A Geological Tour of Denver, Golden, and Colorado's Front Range

Geologic Time Period

• Precambrian - 4.565 Billion Years Ago - 545 Million Years Ago (M.Y.A.) (4.6 Billion - 570)
• [Boulder Creek Batholith]
• [Idaho Springs Batholith]
• Pikes Peak Batholith
• Fountain Formation
• Lyons Sandstone
• Lykins Formation
• Inland Sea - Seashore
• Pierre Shale
• 75 -72 M.Y.A. - Beginnings of the Rocky Mountains
• Flatirons and Hogbacks
• Flatirons and Hogbacks
• Flatirons and Hogbacks
• 70-69 M.Y.A. - Fox Hills Formation - Retreating Sea
• Sandstone and Shale