1. Convention Bandung 2004 (CB2004)
rd
The 33 Annual Convention & Exhibition 2004
Indonesian Association of Geologist
Horizon Hotel, 29-30 Nov, 1 Oct 2004, Bandung
RELATIONSHIP BETWEEN ICHNOLOGY
AND SEQUENCE STRATIGRAPHY:
EXAMPLE FROM MIOCENE OUTCROP IN
KESEJAHTERAAN QUARRY ? SAMARINDA EAST
KALIMANTAN
Ery Arifullah
Master Student, Department of Geology, ITB:
Abstract
Ichnologic studies can aid in recognition and interpretation of sequence
stratigraphic surface. Studies in a sequence stratigraphy framework can
provide understanding of factors that control ichnofacies and ichnofabric
distribution. This mutually beneficial relationship between ichnology and
sequence stratigraphy can be observed in Kesejahteraan Quarry outcrop in
Samarinda City, East Kalimantan. Integration of ichnology? sedimentology will
guide for picking bounding surface in sequence stratigraphy. Lower part of
bounding surface is succession of shally sandstone, dark gray, almost totally
bioturbated with ichnofossil content: Planolites, Thallasinoides, Teichichnus,
Arenicolites, Rhizocorallium, with sharp-walled, unlined. Upper part of
bounding surface characterized by HCS & sigmoid cross stratification (?)
sandstone with dominance of Ophiomorpha and Skolithos ichnofossils. Abrupt
changes in ichnofacies and ichnofabric across bounding surface record a
significant change in the depositional environment and relative sea level.
Abstrak
Studi ichnologi dapat mengenali dan interpretasi batas sekuen stratigrafi.
Studi sekuen stratigrafi mendukung dalam pemahaman faktor-faktor yang
mengontrol distribusi ichnofasies dan ichnofabrik. Hubungan mutualisme
antara ichnologi dan sekuen stratigrafi dapat diamati pada singkapan Miosen
di Kesejahteraan Quarry di Kota Samarinda Kalimantan Timur. Integrasi
ichnologi ? sedimentologi akan membimbing dalam menarik bidang batas
dalam sekuen stratigrafi. Bagian bawah bidang batas merupakan suksesi
batupasir serpihan, abu-abu gelap, hampir seluruhnya terbioturbasi, dengan
kandungan ichnofosil: Planolites, Thallasinoides, Teichichnus, Arenicolites,
Rhizocorallium, dengan dinding yang tegas, tidak bergaris. Bagian atas
bidang batas dicirkan dengan batupasir HCS & sigmoid cross stratification(?)
dengan dominasi ichnofosil Ophiomorpha dan Skolithos. Perubahan tiba-tiba
tipe ichnofasies dan ichnofabrik yang melewati bidang batas menunjukkan
adanya perubahan lingkungan pengendapan dan muka laut relatif yang
signifikan.
Poster Papers
103