TY - JOUR
T1 - Digital processing of back-scatter electron imagery
T2 - a microscopic approach to quantifying chemical weathering
AU - Dorn, Ronald
PY - 1995/1/1
Y1 - 1995/1/1
N2 - This paper introduces digital processing of back-scattered electron (BSE) imagery as a microscopic approach to measure porosity from in situ dissolution of minerals. Four case studies exemplify this technique. In case one, alveoli start in the Sedona area of Arizona when sandstone porosity exceeds ~32%. Case two examines the maintenance of gnamma pits and polygonal cracks on a basalt boulder on the island of Maui, Hawaii. Cases three and four involve measuring rates of dissolution over thousands of years. Case three concerns rock dissolution in weathering rinds formed on ventifacted aplite boulders. Case four addresses the classic topic of which variable is most important in chemical weathering: temperature, precipitation, or microenvironment. Microenvironment is a more important control on plagioclase dissolution; organic-rich positions (under lichens) weather two to seven times faster than adjacent organic-poor positions away from epilithic organisms and rock coatings. Cases three and four illustrate that in situ measurements of rock and mineral porosity can yield data on mass weathered per unit area over time. This information is comparable to mass balance approaches in watershed- and soil-based weathering research. -from Author
AB - This paper introduces digital processing of back-scattered electron (BSE) imagery as a microscopic approach to measure porosity from in situ dissolution of minerals. Four case studies exemplify this technique. In case one, alveoli start in the Sedona area of Arizona when sandstone porosity exceeds ~32%. Case two examines the maintenance of gnamma pits and polygonal cracks on a basalt boulder on the island of Maui, Hawaii. Cases three and four involve measuring rates of dissolution over thousands of years. Case three concerns rock dissolution in weathering rinds formed on ventifacted aplite boulders. Case four addresses the classic topic of which variable is most important in chemical weathering: temperature, precipitation, or microenvironment. Microenvironment is a more important control on plagioclase dissolution; organic-rich positions (under lichens) weather two to seven times faster than adjacent organic-poor positions away from epilithic organisms and rock coatings. Cases three and four illustrate that in situ measurements of rock and mineral porosity can yield data on mass weathered per unit area over time. This information is comparable to mass balance approaches in watershed- and soil-based weathering research. -from Author
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U2 - 10.1130/0016-7606(1995)107<0725:DPOBSE>2.3.CO;2
DO - 10.1130/0016-7606(1995)107<0725:DPOBSE>2.3.CO;2
M3 - Article
AN - SCOPUS:84879882188
VL - 107
SP - 725
EP - 741
JO - Bulletin of the Geological Society of America
JF - Bulletin of the Geological Society of America
SN - 0016-7606
IS - 6
ER -