Fig. 2

Simplified geological map of the BVF. Volcanic units younger (orange) than the inferred Australasian impact crater cover the majority of the field, likely burying most older units (purple where exposed). Some of the youngest flows are indicated on the map. All mapped vents (black polygons) are scoria cones. Main cities are outlined in white. The Mekong river is flowing southward. Basemap is the shaded relief obtained from the SRTM. Yellow stars indicate locations shown in Fig. 3