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1.
Tor H. Nilsen 《Geo-Marine Letters》1983,3(2-4):167-171
The Eocene Butano Sandstone was deposited as a submarine fan in a relatively small, partly restricted basin in a borderland setting. It is possibly as thick as 3000 m and was derived from erosion of nearly Mesozoic granitic and older metamorphic rocks located to the south. Deposition was at lower bathyal to abyssal water depths. The original fan may have been 120-to 160-km long and 80-km wide. Outcrops of submarine-canyon, innerfan, middle-fan, and outer-fan facies associations indicate that the depositional model of Mutti and Ricci Lucchi can be used to describe the Butano Sandstone. 相似文献
2.
The Upper Cretaceous and Paleocene Gottero Sandstone was deposited as a small deep-sea fan on ophiolitic crust in a trench-slope
basin. It was thrust northeastward as an allochthonous sheet in Early and Middle Cenozoic time. The Gottero, as thick as 1500
m, was probably derived from erosion of Hercynian granites and associated metamorphic rocks in northern Corsica. Outcrops
of inner-fan channel, middle-fan channel and interchannel, outer-fan lobe, fan-fringe, and basin-plain facies associations
indicate that the depositional model of Mutti and Ricci Lucchi for mixed-sediment deep-sea fans can be used. The original
fan had a radius of 30 to 50 km.
Margin setting represents fan and/or source area 相似文献
3.
The 0.5- to 2-km thick Quaternary Laurentian Fan is built over Tertiary and Mesozoic sediments that rest on oceanic crust.
Two 400-km long fan valleys, with asymmetric levees up to 700-m high, lead to an equally long, sandy, lobate basin plain (northern
Sohm Abyssal Plain). The muddy distal Sohm Abyssal Plain is a further 400-km long. The sediment supplied to the fan is glacial
in origin, and in part results from seismically triggered slumping on the upper continental slope. Sandy turbidity currents,
such as the 1929 Grand Banks earthquake event, probably erode the fan-valley floors; but thick muddy turbidity currents build
up the high levees.
Margin setting represents fan and/or source area 相似文献
4.
Remnants of an Eocene fan system are preserved onshore at San Diego and in the central part of the southern California borderland.
Even though faults and erosion have truncated its margins, geophysical data and exploratory wells indicate that remaining
parts of the fan extend beneath an offshore area nearly 400-km long and 40- to 100-km wide. Environments representing fluvial,
fan-delta, shelf-channel, overlapping inner- to outer-fan, and basin-plain facies are recognized or inferred. Three progradational
cycles onshore and two distinct pulses of sand accumulation offshore are attributable to eustatic low sea-level stands rather
than to tectonic uplift or shifts in depositional patterns.
Margin setting represents fan and/or source area 相似文献
5.
Tor H. Nilsen 《Geo-Marine Letters》1984,3(2-4):179-185
Turbidites of the Upper Cretaceous Chugach terrane of southern Alaska were deposited in a trench during northward-directed
subduction. The fault-bounded outcrop belt of the Chugach terrane is about 2000-km long and 100-km wide and was accreted to
Alaska during the Cenozoic. Turbidites are at least 5000 m thick, are extensively deformed, have been regionally metamorphosed,
and have been intruded by anatectic granites. Facies associations indicate an east-to-west progression from inner-fan to middle-fan,
outer-fan, fan-fringe, and basin-plain deposits. To the north is a marginal trench-slope facies association and a basin.
Margin setting represents fan and/or source area 相似文献
6.
Bengal Submarine Fan, with or without its eastern lobe, the Nicobar Fan, is the largest submarine fan known. Most of its sediment
has been supplied by the Ganges and Brahmaputra Rivers, probably since the Early Eocene. The “Swatch-of-No-Ground” submarine
canyon connects to only one active fan valley system at a time, without apprent bifurcation over its 2500-km length. The upper
fan is comprised of a complex of huge channel-levee wedges of abandoned and buried older systems. A reduction of channel size
and morphology occurs at the top of the middle, fan, where meandering and sheet flow become more important.
Margin setting represents fan and/or source area 相似文献
7.
The Upper Cretaceous and Paleocene Gottero Sandstone was deposited as a small deep-sea fan on ophiolitic crust in a trench-slope basin. It was thrust northeastward as an allochthonous sheet in Early and Middle Cenozoic time. The Gottero, as thick as 1500 m, was probably derived from erosion of Hercynian granites and associated metamorphic rocks in northern Corsica. Outcrops of inner-fan channel, middle-fan channel and interchannel, outer-fan lobe, fan-fringe, and basin-plain facies associations indicate that the depositional model of Mutti and Ricci Lucchi for mixed-sediment deep-sea fans can be used. The original fan had a radius of 30 to 50 km. 相似文献
8.
