Karakteristik ichnologi dan sistem pengendapan delta. Studi kasus delta Mahakam Modern dan Miosen, Cekungan Kutai, Kalimantan Timur
| Main Author: | Arifullah, Ery |
|---|---|
| Format: | info publication-thesis |
| Terbitan: |
, 2005
|
| Subjects: | |
| Online Access: |
https://zenodo.org/record/3992511 |
Daftar Isi:
- Detailed analysis of Modern and Miocene Mahakam Delta deposits at Kutai Basin, East Kalimantan focused on identifying their ichnological and sedimentological characteristics. The study in the Modern Mahakam Delta is focused in environments: estuary, interdistributary and active distributary. The ichnological characteristics in the estuary environment typically consist of Psilonichnus, Skolithos, Cruziana, and sporadic Zoophycos ichnofacies. Those ichnofacies have high index and diversity and relative large burrow diameter. The interdistributary environment typically consists of Skolithos ichnofacies, sporadic Cruziana ichnofacies and very rare Zoophycos ichnofacies. The index and diversity are not higher than their present in estuary zone. Possibility it is caused by their difference salinity. The contrast ichnological characteristic in the active delta environment typically low index and diversity, smallest burrow diameter, sporadic distribution and very rare Skolithos and Cruziana ichnofacies. The wave-, tidal- and fluvial dominated deltas have been identified in the Miosen outcrops. The fluvial dominated delta characterized by low index, low diversity, small burrow diameter and their sporadic distribution. Ichnological characteristic in the tidal dominated delta almost the same to fluvial dominated delta. The contrast to wave dominated delta, which are typically high index, high diversity, large burrow diameter and regular distribution. The difference ichnological characteristic between modern and Early Miocene deltaic deposit indicate the difference fluvial discharge in the both of the times. The most fluvial discharge was occurred in Early Miocene. The similar ichnological characteristic between Modern and Middle-Upper Miocene Mahakam Delta is indicated by their equal fluvial discharge. Substrate controlled ichnofacies has been studied both of the modern and Miocene Mahakam Delta. Glossifungites ichnofacies associated with firmground substrate well developed in the one of estuary tidal bar in the modern Mahakam delta.Glossifungites ichnofacies in the Miocene outcrops crosscuts the pre-existing softground ichnofacies in the prodeltaic deposit. While in coal bed, Psilonichnus and Thallasinoides is indicated assemblage of borings or burrow in the woodground.
- Master's thesis