the North Pyrenean frontal thrust. From the Middle Cenomanian to the Lower Santonian included (96 to 85 Ma ago), the sedimentation in the Mouthoumet Massif indicates shallow marine carbonate or mixed (carbonate to terrigenous) conditions. The different facies depend mainly on two parameters : the variations of the accommodation space for sedimentation and the location of the numerous rudist buildups. The deposits are first organized in a homoclinal ramp until the Turonian. From the Coniacian up to the early Santonian, drowned platform patterns prevail. During the late Santonian and more precisely around 85 Ma with an other event around 84 Ma, the Mouthoumet Massif and its cover broke up under tectonic stresses. Positive and negative topographies reactivate the Variscan fault system. Platform – slope/basin morphologies substituted the preceeding ramp and drowned platform morphology. Looking to the south and in the direction N120°E, the distal slope received gravitational and turbiditic sediments called the Grès de Labastide (fig. 7). The sediment supply shifted from north to south and from east to west. To the north of this slope, the platform itself broke up into a mosaic of rhomboedric blocks, leading to a graben and horst morphology. Those units are clearly different according to the character of their sedimentary facies, deltaic or reefal (Montagne des Cornes, Calcaires de Camps – Peyrepertuse). The detailed stratigraphic and sedimentologic studies of some of these systems reveal a tectono-sedimentary evolution involving two successive cycles Ss1 (lower Upper Santonian) and Ss2 (Uppermost Santonian). In the western part of the Mouthoumet Massif this cyclic evolution is recorded from south to north, on the Parahou slope, the Rennes-les-Bains graben and the Bugarach horst. The lower cycle Ss1, located on the Rennes-les-Bains graben, is approximatively 85 Ma to 84 Ma in age. It starts with reworked deposits (lowstand systems tract) made up of sometimes several m3 elements derived from former sedimentary deposits (from Turonian up to Lower Santonian) even when the same deposits are in place on the adjacent horsts (e.g. the eastern horst of Bugarach). Those reworked deposits fill the bottom of the graben, principally in the transit zones (debris-flows of the Conglomerat de la Ferrière), or in the Parahou slope (slumps and debris-flows of the Cascade des Mathieux); then the deltaic complex of Rennes-les-Bains covers the older chaotic deposits; the blue marls and the overlying sandy facies (transgressive and highstand systems tracts) related to prodelta and deltafront deposits represent the infilling of the Rennes-les Bains graben. The upper cycle Ss2 developed probably between 84 Ma to 83,5 Ma; its geographical extension overlaps the limits of the lower cycle (e.g. the Bugarach horst), but its sedimentary organisation is still the same including: on the Parahou slope debris-flow and intrabasinal reworking (Conglomérat des Gascous: lowstand systems tract); on the northern platform transgressive and highstand systems tracts, present in the Montagne des Cornes delta where the Marnes bleues de Sougraigne represent the prodelta deposits, and the terrigenous and rudist buildups of the delta front deposits (fig.7). The final infilling results from the spreading from NE to SW, of the (estuarine ? to) fluvial deposits of the Grès d’Alet Formation at around 83 Ma. In the eastern part of the Mouthoumet Massif, sedimentary development is punctuated by tectonic events. Nevertheless, it is possible to identify in some outcrops the main elements of the two tectono-sedimentary cycles. – The cycle Ss1 is partly preserved in the genetic sequence which links the Calcaires de Camps-Peyrepertuse (shelf margin wedge systems tract) and the Marnes du Pla de Sagnes (transgressive systems tract). The cycle Ss2 is only known through different facies of the Grès de Labastide Formation: reworked deposits on the slope; coarse-grained silicoclastic deposits on the transit zones. – In the cycle Ss1 differences appear between the western and the eastern parts of the Mouthoumet massif. When in the western area deltaic conditions prevailed, in the eastern area a shallow carbonate and buildup facies developed. Such differences disappear in the cycle Ss2 by the general establishment of fore slope deltaic deposits. The geodynamic reconstruction resulting from plate kinematics indicates a major change between the early Coniacian (89 Ma) and the Middle Campanian (79 Ma), when the sinistral/divergent motion of Iberia with respect to stable Europe turned to a dextral/convergent movement. The tectono-sedimentary events presented here took place during this period (85 Ma to 83 Ma). The tectono-sedimentary evolution of the subpyrenean trough and the shift of the European and Iberian plates are thought to be intimately linked. The new chronological and geodynamical data proposed herein show that the genesis and the evolution of the subpyrenean sedimentary processes related to the northern Aquitanian margin of the Subpyrenean trough allow to draw some basic conclusions: – the opening of the Subpyrenean trough occurred in two steps, the first around 85 Ma and the second around 84 Ma; – this caused a change in the sedimentary setting with platform environments replacing the earlier ramp geometry; – the Subpyrenean trough formed and evolved under transtensive tectonic conditions; – during the late Santonian two tectono-eustatic sequences marked the former stages of the eastward opening and infilling of this basin; – the diachronous infilling which began here around 83,5 Ma prograded to the western Plantaurel and Petites-Pyrénées area; – no significant northward shifting of the depositional-axis of the Senonian basins occurred; – only a gradual westward shift of the depositional centers, along the subpyrenean direction of the slope area (N110°E to N130°E) was noticed.
