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1.
Sediment yield from modern continental blocks is a function of the area (dissolved load) and hypsometry (mechanical load) of the blocks. Hypsographic curves for modern continental blocks show that the change in the percentage area flooded for any change in eustatic sea level depends on the size of the block and the absolute sea level. This allows predictions of changes in sediment yield around different sized blocks for any given eustatic change. The range in size of continental blocks is such that, for any given sea level change, the blocks will show different percentage changes in yield. Data from modern continental blocks are compared with theoretical results. Assuming that the rules governing modern hypsometries applied in the past, and a constant volume of continental crust, it is possible to estimate the hypsographic curves of former continental blocks. The implications of suggested past continental configurations and sea levels for sediment yield are discussed.  相似文献   
2.
La série sédimentaire du Crétacé moyen et supérieur étudiée dans l'Ouest du Bassin de Paris et sur la bordure du Massif armoricain comporte sept pulsations transgressives qui peuvent être reconnues en fonction de la disposition géomètrique des dépôts et de l'enchaînement vertical des faciès.Les épisodes transgressifs atteignent leur phase paroxysmale, en alternance avec des stades de régression, successivement:
1. (1) à la fin de l'Aptien supérieur —(régression début Albien)
2. (2) au milieu de l'Albien supérieur —(régression fin Albien-début Cénomanien)
3. (3) au milieu du Cénomanien inférieur —(régression fin Cénomanien inférieur)
4. (4) à la fin du Cénomanien moyen —(régression fin Cénomanien)
5. (5) au milieu du Turonien inférieur —(régression du Coniacien)
6. (6) au Santonien puis Campanien —(régression fin Campanien)
7. (7) au Maestrichtien —(régression fin Maastrichtien)
Ces dépôts crétacés présentent une succession de séquences séparées par des discontinuités et des surfaces d'érosion plus ou moins marquées. Les caractères et la répartition de ces séquences sont analysés en domaine de sédimentation terrigène littorale et dans le bassin envahi par la craie. Il est alors tenté d'interpréter les variations bathymétriques d'une part en fonction d'évènements tectoniques locaux, d'autre part en relation avec des variations eustatiques plus générales.Middle and Upper Cretaceous deposits studied in the western Paris Basin and on the Armorican Massif margin show seven transgressive pulses that can be detected in the geometrical arrangement of the sedimentary bodies and the vertical succession of facies.The transgressive episodes, each delimited by a regressive phase, reached their peak during:
1. (1) late Late Aptian —(Early Albian regression)
2. (2) mid Late Albian —(Late Albian-Early Cenomanian regression)
3. (3) mid Early Cenomanian —(late Early Cenomanian regression)
4. (4) late Middle Cenomanian —(Late Cenomanian regression)
5. (5) mid Early Turonian —(Coniacian regression)
6. (6) Santonian-Campanian —(Late Campanian regression)
7. (7) Maastrichtian —(Late Maastrichtian regression)
The Cretaceous sediments occur as a series of sequences, separated by more or less important discontinuities and erosion surfaces. The features and distribution of these sequences have been studied in the nearshore region of terrigenous sedimentation and in the Chalk basin. An attempt is made to relate the bathymetric changes to either tectonic movements or more widespread eustatic oscillations.  相似文献   
3.
This paper is a brief explanation of the diagrams of the Cretaceous transgressions and regressions on the Russian Platform, in the Crimea (Figures 1–3) and some regions of central Asia—the western flanks of the Tien Shan mountains, the Fergana basin, the Zeravshan-Gissar and Alaj mountains, and the Northern Pamirs (Figures 5–7).Internationally recognized stages are employed. They are interpreted by Sasonova (1967) for the Lower Cretaceous (K1) of the Russian Platform, by Naidin (1977) for the Upper Cretaceous (K2) of the Platform and the Crimea, by Djalilov (1971) and Pojarkova (1976) for the Upper Cretaceous of central Asia. General data on the stratigraphy of the Cretaceous of central Asia may be found in Anon 1977.  相似文献   
4.
