The submarine eruption and emplacement of the Lower Rhyolitic Tuff Formation (Ordovician), N Wales

  title={The submarine eruption and emplacement of the Lower Rhyolitic Tuff Formation (Ordovician), N Wales},
  author={Malcolm F. Howells and A. J. Reedman and S. Diarmad G. Campbell},
  journal={Journal of the Geological Society},
  pages={411 - 423}
The Lower Rhyolitic Tuff Formation (up to 600 m thick) represents an eruptive cycle of acidic ash-flow tuff which is stratigraphically associated with marine sediments and subaqueously emplaced basalt lavas. The formation comprises volcaniclastic and pyroclastic megabreccias and breccias, massive welded and non-welded acidic ash-flow tuffs, reworked tuffs and tuffities, siltstones, rhyolite intrusions and extrusions. Its basal contacts vary from conformable, to disconformable and unconformable… 

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