25
Cabato, Ma Edweena Joan A., Kelvin S. Rodolfo e Fernando P. Siringan. "History of sedimentary infilling and faulting in Subic Bay, Philippines revealed in high-resolution seismic reflection profiles". Journal of Asian Earth Sciences 25, n.º 6 (novembro de 2005): 849–58. http://dx.doi.org/10.1016/s1367-9120(04)00170-1.
26
Tang, Qiang, Shuai Wang, Bojie Fu, Yafeng Wang e Guangyao Gao. "Check dam infilling archives elucidate historical sedimentary dynamics in a semiarid landscape of the Loess Plateau, China". Ecological Engineering 118 (agosto de 2018): 161–70. http://dx.doi.org/10.1016/j.ecoleng.2018.05.004.
27
Latham, A. G., e A. I. R. Herries. "The formation and sedimentary infilling of the Cave of Hearths and Historic Cave complex, Makapansgat, South Africa". Geoarchaeology 19, n.º 4 (2004): 323–42. http://dx.doi.org/10.1002/gea.10122.
28
Ning, Bo, Junjian Li, Taixian Zhong, Jianlin Guo, Yuyang Liu, Ninghai Fu, Kang Bie e Fankun Meng. "Enhanced Gas Recovery for Tight Gas Reservoirs with Multiple-Fractured Horizontal Wells in the Late Stages of Exploitation: A Case Study in Changling Gas Field". Energies 16, n.º 24 (5 de dezembro de 2023): 7918. http://dx.doi.org/10.3390/en16247918.
Resumo:
To initially improve the gas production rate and shorten the payback period for tight gas reservoirs, the multiple-fractured horizontal well (MFHW) model is always applied. However, in the late stages of exploitation, it is difficult to adopt reasonable measures for enhanced gas recovery (EGR), particular for continental sedimentary formation with multiple layers, and efficient strategies for EGR in this type of gas field have not yet been presented. Therefore, in this paper, a typical tight gas reservoir in the late stages of exploitation, the Denglouku gas reservoir in Changling gas field, in which MFHWs were utilized and contributed to the communication of the higher Denglouku formation (0.34 mol% CO2) and lower Yingcheng formation (27 mol% CO2) during hydraulic fracturing, is studied comprehensively. Firstly, alongside the seismic, logging, drilling and experimental data, 3D geological and numerical simulation models are developed. According to the differences in CO2 mole fractions for different formations, the gas production rate of MFHWs produced from Denglouku formation is accurately calculated. Then, the well gas production rate (WGPR) and the well bottom-hole pressure (WBHP) history are matched with the calculated values, and thus the types of remaining gas are provided through the fine reservoir description. Finally, in a combination of gas recovery and economics, the optimal infill well type and the adjustment scheme are determined. The results show that there are three main categories of remaining gas, which are areal distribution, abundant points, and marginal dispersion, and the ratios of reaming gas reserve for these three types are 80.3%, 4.2%, and 15.5%, respectively. For the tight gas reservoir developed by MFHWs with parallel and zipper patterns, the best infilling well type is the vertical well. The combination of patching holes, sidetracking, infilling and boosting can obtain the highest gas recovery, while the scheme with patching holes and sidetracking has the best economic benefits. To balance the gas recovery and economics, the measurement of patching holes, sidetracking and infilling with vertical wells is utilized. In the final production period, compared with the basic schemes, the gas recovery can increase by 5.5%. The primary novelty of this paper lies in the determination of the optimal infilling well types and its presentation of a comprehensive adjustment workflow for EGR in tight gas reservoirs. The conclusions in this paper can provide some guidance for other similar tight gas reservoirs developed with MFHWs in the later period.
29
Wang, Jiaze, Kehui Xu, Chunyan Li e Jeffrey Obelcz. "Forces Driving the Morphological Evolution of a Mud-Capped Dredge Pit, Northern Gulf of Mexico". Water 10, n.º 8 (28 de julho de 2018): 1001. http://dx.doi.org/10.3390/w10081001.
Resumo:
Sandy sediments preserved as paleo-channel fill on the inner shelf, some of which are overlain by modern muds, have been mined for barrier island restoration along the northern Gulf of Mexico. These mined areas have been termed “mud-capped” dredge pits. The processes governing the morphological evolution of the pits are poorly constrained due to limited observational data. Physical oceanographic (e.g., currents and waves) and sedimentary data were collected at Sandy Point dredge pit offshore Plaquemines Parish, Louisiana in summer 2015. Currents outside the pit flowed southward and/or southeastward at speeds of 8–20 cm/s, while currents inside the pit had speeds less than 2 cm/s with no clear dominant direction. Wave heights detected inside the pit were less than 0.4 m. A high turbidity layer with suspended sediment concentration around 4 g/L was observed above the pit floor, and its thickness was ~0.5 m. With observational data as input, three 2–D numerical models were employed to predict pit morphological responses, including pit infilling, margin erosion and slope change. The model results suggest that resuspension events were rare on the seafloor adjacent to the pit under summer fair weather conditions. Modeled pit margin erosion was very limited. With little resuspension of seafloor sediment locally, weak margin erosion and stable pit walls, the dominant process governing pit evolution was infilling sourced by the deposition of suspended sediments from the Mississippi River plume.
