Overview of the Cerro Chivo Volcanic Field (CCVF), Chubut Province, Argentina: Basalt sheets, root zones, diatremes and ?plugs?

HALLER, MJ; ROSS, P-S; WHITE, JDL; LEFEBVRE, N

San Miguel del Tucumán

Congreso; 20º Congreso Geológico Argentino; 2017

Asociación Geológica Argentina

The Cerro Chivo Volcanic Field (CCVF) in Chubut Province dates from early Tertiary and exposes he sub-surface manifestations of basaltic monogenetic volcanoes, mostly of the maar-diatreme type. Documented features include unfragmented basalt sheets, root zones, where the dikes and/or the country rocks are fragmented, and which may have fed diatremes; phreatomagmatic diatremes including bedded pyroclastic rocks; unusual "phreato-strombolian" diatremes; and large coherent basalts massifs ("plugs") that may have originated as phreatomagmatic diatremes. The CCVF offers numerous opportunities for more detailed volcanological studies which have the potential to significantly improve our understanding of maar-diatreme volcanoes.