Oxaya Formation () is a geological formation in
northern Chile made up of
ignimbrite
Ignimbrite is a type of volcanic rock, consisting of hardened tuff. Ignimbrites form from the deposits of pyroclastic flows, which are a hot suspension of particles and gases flowing rapidly from a volcano, driven by being denser than the surrou ...
sheets. The formation formed about 25 to 19
million years ago
Million years ago, abbreviated as Mya, Myr (megayear) or Ma (megaannum), is a unit of time equal to (i.e. years), or approximately 31.6 teraseconds.
Usage
Myr is in common use in fields such as Earth science and cosmology. Myr is also used w ...
in the
Late Oligocene
The Chattian is, in the geologic timescale
The geologic time scale or geological time scale (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the pro ...
and
Early Miocene
The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages: the Aquitanian age, Aquitanian and Burdigalian stages.
The sub-epoch lasted from 23.03 ± 0.05 annum, Ma to ...
.
Oxaya Formation is deformed by the
Oxaya anticline.
References
{{Geology of Chile
Geologic formations of Chile
Miocene Series of South America
Oligocene Series of South America
Neogene Chile
Miocene volcanism
Oligocene volcanism
Geology of Arica y Parinacota Region