| 31. | Most pegmatites are composed of quartz, feldspar and mica, having a similar silicic composition as granite.
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| 32. | The history of the Huaynaputina region is marked by silicic volcanism, where lava is rich in silica.
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| 33. | The silicic acid, when weathered, forms black streaks, which give the rock its characteristic appearance.
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| 34. | The rocks follow the calc-alkaline trend of magmatic differentiation, containing silicic lavas such as dacite.
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| 35. | This allows the formation of large magma chambers, in which the magma can evolve to more silicic compositions.
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| 36. | The magma then continues to migrate upwards causing differentiation and becomes even more sodic and silicic as it rises.
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| 37. | Socorro Island is unusual in that it is the only dominantly silicic peralkaline volcanic island in the Pacific Ocean.
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| 38. | Another positive attribute of porous silicon is the degradation of porous silicon into monomeric silicic acid ( SiOH4 ).
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| 39. | These blocks of sedimentary material are unique to the mountain, which otherwise is uniformly composed of silicic dacite.
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| 40. | Hager Mountain is a large silicic lava dome structure that was formed approximately 5.9 million years ago.
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