Abstract
The Miocene Teradomari Formation is a major source rock in the Niigata oil field. The samples, collected from the type locality of the Teradomari Formation, were classified as (hemi) pelagic mudstone (Ep) or turbidite mudstone (Et) according to their Bouma sequence division. Kerogen maceral composition was identified under a fluorescent microscope. Based on its fluorescent characterization, amorphous kerogen was divided into three types; namely, FA (fluorescent amorphous kerogen), WFA (weakly fluorescent amorphous kerogen) and NFA (non-fluorescent amorphous kerogen). Ep kerogen was mainly composed of WFA, while Et kerogen was mainly of NFA and vitrinite. Relative quantities and chain lengths of aliphatic moieties estimated by FTIR indicate that Ep kerogen has a higher oil generation potential than Et kerogen.
