The calcareous oozes of Costa Rica plot approximately in the same permeability range as
those from Peru, near the upper boundary of Neuzil's (1994) plot.
Table 2-1. Log linear permeability-porosity relationships predicted for varying
depositional environments at Barbados, Costa Rica, Nankai and Peru.
Location and Depositional environment Permeability-porosity relationship
Barbados hemipelagics log (k) = -22.02 + 8.25n (R2 0.20)
Costa Rica hemipelagics log (k) = -20.84 + 6.27n (R2= 0.70)
Nankai hemipelagics log (k) = -19.80 + 5.37n (R2= 0.79)
Costa Rica calcareous oozes log (k) = -18.09 + 4.83n (R2= 0.33)
Peru calcareous oozes log (k) = -20.87 + 7.79n (R2= 0.40)
Peru siliceous oozes log (k) = -18.64 + 3.55n (R2= 0.67)
-12 I -12 I
A B
-14 -14 -
-16 16 -
SCosta Rica calcareous oozes
Barbados hemipelagics -20 -- =-18 9 + 83rn, R2 33)
-20 -1-. log k=-22 02 + B25n, (R2 =020)
Costa Rica hemipelagics / Peru calcareous oozes
logk =-2084 + 27n, (R2 = 70) -- log k -20 87+7 79n, (R2 = 040)
x Nankai hemipelagics r Peru sliceous oozes
-22 log k=-19BO +537n, (R2= D79) 22,
-- -- log k =-18 64 + 355n, (R2 =U 67)
Allheipelaic All Calcareous oozes
g k =-1 91 +4 90n. (R2 = 50) log k =-1827 1421n, (2 =0 14)
1 1 I I I I I -24 1 1 1
-24 T 02 04 06 08 1 0 02 04 06 08
Porosity Porosity
Figure 2-6. Permeabilities classified based on depositional environment and location. A)
Predicted log-linear permeability-porosity relationships for hemipelagic
samples. B) Permeabilities and predicted log-linear permeability-porosity
relationships for pelagic samples.
Peru calcareous oozes lie at a higher porosity range (0.55-0.80) while Costa Rica
calcareous oozes represent porosities between 0.45 and 0.70. The Peru siliceous oozes
plot between the lower permeability values of calcareous oozes and the higher
permeability values of hemipelagic sediments for porosities ranging from 0.45-0.8.
Although the predicted R2 values were fairly low for the two calcareous oozes, a linear
relationship between the logarithm of permeability and porosity for those two groups was