permeability-porosity relationship (e.g., Gamage and Screaton, 2006). Prior to the

availability of core samples of marine sediments, many studies extrapolated

permeabilities from fine-grained terrigenous sediments found on-shore and in many cases

these values produced ambiguous results (Bryant et al., 1981). With the availability of

more samples, the quantity of permeability data has significantly increased. However,

difficulties in laboratory measurements and finding undisturbed cores have limited the

amount of permeability measurements representative of different lithologies and

structural domains at subduction zones.

 The focus of this study is to synthesize available permeability data from four

different subduction zones with the aim of predicting permeability-porosity relationships

for a number of sediment types found in modern accretionary complexes and to examine

what parameters affect the relationship between permeability and porosity. The samples

used in this study represent sediments from Northern Barbados, Costa Rica, Nankai, and

Peru. Samples representative of the Northern Barbados and Nankai subduction zones

mainly consist of fine-grained clays and silts that are commonly grouped as

hemipelagics. Samples from Costa Rica consist of both hemipelagics and calcareous

oozes while samples from Peru consisted of calcareous oozes and siliceous oozes. Using

existing permeability data, permeability-porosity relationships were developed based on

depositional environment, grain size distribution and structural domain. These

relationships were compared and examined to evaluate the relative importance of each

variable.