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)
• 1.7 Billion Years Ago
• [Boulder Creek Batholith]
• [Idaho Springs Batholith]
• [Idaho Springs Batholith - Apex Trail]
• [Idaho Springs Batholith - Chimney Gulch]
• Pikes Peak Batholith
• Fountain Formation
• Lyons Sandstone
• 254-208 (250-210) Million Years Ago - Lykins Formation
• Lykins Formation
• Lykins Limestone
• Lykins Limestone
• 251 M.Y.A. - The end-Permian Extinction
• The end-Permian Extinction - 251 M.Y.A.