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Five deep crustal holes were drilled into the Mid‐Atlantic Ridge near 37°N by Glomar Challenger on Leg 37 of the Deep Sea Drilling Project. The drilling results and laboratory measurements of seismic velocity on samples from one hole of over 500 m into basement have shown that the low velocity upper crustal layer 2a consists of interlayered solid basalt and shattered and fractured volcanic material with extensive large scale porosity and voids and some intercalated sediments. Gabbros and serpentinites with velocity appropriate for the lower crust were recovered from another hole.

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Microfossils recovered from the Roseburg, Lookingglass, and Flournoy Formations (Umpqua Group) of southwest Oregon include 33 species and subspecies of planktonic foraminifers. Some of the faunas from these units include as many as 14 species per sample, and specimen preservation is moderate to good. The assemblages are similar to those from central and southern California but differ in that they are dominated by longranging, high-latitude species.The Roseburg and Lookingglass Formations were deposited during early Eocene time and are assigned on the basis of planktonic foraminifers to Zone P7-8 of the standard tropical zonation. The planktonic foraminiferal faunas of these units are indistinguishable. The Flournoy Formation is assigned to lower middle Eocene Zone P10. Planktonic foraminifers and calcareous nannofossils indicate that the unconformity between the Lookingglass and Flournoy Formations represents an interval of approximately 1 to 2 m.y.

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