There are many crustal fragments in northeast Borneo that are derived from Mesozoic ophiolites placed during the initiation of the western Pacific Ocean plate subducting beneath southeast China and southeast Asia. This ophiolite basement underlies regions from Sabah in northeast Borneo and the Meratus Mountains in southeast Borneo. The ophiolite crustal fragments were also emplaced in Central Java to the south of Borneo and Palawan and the Philippines in the North.