Southern Mountains Arc underlain by continental crust of the East Java–West Sulawesi block.

Continental crust (Southwest Borneo block) in the north of Java.

Thinning of the crust beneath the Kendeng Basin indicates ophiolitic basement of the Meratus suture.

Aligned thick crustal bodies indicate the boundary between Southwest Borneo block and the Meratus suture zone.

Inner-crustal low-velocity layer of unknown origin beneath almost the entire area under investigation.