Sediment accumulation rates, computed using agesediment thickness curves obtained from DSDP cores, are rarely corrected for compaction or bedding attitude to better approximate true sediment accumulation rates (c.f. van Andel et al., 1975; Davies et al., 1977; and Whitman and Davies, 1979). Variations with depth in either of these factors can hinder interpreting relative rates of sedimentary processes associated with a particular depositional environment. This problem becomes particularly relevant for convergent margin sediments, which often display variable bedding attitudes and pronounced changes in porosity, bulk density, and other parameters related to the compaction process at shallow depth. These rapid shallow changes render correlation of sedimentation rates within a single transect of holes very difficult. Two techniques have been applied to data collected from a transect of holes along the southwestern Mexico continental margin, DSDP Leg 66 (Fig. 1), to correct sediment accumulation rates for variations in compaction and bedding attitude. These corrections should help resolve true fluctuations in accumulation rates and their implications regarding convergent margin processes.

Sediment thickness drilled is the apparent thickness penetrated by drilling. True sediment thickness is corrected for bedding attitude.

Supplement to: Shephard, Les E; McMillen, Kenneth J (1982): Sedimentation rates of the southern Mexico Continental Margin, Deep Sea Drilling Project Leg 66. In: Watkins, JS; Casey Moore, J; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 66, 445-452