30
Vejrostová, Lenka, Lenka Lisá, Aleš Bajer e Jan Pacina. "Evaluation of human impact on valley bottom sedimentation in Highlands: case study from Česká Bělá, Czechia". Geografie 122, n.º 1 (2017): 21–44. http://dx.doi.org/10.37040/geografie2017122010021.
Resumo:
The formation processes of small valleys and long-term anthropogenic impact on its sedimentary archives may be studied by GIS, sedimentology and investigation into spatial and vertical geochemical characteristics in the context of mining activities. The case study from the Bohemian-Moravian Highlands with well documented medieval mining activities demonstrates the typical dynamics of a small valley during the last centuries and also the possible rate of human impact. The information value of the floodplain record as well as the development of the landscape geomorphology is discussed. The infilling of the river bottom is comprised of two main lithological units keeping information about medieval mining and ore processing as well as about past and recent agricultural activities. The most recent land use influenced the aggradation of the valley bottom less than land use during the Medieval times.
31
Evans, D. J., e R. A. Chadwick. "Basement–cover relationships in the Shaftesbury area of the Wessex Basin, southern England". Geological Magazine 131, n.º 3 (maio de 1994): 387–94. http://dx.doi.org/10.1017/s0016756800011134.
Resumo:
AbstractIn the northwestern part of the Wessex Basin of southern England, interpretation of seismic reflection and recently released borehole data provides detailed information of the major unconformity at the base of the sedimentary-fill. Seismic mapping of the top of Variscan basement reveals a concealed, faulted, dome-like Palaeozoic basement culmination or structural ‘high’ lying within the larger Cranborne–Fordingbridge High, southwest of Shaftesbury. This structure profoundly affected the deposition of the overlying Permo-Triassic sequence. The culmination, composed of Carboniferous Limestone, lies to the south of northwards-throwing, basement-controlled, syn-sedimentary faults which form the southern margin of the Mere Basin. In this area, the main phase of faulting occurred during Permo-Triassic times with little or no faulting during the Jurassic. Triassic strata onlap the basement culmination which was overstepped and finally submerged in late Triassic times. The structure has much in common with the basement ‘highs’ at Bruton and in the Mendips and provides further evidence for the existence of such features close to the main lines of Mesozoic faulting within the Wessex Basin. It is considered that differential subsidence related to syn-depositional normal faulting was the dominant factor controlling development of the highs. The simple infilling of a pre-existing post-orogenic topography played a minor role.
32
André, Grégoire, Christian Hibsch, Bernard Beaudoin, Cédric Carpentier, Serge Fourcade, Michel Cathelineau e Pascal Élion. "Oxfordian sedimentary dykes : tectonic and diagenetic implications for the eastern Paris basin". Bulletin de la Société Géologique de France 175, n.º 6 (1 de novembro de 2004): 595–605. http://dx.doi.org/10.2113/175.6.595.
Resumo:
Abstract Vertical fractures in Oxfordian limestones of the eastern part of the Paris Basin are interpreted as resulting from synsedimentary extensional deformations which occurred during the Mesozoic. These NNE-SSW striking fractures are 10 to 20 meters in height, and filled with microgranular material. The fractures mainly affect crinoidal and oolitic grainstones. Their micritic to microsparitic, lithoclast-bearing infills may have resulted from the solidification of an ancient mud injected from non-lithified, overlying layers of marine sediments. They should therefore be referred to as sedimentary dykes. Graded layering suggests deposition under turbulent flow conditions, whereas later plastic deformation and breccia formation indicate a syndiagenetic reworking. Such observations are consistent with a predominance of the sedimentary dykes in grainstones, which are more rapidly lithified and therefore subject to early fracturing. On the contrary, these dykes are rare in mudstones which may constitute the source of the material for the infills in the grainstones. Both the analysis of the wall geometry and the reconstruction of the diagenetic history of the infills make possible to distinguish two types of sedimentary dykes. The first type corresponds to a fracturation characterized by irregular walls around the rock-constituting grains (i.e. crinoidal debris or ooids), whereas the walls in the second type are cross-cutting the grains and present a fringe of sparite predating the microsparite infill. The following scenario is proposed for the first type of sedimentary dykes: i) syntaxial cementation of crinoidal debris and early cementation of ooids; ii) fracturing along grain boundaries under low burial strain; iii) filling of fractures and open porosity by the mud. The second type of sedimentary dykes was formed under deeper burial conditions, which is indicated by both pre-existing bedding-parallel stylolites and the precipitation of sparite on the walls before the sedimentary infill. This early fracturation and the availability of a sedimentary filling, non-lithified material point to a late Jurassic age for these sedimentary dykes. The δ18OSMOW isotopic signatures measured for the infilling sparite and microsparite materials indicate that these were precipitated from meteoric waters, either early during the formation of the sedimentary dykes or during a later recrystallization event. The sedimentary dykes have recorded an E-W extension during the Oxfordian-Kimmeridgian period, which is in good agreement with the late Jurassic tectonic history of the western European platform. This early Oxfordian-Kimmeridgian fracturing and its associated fluid paleocirculations is of major interest in the context of the tectonic history of the Paris Basin, since most of these N-S to NNE-SSW tension gashes have been previously attributed to the Eocene Pyrenean shortening and Oligocene rifting stages.
