Technical Luncheons
The Sedimentology of Ancient Mangroves: Swamped with Hydrocarbon Potential
Speaker(s):
Jon Noad,
Shell Canada
Date/Time: Thursday, June 18, 2009 - 11:30am
Location: Telus
Convention Centre - Calgary, Alberta
The cut-off date for ticket sales is 1:00 pm, Monday, June 15, 2009.*
CSPG Member Ticket Price: $38.00 + GST.
NON-MEMBER Ticket PRICE: $45.00 + GST.
*Please note: Due to the popularity of talks, we strongly suggest purchasing tickets early, as we cannot guarantee seats will be available on the cut-off date.
ABSTRACT
Series of steep sided mangrove channels, incised into
mudstones bearing rooted trees, from eastern Borneo.
Rooted mangrove tree, from eastern Borneo.
Heavily rooted limestone beds, separated by thin,
laterally persistentpalaeosol horizons, from Mallorca.
Fossil mangrove deposits have received relatively little attention in the published literature, despite their significant potential as hydrocarbon-prone source rocks. Recent fieldwork examining both ancient and modern deposits suggests that mangroves may also host significant oil deposits. Fossil mangroves can be classified as either humid or arid mangroves. The former are clastic in character, comprising shales encasing both channelised and sheet-like sandstones. Detailed sedimentological analysis of Miocene coastal clastic deposits in the Sandakan region of eastern Borneo has identified several well preserved mangrove systems, and enabled the development of new criteria enabling the recognition of these facies in other locations. Ancient arid, or carbonate mangroves, were studied in Mallorca.
Unpublished data from Brunei suggests that mangrove mudstones may provide a significant source of oil, sourced mainly from the waxy cuticles of mangal species. Using analogue data to give an indication of the lateral extent of the fossil mangrove sandbodies, plays can be developed invoking stratigraphic traps sourced from the associated organic-rich mudstone deposits. Both arid (carbonate) and humid (clastic) fossil mangroves show great potential as self sourcing hydrocarbon reservoirs, and may indeed already be producing oil from misidentified or unrecognised ancient mangroves.
Several morphologically distinct sandbody classes within the successions from Borneo have been assigned to channel and inter-mangrove broads, based on analogues from both the Everglades of Florida and modern Bornean mangroves. The channelised sandstones have extremely steep banks and appear to accrete vertically, thought to be due to the constraining mangrove root systems. The sheet-like sandstones are massive with rare rooted intervals, and are interpreted as shallow extensive broads, open areas within the mangrove system. All of these sandbodies are potential reservoirs. A variety of beautifully preserved plant and animal fossils support these interpretations
Several morphologically distinct sandbody classes within the successions from Borneo have been assigned to channel and inter-mangrove broads, based on analogues from both the Everglades of Florida and modern Bornean mangroves. The channelised sandstones have extremely steep banks and appear to accrete vertically, thought to be due to the constraining mangrove root systems. The sheet-like sandstones are massive with rare rooted intervals, and are interpreted as shallow extensive broads, open areas within the mangrove system. All of these sandbodies are potential reservoirs. A variety of beautifully preserved plant and animal fossils support these interpretations.
BIOGRAPHY
Jon Noad works for Shell Canada as an exploration geologist in basin centred gas. He began his career in gold and platinum mining in South Africa after graduating in 1985 from Imperial College, London. Returning to the UK he joined British Telecom as their first marine geologist, responsible for routing and burial of international subsea telecommunications cables. He also completed a Masters in Sedimentology at evening classes, with a thesis project based in Dinosaur Provincial Park here in Alberta, leading on to a full time PhD at University College London. There he worked on the sedimentary evolution of eastern Borneo, kindling a lifetime interest in fossil mangroves. He joined Shell in 1998, based in Holland, and worked mainly on Middle Eastern exploration before moving to Canada in 2006. He also taught at Delft University for two years half time. Jon is currently President of the British Sedimentological Research Group.
