SLUMPS, DEBRIS FLOWS AND SANDY DEEP-WATER CHANNEL SYSTEMS - IMPLICATIONS FOR THE APPLICATION OF SEQUENCE STRATIGRAPHY TO DEEP-WATER ELASTICSEDIMENTS

The Hecho Group is a classic sedimentary system from which turbidite c lassifications have been defined. This study of mudstone-rich interval s from this group suggests that published models in which Type 2 and 3 systems develop in response to changes in relative sea level or tecto nic activity need to be reassessed. Intervals developed between channe l/lobe sandstones comprise mud-matrix supported conglomeratic debris f lows and/or slump deposits which blanket the underlying sand-rich chan nel-fills. They record periods of major disturbance and re-organizatio n of the sedimentary regime. The sandstone bodies are not strongly inc ised and have high aspect ratios. Previous interpretations of these in tervening muddy intervals as overbank wedge/levee deposits, developed during a relative rise in sea level (Type 3) are considered inappropri ate for the sections studied.