Convention Bandung 2004 (CB2004) The 33^rd Annual Convention & Exhibition 2004

Indonesian Association of Geologist Horizon Hotel, 29-30 Nov, 1 Dec 2004, Bandung

ICHNOLOGICAL CHARACTERISTICS IN THE MODERN MAHAKAM DELTA, EAST KALIMANTAN

Ery Arifullah ¹⁾, Andang Bachtiar ²⁾ , Djuhaeni 3)

1 Master Student, Department of Geology, ITB
²GDA Consultant Jakarta
³Department of Geology, ITB

earifullah@plasa.com

Abstract

Detailed analysis of Modern Mahakam Delta sediments concentrated on identifying ichnological and sedimentological characteristics of four deltaic environments. These include: 1) distributary channel, which are typically low diversity and bioturbation index with displaying Psilonichnus, Skolithos, Ophiomorpha, Monocraterion, Teichichnus Arenicolites, Planolites, Thallasinoides, escaping traces, and Glossifungites ichnofacies; 2) estuarine tidal bar which are typically balanced diversity and biotu rbation index with displaying Psilonichnus, Ophiomorpha, Arenicolites, Skolithos, Siponichnus, Monocraterion, Paleophycus, Helminthopsis, Teichichnus, Planolites, Chondrites, Paleodictyon, crawling traces, and vertebrate track; 3) interdistributary area which are typically medium diversity and high biotu rbation index with displaying dominated Arenicolites, Ophiomorpha, Conichnus, Skolithos, Scaubcylindrichnus, Diplocraterion, Rosselia, Teichichnus, Chondrites; 4) mouth bar sediments are displaying Ophiomorpha, Planolites, grazing traces, crawling traces, fecal casting, and abundance dwelling tubes Skolithos like.

Ichnological research in the Modern Mahakam Delta potentially improves our understanding of deltaic facies sedimentology. Our findings suggest that sedimentological processes, substrate types and salinity control ichnological characteristics.