Page 198 - The Geology and Ore Deposits of Sierra County, New Mexico - Bulletin 10

MINING DISTRICTS 195
Crown. The Vittorio Land & Cattle Co., the owners, had a geo- logical survey made of the grant, and they report that no mineral deposits of interest were found. The following description is based largely on available reports and on observations made from outside the grant.
GEOLOGY
The main Fra Cristobal Range is a fault block of eastward- dipping sedimentary rocks. West of this block is another fault block, which is higher structurally but which has been eroded down until only a low ridge of granite remains. As viewed from
the west the sediments of the northern part of the range are partly hidden from view by this granite ridge. Farther south the granite mass decreases in height and disappears under allu- vial fans.
Most of the steep westward-facing fault scarp of the range consists of Magdalena limestone. To the east the range presents a long dip slope of Magdalena limestone, upon which near the southeast end of the range are low cuestas of Permian and Creta- ceous sedimentary rocks, with here and there a small remnant of lava flows of Tertiary age. At the west base of the range are steep alluvial fans, which coalesce at their bases and merge with