Remnants of an Eocene fan system are preserved onshore at San Diego and in the central part of the southern California borderland. Even though faults and erosion have truncated its margins, geophysical data and exploratory wells indicate that remaining parts of the fan extend beneath an offshore area nearly 400-km long and 40- to 100-km wide. Environments representing fluvial, fan-delta, shelf-channel, overlapping inner- to outer-fan, and basin-plain facies are recognized or inferred. Three progradational cycles onshore and two distinct pulses of sand accumulation offshore are attributable to eustatic low sea-level stands rather than to tectonic uplift or shifts in depositional patterns. 相似文献
9.
The 0.5- to 2-km thick Quaternary Laurentian Fan is built over Tertiary and Mesozoic sediments that rest on oceanic crust. Two 400-km long fan valleys, with asymmetric levees up to 700-m high, lead to an equally long, sandy, lobate basin plain (northern Sohm Abyssal Plain). The muddy distal Sohm Abyssal Plain is a further 400-km long. The sediment supplied to the fan is glacial in origin, and in part results from seismically triggered slumping on the upper continental slope. Sandy turbidity currents, such as the 1929 Grand Banks earthquake event, probably erode the fan-valley floors; but thick muddy turbidity currents build up the high levees. 相似文献
10.
Bengal Submarine Fan, with or without its eastern lobe, the Nicobar Fan, is the largest submarine fan known. Most of its sediment has been supplied by the Ganges and Brahmaputra Rivers, probably since the Early Eocene. The “Swatch-of-No-Ground” submarine canyon connects to only one active fan valley system at a time, without apprent bifurcation over its 2500-km length. The upper fan is comprised of a complex of huge channel-levee wedges of abandoned and buried older systems. A reduction of channel size and morphology occurs at the top of the middle, fan, where meandering and sheet flow become more important. 相似文献
11.
The Amazon Deep-Sea Fan began to form in the Early Miocene and is characterized by a highly meandering distributary channel
system. On the middle fan, these leveed channels coalesce to form two broad levee complexes. Older, now buried levee complexes
are also observed within the fan. These levee complexes grow through channel migration, branching, and avulsion. Probably
only one or two channels are active at any given time. Sediments reach the fan only during glacio-eustatic low stands of sea
level. Coarse sediments largely by-pass the upper and middle fan via the channels and are deposited on the lower fan.
Margin setting represents fan and/or source area 相似文献
12.
To help understand factors that influence submarine fan deposition, we outline some of the principal sedimentary, tectonic,
and sea-level controls involved in deep-water sedimentation, give some data on the rates at which they operate, and evaluate
their probable effects. Three depositional end-member systems, two submarine fan types (elongate and radial), and a third
nonfan, slope-apron system result primarily from variations in sediment type and supply. Tectonic setting and local and global
sea-level changes further modify the nature of fan growth, the distribution of facies, and the resulting vertical stratigraphic
sequences.
Margin setting represents fan and/or source area 相似文献
13.
Franco Ricci Lucchi Albina Colella Gianni Gabbianelli Sergio Rossi William R. Normark 《Geo-Marine Letters》1984,3(2-4):71-77
The Crati Fan is located in the tectonically active submerged extension of the Apennines chain and foretrough. The small fan
system is growing in a relatively shallow (200 to 450 m), elongate nearshore basin receiving abundant input from the Crati
River. The fan is characterized by a short, steep, channelized section (inner or upper fan) and a smooth, slightly bulging
distal section (outer or lower fan). The numerous subparallel channels head in the shelf or littoral zone and do not form
branching distributary patterns. Sand and mud depositional lobes of the outer fan stretch over more than 60% of fan length.
Margin setting represents fan and/or source area 相似文献
14.
Blanca fan is a submarine fan composed of Miocene volcaniclastic strata. Parts of the fan system are exposed on Santa Cruz
and Santa Rosa Islands, and possibly correlative strata crop out on San Miguel and Santa Catalina Islands.
The Blanca fan and underlying breccia reflect regional transcurrent faulting in the California Continental Borderland and
development of a system of rapidly subsiding basins and uplifted linear ridges during early and middle Miocene time. Erosion
of uplifted crystalline basement rocks followed by the onset of silicic volcanism created linear sediment sources for the
alluvial and submarine fans, respectively.
Margin setting represents fan and/or source area 相似文献
15.
The newly discovered Weddell Fan, Antarctica, covers 0.75 million km2. The adjacent continental shelf is characterized by deep, rugged topography; the inner shelf is covered by a grounded polar ice sheet. The upper fan has numerous deep, V-shaped canyons that intersect a slope-base, leveed fan valley. Piston cores from the valley contain disorganized gravel grading upward into graded gravel and sand. Levee cores contain interbedded hemipelagic sediments and fine-grained turbidites. The lower fan is sand-rich. Sediment supply to the fan apparently occurred before development of glacial shelf topography and during a more temperate glacial setting. 相似文献
16.