Well-preserved Quaternary staircased marine terraces appear on Ras Leona limestone relief. This is a peculiar sector of the Betic-Rif Cordillera, lying in the four-way junction between the Atlantic and the Mediterranean, and Europe and Africa. The age and altitude correlation of the Ras Leona terraces with travertine-covered lateral equivalent terraces fashioned in the neighbouring Beni Younech area, and comparison with those along the Moroccan Atlantic coasts, would suggest that the Ras Leona terraces were mainly formed by eustatic factors. The importance of the eustasy is supported by further comparisons with Spanish and Moroccan Mediterranean terraces and with different marine terraces developed on passive-margin coasts around the world. A tectonic event occurred mainly during the period between the formation of the Maarifian and the Ouljian terraces (i.e., between 370 and 150 ka). The moderate Quaternary tectonic uplift deduced from the marine terraces and its comparison with uplifted marine terraces developed in active subduction setting disagrees with the model of an active eastwards subduction below the Gibraltar tectonic arc.  相似文献   
5.
The Cap Bon Peninsula, belonging to northeastern Tunisia, is located in the Maghrebian Alpine foreland and in the North of the Pelagian block. By its paleoposition, during the Cenozoic, in the edge of the southern Tethyan margin, this peninsula constitutes a geological entity that fossilized the eustatic, tectonic and climatic interactions. Surface and subsurface study carried out in the Cap Bon onshore area and surrounding offshore of Hammamet interests the Miocene deposits from the Langhian-to-Messinian interval time. Related to the basin and the platform positions, sequence and seismic stratigraphy studies have been conducted to identify seven third-order seismic sequences in subsurface (SM1-SM7), six depositional sequences on the Zinnia-1 petroleum well (SDM1-SDM6), and five depositional sequences on the El Oudiane section of the Jebel Abderrahmane (SDM1–SDM5). Each sequence shows a succession of high-frequency systems tract and parasequences. These sequences are separated by remarkable sequence boundaries and maximum flooding surfaces (SB and MFS) that have been correlated to the eustatic cycles and supercycles of the Global Sea Level Chart of Haq et al. (1987). The sequences have been also correlated with Sequence Chronostratigraphic Chart of Hardenbol et al. (1998), related to European basins, allows us to arise some major differences in number and in size. The major discontinuities, which limit the sequences resulted from the interplay between tectonic and climatic phenomena. It thus appears very judicious to bring back these chronological surfaces to eustatic and/or local tectonic activity and global eustatic and climatic controls.  相似文献   
6.
The Telychian succession in the central Oslo region was previously interpreted as deposited in a relatively deep, calm environment showing a continuous transgressive development. A new analysis of fossil assemblages shows that sediments in the central districts were deposited at varying water depths in an environment marked by intense infaunal activity in soft substrates. Two small-scale fluctuations in sea level are attributed to eustasy. The maximum deepening events occurred during the Monograptus turriculatus and Monoclimacis crenulata graptolite zones. Previous depositional models include development of a trough to the north of the Oslo region in early Telychian time, which formed due to isostatic loading caused by an advancing thrust front of the Caledonian Orogeny. Bathymetric analysis shows a deepening in the Ringerike district in the latest Aeronian, which here is interpreted as a distal effect of the loading to the north. The local deepening led to reversal of the epicontinental slope between the northern and western districts and the central districts and the development of an east–west elongate positive area further south. The thrust front acted as a source of siliciclastic material; and when the front halted in mid-Telychian time the trough was filled in gradually by a prograding coast or delta. The diachronous Vik Formation is viewed as a distal development of this progradation. When the east–west oriented positive area subsided the Vik Formation was deposited in Skien to the south.  相似文献   
7.
Yoshiki Yamada  Masao Nakada   《Tectonophysics》2006,415(1-4):103-121
The stratigraphic architecture of sedimentary basin provides important constraints on the rheological structure of the upper mantle and the crust, eustatic events and tectonic movements. In this study, we examined the convective coupling between the uppermost mantle and ductile lower crust as a formation mechanism of sedimentary basins. In this mechanism, the lower crust is squeezed by the upper mantle flow associated with mantle diapiric upwelling, resulting in the surface subsidence and formation of sedimentary basin. We investigated the stratigraphic architecture by taking into account the horizontal migration of the upwelling in time and spatial domains. The sedimentary basin is characterized by both the thickness and formation period for its gross feature and the sequence stratigraphy. The decay of the upwelling causes the surface uplift, and some parts of sediments deposited during the surface subsidence are consequently eroded. The subsidence area moves as the activity of upwelling horizontally migrates, resulting in the formation of unconformity for the uplifted and eroded area over the previous upwelling. We also incorporated the effects of third order eustasy, with amplitude of 100 m and period of 1 Myr, into convective coupling model. An application of our model to Karatsu-Sasebo coalfield in the Tertiary of the northwest Kyushu, Japan, indicates that the stratigraphic architecture of sedimentary basin including two effects, i.e. convective coupling and eustasy, may provide important information about the viscosity structure of the lower crust and uppermost mantle and spatio-temporal growth and decay histories of the mantle diapiric upwelling.  相似文献   
8.
