From Lane Co Oregon

1890

During the summer of 1890 Wm. H. Dall collected at several of these Miocene localities, and by the assistance of Prof. Condon has been able to note a wider distribution of the Eocene than has heretofore been recognized in this State.

Miocene rocks are well exposed at Smith's quarry, 1 mile east of Eugene City, and at Springfield bridge, 2 miles farther east. At the former locality the rocks consist of grayish hard sandstone weathering to a yellowish color, irregularly bedded above, but massive below, dipping about 6° southeast, with a total exposure of about 37 feet. The fossils—Mytilus, Modiola, Mactra, Solen, Natica, Neverita, Purpura, and Lirofusus—are crowded or crushed together along certain lines or layers, and are usually in form of molds recrystallized into spar. The second locality, or that near Springfield, affords an excellent exposure of nearly a mile in length, extending southward from the abutment of the new bridge. The rocks have an easterly dip of from 5° to 8° and form a total perpendicular exposure of about 160 feet; they are overlain unconformably by 5 or 10 feet of alluvial matter which lies on their eroded edges. In the hilly regions, according to the observations of Prof. Condon, they are capped with basalt.

Harris, Gilbert Dennison and William Healey Dall. Correlation Papers: Neocene. Washington: Government Printing Office, 1892. p. 227.