33
Chatterjee, Sreejita, e Dhiren Kumar Ruidas. "Facies Evaluation and Depositional Environments of Carbonates of the Bagh Group, Dhar District, Madhya Pradesh, India". Journal of The Indian Association of Sedimentologists 38, n.º 1 (30 de junho de 2021): 33–40. http://dx.doi.org/10.51710/jias.v38i1.154.
Resumo:
A significant event of marine transgression took place in Central India during Late Turonian-Coniacian. Fossiliferous marine succession of Bagh Group is one of the few carbonate successions exposed in peninsular India which was in focus of the current study for understanding this event. The signatures of this event were identified in the carbonate succession. The carbonates of Bagh Group are composed of two formations: the lower part is represented by Nodular limestone Formation which is overlain by Bryozoan limestone Formation at the top. On the basis of grain size variation and sedimentary structures, the Nodular limestone is divisible into three facies: facies ‘A’, facies ‘B’ and facies ‘C’. A hardground exists between facies B and facies C. Lack of sedimentary structures and high mud content indicates low energy depositional setting for the Nodular limestone Formation. Similarly, Bryozoan limestone Formation is divisible into five facies: facies ‘D’, facies ‘E’, facies ‘F’, facies ‘G’ and facies ‘H’ based on grain size variation and sedimentary structures. All of these five facies are fossiliferous. Glauconites are present within facies ‘G’ and have two modes of occurrence - as infilling within Bryozoan limestone and as altered feldspar. Presence of both small- and large-scale cross-stratification in Bryozoan limestone with lesser mud content are indicative of high energy shallow marine conditions. Large-scale cross-stratifications are possibly representing tidal bars while the small scale cross stratifications are formed in inter bar setting. Presence of reactivation surfaces within facies ‘E’ also supports their tidal origin. Increase in depositional energy condition is also evident from dominated by packstone facies.
34
Gonchar, Victor. "GEODYNAMICS". GEODYNAMICS 1(32)2022, n.º 1(32) (28 de junho de 2022): 80–91. http://dx.doi.org/10.23939/jgd2022.02.080.
Resumo:
The article focuses on the formation mechanisms of fold’s diversity of sedimentary basin inversion. They are investigated on the example of structures of the Dnieper-Donets paleorift system. To achieve this aim we systematized structural and lithofacial data of the Dnieper-Donets basin and Donbas; used numerical modelling to establish the regularities of deformations within lithosphere and sedimentary cover in collisional compression setting. It is shown that the formation of main folding styles as discontinuous (intermittent), transitional and continuous (full) is accompanied by characteristic features of the cover. In this respect, we formulated the basic dependence principle of folding from lithofacial and lithogenic factors, which defined different mechanical properties of sedimentary cover complexes (the lithomechanics principle). Modelling results confirm prime significance of horizontal compressional conditions of basin’s folds development. Moreover, the sedimentary basin plays the role of independent deformation attractor in the lithosphere. The main conclusion is that the transitional fold paragenesis of Donbas with crest-like Main anticline may be the result of particular strength’s distribution, i.e. axial weak zone and competent layer of variable thickness with central minimum. Main anticline formation mechanism is complex. It includes vertical, axial-parallel viscous-plastical flow with distant bending. It is shown that intermittent folds (uplifts) of the Dnieper-Donets basin may be a result of sedimentary cover compression with a random combination of weakened and strengthened zones. On the contrary, full folding of East Donbas and the Karpinsky ridge corresponds to a bending mechanism of competent layer compression of constant thickness. For the first time we obtained the evidence for the folding inversion mechanisms within Dnieper-Donets aulagogen (including Main anticline), which was problematic for many years. Folding is directly related to peculiarities of sedimentary basin infilling within formulated principle of lithofacial mechanics. With necessary caution, the study offers the results of modelling and conclusions for explanations of fold development within intracontinental basins and marginal folded belts. Practical significance. Numerical modelling and elaborated principles of analysis may be used in reconstructions, numerical investigations of fold structures (uplift) within inverted basins, as well as in prognosis of ore, oil-and-gas deposits.
35
Abdulkarim, Mubarak, Stoil Chapkanski, Damien Ertlen, Haider Mahmood, Edward Obioha, Frank Preusser, Claire Rambeau, Ferréol Salomon, Marco Schiemann e Laurent Schmitt. "Morpho-sedimentary characteristics of Holocene paleochannels in the Upper Rhine alluvial plain, France". E&G Quaternary Science Journal 71, n.º 2 (8 de setembro de 2022): 191–212. http://dx.doi.org/10.5194/egqsj-71-191-2022.
