Abstract

A Middle to Upper Devonian Clastic Wedge was deposited across the Canadian Arctic Islands in response to tectonism. Three subwedges are discernible, and are apparently separated by regional disconformities. All three subwedges are preserved on Melville Island. Four major sediment pulses were deposited in a variety of slope, shelf, and deltaic environments.

The lowest subwedge, the Hecla Bay subwedge, contains deposits of pulses 1 and 2. On Melville Island Pulse 1 comprises submarine fan/slope turbidites (Blackley Formation) in the extreme west and a southwestward prograding shelf system in the east consisting of slope/outer shelf (Cape De Bray Formation), and mid-inner-shelf deposits (Weatherall Formation). Pulse 2 contains slope/outer shelf (Cape De Bray Formation), mid- and inner-shelf (Weatherall Formation), and fluviodeltaic deposits (Hecla Bay Formation), and exhibits southwestward facies progradation. Variation in sediment supply and relative sea-level are reflected in the see-sawing of these facies in the overall southwestern progradation.

The Beverley Inlet Subwedge and the Parry Islands subwedges are neither as well exposed nor as extensively preserved as the Hecla Bay subwedge, consequently they are not as well understood. Both these subwedges exhibit oscillation of shelf and deltaic environments. The Beverley Inlet subwedge displays a northeastward deltaic-shelf to fluviodeltaic transition on southwestern Melville Island.