La Liga Formation ( es, Formación La Liga) is a

geologic formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

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 ...

and

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 ...

age cropping out in

Coquimbo Region The Coquimbo Region ( es, Región de Coquimbo, ) is one of Chile's 16 regions (first order administrative divisions). It is bordered by Atacama to the north, Valparaíso to the south, Argentina to the east, and the Pacific Ocean to the west. ...

, Chile. Rocks of the formation are

andesite Andesite () is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite. It is fine-grained (aphanitic) to porphyritic in texture, and is composed predomi ...

s. Locally the rocks of the formation present

epidote Epidote is a calcium aluminium iron sorosilicate mineral. Description Well developed crystals of epidote, Ca2Al2(Fe3+;Al)(SiO4)(Si2O7)O(OH), crystallizing in the monoclinic system, are of frequent occurrence: they are commonly prismatic in habi ...

alteration Alteration(s) may refer to: * Alteration (music), the use of a neighboring pitch in the chromatic scale in place of its diatonic neighbor. ** Alteration, in the mensural notation used by renaissance music, the lengthening of a breve, semibreve or ...

. The iron ores of

El Romeral mine El Romeral is an iron mine in north-central Chile. The mine benefits from being located only 22 km NNE of the city of La Serena and being next to Guayacán, a port with conditions for high-tonnage cargo ships.Millán 1999, p. 153 The mine emerg ...

are emplaced on La Liga Formation.

References

{{Geology of Chile Geologic formations of Chile Lower Cretaceous Series of South America Late Jurassic South America Mesozoic Chile Geology of Coquimbo Region Jurassic volcanism Cretaceous volcanism Andesite formations