Resumo:
Abstract. The French Upper Rhine alluvial plain is characterized by a complex system of paleochannels inherited from Late Glacial to Holocene fluvial dynamics of the Rhine and Ill river systems, among other smaller rivers. These paleochannels represent valuable archives for understanding and reconstructing the fluvial and landscape evolution of the area. However, the Holocene temporal trajectories of the paleochannels, in response to a range of environmental changes, remain poorly understood. This study presents a detailed and systematic mapping and characterization of an extensive network of paleochannels spanning the entire width (19 km) of a reach of the central French Rhine plain. Based on qualitative and quantitative lidar analysis, field investigations, and provenance investigations of paleochannel infill sequences, five distinct paleochannel groups (PG 1 to PG 5) were identified in the study area. These paleochannel groups differ considerably regarding their channel patterns, morphological characteristics, and sedimentary sources of the infilling sediments. The interpretation of the different datasets indicates that the development of these different paleomorphologies is attributed to significant changes in hydro-geomorphodynamic processes in the area during the Holocene, especially lateral migrations of the Rhine and Ill rivers. The findings reported here are promising and will have significant implications for reconstructing the long-term (Late Glacial to Holocene) evolution of the Upper Rhine fluvial hydrosystem in response to various controlling factors.
36
Tessier, Bernadette, Isabelle Billeaud e Patrick Lesueur. "Stratigraphic organisation of a composite macrotidal wedge: the Holocene sedimentary infilling of the Mont-Saint-Michel Bay (NW France)". Bulletin de la Société Géologique de France 181, n.º 2 (1 de março de 2010): 99–113. http://dx.doi.org/10.2113/gssgfbull.181.2.99.
Resumo:
Abstract The Mont-Saint-Michel Bay (NW France) is a composite macrotidal environment that was filled up in the course of the Holocene transgression and sea-level highstand. Three main sub-environments constitute the present-day landscape of the bay: 1) a wide embayment with extensive mud to sandflats in the south, 2) a sandy to muddy channel-and-shoal estuarine system in the east, 3) a wave-dominated sandy coast composed of beach and dune barrier in the north. The Holocene infill of this composite macrotidal basin has been studied thanks to a set of vibrocores and VHR seismic data. The main results are summarized as follows: the TST is composed by a low-energy aggradational unit in the axis of the estuarine valley, and by high-energy sediment bodies (tidal dunes and banks) outside the valley; the HST (post 6500 yr B.P.) constitutes the main component of the infill. In the north, it is characterised by an aggradational unit made of back-barrier tidal lagoonal infill successions. In the embayment, it is represented by an aggradational unit composed of tidal-flat deposits. In the estuarine axis, the HST is constituted by a sand-dominated tidal channel-and-shoal belt. The rate of the Holocene sea-level rise appears to be the main factor of control of the infill architecture of the Mont-Saint-Michel Bay since the most significant change occurred around 6500 yr B.P. when the transgression slowed down. The interaction between hydrodynamic agents and sediment supply exerts as well a key control, especially during the late Holocene, when transgression is slow. The impact of climate changes is recorded in the infill during this period. The rocky substrate hypsometry should be considered also as a major forcing parameter as it determines the potential of preservation of the infill in relation with the depth of ravinement by tidal currents.
37
Gregoire, Gwendoline, Pascal Le Roy, Axel Ehrhold, Gwenael Jouet e Thierry Garlan. "Control factors of Holocene sedimentary infilling in a semi-closed tidal estuarine-like system: the bay of Brest (France)". Marine Geology 385 (março de 2017): 84–100. http://dx.doi.org/10.1016/j.margeo.2016.11.005.
38
Stéphan, Pierre, Jérôme Goslin, Yvan Pailler, Rose Manceau, Serge Suanez, Brigitte Van Vliet-Lanoë, Alain Hénaff e Christophe Delacourt. "Holocene salt-marsh sedimentary infilling and relative sea-level changes in West Brittany (France) using foraminifera-based transfer functions". Boreas 44, n.º 1 (4 de agosto de 2014): 153–77. http://dx.doi.org/10.1111/bor.12092.
39
Liu, Yi Kun, Xue Ming Wang, Shi Yuan Shao, Ming Yang e Yong Ping Wang. "Analysis all Kinds of Reservoir Water Degree Condition of East Xing Six District of Daqing Oilfield". Advanced Materials Research 868 (dezembro de 2013): 585–88. http://dx.doi.org/10.4028/www.scientific.net/amr.868.585.
Resumo:
East Xing Six District of Daqing oilfield development has 50 years of history, the block has entered high well density, high water cut stage. The apricot East Xing Six District demonstration zone development belongs to the continental sedimentary system, it has reservoir types and physical properties have large differences, It was long-term effected by injected water, after water flooding, water degree condition becomes very complex and unpredictable, so the washing condition analysis is an important guarantee for Daqing oilfield stable production. Using the oil field sealed coring well data, various types of reservoirs washing degree thickness change and growth are analyzed, We can know that with the further water flooding development and well pattern infilling, all kinds of oil reservoir production status; and then analyzes the potential distribution of the oilfields, and provides a basis for the development of the block and the adjustment of the next step of work, has an important guiding significance.
40
BEACOM, L. E., T. B. ANDERSON e R. E. HOLDSWORTH. "Using basement-hosted clastic dykes as syn-rifting palaeostress indicators: an example from the basal Stoer Group, northwest Scotland". Geological Magazine 136, n.º 3 (maio de 1999): 301–10. http://dx.doi.org/10.1017/s0016756899002605.
