The Blake River Megacaldera Complex consists of mainly
mafic to intermediate volcanic flows and less abundant
felsic volcanic flows and intercalated
pyroclastic rocks, which underwent three stages of major volcanic activity. • The first phase resulted in the creation of the long, wide, east-west striking
Misema Caldera which has been dated to 2704–2707 Ma. It is a coalescence of at least two large mafic
shield volcanoes that formed more than 2703 million years ago. • The second phase resulted in the creation of the long, wide, northwest–southeast trending
New Senator Caldera which formed 2701–2704 Ma. Its formation consists of thick massive
mafic sequences which has inferred to be a subaqueous
lava lake during the early stages of the caldera's development. As a result, the Blake River Group is best categorized as a meganested caldera complex. ==See also==