Old Geology

Antelope Valley Physiography

By Harry R. Johnson – 1911

The physiographic history of the buttes and heights of land east of the Antelope Valley is obscure. No such striking evidence of the origin of the region as that just presented for the Rosamond Buttes was found, yet erosion seems inadequate to fully explain the topography. It is tentatively suggested that this region of irregular buttes and shallow intervening valleys has been less deformed by depression or elevation than either Antelope Valley or the marginal ranges.

Figure 1 is a purely theoretic representation of what are believed to be the main blocks and faults involved in the production of the larger physiographic features of the Antelope Valley region. The small northwestward-dipping block in front of the Portal Ridge block, represents the Antelope Buttes near Fairmont. As the tuffs on the west side of these buttes dip at angles of 35° to 55° northwestward a direction at right angles to the San Gabriel fault system—it is assumed that the underlying granite has been tilted in accordance with the Tehachapi rather than the San Gabriel faults.