Salta Basin or Salta Rift Basin is a

sedimentary basin Sedimentary basins are region-scale depressions of the Earth's crust where subsidence has occurred and a thick sequence of sediments have accumulated to form a large three-dimensional body of sedimentary rock. They form when long-term subsidence ...

located in the

Argentine Northwest The Argentine Northwest (''Noroeste Argentino'') is a geographic and historical region of Argentina composed of the provinces of Catamarca, Jujuy, La Rioja, Salta, Santiago del Estero and Tucumán. Geography The Argentine Northwest comprises v ...

. The basin started to accumulate sediments in the

Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro ...

(

Neocomian In geology, Neocomian was a name given to the lowest stage of the Cretaceous system. It is generally considered to encompass the interval now covered by the Berriasian, Valanginian and Hauterivian, from approximately 145 to 130 Ma. It was introduce ...

) and at present it has sedimentary deposits reaching thicknesses of . The basin contains seven sub-basins: Tres Cruces, Lomas de Olmedo, Metán, Alemanía, Salfity, El Rey, Sey and Brealito. The basin environment has variously been described as a " foreland

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-grabe ...

" and an "intra-continental rift". The basin developed under conditions of

extensional tectonics Extensional tectonics is concerned with the structures formed by, and the tectonic processes associated with, the stretching of a planetary body's crust or lithosphere. Deformation styles The types of structure and the geometries formed depend on ...

and rift-associated

volcanism Volcanism, vulcanism or volcanicity is the phenomenon of eruption of molten rock (magma) onto the surface of the Earth or a solid-surface planet or moon, where lava, pyroclastics, and volcanic gases erupt through a break in the surface called ...

Description

The basin basement is composed of rocks belonging to the

Puncoviscana Formation Puncoviscana Formation ( es, Formación Puncoviscana) is a formation of sedimentary and metasedimentary rocks Late Ediacaran and Lower Cambrian age, estimated at between 700 and 535 Ma, that crop out in the Argentine Northwest. Most of the formati ...

.Grier et al., 1991 The volcanism that began in the

Late Jurassic The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.Owen 1987. In European lithostratigraphy, the name ...

was initially of subalkaline character (low

sodium Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable iso ...

and

potassium Potassium is the chemical element with the symbol K (from Neo-Latin ''kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmosphe ...

content), but turned increasingly alkaline in the Early Cretaceous.Marquillas et al., 2005 The rifts of Salta Basin developed in a time of generalized

along western South America.Ramos, 2009 It has been proposed that the

Salar de Atacama Salar de Atacama is the largest salt flat in Chile. It is located south of San Pedro de Atacama, is surrounded by mountains, and has no drainage outlets. In the east it is enclosed by the main chain of the Andes, while to the west lies a secondar ...

depression in Chile was once a westward rift arm of the Salta Basin.Reutter et al., 2006

Stratigraphy

References

Bibliography

;General * * * * * * ;Guanaco Sonso Formation * ;Lumbrera Formation * * * ;Maíz Gordo Formation * ;Mealla Formation * ;Palo Pintado Formation * * * ;Piquete Formation * ;Quebrada de Los Colorados Formation * * * *

Description

Stratigraphy

References

Bibliography

Further reading