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Transfer Zone
A transfer zone in geology is an area where deformational strain is transferred from one structural element to another typically from fault to fault in rift systems. Therefore, listric faults and monoclinal folds in the hanging wall are typical structures linked by transfer zones; however, complexities do exist. The terms interbasin and intrabasin transfer zones have been proposed to delineate the magnitude of the transfer zone. Transfer zones can be described according to the fault dip directions; synthetic or conjugate and according to their deformation style; convergent or divergent. Transfer zones can be farther identified by its maturity or (fault propagation evolution); whether the major fault relationship is approaching, overlapping, collateral or collinear. Since transfer zones are normally found in extensional settings many studies have been done within the East African rift system and the Gulf of Suez rift system. Transfer zones have also played a role in hydrocarbon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fault (geology)
In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic forces, with the largest forming the boundaries between the plates, such as the megathrust faults of subduction zones or transform faults. Energy release associated with rapid movement on active faults is the cause of most earthquakes. Faults may also displace slowly, by aseismic creep. A ''fault plane'' is the plane that represents the fracture surface of a fault. A '' fault trace'' or ''fault line'' is a place where the fault can be seen or mapped on the surface. A fault trace is also the line commonly plotted on geologic maps to represent a fault. A ''fault zone'' is a cluster of parallel faults. However, the term is also used for the zone of crushed rock along a single fault. Prolonged motion along closely spaced faults can bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rift
In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-graben with normal faulting and rift-flank uplifts mainly on one side. Where rifts remain above sea level they form a rift valley, which may be filled by water forming a rift lake. The axis of the rift area may contain volcanic rocks, and active volcanism is a part of many, but not all, active rift systems. Major rifts occur along the central axis of most mid-ocean ridges, where new oceanic crust and lithosphere is created along a divergent boundary between two tectonic plates. ''Failed rifts'' are the result of continental rifting that failed to continue to the point of break-up. Typically the transition from rifting to spreading develops at a triple junction where three converging rifts meet over a hotspot. Two of these evolve to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
East African Rift
The East African Rift (EAR) or East African Rift System (EARS) is an active continental rift zone in East Africa. The EAR began developing around the onset of the Miocene, 22–25 million years ago. In the past it was considered to be part of a larger Great Rift Valley that extended north to Asia Minor. A narrow zone, the rift is a developing divergent tectonic plate boundary where the African Plate is in the process of splitting into two tectonic plates, called the Somali Plate and the Nubian Plate, at a rate of 6-7 mm per year. The rift system consists of three microplates, the Victoria Microplate to the north, and the Rovuma and Lwandle microplates to the south. The Victoria Microplate is rotating anti-clockwise with respect to the African plate. Its rotation is caused by the configuration of mechanically weaker and stronger lithospheric regions in the EARS. Extent A series of distinct rift basins, the East African Rift System extends over thousands of kilometer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gulf Of Suez Rift
The Gulf of Suez Rift is a continental rift zone that was active between the Late Oligocene ( 28 Ma) and the end of the Miocene (c. 5 Ma). It represented a continuation of the Red Sea Rift until break-up occurred in the middle Miocene, with most of the displacement on the newly developed Red Sea spreading centre being accommodated by the Dead Sea Transform. During its brief post-rift history, the deepest part of the remnant rift topography has been filled by the sea, creating the Gulf of Suez. North of the Gulf of Suez the rift becomes indistinct and its exact geometry uncertain, linking eventually to the Manzala rift beneath the Nile delta. Plate tectonic setting The formation of the Red Sea – Gulf of Suez rift system was caused by the anticlockwise rotation of the Arabian Plate with respect to the African Plate. This model is consistent with near orthogonal rifting along the entire length of the rift system. Alternative models that suggest initiation by strike-slip faulting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Malawi
Lake Malawi, also known as Lake Nyasa in Tanzania and Lago Niassa in Mozambique, is an African Great Lake and the southernmost lake in the East African Rift system, located between Malawi, Mozambique and Tanzania. It is the fifth largest fresh water lake in the world by volume, the ninth largest lake in the world by area—and the third largest and second deepest lake in Africa. Lake Malawi is home to more species of fish than any other lake in the world, including at least 700 species of cichlids.Turner, Seehausen, Knight, Allender, and Robinson (2001). "How many species of cichlid fishes are there in African lakes?" ''Molecular Ecology'' 10: 793–806. The Mozambique portion of the lake was officially declared a reserve by the Government of Mozambique on June 10, 2011,WWF (10 June 2011)"Mozambique’s Lake Niassa declared reserve and Ramsar site"Retrieved 17 July 2014. while in Malawi a portion of the lake is included in Lake Malawi National Park. Lake Malawi is a meromic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structural Geology
Structural geology is the study of the three-dimensional distribution of rock units with respect to their deformational histories. The primary goal of structural geology is to use measurements of present-day rock geometries to uncover information about the history of deformation ( strain) in the rocks, and ultimately, to understand the stress field that resulted in the observed strain and geometries. This understanding of the dynamics of the stress field can be linked to important events in the geologic past; a common goal is to understand the structural evolution of a particular area with respect to regionally widespread patterns of rock deformation (e.g., mountain building, rifting) due to plate tectonics. Use and importance The study of geologic structures has been of prime importance in economic geology, both petroleum geology and mining geology. Folded and faulted rock strata commonly form traps that accumulate and concentrate fluids such as petroleum and natural gas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
