Skip to Main Content
Skip Nav Destination
GEOREF RECORD

Crystal growth mechanisms of quartz overgrowths in a Cambrian quartz arenite

Astrid Makowitz and Duncan Sibley
Crystal growth mechanisms of quartz overgrowths in a Cambrian quartz arenite
Journal of Sedimentary Research (September 2001) 71 (5): 809-816

Abstract

Mechanisms of crystal growth during quartz cementation can be investigated by determining the relationship between growth increments and crystal radii. Crystal growth in theoretically described as (1) dr/dt = k for polynuclear growth and spiral growth, where dr/dt is the rate, r is the radius of crystal, and k is some constant, (2) dr/dt = kr (super 2) for mononuclear growth, and (3) dr/dt = k/r for diffusion-limited growth. Empirical results in this study, where r = detrital grain radius and dr/dt = quartz overgrowth thickness, define another crystal growth mechanism, size-dependent growth described by the rate equation dr/dt = kr. Grain radii and quartz overgrowth thicknesses were measured in 16 thin sections of quartz arenite from the Galesville Sandstone (Cambrian, Wisconsin, U.S.A.) and plotted to determine correlation coefficients between radius and rate. Correlation coefficients ranged from 0.145 to 0.855. Ten of 16 samples show statistically significant correlations between detrital grain radii and overgrowth thickness representing dr/dt = kr. Standard deviation (sorting) of detrital grain size correlate with the correlation coefficient between radius and rate. Samples indicating no correlation may in fact grow by dr/dt = kr, but for smaller grain size ranges the overgrowth thicknesses cannot be measured precisely enough to detect small variations. Size-dependent growth (dr/dt = kr) is a new type of mineral-water interaction that has also been observed in ancient dolomites as well as metamorphic garnets and other various minerals grown in the laboratory and now in quartz-cemented sandstone. This indicates that crystal growth theory may not include some significant growth mechanisms.


ISSN: 1527-1404
EISSN: 1938-3681
Serial Title: Journal of Sedimentary Research
Serial Volume: 71
Serial Issue: 5
Title: Crystal growth mechanisms of quartz overgrowths in a Cambrian quartz arenite
Affiliation: University of Texas at Austin, Department of Geological Sciences, Austin, TX, United States
Pages: 809-816
Published: 200109
Text Language: English
Publisher: Society of Economic Paleontologists and Mineralogists, Tulsa, OK, United States
References: 26
Accession Number: 2002-000702
Categories: Sedimentary petrology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 1 table, sketch map
N43°10'00" - N43°37'60", W90°19'00" - W89°37'00"
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2018, American Geosciences Institute.
Update Code: 200201
Close Modal

or Create an Account

Close Modal
Close Modal