Iglesia 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 northern San Juan Province, western Argentina. It is thought to be a

piggyback basin A piggyback basin (also piggy-back, thrust-sheet-top, detached, or satellite basin) is a minor sedimentary basin developed on top of a moving thrust sheet as part of a foreland basin system. Piggyback basins form in the wedge-top depositional zone ...

. Its sedimentary fill is of

Neogene The Neogene ( ,) is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period million years ago. It is the second period of th ...

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

age and has an estimated maximum thickness of 3.5 km. There are

hot spring A hot spring, hydrothermal spring, or geothermal spring is a Spring (hydrology), spring produced by the emergence of Geothermal activity, geothermally heated groundwater onto the surface of the Earth. The groundwater is heated either by shallow ...

s in the eastern part of the basin. The rock under the sedimentary fill is interpreted to be in part composed of

plutonic Intrusive rock is formed when magma penetrates existing rock, crystallizes, and solidifies underground to form ''intrusions'', such as batholiths, dikes, sills, laccoliths, and volcanic necks.Intrusive RocksIntrusive rocks accessdate: Marc ...

intrusions In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of Intrusive rock, intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety o ...

belonging to the Tocota pluton, which in turn is a part of a larger group of plutonic intrusions known as the

Colangüil Batholith The Colangüil Batholith is a group of plutons in western Argentina between the latitudes of 29 and 31° S. The plutons of the batholith were Methods of pluton emplacement, emplaced and cooled in the Paleozoic, Late Paleozoic and the Triassic. Runs ...

References

Geology of San Juan Province, Argentina Sedimentary basins of Argentina {{sedimentology-stub