Figure F10. Gamma ray (NGR) and resistivity logs, core and log porosities, and in situ pressures at M.C. 810 Ursa geotechnical well #1. The Blue Unit (light gray) lies between 300 and 550 mbsf and is composed of interbedded sandstone and mudstone layers. Core porosity (_core) declines rapidly with depth to 200 mbsf and thereafter is constant. Overpressure (P* = P – P_h) is plotted; thus the vertical axis is hydrostatic pressure (P_h) and the right boundary of the plot is the reduced lithostatic pressure (_v* = _v – P_h). Circles = piezoprobe pressures, triangles = preconsolidation pressures from uniaxial consolidation tests of core, stars = pressure measurements inferred from pressure while driling (PWD) in the Blue Unit. Ostermeier et al. (2000) and Eaton (1999) further describe these data.

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