Tech Division Events
Sedimentology Division
For more information concerning this division, please contact the Sedimentology Division Chairs, Stephen Hubbard at (403) 220-6236 or shubbard@ucalgary.ca or Jeff Reinprecht at (403) 233-1312 or Jeffrey.reinprecht@bp.com.
For more information on division events visit www.cspgsedimentology.org.
Division Profile
The Sedimentology Division's mandate is to provide a forum for CSPG members that are interested in sedimentology and sedimentary processes in order to showcase what is new and current in sedimentology. Topics are wide-ranging and include both clastics and carbonates. Speakers for the luncheon talks are sought from industry and academia to include topics in sedimentology and other subjects pertaining to sedimentary processes. Cross-discipline talks are encouraged including sedimentology in relation to diagenesis, biostratigraphy, and sequence stratigraphy. Field trips and short courses may be organized periodically.
The division aims to provide informal brownbag talks every month throughout the year. The lunch-time talks start at noon and finish before 1:00 pm. Talks typically average about 45 minutes followed by a short question/discussion period. Currently, our talks are held at the Nexen Annex Theatre, +15 level, north of C-Train station, 801-7th Avenue S.W., Calgary, Alberta.
If you are interested in joining the Sedimentology Division e-mail listing which currently provides luncheon reminders, or if you care to suggest a technical topic or present a talk to the division, please contact Scott Rose, Birch Mountain Resources, 262-1838 and roses@birchmountain.com.
Division Talks
The Sedimentology of Mangroves
Speaker
Jon Noad,
Shell Canada
12:00 Noon
October 29, 2008
BP Tower
240, 4 Ave SW, Room 201
Calgary, Alberta
Biography
Fossil mangrove deposits have received relatively little attention in the published literature, despite their obvious potential as hydrocarbon-prone source rocks. Recent fieldwork examining both ancient and modern deposits suggests that mangroves may also host significant oil deposits. Studies on Miocene coastal clastic deposits in the Sandakan region of eastern Borneo have identified several well preserved mangrove systems. Detailed sedimentological analysis has allowed the development of new criteria enabling the recognition of these facies in other locations. These criteria include the sedimentological characteristics of both channelised and sheet-like sandstones, as well as macro- and micro-palaeontological observations.
Several morphologically distinct sandbody classes within these successions have confidently 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 very rare rooted intervals. Unpublished data from Brunei suggests that mangrove mudstones may provide a significant source of oil, mainly from the waxy cuticles of mangal species. Using the 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 mudstone deposits.
Additional plays have been erected for carbonate mangrove systems which, while sharing some of the features of clastic mangrove systems, have other mangal indicators such as well preserved rooted systems, fenestra and an absence of large channels. These features relate to their development in arid climates, which have also led to the preservation of soil horizons which form key marker beds within the stratigraphy. Classic examples of rooted carbonate mangroves from the Miocene of Mallorca have been studied and modelled in a reservoir simulator to assess the impact of high vertical permeability values.
Biography
Jon Noad is an exploration geologist working on tight gas deposits with Shell Canada. After graduating from Imperial College, London in 1985 he spent four years working as a mining geologist in South Africa. Returning to the United Kingdom he joined British Telecom (Marine) as their first marine geologist, evaluating potential submarine cable and pipelines routes. During this time he gained an M.Sc. in Sedimentology at evening classes at London University, with a thesis based in Dinosaur Provincial Park, Alberta. He then completed a Ph.D. in London on the Sedimentary Evolution of Eastern Borneo, before joining Shell in the Netherlands in 1998. Since then he has worked primarily in Exploration, concentrating on the Middle East until moving to Canada in 2006. He is currently President of the British Sedimentology Research Group (BSRG), and was formerly President of the PGK in Holland.
Are Alberta's Foreland Basin Rivers a Key to Understanding Fluvial Deposits of the Western Canada Sedimentary Basin?
Speaker
Godfried Wasser,
Eucalyptus Consulting Inc.
