| 41. | Many ancient rhyolitic quartz-porphyries show on their weathered surfaces numerous globular projections.
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| 42. | The Mugga Mugga Porphyry is a lava flow.
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| 43. | Parts of the feldspar porphyry are hydrothermally altered.
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| 44. | Porphyry was rare and reserved for imperial use.
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| 45. | The Lobster Creek Volcanics is actually an intrusion of plagioclase pyroxene hornblende porphyry from.
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| 46. | The contact relationships with the Johnson Granite Porphyry are on the other hand sharp.
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| 47. | All but one of the stones are Silurian rock; the other being Porphyry.
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| 48. | He later became president of the Porphyry Paving Company and had extensive land holdings.
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| 49. | Phyllic alteration typically forms in the base-metal zone of a porphyry system.
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| 50. | A lightly rusticated porphyry base supports painted brick walls with many square headed windows.
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