Ichnofabric oscillatory curves as an indicator of the tide-dominated depositional system, Samarinda area, Kutai Basin (Indonesia)

The overall purpose of this study was to reinterpret the paleoenvironmental processes in the Samarinda area, Kutai Basin, Indonesia. Ichnofabric methods are used for that. The bioturbation index (BI), ichnodiversity (ID), number of behavior (NB), penetration depth (PD), ichnofossil diameter (Dm), in ichnofabric units were scrutinized. The data were processed by principal component analysis (PCA). The main findings were (1) the PC-1 and PC-2 oscillatory curves, and (2) the phase between PC-1 and PC-2 curves (i.e., out of phase and in phase). The PC-1 curve was loaded by BI, ID, and NB and the PC-2 was loaded by PD and Dm. The generated curves were interpreted as the indicators of colonization window, organism mobility, and space using by the organism. The oscillatory pattern of curve suggested how the organism interact with the substrate are repeated that dictated routinely by the paleoenvironmental processes variation that suggested as the tide-dominated depositional system