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Line 19: − + − * Physical: the density difference between the magma (lower density) and the host rocks is a key factor. Archimedes' principle is the one who acts. The surrounding rocks exert an upward thrust that moves the crustal magma to levels where their density is equated with the host rocks. It may happen that the density remains below the rocks of the environment and that the magma is detained its vertical ascent, the factor involved here are local efforts. If the efforts of the magma pressure can not overcome the resistance of the rocks magma vertically looking for a new way of moving through a plane of weakness such as a stratigraphic unconformity, anisotropy of the medium as fault planes, hinges of [[fold]]s, etc (Figure 3).+ − −
Hydrocarbon reservoirs associated to layered intrusive bodies (view source)
Revision as of 21:59, 2 April 2019
, 21:59, 2 April 2019→Factors Controlling The Emplacement Of Magma
== Factors Controlling The Emplacement Of Magma ==
== Factors Controlling The Emplacement Of Magma ==
[[File:IMAGEN 2.png|250px|thumbnail|right|{{figure number|2}}Schematic profile of the Neuquen Basin, province of Neuquen, Argentina , where you can see the site of lamellar bodies of [[Cenozoic]] age. Taken from Bermúdez & Delpino<ref name=Bermudez>Bermúdez, A., & D. Delpino, 2015, Concentric and radial joint systems within basic sills and their associated porosity enhancement, Neuquén Basin, Argentina: National Council of Scientific and Technical Investigations, Conciet.</ref>]]
[[File:IMAGEN 2.png|250px|thumbnail|right|{{figure number|2}}Schematic profile of the Neuquen Basin, province of Neuquen, Argentina , where you can see the site of lamellar bodies of [[Cenozoic]] age. Taken from Bermúdez & Delpino<ref name=Bermudez>Bermúdez, A., and D. Delpino, 2015, Concentric and radial joint systems within basic sills and their associated porosity enhancement, Neuquén Basin, Argentina: National Council of Scientific and Technical Investigations, Conciet.</ref>]]
The magmatic emplacement in the crust is not a freak of nature, it is controlled by a number of physical factors. It will highlight the constraints posed by the location of sedimentary basins subvolcanic due to the importance of these as part of hydrocarbon systems.
The magmatic emplacement in the crust is not a freak of nature, it is controlled by a number of physical factors. It will highlight the constraints posed by the location of sedimentary basins subvolcanic due to the importance of these as part of hydrocarbon systems.
=== Location factors ===
=== Location factors ===
* Tectonic: the dynamics of plates associated sedimentary basin must have significant magmatic activity, with interspersed relaxation events in time and needed to climb it.
* Tectonic: the dynamics of plates associated sedimentary basin must have significant magmatic activity, with interspersed relaxation events in time and needed to climb it.
* Physical: the density difference between the magma (lower density) and the host rocks is a key factor. Archimedes' principle is the one who acts. The surrounding rocks exert an upward thrust that moves the crustal magma to levels where their density is equated with the host rocks. It may happen that the density remains below the rocks of the environment and that the magma is detained its vertical ascent, the factor involved here are local efforts. If the efforts of the magma pressure can not overcome the resistance of the rocks magma vertically looking for a new way of moving through a plane of weakness such as a stratigraphic unconformity, anisotropy of the medium as fault planes, hinges of [[fold]]s, etc ([[:File:IMAGEN 3.png|Figure 3]]).
[[File:IMAGEN 3.png|300px|thumbnail|center|{{figure number|3}}In this photograph the site of two sills can be seen in a bedrock (Vaca Muerta Fm). Right on the sector focuses it can be clearly seen intense fracturing of columnar pattern. Photo courtesy of Juan Spacapan.]]
[[File:IMAGEN 3.png|300px|thumbnail|center|Figure 3: In this photograph the site of two sills can be seen in a bedrock (Vaca Muerta Fm). Right on the sector focuses it can be clearly seen intense fracturing of columnar pattern. Photo courtesy of Juan Spacapan.]]
Another important physical factor is the pore pressure. In porous sedimentary rocks saturated with fluids such as water and hydrocarbons, [[fracture]] resistance is reduced. This is why it can almost be deduced that the location of the intrusive within a sedimentary basin would be concentrated within shale formations (high porosity) with plenty of oil (Figure 4 and 5).
Another important physical factor is the pore pressure. In porous sedimentary rocks saturated with fluids such as water and hydrocarbons, [[fracture]] resistance is reduced. This is why it can almost be deduced that the location of the intrusive within a sedimentary basin would be concentrated within shale formations (high porosity) with plenty of oil (Figure 4 and 5).