Denver Basin Geochronology
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The following table contains my interpretation of the age of events related to the development of the Denver Basin in Colorado, USA, and the adjacent mountains.
Ma Event (Ma = Million Years before present)
0 Post-Laramide uplift continues (Tectonic and rebound due to erosion. Uplift > 5000 feet)
0.0093 Sudden cooling
0.011 End Wisconsin glaciation (Bull Lake, Pinedale, and Holocene Terraces in Denver Area)
0.1 Begin Wisconsin glaciation
Slocum Alluvium deposited (Sangoman/Illinoian)
0.25 End Illinoisian
0.4 Begin Illinoisian
0.64 Verdos gravel deposited (Age based on volcanic ash bed)
0.75 End Kansan glaciation
0.9 Begin Kansan glaciation
1.65 End Nebraskan glaciation
1.8 Begin Nebraskan glaciation
5 End Post-Laramide magmatism (Left Eocene erosional surface buried under flow and ejecta)
5.3 Beginning of Pliocene
7 Alluvial fans began to form along mountain front
10 Rate of exhumation increases
23 Beginning of Miocene
28 Begin Post-Laramide uplift, extension, and rifting
33.5 End of Eocene
36 Begin Post-Laramide magmatism, faulting, northward tilting of Denver Basin
36.7 Deposition of Castle Rock Conglomerate
37 Wall Mountain Tuff deposited
Rocky Mountain erosion surface developed (Low relief surface extends east onto deposits)
40 End of Laramide deformation and beginning of Oligocene
52 Beginning of D2 deposition
54.8 Beginning of Eocene
64 End of D1 deposition
65.5 Beginning of Paleocene
72 Beginning of Laramide deformation
75 End of Laramie Formation deposition (Laramie deposited by retreating Cretaceous sea)
510 Begin advance of Cambrian sea from west.
1100 Begin Pre-Cambrian erosional period.
Related information is contained in the web page titled Palmer Lake Geology.