Annual report of the United States Geological Survey to the Secretary of the Interior . 45. 40 0. 576 1. 269 Specimen 1165 was taken from a pile of 150 tons of ore from thestock house at the furnace. Specimen 1107 was selected drippings ofthe crystallized ore. The underlying lava, on whose irregular surface the ore was depos-ited, is dark-gray basalt, and usually very vesicular, showing that atthe time of its extrusion it flowed out upon the surface. It is consid-erably decomposed in places, and by the process of decomposition oxideof iron is liberated. This f
Annual report of the United States Geological Survey to the Secretary of the Interior . 45. 40 0. 576 1. 269 Specimen 1165 was taken from a pile of 150 tons of ore from thestock house at the furnace. Specimen 1107 was selected drippings ofthe crystallized ore. The underlying lava, on whose irregular surface the ore was depos-ited, is dark-gray basalt, and usually very vesicular, showing that atthe time of its extrusion it flowed out upon the surface. It is consid-erably decomposed in places, and by the process of decomposition oxideof iron is liberated. This fact points to the adjacent lava slopes thatsurrounded the small lake or swamp in which the ore was deposited asthe original source of the iron. By surface streams or chalybeatesprings the iron was brought to the lake or swamp, where, under theinfluence of organic, chemical, or mechanical agents, it was precipitatedand accumulated to form the bed of ore. At some points in the upper part of the ore bed logs are found,but they are most abundant in the sand rock in places immediately. 510 GEOLOGY OF NORTHWESTERN OREGON. [DILLKK. overlying the ore. Mr. Pomeroy collected some fossil leaves for writes: So far fossils have been found only in the roof, none occurring in the bottom ofthe bed. At this western part of the bed there is 8 to 14 inches of loose sand rockbetween the ore body and the hanging. This is found at the outcrop and continuesfor several hundred feet. The fossils are mostly in this sand rock, which La Boftand easily friable, and presents more or less cleavage, some few isolated piecesof wood being found in the ore body itself, but always more or less completelysilicilied, and near the top. The trees in place have their roots in the sand rock,which is in some places 2 and 3 feet thick. The fallen trees, those in horizontalposition, are found with a part of the trunk in the ore and sand rock and part in thehanging. Some of these trees are almost perfect, showing bar
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