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41-539: The Nam Con Son Basin, located adjacent to the Cuu Long Basin , is approximately 90,000 km. The Basin age ranges from Oligocene to Quaternary in age with sediment thickness of a maximum of 10 km. While a majority of the basin is situated in less than 200 meters of shallow water, the bathymetry can go to deeper than 2000 meters to the north of the Nam Con Son Basin. The Nam Con Son Basin

82-641: A composition of siltstones, friable claystones, and grey calcareous clays intercalated with white or light yellow quartz sandstone. This layer is also rich in carbonate and contains glauconite. Overall, the Bien Dong Formation has a lithological description of shale and claystone interbedded by thin laters of sandstone, rich organic matters and fossils. Extension resulted in the development of NE-SW trending half graben which later lead to rift filled sequence. These half graben were then continuously filled by basin wide deposition of fluvial sediment from

123-463: A controlling fault, or periodic changes of dip in the controlling faults, give the impression of full graben symmetry. As the rift expands, the rift flanks lift up due to isostatic compensation of the lithosphere . This creates the asymmetric topographic profile that is typical of half grabens. The half grabens may have alternating polarities along the rift axis, dividing the rift valley into segments. Intracontinental and marine rift basins such as

164-530: A good local and regional seal. The regional seal are the Lower Miocene shelf mudstones located in the south east Nam Con Son Basin there is a potential for both structural and stratigraphical traps . The trapping styles are dominantly three-way dip and fault, and two-way drip and two faults, closures. Quaternary The Quaternary ( / k w ə ˈ t ɜːr n ə r i , ˈ k w ɒ t ər n ɛr i / kwə- TUR -nə-ree, KWOT -ər-nerr-ee )

205-578: A large carbonate reef buildup and infilled by sandy turbidites. Major transgression caused the depositional process to be interrupted in the early Pliocene. The Nam Con Son Basin has an oil prone source rock, with a dominance of kerogen . Hydrocarbon was found in the Dai Hung field and the Dua field during explorations in the 1970s and 1980s with sequence clastic reservoirs containing structural traps style of fault-segmented four-way dip anticlines occurring in

246-523: A whole, the lithology of the Thong-Man Cau Formation is made from sandstones and claystones with carbonate build up and platform . This formation has a thickness between 100m to 500m.The upper formation consist of Clay, calcareous clay and grey sandstones. The lower formation has whitish grey carbonate and quartz sandstones. The Nam Con Son Formation has a generally lithology of yellow claystone which are interbedded with siltstone. It

287-479: Is a region where the lithosphere extends as two parts of the Earth's crust pull apart. Often a rift will form in an area of the crust that is already weakened by earlier geological activity. Extensional faults form parallel to the axis of the rift. An extensional fault may be seen as a crack in the crust that extends down at an angle to the vertical. As the two sides pull apart, the hanging wall ("hanging over"

328-795: Is also locally fine grained and calcareous. The bottom layer has a composition of brownish grey sandstones intercalated with several beds of silty clay. Overall, the lithology of the Cau Formation is composed of lacustrine shale , alluvial sandstones and minor coals . Overlying unconformably in the Cau Formation, the Dua Formation is between 200m to 800m thick, composed of light and bright grey sandstone, interbedded with blackish-grey silty clay. The sandstone has characteristics of fine to medium grained, angular, quarts, with carbonate cement. This formation also has glauconite corresponding with fossil fragments. The overall lithology of

369-496: Is average cemented and have rich organic and fossil properties. The Bien Dong Formation thickness varies from a few meters to 200m. In the Quaternary layer, moving from the bottom to the middle to the top, the Bien Dong Formation is composed of angular to round quartz sand which gradually changes to silty clay in the middle section to quartz sand imbedded with shell fragments at the top of the layer. The Lower Pliocene layer has

410-789: Is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the Phanerozoic eon. It follows the Neogene Period and spans from 2.58 million years ago to the present. The Quaternary Period is divided into two epochs: the Pleistocene (2.58 million years ago to 11.7 thousand years ago) and

