Cover Image: Kasha-Katuwe Tent Rocks National Monument
— Adam Read
View eastward from Kasha-Katuwe Tent Rocks National Monument across the southern Jemez Mountains. The snow-capped Sangre Cristo Range is on the skyline. Dark hills in front of the Sangre de Cristo Range belong to the Cerros del Rio volcanic field (late Pliocene-early Pleistocene). In the foreground lies the light-colored, tuffaceous Peralta Tuff Member of the Bearhead Rhyolite (7.1-6.5 Ma). This unit consists of ash and sediment derived from rhyolitic lava domes in the southern Jemez Mountains. One of these domes, located alongside Paliza Canyon, is identified as the source of a particular type of obsidian used by prehistoric Native Americans in the Rio Grande and Puerco valleys (i.e., the Bearhead Rhyolite obsidian). How this source was identified is the topic of the lead paper in this issue.