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56th BSRG Annual General Meeting 16-19 December 2017, Newcastle Abstract Book 1 56th BSRG Annual General Meeting 16-19 December 2017, Newcastle Conveners Sanem Acikalin Cees van der Land In partnership with 2 Contents Keynote Talks 4 Oral Presentations 8 Deepwater Clastic Sedimentary Systems 8 Shallow Marine and Coastal Sedimentary Systems 36 Fluvial and Lacustrine Sedimentary Systems 47 Glacial Sedimentary Systems 58 Society for Sedimentary Geology (SEPM) Open Session 64 Sedimentology And Stratigraphy As Tectonic Tape Recorders 70 As Clear as Mud: Removing the Irony from the Idiom 86 The Afterlife of Sediments – Diagenesis and Fluid-Rock Interactions 91 Fluid-Particle Interaction And Its Sedimentary Products 101 Poster Presentations 107 Deepwater Clastic Sedimentary Systems 107 Shallow Marine And Coastal Sedimentary Systems 117 Fluvial And Lacustrine Sedimentary Systems 126 Glacial Sedimentary Systems 133 Society For Sedimentary Geology (SEPM) Open Session 135 As Clear As Mud: Removing The Irony From The Idiom 144 The Afterlife Of Sediments – Diagenesis And Fluid-Rock Interactions 146 Fluid-Particle Interaction And Its Sedimentary Products 151 3 Keynote Talks Vanished Ocean: How Tethys Re-Shaped the World Dorrik Stow Heriot Watt University, Edinburgh EH14 4AS, UK The Tethys Ocean once dominated the Earth. Between 260 and 6 Ma (million years ago) its vast waters bore witness to some of the most significant and dramatic episodes in the history of our planet. Two mass extinctions – the end Permian and end Cretaceous – rocked the world during this long period of time. Global environmental stress and changes in ocean chemistry are more correctly implicated in the cause of these events, rather than bolide impact. The warm shallow waters of Tethys then nurtured the ensuing rebirth of new organisms: exuberant Jurassic marine life; the development of sponge reefs, coral reefs, rudistid bioherms, nummulitic shell banks and the myriad fishes that adapted to each new ecosystem; the evolution of feathered birds from Tethys lagoons and cetaceans from the strandline to the deep sea. Repeated black-shale episodes (180-80 Ma) when the ocean was close to its maximum extent have given the world the majority of its oil resources. Progressive closure of the Tethys led to uplift of the Alpine-Himalayan mountain ranges, and their dramatic erosion fed the world’s largest deepwater fans. Many of these play host to important oil and gas reservoirs. Ocean circulation patterns also changed and so impacted global climate, the resultant changes causing the world to plunge into its current icehouse climatic phase. Opening of the Gibraltar gateway after final closure of the Tethys reign (5.2 Ma) resulted in the outpouring of warm salty water into the North Atlantic Ocean. This is likely to help keep the Atlantic Overturn in operation and so, at least initially, stem the worst effects of global warming. From this remarkable history of environmental change through the geological past we can learn much about our global environment today. What is robust and what precarious? How does life respond to changing stress? How does the ocean-climate nexus affect climate? Where are the tipping points towards irreversible change? 4 Meteoric alteration of carbonate-evaporite sequences – insights from the Tertiary Aquifer System in Qatar. Fiona Whitaker, Rattana Thirathititham and Elizabeth Stanmore School of Earth Sciences, University of Bristol, Bristol, United Kingdom [email protected] Shallow marine sequences formed under arid conditions commonly comprise limestones and dolomites interbedded at a range of scales with evaporite minerals. Across the Arabian Gulf such deposits of Tertiary age comprise a thick and laterally extensive reservoir that in some areas hosts oil and gas reserves, and in others represents an important aquifer for groundwater supply. These rocks formed from waters at, or considerably in excess of, seawater salinity, and experience significant diagenetic alteration when exposed to meteoric fluids. The resulting dissolution of evaporites poses an important hazard for construction, but also drives alteration of associated carbonates. Here we use observations of fluid chemistry to inform and understanding of these diagenetic processes. Our study focusses on the Tertiary sequence of Qatar, which records shallow marine to sabkha deposition from the Paleocene to the late Eocene, after which an extended (c.30 Ma) period of exposure has allowed for extensive karstification. The modern climate is very arid, with high rates of evaporation and a mean annual rainfall ranging from <50 mm in the south of the country, to >100 mm in the north. Rare intense rainfall events recharge the shallow aquifer via overland flow to numerous low-relief terminal depressions. Recharge is facilitated by fractures and karst features developed over the extended period of subaerial exposure. Ground waters are hosted in largely dolomitic aquifers, which include the Paleocene to Lower Eocene Umm er Radhuma and overlying Lower Eocene Rus Formation, with