The Chibanian, widely known by its previous designation of Middle Pleistocene, is an
age in the international
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 process of relating strata to time) and geoch ...
or a
stage in
chronostratigraphy
Chronostratigraphy is the branch of stratigraphy that studies the ages of rock strata in relation to time.
The ultimate aim of chronostratigraphy is to arrange the sequence of deposition and the time of deposition of all rocks within a geologica ...
, being a division of the
Pleistocene
The Pleistocene ( , often referred to as the '' Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed ...
Epoch within the ongoing
Quaternary Period.
The Chibanian name was officially ratified in January 2020. It is currently estimated to span the time between 0.770
Ma (770,000 years ago) and 0.126 Ma (126,000 years ago), also expressed as 770–126 ka. It includes the transition in
palaeoanthropology from the
Lower to the
Middle Palaeolithic
The Middle Paleolithic (or Middle Palaeolithic) is the second subdivision of the Paleolithic or Old Stone Age as it is understood in Europe, Africa and Asia. The term Middle Stone Age is used as an equivalent or a synonym for the Middle Paleo ...
over 300 ka.
The Chibanian is preceded by the
Calabrian and succeeded by the proposed
Tarantian.
The beginning of the Chibanian is the
Brunhes–Matuyama reversal
The Brunhes–Matuyama reversal, named after Bernard Brunhes and Motonori Matuyama, was a geologic event, approximately 781,000 years ago, when the Earth's magnetic field last underwent reversal. Estimations vary as to the abruptness of the rever ...
, when the Earth's magnetic field last underwent reversal. It ends with the onset of the
Eemian interglacial per