451-579: Is used to fuel the Phú Mỹ Power Plants which provides 40% of Vietnam's total electricity. Đại Hùng oilfield was discovered in 1988 with an estimated reserves of 354.6 million barrels of oil and 8.482 trillion cubic meters of natural gas. Dai Hung field was one of the first three fields in Vietnam to come on-stream in October 1994 under operator Vietsovpetro . The average production from this field

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492-716: The Gelasian Stage, which was formerly considered part of the Neogene Period and Pliocene Epoch. This was later revised to 2.58 mya. The Anthropocene was proposed as a third epoch as a mark of the anthropogenic impact on the global environment starting with the Industrial Revolution , or about 200 years ago. The Anthropocene was rejected as a geological epoch in 2024 by the International Union of Geological Sciences (IUGS),

533-565: The Gulf of Suez , East African Rift , Rio Grande rift system and the North Sea often contain a series of half-graben sub-basins, with the polarity of the dominant fault system changing along the axis of the rift. Often the extensional fault systems are segmented in these rifts. Rift border faults with lengths over 10 kilometres (6.2 mi) are separated by relay ramp structures. The relay ramps may provide pathways for sediment to be carried into

574-718: The Holocene (11.7 thousand years ago to today); a proposed third epoch, the Anthropocene , was rejected in 2024 by IUGS , the governing body of the ICS. The Quaternary is typically defined by the Quaternary glaciation , the cyclic growth and decay of continental ice sheets related to the Milankovitch cycles and the associated climate and environmental changes that they caused. In 1759 Giovanni Arduino proposed that

615-403: The Cau Formation. This formation varies between 200m to 800m with the top formation composed of dark grey, greenish grey clay, intercalated with beds of sandstone , and siltstone . The middle layer of the basin is composed of quartz sandstone intercalated with greyish black, firm claystone and a thick bed of dark grey clay intercalated with light coloured oil shale . The later of this basin

656-678: The Dua Formation in the Nam Con Son Basin consist of coastal plain sandstones and has claystones and interbedded minor coals. Varying from 10m to 100m in the Thong-Man Cau formation, the upper formation has a composition of light grey, whitish/grey, locally reddish brown dolomitized carbonates and it is also intercalated with clays friable siltstones and fine grained, calcite-cemented sandstones. The lower formation consists of sandstone and calcareous sandstones interbedded with clays and siltstones. It has fine to medium grained sandstones with carbonate cement, glauconite and fossil fragments. As

697-552: The Pleistocene includes a portion of what was, prior to 2009, defined as the Pliocene . Quaternary stratigraphers usually worked with regional subdivisions. From the 1970s, the International Commission on Stratigraphy (ICS) tried to make a single geologic time scale based on GSSP 's, which could be used internationally. The Quaternary subdivisions were defined based on biostratigraphy instead of paleoclimate . This led to

738-483: The basement, faults cause subsidence troughs . The cover is divided into the three sequences: The upper sequence consist of clastic and coastal marine carbonates from the Bien Dong Formation. The middle sequence have a composition of Miocene sediments of the Dua Formation, Thong-Man Cau Formations and the Nam Con Son Formation. The lower sequence which is composed from Paleogene sediments from

779-425: The basin wall. Other material is transported across or along the basin to the deep water parts of a rift lake along the escarpment margin. Most of the sediment will enter the half-graben along the unfaulted hanging wall side. On the side of the basin opposite the main border fault, sedimentation occurs along the "hinged margin", which may also be called the "shoaling margin" or the "flexural margin". In this part of

820-449: The basin, slopes are usually gentle and large river systems may carry sediment into the basin, which could be stored in deltas where they enter a rift valley lake. Littoral and sub-littoral carbonate deposits may accumulate in these conditions. The "axial margins" at the ends of basins often include low-gradient ramps where major rivers enter the basin, building deltas and form currents within a rift lake that can carry sediment from one end to

