San Luis Valley


(Tandon et al. 1999 fig. 4)

There are no exposures of Laramide aged rocks in the San Luis Valley, seismic profiles across the valley show an angular uncomformity between Paleocene and older sediments (shaded light brown) and Oligocene volcanic clasts associated with the San Juan volcanic field (shaded red) to the west. The profile also demonstrates that during the Laramide Orogeny the San Luis Valley was a fraction of its current size (Brister & Gries, 1996; Tandon et al. 1999).

Brister, B. S., & Gries, R. R. (1996). Tertiary stratigraphy and tectonic development of the alamosa basin (northern san luis basin), rio grande rift, south-central colorado. In History, geology, hydrogeology, summitville mine and downstream effects, and other nearby mines of the san luis valley, colorado (12 Stratigraphy; 16 Structural geology No. 96-4) Colorado Geological Survey Open-File Report, Report: 96-4.
Tandon, K., Brown, L. and Hearn, T. (1999) Deep structure of the northern Rio Grande rift beneath the San Luis basin (Colorado) from a seismic reflection survey: implications for rift evolution, Tectonophysics, Volume 302, Issues 1-2, 15 Pages 41-56.