In-situ growth of calcite at Devils Hole, Nevada--Comparison of field and laboratory rates to a 500,000 year record of near-equilibrium calcite growth

Aquatic Geochemistry
By: , and 

Links

Abstract

Calcite grew continuously for 500,000 years on the submerged walls of an open fault plane (Devils Hole) in southern Nevada, U.S.A. at rates of 0.3 to 1.3 mm/ka, but ceased growing approximately 60,000 years ago, even though the fault plane remained open and was continuously submerged. The maximum initial in-situ growth rate on pre-weighed crystals of Iceland spar placed in Devils Hole (calcite saturation index, SI, is 0.16 to 0.21 at 33.7 °C) for growth periods of 0.75 to 4.5 years was 0.22 mm/ka. Calcite growth on seed crystals slowed or ceased following initial contact with Devils Hole groundwater. Growth rates measured in synthetic Ca-HCO3 solutions at 34 °C, CO2 partial pressures of 0.101, 0.0156 (similar to Devils Hole groundwater) and 0.00102 atm, and SI values of 0.2 to 1.9 were nearly independent of PCO2, decreased with decreasing saturation state, and extrapolated through the historical Devils Hole rate. The results show that calcite growth rate is highly sensitive to saturation state near equilibrium. A calcite crystal retrieved from Devils Hole, and used without further treatment of its surface, grew in synthetic Devils Hole groundwater when the saturation index was raised nearly 10-fold that of Devils Hole water, but the rate was only 1/4 that of fresh laboratory crystals that had not contacted Devils Hole water. Apparently, inhibiting processes that halted calcite growth in Devils Hole 60,000 years ago continue today.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title In-situ growth of calcite at Devils Hole, Nevada--Comparison of field and laboratory rates to a 500,000 year record of near-equilibrium calcite growth
Series title Aquatic Geochemistry
DOI 10.1023/A:1009627710476
Volume 6
Issue 2
Year Published 2000
Language English
Publisher Kluwer Academic Publishers
Contributing office(s) Toxic Substances Hydrology Program
Description 18 p.
First page 257
Last page 274
Google Analytic Metrics Metrics page
Additional metadata about this publication, not found in other parts of the page is in this table