SMOOTHING AND EXTRAPOLATION OF CRUSTAL STRESS ORIENTATION MEASUREMENTS

The theory and mechanics of a statistical smoothing algorithm for estimating stress fields based on observed data are described. Fitted stress fields can be displayed as either a gridded map (axes of maximum, or minimum, horizontal stress are shown as short bars located at each point in an evenly spaced grid), or as a stress trajectory map. Examples of predicted stress fields for southern California and western Canada, based on borehole elongation data, are displayed as stress trajectory maps. A predicted paleostress field for the Spanish Peaks intrusion complex in Colorado, based on vertical dike orientations, is displayed as a gridded map. -from Authors