The Chon Aike Formation forms part of the Chon Aike Province, also known as the Tobífera Series, a
large igneous province that covers . The northern part of the formation, Río Pinturas, has been dated to the Late Jurassic (140–160 ), while the western and eastern sections have been dated to 162 ± 11 Ma and 168 ± 2 Ma respectively, indicating Middle Jurassic eruptions. Fossil flora, however, suggests a Middle to Late Jurassic age. (See
La Matilde Formation.) During the break-up of
Gondwana around 180–165 Ma, the opening of the
Weddell Sea lead to
extension along the western margin of the
South American Plate, resulting in intra-plate volcanism in the Chon Aike area and rifting in the
Magallanes Basin. The Chon Aike volcanism was probably related to the subduction of the Pacific
Phoenix and
Farallon plates. According to Riley, "
Early Jurassic silicic volcanic rocks of the Chon Aike Province (V1: 187-182
Ma) are recognized from many localities in the southern Antarctic Peninsula and northeast Patagonia and are essentially coeval with the extensive
Karoo (182 Ma) and Ferrar (183 Ma) large igneous provinces of pre-breakup Gondwana. == See also ==