Resumo:
Clastic infills of fractures (here termed clastic veins) in basement rocks immediately underlying sedimentary cover sequences can be used to date fault movements if these demonstrably occurred at the time of infilling or prior to the lithification of the entrained clastic material. This allows reconstruction of the syn-rifting palaeostress system using stress inversion techniques. During Riphean intracontinential rifting of Laurentia, the Torridonian Stoer Group sediments of northwest Scotland were deposited in half-graben basins controlled by faults, e.g. the Coigach and Clachtoll faults. At Clachtoll, northeast–southwest oblique sinistral normal faulting in the underlying basement is associated with extensive development of shear, hybrid and tensile clastic veins filled with Stoer Group sediment, infilled and deformed prior to sediment lithification. Clastic veins initially formed by gravitational infilling of sediment from above, followed by tectonically-driven, forceful hydraulic injection of fluidized sand into new fractures and reactivated pre-existing basement faults. Palaeostress axes, determined from fault lineation data and tensile fracture extension directions in the Clachtoll Fault zone, indicate west-northwest–east-southeast directed extension during rifting. On a regional scale, this implies oblique-dextral extension on the north- to north-northeast-trending Coigach Fault during Stoer Group deposition. Similar orientations, age relationships and kinematics have been obtained from pre-Torridon Group fault arrays developed in the Lewisian basement near Gairloch and Loch Maree. Overall, the faulting patterns reflect a three-dimensional strain (k≠1) formed by east-southeast–west-northwest-directed extension during deposition of the Stoer Group. More speculatitively, asymmetric density patterns of sinistral and dextral faults may indicate that rifting occurred in a regional zone of broadly north–south-oriented dextral transtension.
41
Freitas, T. A. de, e U. Mayr. "Middle Paleozoic tear faulting, basin development, and basement uplift, central Canadian Arctic". Canadian Journal of Earth Sciences 30, n.º 3 (1 de março de 1993): 603–20. http://dx.doi.org/10.1139/e93-046.
Resumo:
The Boothia Uplift of the central Canadian Arctic Islands, located some 1200 km west of the Caledonian collision zone, is a "Laramide-type" basement-cored uplift that affected Precambrian crystalline basement and lower Paleozoic carbonate platform sequence. The two major segments of the Boothia Uplift, separated by the east-trending Barrow Strait, had different deformational histories. In the southern segment, uplift of the basement began in Late Silurian time, while in the northern segment, there was subsidence and platform drowning.In the northern segment, a thick sedimentary succession, containing numerous potential detachment surfaces, was involved in Early Devonian deformation. Folding of the cover along northerly trends resulted in the longitudinal infilling of two small, synclinal basins in the hanging wall of the uplift. The type of basin fill was dependent on source proximity and was influenced by contemporaneous flexure of the sedimentary cover. The western basin, the Grove Lake basin, received predominantly terrestrial sediments, and the eastern one, the Sutherland River basin, received mostly marine sediments, including a thick, possibly submarine, synsedimentary breccia that accumulated in response to tilting of partly lithified, carbonate strata. Southward-transported clastic sediments of the basin-fill sequence and contours showing the amount of pre-Emsian erosion suggest that a high-angle tear fault influenced sedimentation in the Grove Lake basin.The areally restricted and variably transported syntectonic clastics of the northern segment are different from coeval clastics of the southern segment. This is attributed to different deformational histories along the uplift and, in particular, to the deformation of a thick, locally anisotropic sedimentary cover sequence in the northern segment.A thick Emsian to early Eifelian carbonate platform sequence onlapped the eroded Boothia Uplift which had acted as a paleohigh for some 10–15 Ma. Early Devonian basement faults appear to have been reactivated as dextral wrench faults during Tertiary time.
42
SIEMES, ANDREAS, TOM McCANN e ANNE FISCHER. "Palaeogene alluvial–volcaniclastic deposits in the Mesta Basin (SW Bulgaria): depositional setting and basin evolution". Geological Magazine 147, n.º 3 (27 de outubro de 2009): 321–38. http://dx.doi.org/10.1017/s001675680999046x.
Resumo:
AbstractThe Mesta half-graben is one in a series of extensional basins in SW Bulgaria that record the onset of extension within the Rhodope Zone in the Late Eocene. Tectonic activity on a continuous detachment along the eastern margin was a major control on subsidence, accommodation space creation, sediment supply and facies distribution in the basin. The sedimentary architecture was complicated by synsedimentary rotation, the presence of intrabasinal faults and the resulting compartmentalization, as well as synsedimentary volcanic activity. Facies and structural analysis of a key transverse section in the central part of the basin, together with supporting observations from other parts of the basin, indicate a pulsed tectono-sedimentary evolution of the basin with three distinct stages. The first stage (Late Eocene) is a phase of rapid extension with an initial alluvial setting. Basin margin fans and an axial fluvial through-drainage system were the major depositional systems in this stage. The second stage (Early Oligocene) marks the onset of volcanic activity within the Mesta Basin and is characterized by the formation of volcanic centres, an intense phase of explosive volcanism and rapid infilling of the previous basin topography with volcanic material deposited from pyroclastic density currents. The third stage (Late Oligocene) represents waning volcanic activity in a mixed alluvial–volcaniclastic environment. This stage is characterized by alternating alluvial and volcaniclastic depositional cycles, as well as partial reworking of volcanic material.
