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Sedimentology of the Late Cretaceous in the Western Aude Valley, Southern FranceThe closure of the Tethys seaway between Iberian and European plates and early stage development of the Pyrenees produced continental sedimentation in the Western Aude Valley south of Carcassonne. Although timing is difficult in continental deposits, fluvial sedimentation occurred in much of Campanian time and changed gradually to lacustrine/ palustrine by Maastrichtian time. The aim of this poster is to assess sedimentary changes laterally and over time. Sedimentary logs over an area of 16 x 30 km have been measured to correlate main bodies of sandstone and initiation of carbonate sedimentation. Siliciclastic deposits can be grouped into 4 facies: trough cross-bedded conglomerate, massive conglomerate, trough cross-bedded sandstone and horizontally bedded sandstone. They suggest that they were formed in a high energy, low sinuosity braided river system with significant topography and coarse sediment supply. Breaks in coarse sedimentation, characterized by paleosols and fluvial stromatolites, suggest episodic high-energy sedimentation and are consistent with semi-arid climate hypothesized for the Campanian. Above coarse Campanian sediments are Maastrichtian-aged thick marls and several-metre sandstone beds. Marl deposits indicate generally lower-energy conditions and contain dinosaur bones whereas sandy beds can be rich in dinosaur egg fragments and Microcodium associated with vegetation. Fine-grained carbonates and marls continue to the end of the Cretaceous. The presence of charophyte stems and gyrogonites, lack of desiccation cracks and medium gray colour with some preserved organic matter suggest lacustrine carbonates. Above and often interbedded with gray carbonate is mottled pink, yellow and cream limestone with roots, nodules and desiccation cracks interpreted to be marginal lacustrine to palustrine. The interbedded nature of these deposits suggests fluctuating water level controlling lacustrine/palustrine cycles and episodic high-energy clastic input. Relatively thin gray carbonate may mean perennial lakes were shorter-lived whereas palustrine conditions persisted over a longer time. The Tethys seaway existed in the area until Santonian time, but was closed by the Campanian due to the IberiaEurope collision creating a continental basin. Early stage of Pyrenean uplift and moderate topographic relief promoted fluvial deposition in the basin. Palaeocurrents and clast types will be assessed to differentiate among potential source mountains to the north (Montagne Noire), east (Massif de Mouthoumet) and/or south (Pyrenees). Over time, sediment transport energy decreased suggesting lower topography and, possibly, sufficient uplift to the south to confine lacustrine deposits. Infill logging next field season will attempt to define Campanian and Maastrichtian sediment sources, lake boundaries, dinosaur nesting areas and the transition to early Paleocene deposits.
Teaching sedimentology: opportunities for interdisciplinary, variety, innovation and employability.The breadth of content and skills embodied by the subject of sedimentology provides the opportunity teach in multiple learning environments, engage in innovative teaching practice and embed employability skills. Field and practical-based work are essential components of sedimentology and provide opportunities to teach in different environments outside the normal classroom setting. This allows the inclusion of a variety of learning experiences, which can in turn address different student learning styles. Field-based studies in particular create learning environments that can contribute to transformative learning experiences. The emphasis on field and practical based learning experiences in sedimentology promotes experiential learning, founded on the tenets of Kolb’s learning cycle. For example field examination of clastic sequences can be used to determine their economic potential as oil, gas or water reservoirs, thus connecting experiential learning in the field with theoretical calculations. The use of a variety of teaching environments can also facilitate experimentation with innovative teaching practice. Teaching outdoors or in a laboratory or practical class setting opens up possibilities for using technology that may not be possible in a standard classroom setting. For example students can create mini documentaries in the field that focus on modern sedimentary environments and structures using simple equipment, multimedia presentation techniques and software. Sedimentology requires the development of a variety of field, practical, quantitative and problem solving skills. These skills are highly transferrable and can help build student employability. For example, students develop practical, geoscience specific skills in the study of an oil well, combining analysis and interpretations of thin sections, core and wireline data; in grain size analysis exercises they develop more generic statistical skills. Teaching sedimentology gives the instructor scope to create innovative, experiential learning exercises and assessments in which transferrable skills can be embedded across a variety of learning environments. The subject provides a rich learning experience for students and a stimulating teaching environment for instructors.