Cover Image: Aden shield and crater rim
— René De Hon
The Aden shield and crater rim, located 40 km southwest of Las Cruces, New Mexico, lies within the Organ Mountains-Desert Peaks National Monument administered by the Bureau of Land Management. Aden is situated along the northeastern side of the Potrillo Volcanic Field, which covers 1,000 square kilometers and is represented by numerous eruptive centers and associated lava fields that were active during the Late Quaternary. The lava flows at Aden resulted from the extrusion of relatively low-viscosity basaltic magmas that spread passively across the landscape similar to present-day eruptions on Hawaii. Successive eruptions created a shield volcano with a well-preserved, central crater. Aden Crater exhibits a rugged, circular rim consisting of solidified spatter, and contained a molten lake of lava when the volcano was last active. Volcanic features of the Potrillo Volcanic Field also include maars, including the extensively studied Kilbourne Hole, which result when rising magma encounters groundwater, resulting in a violent eruption of steam, country rock, and magma into the atmosphere. Description and interpretation of features of the Aden basalt field are discussed in the paper beginning on page 17 of this issue. Photograph and caption courtesy of René De Hon.