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Feng, Congjun, Mengsi Sun, Chiyang Liu, Xili Deng, Yuze Xue e Li Dong. "Seismic sedimentary characteristics and filling structure of the Upper Triassic Yanchang Formation, Ordos Basin, China". Interpretation 8, n.º 2 (1 de maio de 2020): T259—T274. http://dx.doi.org/10.1190/int-2019-0138.1.
Resumo:
Following the analysis of cores, outcrops, well log, and seismic sections, we have studied the seismic reflection configuration and depositional history of the hydrocarbon-rich Yanchang Formation in the Ordos Basin. We divided the seismic reflection configurations into five types: subparallel reflection, parallel reflection, tangential progradational reflection, shingled progradational reflection, and chaotic reflection. Based on our study results, we concluded that the slopes exhibit differences in the different regions of the Ordos Basin during the sedimentary period of the Yanchang Formation: The slope with the largest gradient of approximately 10°–20° occurred in the southwestern basin, followed by the northwestern basin (with a slope of approximately 1.6°–3.3°), but the slope was relatively gentle in the northeastern basin (approximately 0.8°–1.2°). We also found that the paleocurrent direction of the basin mainly includes two directions: The paleocurrent direction of the southwest region is 186°–259°, which indicates the provenance came from the southwestern region, whereas the paleocurrent direction of the northeast region is 10°–79°, which indicates that the provenance came from the northeastern region. In addition, the Ordos Basin was under isostatic subsidence as a whole during this period, and its sedimentary infilling evolution underwent five stages: the initial depression, intense depression, progradational filling, uplifting and denudation, as well as shrinking and extinction stages, just corresponding with the Chang 10-Chang 9, the Chang 8-Chang 7, the Chang 6-Chang 4+5, the Chang 3-Chang 2, and the Chang 1 depositional age, respectively.
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Calvo, José P., Manuel Pozo, Pablo G. Silva e Jorge Morales. "Pattern of sedimentary infilling of fossil mammal traps formed in pseudokarst at Cerro de los Batallones, Madrid Basin, central Spain". Sedimentology 60, n.º 7 (7 de junho de 2013): 1681–708. http://dx.doi.org/10.1111/sed.12048.
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Sorrel, Philippe, Bernadette Tessier, François Demory, Nicolas Delsinne e Dominique Mouazé. "Evidence for millennial-scale climatic events in the sedimentary infilling of a macrotidal estuarine system, the Seine estuary (NW France)". Quaternary Science Reviews 28, n.º 5-6 (março de 2009): 499–516. http://dx.doi.org/10.1016/j.quascirev.2008.11.009.
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Symons, David T. A., Kazuo Kawasaki e Jimmy F. Diehl. "Magnetization age from paleomagnetism of the Copper Harbor red beds, Northern Michigan, USA, and its Keweenawan geologic consequences". Canadian Journal of Earth Sciences 56, n.º 1 (janeiro de 2019): 1–15. http://dx.doi.org/10.1139/cjes-2017-0094.
Resumo:
The Copper Harbor Formation on Lake Superior’s Keweenaw Peninsula records the transition from volcanic to sedimentary infilling of North America’s 1.1 Ga Keweenawan rift. Radiometric dating shows that the formation’s primary mafic sediments and interbedded “Lake Shore” flows were deposited between ∼1092 and ∼1082 Ma. Our regional paleomagnetic results for the Copper Harbor’s red beds yield a dominantly prefolding normal-polarity secondary chemical characteristic remanent magnetization in hematite at 18 of 21 sites with a mean direction of declination = 274.9°, inclination = +10.9° (k = 69.5, α95= 4.2°), and a paleopole at 7.4°N, 181.7°E (A95= 3.3°). Using paleopoles from Keweenawan volcanic rocks with U–Pb zircon age dates, an apparent polar wander path is constructed from 1106 ± 2 to 1087 ± 2 Ma. Extrapolation of this path dates oxidation of the Copper Harbor’s primary gray beds to red beds at 1060 ± 5 Ma. The path implies an apparent polar wander rate of ∼18 cm per year from ∼1108 to 1096 Ma and of 6.8 cm per year from 1096 to 1087 Ma, along with a consistent clockwise rotation of 0.30 ± 0.05°per million years for the Laurentian Shield from ∼1108 to ∼1160 Ma. Further, most Keweenawan volcanic rocks around the Lake Superior region carry an endemic ∼1060 Ma normal-polarity hematite remanence overprint, acquired during the initial stages of Grenvillian tectonic uplift, that has caused asymmetry in a unit’s normal and reverse paleopoles. Also, the Copper Harbor paleopole dates emplacement of the White Pine stratiform sedimentary copper mineralization more precisely at 1060 ± 5 Ma.
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Michel, Charlotte, Sophie Le Bot, Flavie Druine, Stéphane Costa, Franck Levoy, Carole Dubrulle-Brunaud e Robert Lafite. "Stages of sedimentary infilling in a hypertidal bay using a combination of sedimentological, morphological and dynamic criteria (Bay of Somme, France)". Journal of Maps 13, n.º 2 (26 de outubro de 2017): 858–65. http://dx.doi.org/10.1080/17445647.2017.1389663.