861-412: The basin. Typically the rift is broken along its axis into segments about 50 to 150 kilometres (31 to 93 mi) long. Four zones of sedimentation can be defined in a half-graben. The first is "escarpment margin" sedimentation, found along the major border faults bounding the half graben, where the deepest part of the basin meets the highest rift-shoulder mountains. Comparatively little sediment enters

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902-644: The emergence of the straits of Bosphorus and Skagerrak during glacial epochs, which respectively turned the Black Sea and Baltic Sea into fresh water lakes, followed by their flooding (and return to salt water) by rising sea level; the periodic filling of the English Channel , forming a land bridge between Britain and the European mainland; the periodic closing of the Bering Strait , forming

943-728: The establishment of the Glacial Theory. In time, thanks to the refinement of geology, it has been demonstrated that there were several periods of glacial advance and retreat and that past temperatures on Earth were very different from today. In particular, the Milankovitch cycles of Milutin Milankovitch are based on the premise that variations in incoming solar radiation are a fundamental factor controlling Earth's climate. During this time, substantial glaciers advanced and retreated over much of North America and Europe, parts of South America and Asia, and all of Antarctica. There

984-418: The geological strata of northern Italy could be divided into four successive formations or "orders" ( Italian : quattro ordini ). The term "quaternary" was introduced by Jules Desnoyers in 1829 for sediments of France 's Seine Basin that clearly seemed to be younger than Tertiary Period rocks . The Quaternary Period follows the Neogene Period and extends to the present. The Quaternary covers

1025-472: The glacial period ended about 11,700 years ago. Modern humans evolved about 315,000 years ago. During the Quaternary Period, mammals, flowering plants, and insects dominated the land. Half graben A half-graben is a geological structure bounded by a fault along one side of its boundaries, unlike a full graben where a depressed block of land is bordered by parallel faults. A rift

1066-450: The governing body of the ICS. The 2.58 million years of the Quaternary represents the time during which recognisable humans existed. Over this geologically short time period there has been relatively little change in the distribution of the continents due to plate tectonics . The Quaternary geological record is preserved in greater detail than that for earlier periods. The major geographical changes during this time period included

1107-539: The half-graben across the major bounding fault, since uplift of the footwall causes the land on the footwall side to slope away from the fault. Rivers on that side therefore carry sediment away from the rift valley. But as the lowest part of the basin with the greatest rate of subsidence, the escarpment margin experiences the highest rates of sedimentation, which may accumulate to several kilometers in depth. This sedimentation often includes very coarse debris such as huge blocks from rock falls, as well as fans of sediment from

1148-551: The hanging walls of the main faults during the Mid-Miocene period. However, as the Nam Con Son Basin has a complex tectonic setting, the probability of success for commercial discovery is only at 16%. The Nam Con Son Basin, along with the Malay-Tho Chu Basins, are the two major gas supply caters towards Vietnam's energy demand. One such example is that natural gas from the Nam Con Son Basin and Bạch Hổ oil field

1189-596: The land bridge between Asia and North America ; and the periodic flash flooding of Scablands of the American Northwest by glacial water. The current extent of Hudson Bay , the Great Lakes and other major lakes of North America are a consequence of the Canadian Shield 's readjustment since the last ice age; different shorelines have existed over the course of Quaternary time. The climate

1230-403: The other. Between adjacent half grabens there will be "accommodation zones" that may include local extension, compression or strike-slip faulting. These can create complex morphologies within which different mechanisms affect sedimentation. The types of sedimentation in half grabens also depend on lake levels in the rift, the climate (e.g. tropical versus temperate) in which the sediments form and

1271-481: The presence of traces of the passage of a glacier at a considerable distance from the Alps. This idea was initially disputed by another Swiss scientist, Louis Agassiz , but when he undertook to disprove it, he ended up affirming his colleague's hypothesis. A year later, Agassiz raised the hypothesis of a great glacial period that would have had long-reaching general effects. This idea gained him international fame and led to

