Course leaders: Dr Stu Clarke (Keele University) and Dr Phil Richards (BGS)

The course leaders have many years experience of conducting basin analysis evaluations and of teaching professional level field based training courses. Dr Clarke completed his PhD on three dimensional modelling of the Moab Fault system in Utah and Dr Richards has led many field courses to the region to examine the petroleum geology, tectonics and sequence stratigraphic evolution of the area.

The venue

The field course is split between two locations within the south-western U.S.A and operates out of two field bases. The first part is based around Moab, Arches National Park and Canyonlands National Park, Utah, U.S.A.

The region of Utah, U.S.A., local to the town of Moab, provides excellent opportunities to examine three-dimensional extensional structures, their regional relationships and effects on basin strata, the local effects of faulting and the development of fault-related rocks, and the effects of extensional faulting on fluid migration, including hydrocarbons, through extensional basins.

The near-total surface outcrop, combined with deep canyons that cut the stratigraphy in a variety of directions, expose a variety of extensional structures and structural relationships on the small and medium scale.

The field base for this part of the course is Moab, Utah, U.S.A.

The second part of the course is based in the Colorado River Extensional Corridor, Basin and Range, Nevada, U.S.A.

The Basin and Range on the western margin of the Colorado Plateau is a highly extended terrane in which extension on large, listric normal faults exceeds 100% and detachment regions of faults are exposed at the surface. It provides excellent opportunities to examine large-scale structural geometries and extend principles examined at the small and medium scale in the Moab area up to the basin scale, and to add and build upon techniques for the structural analysis of extensional basins.

The northern Lake Mead and southern Whipple domains of the Colorado River Extensional Corridor, within the Basin and Range terrane, are characterised by large, listric normal faults that throw down to the west and east respectively. As a result, an accommodation zone exists between these two domains in which faults of opposing dip sense interact to produce a variety of structure geometries. Such geometries have a significant impact on the sedimentary basin fill and on the subsurface migration of fluids; many of the world’s largest hydrocarbon reserves are found in accommodation zones. Consequently, the well exposed structures that will be examined within the Corridor serve as analogues for hydrocarbon-rich structures submerged on passive margins or buried within the interior of continental basins.

The field base for this part of the course is Boulder City, Nevada, U.S.A.

Duration and number of participants

The course lasts 10 days, with a maximum of 10 participants.

Course objectives

The principle aims of the course are:

1. To give participants the opportunity to ‘see’ three-dimensional extensional fault relationships in the field that are often inferred in the geological ‘model’ of survey geologists and translated into their standard products (maps, sections and three-dimensional models).
2. To examine the three-dimensional form of extensional geometries, faulted geology, and the dynamics of faulting on a full range of scales from that of the fault zone to that of the basin.
3. To examine and analyse three-dimensional structural modelling techniques commonly applied to the analysis of both two-dimensional and three-dimensional remotely-sensed subsurface data.
4. To develop concepts and models of extension that are applicable on a variety of scales and to many geological terranes of the UK, particularly the Devono-Carboniferous basins of central and northern England and southern Scotland.
5. To examine the effects of faulting and three-dimensional fault relationships on the syn-rift sedimentary fill of basins and the migration of economic fluids (hydrocarbons, mineralising fluids, water), and to develop three-dimensional models of the ways in which structure can aid or inhibit migration.

The course places an extremely heavy emphasis on the three-dimensional aspects of faulting and fault interpretation. It will equip participants with a three-dimensional understanding of the principles and geometries involved, that will allow them to make rigorous, three-dimensionally sound, geological interpretations in areas of limited data and from spatially limited, remotely sensed datasets such as seismic sections, satellite imagery and air photographs.

To this end, the course integrates examples of extensional structures visible in remotely sensed data, both of the field areas and elsewhere in the world, as a comparison with structures visible in the field. The course also makes extensive use of computer modelling to demonstrate and explain the three-dimensional application of structural modelling techniques examined in the field. In-the-field analysis of three-dimensional structural geometries and modelling techniques will be performed using three-dimensional computer models of both the field area itself and other extensional terrains of the world, in order to demonstrate the applicability and limitations of discussed techniques and compare results with field analysis.

The field studies can be placed broadly into two categories:

• Extensional tectonics at the small-, medium- and basin-scale, including the local effects of faulting on strata of varied lithological properties, the interaction of faults in extensional regimes, and basin-controlling extensional faulting. These aspects of the course are designed to integrate with the classroom-based BGS Continental Extensional Tectonics course administered by R. A. Chadwick.
• The effects of structure on hydrocarbon (and other fluid) migration including the basin-scale effect of faults on the sedimentary distribution of potential source and reservoir lithologies and the analysis of basin and smaller scale faults in the exploration and exploitation of these economic reserves. These aspects of the course compliment the BGS Sequence Stratigraphy course administered by P. Richards & G. Kirby.

Contact Training for course fees, scheduling and availability