Well investigated platforms have been selected in each continent, and the history of Cretaceous transgressions and regressions there is concisely reviewed from the available evidence. The factual records have been summarized into a diagram and the timing of the events correlated between distant as well as adjoining areas.On a global scale, major transgressions were stepwise enlarged in space and time from the Neocomian, via Aptian-Albian, to the Late Cretaceous, and the post-Cretaceous regression was very remarkable. Minor cycles of transgression-regression were not always synchronous between different areas. Some of them were, however, nearly synchronous between the areas facing the same ocean.Tectono-eustasy may have been the main cause of the phenomena of transgression-regression, but certain kinds of other tectonic movements which affected even the so-called stable platforms were also responsible for the phenomena. The combined effects of various causes may have been unusual in the Cretaceous, since it was a period of global tectonic activity. The slowing down of this activity followed by readjustments may have been the cause of the global regression at the end of the Cretaceous.  相似文献   
9.
Integrated palaeoecological studies of two fiord sediment sequences in the province of Blekinge, SE Sweden, covering the time span 11,000–5000 cal BP, reveal the timing and the environment for the Ancylus Lake/Littorina Sea transition 9800–8500 cal BP. The first ingression of saline water into the Baltic Sea through the Danish Straits occurred earlier than formerly assumed. New evidence, particularly mineral magnetic and palaeobotanical analyses, demonstrate that on the general trend of the eustatically caused Littorina transgression several minor fluctuations of the water level can be identified between 8500 and 5000 cal years BP. A distinct regression phase around 8100 cal BP is correlated with the Greenland ice-core cold event dated to 8200 ice-core years BP. This is described as a regional climatic catastrophe for the Baltic Sea region. The coastal stratigraphy is compared with the offshore stratigraphy earlier studied. A tentative shore displacement curve for Early and Middle Holocene is presented.  相似文献   
10.
We present new biostratigraphic analyses of approximately 200 outcrop samples and review biostratigraphic data from 136 public domain exploration wells across western New Guinea. Biostratigraphic ages and palaeodepositional environments were interpreted from occurrences of planktonic and larger benthic foraminifera, together with other fossils and environmental indicators where possible. These data were compared with existing geological maps and exploration well data to reconstruct the palaeogeography of western New Guinea from the Carboniferous to present day. In addition, we used the known bathyal preferences of fossils to generate a regional sea-level curve and compared this with global records of sea-level change over the same period. Our analyses of the biostratigraphic data identified two major transgressive-regressive cycles in regional relative sea-level, with the highest sea levels recorded during the Late Cretaceous and Late Miocene and terrestrial deposition prevalent across much of western New Guinea during the Late Paleozoic and Early Mesozoic. An increase in the abundance of carinate planktonic foraminifera indicates a subsequent phase of relative sea-level rise during a regional transgressive event between the Late Jurassic and Late Cretaceous. However, sea-levels dropped once more during a regressive event between the Late Cretaceous and the Paleogene. This resulted in widespread shallow water carbonate platform development in the Middle to Late Eocene. A minor transgressive event occurred during the Oligocene, but this ceased in the Early Miocene, likely due to the collision of the Australian continent with intra-Pacific island arcs. This Miocene collision event resulted in widespread uplift that is marked by a regional unconformity. Carbonate deposition continued in platforms that developed in shallow marine settings until these were drowned during another transgressive event in the Middle Miocene. This transgression reached its peak in the Late Miocene and was followed by a further regression culminating in the present day topographic expression of western New Guinea.  相似文献   
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