Miocene to pleistocene biostratigraphy of Rembang Zone based on nannofossil, Nglebur River section, Blora, Central Java

Abstract

Nannofossil analyses of Miocene to Pleistocene, the section of Nglebur River, Jiken, Blora of Central Java included of Rembang Zone, North East Java Basin. This study uses 70 samples from this section. The result of this analysis consists of 18 genus was obtained with 57 species of nannoplankton. The research method used in field study (measure section) quantitative analysis. The samples from taken include fine-grain stone (marl, shale) and carbonaceous. The river section that has been selected consist of a continuous sediment sequence from Miocene (Wonocolo, Ledok, and Mundu Formation) to Pleistocene (Lidah Formation). The sample preparation uses the smear slide method and species determination uses Nannotax3 determination. The biostratigraphy consist of 11 zones, and there consists of 2 Partial Zones and 9 Interval Zones. These Zone are Discoaster hamatus Partial Zone/NN9, Interval Zone of Discoaster hamatus-Discoaster quinqueramus /NN10, Zone of Discoaster quinqueramus /NN11, Zone of Discoaster quinqueramus-Ceratolithus rugosus/NN12, Zone of Ceratolithus rugosus-Discoaster asymmetricus/NN12, Zona of Discoaster asymmetricus-Pseudoemiliania lacunosa/NN14, Zona of Pseudoemiliania lacunosa with Reticulofenestra pseudoumbilicus/ NN15, Zona of Reticulofenestra pseudoumbilicus with Discoaster surculus/NN16, Zona of Discoaster surculus-Discoaster asymmetricus/NN17, Zona of Discoaster asymmetricus-Discoaster brouweri/NN18, and Partial Zone Discoaster brouweri and Gephyrocapsa caribbeanica/NN19.