Particular emphasis has been placed upon the sedimentary structures that can be used as paleocurrent indicators. The Stanley Group is interpreted as flysch deposits with the present exposures revealing mainly the axial portion of the trough. The normal environment was one of mud accumulation under reducing conditions in a poorly circulated, possibly deep water basin. Siliceous shales mark occasional, widespread quiescent conditions. Volcanism occurred during the infilling of the trough. Rapid introduction of sand frequently interrupted the normal settling. Turbidity currents, triggered by the instability associated with rapid subsidence and an active source area, brought in the sand from the marginal source areas to the southeast. An axial trend of transport was present and became progressively better developed in the later stages.

First Page Preview

First page PDF preview
You do not currently have access to this article.