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Grenfell, S., e M. Grenfell. "Characterising the late Quaternary facies stratigraphy of floodplains in South Africa". South African Journal of Geology 124, n.º 4 (1 de dezembro de 2021): 963–76. http://dx.doi.org/10.25131/sajg.124.0056.
Resumo:
Abstract South African river floodplains and their alluvial deposits reflect a diversity of geological and geographical drivers. We use a genetic geomorphic classification system originally developed for dryland wetlands to characterise geomorphic processes and potential successions of sedimentary fill for South African floodplains. Using case studies from the literature, we consider differences between alluvial rivers and mixed bedrock-alluvial rivers in the context of macro-scale geomorphic setting, and evaluate the impact of the setting on floodplain persistence and potential as a palaeo-environmental archive. Sedimentary facies associations represented in South African floodplains, including lateral and oblique accretion, channel, channel infill, levee vertical accretion, floodplain vertical accretion and debris flow deposits, are also evaluated. Floodplains of South Africa’s interior are typically mixed bedrock-alluvial as channel beds are set upon or close to bedrock and sediment thickness is limited. By contrast some floodplains in tectonic basin settings have sediment deposits exceeding 30 m in thickness. The resulting rivers are alluvial, and thus able to adjust their width, depth and slope to accommodate changes in discharge and sediment supply. Similarly, coastal floodplain rivers are alluvial due to downcutting during the last glacial maximum and subsequent sedimentary infilling as sea levels rose. When considering the potential of floodplains as palaeoarchives of environmental change, two considerations emerge. First, floodplain stratigraphy is not a response to a single variable due to complex process-form feedbacks. Rather, floodplain stratigraphy is an outcome of both autogenic and allogenic processes. Second, most South African floodplains are zones of sediment recycling, and as such, preservation potential is typically low. Thus, although floodplain settings of the interior may be a few million years old, the sediment within them may be only thousands to tens of thousands of years old. Our review indicates that research has historically focused on meandering river and mixed bedrock-alluvial anabranching river floodplains, while understanding of other floodplain sub-types remains limited.
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Kołodyńska-Gawrysiak, Renata. "Holocene evolution of closed depressions and its relation to landscape dynamics in the loess areas of Poland". Holocene 29, n.º 4 (29 de janeiro de 2019): 543–64. http://dx.doi.org/10.1177/0959683618824792.
Resumo:
Past Pleistocene topography of the loess uplands is rich in local sinks (closed depressions (CDs)) influencing sediment fluxes. Soil-sediment sequences from CDs constituting geoarchives where landscape changes under natural and anthropogenic conditions have been recorded. Pedo-sedimentary archives from 10 CDs in the Polish loess belt and human settlements were analysed. Phases of the Holocene evolution of the CDs were correlated with landscape dynamics in loess areas in Poland and Central Europe. Phases of infilling of CDs occurring (2) from the late Boreal/early Atlantic Period until the (middle) late Bronze Age/early Iron Age and (4) since the early Middle Ages until today were documented. These were phases of long-term soil erosion and colluviation corresponding to the increasing agricultural land use of Polish loess uplands. Phases of soil formation related to geomorphic stabilization of CDs occurred (1) from the late Vistulian until the late Boreal/early Atlantic Period and (3) from the late Bronze Age/early Iron Age until the early/high Middle Ages. These were phases of decreased soil erosion and landform conservation in a considerable part of Poland’s loess areas. Pedo-sedimentary archives from the CDs have recorded soil erosion strongly related with human-induced land-use changes. The mean soil erosion rate in the catchment of CDs was 0.33 t·ha−1·yr−1 during prehistory and 4.0 t·ha−1·yr−1 during the last approximately 1000 years. Phases of CD evolution are representative for the main phases of sediment and landscape dynamics in Poland’s loess areas recorded in various archives, and are not synchronous with some of these phases in Central Europe.
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St-Hilaire, Vikki M., e Dan J. Smith. "Holocene glacier history of Frank Mackie Glacier, northern British Columbia Coast Mountains". Canadian Journal of Earth Sciences 54, n.º 1 (janeiro de 2017): 76–87. http://dx.doi.org/10.1139/cjes-2015-0236.
Resumo:
Frank Mackie Glacier repeatedly advanced across the Bowser River valley in northwestern British Columbia to impound Tide Lake during the Holocene. The most recent infilling of Tide Lake was associated with a late Little Ice Age glacier advance and ended around 1930 when the lake catastrophically drained. Over the last century Frank Mackie Glacier has retreated and down wasted to reveal multiple glaciogenic sedimentary units within the proximal faces of prominent lateral moraines. The units are separated by buried in-situ tree stumps and laterally contiguous wood mats deposited on paleosols. Dendroglaciological and radiocarbon dating of these wood remains show that Frank Mackie Glacier expanded into standing forests at 3710–3300, 2700–2200, 1700–1290, 900–500, and 250–100 cal. years BP. These advances coincide closely in time with the previously established Tide Lake glacier dam chronology and with the Holocene history of other glaciers in the Bowser River watershed. The findings emphasize the likelihood that most glaciers within northwestern British Columbia underwent substantial size and mass balance changes over the last 4000 years, and often spent hundreds of years in advanced positions before retreating.