Pustaka Ilmiah Universitas Padjadjaran

Abstrak

Foraminiferal Biostratigraphy And Paleoenvironment Of Kali Bentur Ngawenan Area, Blora Central Java

Foraminifera analysis from 18 surface samples of sandstone and siltsione unit, Kali Bentur section, Indicate the age of rock is Late Miocene-Early Pliocene (Bolll, 1985) or 6,2 My- 2,4 My Foraminifera assemblages consist of 39 species (218.128 individu) planktonic and 53 species (16.384 Individu) benthortic. The species of foraminifers planktonics which are abundance : Globigennoldes trilobus imaturus, Globigennoldes trilobus trilobus, Globoquadrina altispira, Globoquadrina dehiscens, Orbufine universe and Globorotalia menardi meanwhile foraminifera bentonics are Bolivina, Bailsiphon, Cibicides, Robulus, Planulina, uviigenna and Stilostometa Biostratigraphy zone Is devided into 4 zones: Globorotalia humerosa – humerose -Goborotalla tumida-tumida interval zone, Globorotalia tumida-tumida -Sphaerodinella dehiscens interval zone, Sphaerodinella dehiscens- Globorotalla miccenica interval zone clan Globorotalia miccenica partial zone Planktonic / Bentonic ratio is 77% -99%, Indicated Lower Slope environment (Grimsdale,1955). Paleoenvironment of silt unit is deeper than sandstone unit.