12:00 Noon
Wednesday, November 19, 2008
BP Tower
240, 4 Ave SW, Room 201
Calgary, Alberta
Biography
With nearly half of the ancient clastic deposits of Western Canada related to fluvial sedimentation, fluvial deposits are one of the most understated topics of our profession. Fluvial deposits are often classified as 'braided', 'meandering', and occasionally 'anastomosing', leading geologists to envision idealized sedimentary successions and geometries. Not only are these fluvial classes representative of end-points of a sliding spectrum, they often lead us to ignore that these depositional systems evolve both laterally and through time, and that the final rock geometries preserved are greatly impacted by the development of accommodation space at variable rates.
In this presentation, three fluvial case histories will be presented: two from the Alberta Foreland Basin and one from the Eocene Capella Formation in the Pyrenees of Northern Spain. The Alberta Foreland Basin has isostatically rebounded over the last 10,000 years as a result of the melt-off of the Laurentide Continental Ice sheet(s) and Cordilleran glaciers. The amount of ice in mountain valleys was probably significantly less than that on the plains. Hence rebound in the plains was likely more severe and the topographic gradient between the mountains and the plains has likely declined over the past 10 millennia.
The Milk River Valley at the Pinhorn Grazing Reserve in Southern Alberta is incised into Belly River Formation bedrock and situated approximately 100 metres below the adjacent prairie plateau. The valley is approximately 800 metres wide. Assuming that most valley incision by the Milk River has taken place in the last 10,000 years, the average rate of glacial rebound in Southern Alberta would approximate 10 millimetres per annum. Comparing measured glacial rebound rates in Finland (~2 mm/yr) with that estimated in southern Alberta suggests that the Albertan estimate is too high and probably an ancestral valley existed prior to glacial rebound.
The Recent Milk River channel geometry is 'typical meandering', yet the environment is governed by highly variable discharge, a sandy sediment source, very high rates of cut bank erosion (1-2 metres per year) and 25-year floods capable of significant erosion. Its older deposits form an extremely intricate mosaic of overbank and point bar deposits. If preserved, the architecture of Milk River channel deposits should be similar to that of the Eocene Capella Formation with a pattern of abrupt lateral channel migration. However, this formation's sedimentary successions are associated with high rates of accommodation generation, whereas the Milk River has a very low, or even a negative rate of accommodation generation.
The Bow River Basin is also experiencing glacial rebound, but its ancestral valley dates back to the Late Tertiary based on gravel deposits of that period as described by Moran (1987). Discharge of the Bow River is highly seasonal and flow rates during the last approximately hundred years have seldom been high enough to move large boulders; water energy is rarely sufficient to move pebbles 10 centimetres in diameter. Yet, the Bow River displays typical braided river features. Moran's work (1987) suggests the Bow River reworks glacial deposits that filled the ancestral Bow Valley including older pre-glacial and glacial-fluvial braid bar deposits.
It can be concluded that if recent rivers behave so differently than those idealized with traditional 'end-member' fluvial models, than subsurface fluvial deposits are unlikely to resemble the deposits proposed in these classifications either.
Biography
Godfried Wasser has a M.Sc. in sedimentology from the University of Utrecht, Holland. He has worked in the Canadian and international oil industry for nearly 30 years both on staff and as a consultant. Wasser currently offers industry courses, fieldtrips and consulting services focusing on sandstone reservoirs through Eucalyptus Consulting Inc.
Information
Talks are free – don't forget to bring your lunch! Coffee and donuts
will be provided. If you are interested in joining the Sedimentology
Division e-mail listing which currently provides luncheon reminders,
or if you care to suggest a technical topic or present a talk to
the division, please contact Sedimentology Division Chairs, Stephen Hubbard at (403) 220-6236 or shubbard@ucalgary.ca or Jeff Reinprecht at (403) 233-1312 or Jeffrey.reinprecht@bp.com.
Visit the sedimentology division website for extended abstracts, forum discussion, photo gallery, upcoming events, and much more at: www.cspgsedimentology.org.
Lunch talks are sponsored by IHS Energy (www.ihs.com) and Birch Mountain Resources Ltd. (www.birchmountain.com).
