Changes

The location of magmatic sill type bodies within sedimentary lithologies has four major

The location of magmatic sill type bodies within sedimentary lithologies has four major

consequences:

consequences:

[[File:IMAGEN 7.png|200|thumbnail|right|Figure 6: Scheme of northern Neuquen basin where it can be seen as most sills are deployed in the Vaca Muerta Formation (hydrocarbon source rock).]]

[[File:IMAGEN 7.png|center|framed|{{figure number|6}}Scheme of northern Neuquen basin where it can be seen as most sills are deployed in the Vaca Muerta Formation (hydrocarbon source rock).]]

* '''Location in bedrock''': has been observed in numerous world sites, site of intrusive occurs in petroleum source rocks, whose cause is still not fully understood but presumably has to do with three factors: pore pressure, level weakness is the bedrock (being shale is less competent ) and plans anisotropy generated in the shales facilitate deflection of the levees that are rising from lower levels (Fig 6).

* '''Location in bedrock''': has been observed in numerous world sites, site of intrusive occurs in petroleum source rocks, whose cause is still not fully understood but presumably has to do with three factors: pore pressure, level weakness is the bedrock (being shale is less competent ) and plans anisotropy generated in the shales facilitate deflection of the levees that are rising from lower levels (Fig 6).

   

   

* '''Radial fractures''' fracture pattern generated in the sediments by the efforts of the magma pressure, radiating from a central point.

* '''Radial fractures''' fracture pattern generated in the sediments by the efforts of the magma pressure, radiating from a central point.

   

   

* '''Fractures located at the corners of the sill:''' as seen in Figure 4 the stress concentration at the ends of the sill is very rich and very intense fracturing in consequence.

* '''Fractures located at the corners of the sill:''' as seen in [[:File:IMAGEN 5.png|Figure 4]] the stress concentration at the ends of the sill is very rich and very intense fracturing in consequence.

   

   

* '''Concentric fractures:''' generated at the edges of the sill and parts of the country rock by the circulation of metasomatic fluids or lithostatic decompression.

* '''Concentric fractures:''' generated at the edges of the sill and parts of the country rock by the circulation of metasomatic fluids or lithostratic decompression.

   

   

* '''Columnar or polygonal fractures:''' are generated by cooling and solidification of magma, where its volume is reduced contraction columnar cells formed orthogonal to the surface through which heat is lost (Fig 7 and 8).

* '''Columnar or polygonal fractures:''' are generated by cooling and solidification of magma, where its volume is reduced contraction columnar cells formed orthogonal to the surface through which heat is lost ([[:File:IMAGEN 8.png|Figures 7]] and [[:File:IMAGEN 9.png|8]]).

[[File:IMAGEN 8.png|500px|thumbnail|left|Figure 7: Scheme of columnar fractures. Taken from Bermúdez & Delpino<ref name=Bermudez />]]

[[File:IMAGEN 8.png|500px|thumbnail|left|{{figure number|7}} Scheme of columnar fractures. Taken from Bermúdez & Delpino<ref name=Bermudez />]]

[[File:IMAGEN 9.png|400px|thumbnail|center|Figure 8: Variation of fracture patterns in a vertical section of a sill. Taken from Bermúdez & Delpino<ref name=Bermudez />]]

[[File:IMAGEN 9.png|400px|thumbnail|center|{{figure number|8}}Variation of fracture patterns in a vertical section of a sill. Taken from Bermúdez & Delpino<ref name=Bermudez />]]

   

   

* '''Folding:''' the movement of material not only produces fracturing but also the folding of the overlying material. These folds are important because they may constitute important reservoirs and traps, even exploited in several basins in the world (Fig 9).

* '''Folding:''' the movement of material not only produces fracturing but also the folding of the overlying material. These folds are important because they may constitute important reservoirs and traps, even exploited in several basins in the world ([[:File:IMAGEN 10.png|Figure 9]]).

[[File:IMAGEN 10.png|400px|thumbnail|center|Figure 9: 2D seismic conducted northeast of Rockall basin, North Sea Norway. Observe normal faults as a product to accommodate the [[deformation]] of the fold. Taken from Hansen & Cartwright.<ref>Cartwright, J. & D. M. Hansen, 2006, The three-dimensional geometry and growth of forced folds above saucer-shaped igneous sills. Journal of Structural Geology 28, pp. 1520-1535.</ref>]]

[[File:IMAGEN 10.png|400px|thumbnail|center|{{figure number|9}}2-D seismic conducted northeast of Rockall basin, North Sea Norway. Observe normal faults as a product to accommodate the [[deformation]] of the fold. Taken from Hansen & Cartwright.<ref>Cartwright, J., and D. M. Hansen, 2006, The three-dimensional geometry and growth of forced folds above saucer-shaped igneous sills: Journal of Structural Geology, v. 28, pp. 1520-1535.</ref>]]

''' Thermal Maturity:''' the intrusion of magma of high temperatures (up to 1200 ° C) has a thermal effect on the country rock can get to promote [[maturation]] of hydrocarbons when diagenetic conditions are not optima (Fig 10) .

''' Thermal Maturity:''' the intrusion of magma of high temperatures (up to 1200 ° C) has a thermal effect on the country rock can get to promote [[maturation]] of hydrocarbons when diagenetic conditions are not optimal ([[:File:IMAGEN 11.png|Figure 10]]) .

[[File:IMAGEN 11.png|200|thumbnail|center|Figure 10: modeling of the distribution and direction of migration of oil and gas after the intrusion and cooling of a lacolito in the north of the Neuquen Basin and into the Vaca Muerta Fm province of Neuquen, Argentina ]]

[[File:IMAGEN 11.png|200|thumbnail|center|Figure 10: modeling of the distribution and direction of migration of oil and gas after the intrusion and cooling of a lacolito in the north of the Neuquen Basin and into the Vaca Muerta Formation, in the province of Neuquen, Argentina.]]

== Conclusions ==

== Conclusions ==