Miocene larger benthic foraminifera have been discovered from a limestone unit of the Kalumpang Formation. The limestone is exposed at the Teck Guan Quarry, Tawau, southeast Sabah. The Kalumpang Formation consists predominantly of interbedded mudstone and sandstone (graywacke), conglomerate, limestone, marl, chert and volcanic rocks. Five limestone samples have been collected and processed for petrographic analysis and identification of larger benthic foraminifera. The limestone is classified as packstone and mudstone. A total of seventeen species of larger benthic foraminifera have been identified. The foraminifera are divided into two assemblages namely Assemblage I and Assemblage II. Assemblage I is characterized by the presence of Lepidocyclina (Nephrolepidina) parva, Operculina sp. and Lepidocyclina (Eulepidina) formosa. This assemblage is an indicative of Aquitanian to Burdigalian in age (Early Miocene). Assembalge II comprises of Lepidocyclina (Nephrolepidina) sumatrensis, Lepidocyclina (Nephrolepidina) angulosa, Lepidocyclina (Nephrolepidina) ferreroi Lepidocyclina sp., Miogypsina sp., Katacycloclypeus annulatus, Katacyloclypeus martini, Cycloclypeus carpenteri, Cycloclypeus indopacificus, Cycloclypeus sp., Flosculinella bontangensis, Operculina complanata, Amphistegina bowdenensis and Amphistegina sp. This assemblage is an indicative of Langhian to Serravallian age (Middle Miocene). The foraminiferal assemblages suggest that the depositional environment was a warm tropical shallow-marine at the fore-reef shelf zone.
The Kuamut Melange is located in the Kunak district, south east Sabah. The mélange consists of clasts and blocks of broken Paleogene formations and dismembered ophiolite blocks embedded in shale matrix. Fourteen samples were collected from sections S1 and S2 of the Kuamut Melange. A total of 45 species of radiolarians have been identified and only 36 selected species are used for age determination. Three assemblages (I-III) were identified. Assemblage I consists of dictyomitra
excellence, Crucella bossoensis, Hiscocapsa asseni, Hexapyramis precedis, Thanarla brouweri, Acanthocircus levis, Obeliscoites vinassai, Stichomitra communis, Staurosphaeretta longispina, Xitus spicularius, Triactoma cellulosa, and dactyliosphaera maxima. This assemblage is marked by the occurrence of Crucella gavalai indicative of Aptian to Albian in age. Assemblage II was characterized by zonal maker Xitus mclaughlini. Other species in this assemblage are Xitus
spinosus, Stichomitra tosaensis, dictyomitra gracilis, dictyomitra montisserei, Pseudodictyomitra pseudomacrocephala, Pessagnobrachia fabianii, Crucella messinae, Tuguriella pagoda, dictyomitra obesa, Triactoma paronai, Rhopalosyringiumeuganeum, Acanthocircus venetus, Acaeniotyle rebelis, dictyomitra formosa, Pseudodictyomitra tiara and Patellula helios. This assemblage ranges from Albian to Cenomanian. Assemblages III is represented by zonal maker Crucella cachensis and others species in this assemblage are Hemicryptocapsa polyhedra, Eostichomitra bonum, Pseudotheocampe tina, ultranapora cretacea and Alievium superbum. Assemblage III is Turonian in age. The radiolarian assemblages suggest that the age of chert blocks ranges from Aptian to Turonian, Cretaceous. The cherts were originally deposited on an oceanic crust of a marginal basin during Cretaceous and were tectonically deformed to form melange in Miocene time.