Facies and Stratigraphic
Organization of the E-D-B Groups (Middle Miocene) Incised Valley Successions of
the Noring Field,
Abd Rahman, Abdul Hadi1, Mohd Rapi Mohamed Som2, Moh’D. Nurein Bushara3
(1) Universiti Sains Malaysia, Penang, Malaysia (2) Petronas Research Malaysia,Bangi, Selangor, Malaysia (3) Petronas Carigali Sdn Bhd, Kuala Lumpur, Malaysia
The Noring field is located towards
the northeastern margin of the
Facies and stratigraphic analysis of the sections identified a total of seventeen lithofacies that are grouped into: i) a fluvial floodplain, and ii) an estuarine/tidal flat facies-assemblage. The floodplain facies-assemblage includes proximal over bank lithofacies association (finegrained levee deposits, crevasse-channel and crevasse-splay), lacustrine-floodplain lithofacies association (laminated silt, shale and heterolithics) and back swamp lithofacies association (coal and paleosols). These lithofacies defines part of the E Group. Stratigraphic interpretation of the E Group identified a basal coal-bearing meandering fluvial and floodplain sub-interval, a middle sand-prone braided fluvial sub-interval and an upper lacustrine and meandering fluvial succession. The estuarine facies-assemblage is restricted to the D Group, which overlies the floodplain facies. This facies-assemblage is marked by the presence of Diplocraterion and Teichicnus trace fossils within the mudstones and siltstones, and the absence of coal. Thick, coarsening-upward deltaic successions of the B Group is represented by a basal lowstand fluvial facies, a transgressive prodelta mud succession, and capped by a delta-front highstand deposits.
The organization of depositional facies and intervals of the E-D-B Groups represent an incised-valley fill. The westward thickening of the marine-influenced mud-dominated successions within the D and B groups indicates the axis of the paleo-valley in the NNW seaward direction.