To the right is an "exploded" block diagram displaying an emergent anticline penetrated by four vertical wells. The area consists of Paleozoic and Mesozoic sequences of rocks separated by an unconformity. CAETACEOU unit X unit Y Below is a map of well locations from the block diagram and depths to the stratigraphic top of Jurassic unit Y. Tape a piece of tracing paper over the map and using a pencil, neatly draw and label structure contours on the top of this unit. Choose an appropriate contour interval. JURASSIC UNLUNA DEK CAM. -140' -40' 80' 150 205' 25' -60 210 100 200 40' -25' 210 50 30' , 220 •80' 70 190 -130' -30 -160' -115' -160' -110' • -210'

Define Westergaard Stress Distribution.

3. The following convergence measurements (U) have been made in a 4.6-m-diameter circular vertical shaft in good quality granitic rock mass (Em = 40 GPa, ν = 0.2): θ (deg) U (mm) 0 2.25 45 2.39 90 1.50 135 1.00 a) Derive the equations that relate convergence to in situ stress. b) The angle θ is measured (clockwise) with respect to the x-axis, which is oriented 30 degrees clockwise from True North. What is the orientation of the maximum principal stress with respect to True North?