Independent lines of evidence indicate a generally westward regional slope in the vicinity of the southeastern Caliente Range during the middle and late Miocene epoch. Regional lithofacies variation of middle Miocene strata suggests a north-trending shoreline. Lateral variation and internal structures of middle Miocene basalt flows (the lower and middle flows of the "Triple" basalts of Eaton, 1939) indicate that the lava flowed westward. Pebble imbrication within non-marine pebbly sandstones of probable late Miocene age (Caliente Formation of Hill, Carlson, and Dibblee, 1958) likewise denotes westward-flowing paleocurrents. Extrapolation according to Sternberg's Law of the systematic lateral increase in size of the larger clasts suggests a granitic source for these sedime ts in what is now the southern end of the San Joaquin Valley.

Knowledge of paleoslope direction can facilitate the environmental interpretation of lithofacies variation and sedimentary structure in other units of the same sequence. In the Caliente Range, the middle Miocene Branch Canyon Formation of Hill, Carlson, and Dibblee (1958) is a sandstone facies transitional between marine and non-marine sedimentary deposits. Among the many types of cross-stratification present in this sandstone, one distinctive type consists of irregularly spaced, laterally graded foresets in tabular units up to 5 feet thick. This type of cross-bedding is consistently inclined toward the west. Because this direction is normal to the strand line, this particular facies may be interpreted as foreshore terrace deposits of an ancient beach.

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