 Metaconglomerate
This cobble is from river terrace gravel along the San Juan River, downstream of the San Juan Mountains of southwestern Colorado where metaconglomerate of Precambrian age occurs in abundance. The difference between metaconglomerate and conglomerate is that the rock will split through clasts, rather than around them. Also, the clasts may display some stretching or flattening due to compressive shearing. The matrix holding grains together are recrystallized from their original matrix minerals. |
| https://gotbooks.miracosta.edu/rocks/metamorphic/14.html |
2/2/2021 |
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