Emiliano Mutti 《Geo-Marine Letters》1984,3(2-4):199-202
The Eocene Hecho Group submarine-fan and basin-plain turbidites fill an elongate basin in the south-central Pyrenees that
was tectonically active during deposition. The total volume of these sediments is about 21,000 to 26,000 km3. The bulk of the sand by-passed the fan-channel zone and was deposited in the lobe and fan-fringe environments. The stratigraphically
lower part of the Hecho submarine fan was deposited during relative lowering of sea level.
Margin setting represents fan and/or source area 相似文献
17.
The Upper Cretaceous Bordighera Sandstone of NW Italy is a coarse-grained, sand-rich elongated turbidite system (ca. 15 × 45 km in outcrop) up to 250 m thick, interpreted to have been deposited in a trench setting. The siliciclastic succession interfingers with muddy calcareous turbidites, which become more abundant toward the lateral and distal domains. Bed type associations allow the distinction of a proximal channelized domain which transitions to a more distal lobe domain, characterized by abundant mudclast-rich sandstones and by bipartite and tripartite beds with a mud-rich middle or upper division (hybrid event beds). The transition between the proximal and distal domains occurs over a relatively limited spatial extent (ca. 5 km). The presence of lenticular bed-sets made up of coarse grained and mud-poor sandstones throughout the distal domain suggests that distributary channels were present, indicating sediment bypass further down-dip toward the most distal and not preserved parts of the system. Hybrid event beds - commonly associated with distal and marginal fan environments such as fan fringes - are present throughout the lobe domain and extend for up to ca. 30 km in down-dip distance. They are more abundant in the proximal and axial depositional lobe domain and their appearance occurs within a short basin-ward distance from the inferred channel-lobe transition zone. Flow expansion at the termination of the channelized domain and the enhanced availability of cohesive substrate due to the presence of intra-basinal muddy calcareous beds are interpreted as the key controls on the widespread occurrence of mudclast-rich and argillaceous sandstone beds. The abrupt appearance and the persistent occurrence of such beds across an extensive domain have implications for characterizing bed-scale (sub-seismic) heterogeneity of deep-water clastic hydrocarbon reservoirs. 相似文献
18.
The Cengio sandstone member of the Tertiary Piedmont Basin in northwestern Italy has a conservatively estimated volume of
2.5 to 3 km3 (length: 6.4 km; width: 4.8 km; thickness: 170 m). It is interpreted as a sandstone-rich submarine fan deposit. The Cengio
member consists of eight tabular depositional sandstone lobes that are 5- to 25-m thick. These lobes filled a submarine structural
depression and onlap and/or pinch-out against bounding slope mudstones. The stacking of the lobe units was related to synsedimentary
tectonism.
Margin setting represents fan and/or source area 相似文献
19.
Navy Fan is a Late Pleistocene sand-rich fan prograding into an irregularly shaped basin in the southern California Borderland.
The middle fan, characterized by one active and two abandoned “distributary” channels and associated lobe deposits, at present
onlaps part of the basin slope directly opposite from the upper-fan valley, thus dividing the lower-fan/basin-plain regions
into two separate parts of different depths. Fine-scale mesotopographic relief on the fan surface and correlation of individual
turbidite beds through nearly 40 cores on the middle and lower fan provide data for evaluating the Late Pleistocene and Holocene
depositional processes.
Margin setting represents fan and/or source area 相似文献
20.
The Yinggehai and Qiongdongnan basins in the northwestern South China Sea preserve a large volume of Cenozoic sediments. However, their sources are still remain controversial and need a further research. This paper uses discriminant diagrams and bivariate plots of major, trace and rare earth elements, combined with heavy mineral data and detrital zircon U-Pb ages to determine the provenance, source area weathering and tectonic setting of the Upper Miocene to Pliocene sediments in the Yinggehai and Qiongdongnan basins, offshore South China Sea. The sandstone samples used in this study are characterized by four features: (i) The studied sandstones are first-cycle deposits, no recycling processes are recorded in these sediments, and there is a low degree of weathering conditions in the source areas. (ii) The sandstones from the DF fan, LD fan and Central Canyon System may have a similar source, being derived from an old upper continental crust mainly composed of felsic igneous source rocks. (iii) Detrital zircon U-Pb ages suggest that Central Vietnam is likely to be the dominant source of the DF fan, LD fan and Central Canyon System. (iv) The tectonic setting of the sandstones in the DF fan, LD fan and Central Canyon System belongs to the continental island arc (CIA) or the active continental margin (ACM) fields. 相似文献