Basin and Ranges Pluvials

Pleistocene lakes of Southern Oregon

Distribution of Pleistocene lakes in the southern Oregon Basin and Range (Image ID# basin-and-ranges-pluvials2)

Cloudy Peaks

Clouds over St. Marys River.

Bright mountain peaks guard a quiet river. (Image ID# 140720-6)

Earthquake-damage. New Zealand

Earthquake-damage. New Zealand


Three Sisters Volcanoes, Oregon

volcanic, Cascades, arc, Cascade volcanoes

Marine Transgression diagram

Marine transgression

If you look at Time 1, you can see a coastline in cross-section, with sand being deposited closest to shore, mud a little farther out, and eventually carbonate material even farther out. As sea levels rise in Time 2, the sites of deposition for these materials migrates landward, putting mud deposition on top the earlier sand deposition and so on. In time 3, the sequence moves even farther landward, resulting in carbonate over mud over sand. If these materials become preserved and turned into rock, they form the sequence sandstone overlain by shale overlain by limestone – just what we see on top the Great Unconformity. (Image ID# transgression)

Marli Miller

Marli Miller

Geologic Times, Marli Miller. (Image ID# 101218-20lr)