the Middle Eocene Abarug limestone forming a locally important aquifer in the south west the country. In southern Qatar the Rus is subdivided by a unit of gypsum and clays which is up to 50 m thick. This confines the underlying Lower Rus and Umm er Radhuma aquifers, which are fed by recharge from outcrop areas to the south and west within Saudi Arabia. In the north gypsum was either not deposited, or has since been largely dissolved from the Rus, and the two aquifers are in hydraulic continuity. Major ion chemistry data for ground waters from wells distributed across Qatar, has been used to characterize water-rock interaction in the Eocene. Chloride concentrations show clear evidence of salinisation adjacent to the coast due to mixing with adjacent seawater from the Arabian Gulf. Fresher waters are present in the interior of the peninsula in the north compared to those in the south. Using chloride as a conservative tracer for mixing with seawater, we 2+ 2+ 2- calculate concentrations of Ca , Mg and SO4 that are derived from water rock interaction. All waters are significantly enriched in sulfate, but this is most marked in the southern province, likely reflecting the abundance of gypsum in the subsurface. Sulfate enrichment is accompanied 2 2+ by elevated levels of calcium. In the Abarug limestone the molar ratio of rock-derived SO4 :Ca , is 1:1 as expected from gypsum dissolution, but across much of the country the molar ratio is significantly higher, often reaching 2:1 and suggesting a sink for Ca2+. In combination with an enrichment in Mg2+ in waters within the dolomite aquifers, this provides clear evidence for replacement of dolomite by calcite (dedolomitization), driven by the release of Ca2+ from gypsum dissolution. Whilst current rates of gypsum dissolution and dedolomitisation are limited by the arid climate, this process is likely to have been more active during past pluvial periods and likely played a role in karst development. 5 The organic geochemical exploration of degraded metabolites during the early evolution of early land plants Geoffrey Abbott Geosciences, Drummond Building, School of Natural and Environmental Sciences Newcastle University, Newcastle upon Tyne, NE1 7RU UK, [email protected] The appearance of land plants on the earth’s surface is termed phytoterrestrialisation which resulted in critical anatomical developments such as wood (xylem) and leaves (cuticles). These anatomical developments were accompanied by the evolution of biosynthetic pathways for secondary metabolites such as lignin which are concentrated in specific tissues, layers or organs such as the xylem, cuticle and roots and are visible at the submillimetre scale. Metabolites such as lignin can then be degraded following death and deposition of the plants (Robertson et al., 2008; Schellekens et al., 2015). Microanalytical techniques, including pyrolysis/gas chromatography-mass spectrometry (Py- GC/MS), have been used to characterise the degraded metabolites from a range of Devonian land plants (Ewbank et al., 1996) as well as the xylem and stereome in Psilophyton dawsonii (Edwards et al., 1997). Py-GC/MS has also been used in combination with FTIR and 13C NMR to explore the composition of coeval enigmatic organisms including Prototaxites dawsonii (Abbott et al., 1998). The question is whether or not the high resolution spatial distribution of the diagenetic products of such metabolites and cell wall materials can be correlated with microscopic structures. This is often difficult or even impossible to do because normally the fossils have to be milled prior to analysis. The Rhynie Chert in Aberdeenshire (Scotland) has some exquisite examples of early land plants and fungi which are than 400 million years old when its environment was very similar to that of the Yellowstone hot-springs system today. We have studied these plants using X-ray photoelectron spectroscopy (XPS) and time-of- flight mass spectrometry (ToF-SIMS) where milling is not necessary (Abbott et al., 2017). An argon gas cluster ion beam source was rastered over analysis areas to remove any post-depositional ingress from the top 3 nm of the specimen surface. The resolution of the HIM is 0.3 nm. The bonding environments of the organic carbon were identified using XPS on Rhynia gwynne-vaughanii and then ToF-SIMS was used to map the distribution of positively charged fragment ions for both aromatic and aliphatic hydrocarbons as well as silicon across the diameter of a Rhynia stem from the Rhynie Chert. This presentation will also give an overview of these high resolution surface analytical techniques that may help us gain a deeper understanding of the distribution of metabolites within the organs and tissues of fossilised early land plants. REFERENCES Abbott GD, Fletcher IW, Tardio S, Hack E. 2017 Exploring the geochemical distribution of organic carbon in early land plants: a novel approach. Philosophical Transactions of the Royal Society B In the press. Open Access after December 18 2017. http://rstb.royalsocietypublishing.org/content/373/1739/20160499 Abbott GD, E, Edwards D, Wang GY.