From Wood and Kienle (1990)
[1]: "This field consists of numerous lava flows 1.5 to 4.5 m thick, and at least five low shield volcanoes from 30 to 188 m high (four are 166 to 188 m high) and 5 to 11 km across. Although the volcanoes are modified by erosion and widely covered with silt, they are inferred to be Quaternary in age based on their physiographic expression. The volcanoes consist of vesicular and scoriaceous olivine basalt."