Abstract
The Banda Sea is separated into two oceanic fragments, the south and north Banda basins, by a large intervening region of ridges and basins called the Banda ridges. The north and south Banda basins appear to be trapped pieces of pre-Tertiary oceanic crust, whereas the Banda ridges are a submerged and displaced continental borderland, structurally very similar to the southern California offshore borderland. Analysis of dredged rocks from the Banda ridges suggests an origin from western Irian Jaya.