The best way to study geology is to explore the earth, and climb around on its landforms. For a lesson in volcanology, we visited Panum Crater, a textbook example of a complete plug dome volcano, located near the south shore of Mono Lake. The volcano erupted in the 14th century, and consists of a central lava dome surrounded by an intact ring of ejecta. To encouter the geology, we followed two accessible and easy trails, one circumnavigating the rim of the volcano, and the other traversing the crater and plug dome.
The undulating, two-mile Rim Trail completely encircles the volcano, follows the crown of the ejecta ring, and includes a magnificent panoramic view of Mono Lake. Since the trail surface consists of loose sand- and gravel-sized rock blown out of the volcanic crater, the footing is soft and sluggish, like along the crest of a sand dune.The high point of the Rim Trail is at the north end, where a 180-degree vista of Mono Lake unfolds.
The shorter Plug Trail ascends the lava dome in the center of the volcano. The lava dome consists of huge mounds of black volcanic glass (obsidian) and airy beige pumice. Much of the obsidian and pumice are banded together as the frothy pumice floated atop the rapidly cooling lava, like the foam on a pint of Guiness stout.
Thirsty for knowledge, we found Panum Crater an enlightening chapter in the textbook of geologic wonders of eastern California. In my book, it gets 4 stars for its out-of-this-world scenery, birds-eye view, stimulating trails, and textbook geology. read more