thumbnail

The tufas of Pyramid Lake, Nevada

Circular 1267

By:

Links

Abstract

Pyramid Lake is the site of some of the Earth's most spectacular tufa deposits. The Tufas are composed of calcium carbonate (CaCO3). The large tufa mounds, reef- and sheet-like tufas formed within Pyramid Lake, between 26,000 and 13,000 years (yr) ago, when the lake was part of pluvial Lake Lahontan. The mounds are composed of large interlocking spheres that contain multiple generations of a crystalline (thinolite) variety of tufa. Over time many of the mounds have fallen apart, exposing an internal network of tubes. The tubular structures are thought to have been created when springs discharged from the bottom of Pyramid Lake, supplying calcium that combined with carbonate dissolved in lake water to form the mounds. The reef- and sheet-like deposits contain pillow and pendant forms made up of a branching variety of tufa that often grades into dense layers or nodules. Dense layers of tufa also coat cobbles and boulders that were deposited in near-shore shallow-water areas. The thickest tufa deposits formed at lake-bottom sites of ground-water discharge and at overflow elevations1 where the lake was held at near-constant levels for long periods of time.

Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
The tufas of Pyramid Lake, Nevada
Series title:
Circular
Series number:
1267
ISBN:
0607975555
Edition:
-
Year Published:
2004
Language:
ENGLISH
Description:
iv, 14 p. : col. ill., col. maps ; 28 cm.