74 Llao Rock Flow

The Geology and Petrography of Crater Lake National Park, 1902

 PART II.

HYPERSTHENE-DACITES.

DISTRIBUTION AND DESCRIPTION OF DACITE MASSES.

LLAO ROCK FLOW.

As far as may be judged from the few specimens collected from this most conspicuous of the Crater Lake dacite flows, the Llao Rock mass shows three quite distinct varieties of dacite—namely, vitrophyric, lithoidal, and spherulitic dacite.

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