Architecture of Turbidite to Delata Basin-fill Successions: Shannon Basin, Western Ireland

Seismic scale basin slope to deltaic sequence, with turbidite channel cut and fill at the base, Cliffs of Moher, Western Ireland Major slumps and glide planes forming slope healing phase, Windy Bay, Western Ireland Sheet-like non-channelised turbidites arranged in progressively thickening up cycles, Clare Basin, West of Ireland Sheet-like non-channelised turbidites arranged in progressively thickening up cycles, Clare Basin, West of Ireland Geology fieldtrip to Clare Basin, Ireland Tullig Sandstone forming a multi-storey fluvial channel system deeply incised into the underlying deltaic series, Truskilieve Amphitheatre, Clare Basin, West of Ireland Tullig Delta Cycle rootletted interfluve, Doonlicky Cyclothem, Spannish Point, West of Ireland Stigmaria root system in Namurian delta top facies, Clare Basin, West of Ireland Long coastal exposures of the Rehy Cliffs turbidite channel complex are accessed by boat, Clare Basin, West of Ireland Unstable slope system slumps and glide planes, form a slope healing phase associated with synsedimentary faulting, Clare Basin, West of Ireland Sharp based forced regressive sandstone within the lower parts of the Tullig delta system, Clare Basin, West of Ireland Bridges of Ross location displays a major turbidite slump sheet and an upper channelised series of turbidite channels

Field seminar to examine seismic scale deltaic and turbidite basin fill sediment architecture.

Objectives

The Namurian succession of the Shannon Basin affords an opportunity to traverse a complete basin-fill succession passing up from basin-floor turbidites, through slope deposits and into a series of deltaic cycles.

Spectacular seismic-scale coastal cliff exposures allow us to see the various geometries and processes associated with this evolving basin-fill, as well as its sequence stratigraphic architecture and syn-depositional structuration.

Geology

During this trip we will investigate a 400m-thick Upper Carboniferous (Namurian) basin-fill succession which represents the thermal subsidence phase of the Shannon Basin.  This basin-fill 'megasequence' provides superb outcrop examples of:

  • basin-floor turbidite channels and lobe / spillover systems

  • turbidite sheet sands

  • turbidite slump sheets interbedded with channelized turbidites

  • major slumping associated with slope failure and healing

  • mud diapirs and growth faults, and their effect on river capture

  • prodelta deposits

  • incised valley fills

  • river dominated - wave modified delta fronts

  • delta-top facies

Many of the insights to be gained here will be directly transferable to other turbidite and deltaic deposystems elsewhere in the world.

Who Should Attend

This seminar benefits both exploration and reservoir geoscientists, including geologists, geophysicists and reservoir engineers, particularly as it promotes cross discipline team building.

The trip involves moderate levels of walking and also includes a boat trip where we follow seismic / reservoir scale changes in turbidite channel architecture, continuously exposed across several kilometers in the Shannon Estuary.