.TOURING
COLORADO GEOLOGY
Igneous
Dykes|
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.TOURING COLORADO GEOLOGY |
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Igneous
Dykes |
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| As you are driving up 285 west out of Denver up into the mountains headed for Conifer, Bailey, Fairplay or some other destination, you come around a bend in the road (one of quite a few I might add) and see this spectacular roadcut of dark-gray metamorphic schist with large pink igneous dykes. The photo collage above hardly does it justice. The pink granite dykes cut through the dark gray to black schist of the Pre-Cambrian Idaho Springs Formation. |
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 The
contact between the igneous and metamorphic rocks is quite sharp as you
can see in these photos. |
 The small square plates with the bolts through them are embedded in the rocks to help stabilize the cut to reduce the likely-hood of a landslide. One happened on the left side of this cut in 1998 which blocked 285 for several days. |
| Smaller dykes cut through this outcrop in addition to the very large one shown above. A nice one is shown to the right. In the top collage, it can just be seen at the extreme left. |
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Foliation in the dark gray schist is very striking.
Close-ups of the granite (left) and schist (right) from this outcrop are shown below. |
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May 13, 2001 |