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1312-523: The problem that the proposed base of the Pleistocene was at 1.805 million years ago, long after the start of the major glaciations of the northern hemisphere. The ICS then proposed to abolish use of the name Quaternary altogether, which appeared unacceptable to the International Union for Quaternary Research (INQUA). In 2009, it was decided to make the Quaternary the youngest period of the Cenozoic Era with its base at 2.588 mya and including

1353-565: The rift tip by the NW-SE regional extension. NW-SE expansion together with a change in spreading direction in the South China Sea intensified topographic relief while restricting carbonate systems to platform or footwall locations and the facies pattern. Grabens were further deposited upon deeper shelf and slope facies. Nam Con Son Basin was once again reactivated tectonically by a mild inversion followed by thermal subsidence which caused

1394-545: The sloping fault) will move downward relative to the footwall. A rift basin is created as the crust thins and sinks. In the rift basin, warm mantle material wells up, melting the crust and frequently triggering the eruption of volcanoes. Extensional basins may appear to be caused by a graben, or depressed block of land, sinking between parallel normal faults that dip towards the center of the graben from both sides. In fact, they are usually made of linked asymmetrical half-grabens. Faults with antithetic slope directions linked in to

1435-399: The time span of glaciations classified as the Pleistocene , and includes the present interglacial time-period, the Holocene . This places the start of the Quaternary at the onset of Northern Hemisphere glaciation approximately 2.6 million years ago ( mya ). Prior to 2009, the Pleistocene was defined to be from 1.805 million years ago to the present, so the current definition of

1476-420: The water chemistry. Although sediments arrive primarily from the unfaulted side of the half-graben, some erosion takes place on the fault escarpment of the main border fault, and this produces characteristic alluvial fans where confined channels emerge from the escarpment. Lake Baikal is an unusually large and deep example of half-graben evolution. The lake is 630 by 80 kilometres (391 by 50 mi), with

1517-411: The west and thermal subsidence. The rifting phase was follow by a spreading in the seafloor with the axis shifting from WSW to SW trend. Transgressions and backstopping of deltas resulted in sag sequences trending upwards from non-marine to marine features during early Miocene. Continental breakup occurred shortly after seafloor spreading in the Nam Con Son Basin resulted in a second SW extension phase at

1558-580: Was a major extinction of large mammals globally during the Late Pleistocene Epoch. Many forms such as sabre-toothed cats , mammoths , mastodons , glyptodonts , etc., became extinct worldwide. Others, including horses , camels and American cheetahs became extinct in North America . The Great Lakes formed and giant mammals thrived in parts of North America and Eurasia not covered in ice. These mammals became extinct when

1599-515: Was about 3000 barrels of oil per day and is predicted for abandonment in 2025. The source rock were developed in the Oligocene and Miocene and are widely distributed throughout the basin with a dominance of parabolic coal mud rocks. Reservoir rock are typically by quartz sandstones, limestone and poly-mineral sandstones with reservoir thickness between 2m and 80m. Cap rocks in the Nam Con Son Basin consist of thin siltstone and sandstone with

1640-601: Was developed during the Tertiary by complex rifting of a poorly known basement . The geological formation of Nam Con Son Basin can be separated into two major structural elements: A Pre-Cenozoic strata basement and a Cenozoic sedimented cover. The heterogeneous basement is composed of quartz diorite , granodiorite and Mesozoic metamorphic rocks . While the Pre-Tertiary basement shows an assemblage of volcanic, igneous and metasedimentary rocks . At various levels in

1681-464: Was one of periodic glaciations with continental glaciers moving as far from the poles as 40 degrees latitude . Glaciation took place repeatedly during the Quaternary Ice age  – a term coined by Schimper in 1839 that began with the start of the Quaternary about 2.58 Mya and continues to the present day. In 1821, a Swiss engineer, Ignaz Venetz , presented an article in which he suggested

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