Chon Aike Formation

It covers an area of approximately 100,000 square kilometres (39,000 sq mi) and consists of rhyolitic volcanic rocks, particularly ignimbrites and lavas, with smaller amounts of agglomerates and tuffs.

[2] The Chon Aike Formation forms part of the Chon Aike Province, also known as the Tobífera Series, a large igneous province that covers 1,700,000 square kilometres (660,000 sq mi).

)[4] 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.

[5] The Chon Aike volcanism was probably related to the subduction of the Pacific Phoenix and Farallon plates.

[6] 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.