First-day road log, from Gallup to Gamerco, Yah-Ta-Hey, Window Rock, Fort Defiance, Navajo, Todilto Park, Crystal, Narbona Pass, Sheep Springs, Tohatchi and Gallup
— Spencer G. Lucas, Steven C. Semken, Andrew B. Heckert, William R. Berglof, Gretchen Hoffman, Barry S. Kues, Larry S. Crumpler, and Jayne C. Aubele

The first day’s trip takes us around the southern flank of the Defiance uplift, back over it into the southwestern San Juan Basin and ends at the Hogback monocline at Gallup. The trip emphasizes Mesozoic— especially Jurassic—stratigraphy and sedimentation in the Defiance uplift region. We also closely examine Cenozoic volcanism of the Navajo volcanic field.

Stop 1 at Window Rock discusses the Laramide Defiance uplift and introduces Jurassic eolianites near the preserved southern edge of the Middle-Upper Jurassic depositional basin. At Todilto Park, Stop 2, we examine the type area of the Jurassic Todilto Formation and discuss Todilto deposition and economic geology, a recurrent theme of this field conference.

From Todilto Park we move on to the Green Knobs diatreme adjacent to the highway for Stop 3, and then to Stop 4 at the Narbona Pass maar at the crest of the Chuska Mountains. The focus at Stops 3 and 4 is the Cenozoic igneous history of the Navajo volcanic field. The trip then returns to Gallup to end at Stop 5 on the Hogback east of town. Here, we discuss Cretaceous stratigraphy and coal geology.