Development of the San Andreas transform by rise-trench encounter in coastal California
influenced the structural evolution of a large region within the adjacent continent …

In four large Oligocene calderas in the western San Juan Mountains–Lake City, Silverton,
San Juan, and Uncompahgre–spectacular breccias are intermixed with thick intracaldera …

A considerable number of metallic ore deposits are genetically related to subaerial
volcanism. Here four ore types are reviewed: epithermal precious-and base-metal deposits …

Abstract In the southern Rio Grande rift, two extensional regimes of different origin (but
transitional with each other through the Miocene) can be interpreted from structures and …

Locations of 2,100 radiometrically dated igneous rocks were plotted on a series of 20 maps,
each representing an interval within the period 80 my BP to present. Derivative maps …

Abstract The Rio Grande rift encompasses uplifts of the southern Rocky Mountains and their
southern extension as well as axial fault blocks. The rift widens irregularly southward from a …

Voluminous intermediate to silicic composition volcanic rocks were generated throughout
the southern Rocky Mountains, western US, during the mid-Tertiary “ignimbrite flare-up” …

The accessory minerals rutile and apatite are rare or absent in the convecting upper mantle
but occur in shallow, cooler, metasomatized continental lithospheric mantle (CLM) where …

This summary characterizes 28 known or suspected mid‐Tertiary ash flow tuff (ignimbrite)
cauldrons, up to 40 km in diameter, in southwestern New Mexico. A combination of …

Late Eocene to middle Oligocene floras from the area of the present Rio Grande depression
represent a time sequence from the upper part of mixed subtropical forest (Bernalillo flora) …