Ichnofabric of tidal deposit in Balikpapan Formation, Kutai Basin (Indonesia)

In Indonesia, the use of ichnology in sedimentological study is generally lacking. Ichnofabric aspects (e.g. bioturbation index, ichnofossil diversity, burrow diameter, penetration depth, ethology and tiering style) are a potential approach to scrutinize the environmental processes in tidal setting. In this context, penetration depth is used as an independent aspect and other ones as dependent aspects. The response of this approach to ancient tidal deposit has been studied for an outcrop of Balikpapan Formation, Kutai Basin (Indonesia). In this contribution, the nature examples of these applications are presented. The observation showing the penetration depth is unrelated to bioturbation index, ichnofossil diversity and ethology. Conversely, the correlation of penetration depth and burrow diameter and its disparity are indicated in the 4^th tiering style (i.e. multiple of vertical partition, ethologies and ichnofossil diversity). The correlation may suggest the control of (i) biological aspect (e.g. consequences of deeper penetration by the bigger organism than the little one) and/or (ii) physico-chemical aspect (e.g. substrate consistency, water turbidity, oxygenation) in uppermost and lower tier. Skolithos and Ophiomorpha commonly is fabricated in uppermost tier. Conversely, Thallasinoides, Planolites, Teichicnus-Rhizocorallium and Chondrites are fabricated in the lower tier. Moreover, the ichnofabric model is an indicator of environmental conditions in tidal setting during colonization