Diorite (layered)
Intrusive igneous rock
This sample of diorite shows an unusual pattern of layering of crystals of different sizes that have settle out of a melt. the left side show larger, rounded (orbicular) crystal masses compared to the other layers. The pattern of layers suggests it preserves a cyclic history, perhaps warming and cooling cycles in a local melt area, such as within a stock of a volcano or active magma system. This is part of boulder found along the shoreline of San Luis Reservoir in central California. |
| https://gotbooks.miracosta.edu/rocks/igneous/40.html |
2/2/2021 |
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