Structure
Geological types can find almost any kind of rock you can think of in and around Rocky Mountain National Park. High elevations at Longs Peak and along the Continental Divide are made up mostly of metamorphic gneiss and schist. Go west to the Neversummer Mountains along the park's western edge and you find a lot of sedimentary siltstones and shales. Volcanic lava and ash lline certain portions of Trail Ridge Road and pop up here and there in the Neversummers. And here on the east side around Estes Park, you have the granite blobs of the Lumpy Range.
This granite formed about 1.4 billion years ago, when older (probably sedimentary, according to the internet) rock melted deep beneath the Earth's surface, then intruded upward. Imagine a blob of molten rock that looked sort of like the gunk inside a lava lamp. Over time, the buried rock crystalized, and the ground above it slowly weathered away at the same time uplift associated with the formation of the Rockies pushed the blobs upward. Now, the granite blobs poke above ground at Estes Park.
You'll noticed the rock is broken and full of cracks. Structural geologists probably had a lot of fun here at some point, measuring the size and angles of these cracks (or joints, as they're called). As the weight that originally had pushed down on the rock was removed, the rock expanded and cracked. Structural geologists can use the number, size, and angle of the resulting cracks to determine just how much stress the rocks had been under and which direction this stress was pushing. This in turn will tell them how deeply the rocks were buried and how they might have moved.
Structure
Geological types can find almost any kind of rock you can think of in and around Rocky Mountain National Park. High elevations at Longs Peak and along the Continental Divide are made up mostly of metamorphic gneiss and schist. Go west to the Neversummer Mountains along the park's western edge and you find a lot of sedimentary siltstones and shales. Volcanic lava and ash lline certain portions of Trail Ridge Road and pop up here and there in the Neversummers. And here on the east side around Estes Park, you have the granite blobs of the Lumpy Range.
This granite formed about 1.4 billion years ago, when older (probably sedimentary, according to the internet) rock melted deep beneath the Earth's surface, then intruded upward. Imagine a blob of molten rock that looked sort of like the gunk inside a lava lamp. Over time, the buried rock crystalized, and the ground above it slowly weathered away at the same time uplift associated with the formation of the Rockies pushed the blobs upward. Now, the granite blobs poke above ground at Estes Park.
You'll noticed the rock is broken and full of cracks. Structural geologists probably had a lot of fun here at some point, measuring the size and angles of these cracks (or joints, as they're called). As the weight that originally had pushed down on the rock was removed, the rock expanded and cracked. Structural geologists can use the number, size, and angle of the resulting cracks to determine just how much stress the rocks had been under and which direction this stress was pushing. This in turn will tell them how deeply the rocks were buried and how they might have moved.