Road Log Day 2 Geology of the Dry Cimarron Valley: Second-day Road Log from Clayton to Folsom and through the Dry Cimarron Valley
— Kate E. Zeigler, Matthew J. Zimmerer, and Frank C. Ramos
Day 2 of the 2019 NMGS Fall Field Conference traverses the Dry Cimarron valley, which parallels the New Mexico-Col-orado state line and exposes some of the oldest rocks in Union County. The route begins in Clayton and follows the Day 1 log until we arrive in Folsom. From Folsom, we will wend our way northwards, dropping down through ba-salt-capped mesas as we follow the course of the Dry Cimarron River, which begins at a series of springs to the west and east of Folsom. Our first stop will be at Folsom Falls, a gorgeous little waterfall that exposes distal flows sourced from Baby Capulin. After departing the formerly popular picnic area, we will soon turn east and begin to drop slowly down through the Mesozoic strata that make up the heart of Union County’s groundwater system. Stop 2 will take place on the YL- Ranch (read as the Y L Bar Ranch) where we will review the stratigraphy of the area and discuss the interesting “bench” formed by landslides throughout the Dry Cimarron. Continuing eastward, we will begin to see more outcrops of the Triassic Dockum Group peeking through the landslide cover. If you watch carefully, two features will begin to catch your eye – broad, gentle folds in the red beds and sandstone injectites jutting up off the valley floor. At our third stop, we will examine the (apparently) world famous angular unconformity at Steamboat Butte where the Jurassic Exeter Sandstone sits atop steeply dipping Upper Triassic strata. From there, we continue towards the New Mexico-Oklahoma state line where the Dry Cimarron valley broadens out. Our last stop of the day will be at one of these sandstone injec-tites that penetrates Dockum Group rocks and may be capped by Exeter Sandstone. From here, we will then swing south and begin to climb up onto the caprock before making our way back to Clayton via the ghost towns of Moses and Seneca.
The Day 2 road log follows Day 1’s path up until we enter the town of Des Moines, where we will take the cut-off to Folsom to begin our journey into the Dry Cimarron valley.
Note: Full-text Fall Field Conference road logs for recent guidebooks are only available in print.
- Zeigler, Kate E.; Zimmerer, Matthew J.; Ramos, Frank C., 2019, Road Log Day 2 Geology of the Dry Cimarron Valley: Second-day Road Log from Clayton to Folsom and through the Dry Cimarron Valley, in: Geology of the Raton-Clayton Area, Ramos, Frank; Zimmerer, Matthew J.; Zeigler, Kate; Ulmer-Scholle, Dana, New Mexico Geological Society, Guidebook, 70th Field Conference, pp. 21-34. https://doi.org/10.56577/FFC-70.21