Search

Eocene--lower Miocene sandstones of the Crocker turbidite fan of north Borneo were derived from nearby Borneo and southeastern Asian sources, rather than distant Asian sources eroded after India-Eurasia collision. They are compositionaily mature due to tropical weathering, but are mostly first-cycle sandstones derived from granitic rocks and subordinate metamorphic, sedimentary, and ophiolitic rocks. Detrital zircon ages range from Archean to Eocene, and the majority are Mesozoic. The most important source areas were Cretaceous granites of the Schwaner Mountains in southwest Borneo during the Eocene, and Permian--Triassic granites and Proterozoic basement of the Malay-Thai Tin Belt during the Oligocene. Keywords: Southeast Asia, Borneo, turbidites, provenance, zircon geochronology.