First-day road log: Alamogordo to Three Rivers, Carrizozo, Nogal, Ruidoso and Sierra Blanca Peak
Geoffrey Rawling, Daniel Koning, Shari Kelley, Fraser Goff, and Goff, Cathy, McLemore, Virginia
The first-day trip proceeds north on U.S. Highway 54 from Alamogordo to Carrizozo, and then heads southeast to Nogal, Sierra Blanca, and Ruidoso. The first leg travels between Alamogordo and Three Rivers. South of Three Rivers, we will have views of Pennsylvanian-Permian rocks of the northern Sacramento Mountains beyond the creosote-mesquite scrubland of the eastern Tularosa Basin. These mountains become progressively lower northwards, both in elevation and structural level. U.S. Highway 54 rises and falls as it crosses the numerous alluvial fans derived from this part of the Sacramento Mountains. At Three Rivers, we drive northeast, pass the Three Rivers petroglyphs, and then head to the southern Godfrey Hills. Stops 1 and 2, on private property, will discuss new insights on the stratigraphy and evolution of the Sierra Blanca volcanic field, which was active between 38 and 27 Ma. Stop 1 will also address the structural character of the Sierra Blanca Basin and its tectonic evolution.
After returning to Three Rivers, we continue northward on U.S. Highway 54, crossing the eastern boundary fault of the Tularosa Basin and then travel on thin Quaternary sediments blanketing various east-dipping Cretaceous strata. Soaptree-yucca studded grassland soon replaces the thorny desert scrub. To the east the wonderful views of volcanic strata discussed at Stops 1 and 2, followed by various hills capped by sills related to the Sierra Blanca volcanic field. The town of Carrizozo retains its western, earthy character and contrasts with the touristy town of Ruidoso. At Carrizozo, we turn east on U.S. Highway 380 and proceed to Nogal. Mountains generally underlain by felsic stocks stand to the north, while to the south lie volcanic rocks of the northern Sierra Blanca massif. We pass through the quaint town of Nogal and then ascend onto forested, rolling highlands that characterize the Ruidoso area. Stop 3 is in the beautiful valley of the Rio Bonito, east of Ruidoso, where we will eat lunch, and discuss the geology and tectonics of the eastern Sierra Blanca Basin. Lunch will be followed by a scenic hike along bluffs of Dakota Formation sandstone, ending at another fine petroglyph panel. Finally, the caravan climbs the east face of Sierra Blanca to an elevation of nearly 10,000 ft (3050 m) at Windy Point for Stop 4. Here, discussion will focus on the igneous geology of the Sierra Blanca volcanic complex, while enjoying fine roadcut exposures of the Three Rivers Stock and one of the most spectacular views in the state. Retracing our route down the mountain, we end at Cedar Creek campground in Ruidoso for a barbeque dinner amongst the ponderosas.
Note: The full-text of all Fall Field Conference road logs are only available in print.
- Rawling, Geoffrey; Koning, Daniel; Kelley, Shari; Goff, Fraser; Goff, Cathy, McLemore, Virginia, 2014, First-day road log: Alamogordo to Three Rivers, Carrizozo, Nogal, Ruidoso and Sierra Blanca Peak, in: Geology of the Sacramento Mountains region, Rawling, Geoffrey; McLemore, Virginia T.; Timmons, Stacy; Dunbar, Nelia, New Mexico Geological Society, Guidebook, 65th Field Conference, pp. 1-63.