Sequence stratigraphy & ichnology
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The document summarizes a study on the relationship between ichnology and sequence stratigraphy using an example from Miocene outcrops in Kesejahteraan Quarry in Samarinda, East Kalimantan. The study found that ichnologic analysis can help identify and interpret sequence stratigraphy boundaries. Changes in ichnofacies and ichnofabric across boundaries indicate significant changes in depositional environment and relative sea level. Specifically, the lower part of boundaries showed dense bioturbation with ichnofossils like Planolites and Thallasinoides in shaly sandstone. The upper part showed dominance of Ophiomorpha and Skolithos ichnofossils with HCS and sigmoid
Sequence stratigraphy & ichnology
- 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