
Research led by the University of Wyoming shows that physical weather is far more important than previously recognized in rock breaking in mountainous landscapes. Because it is difficult to measure, it is accepted that physical weathering is very low in previous studies.
Cliff Riebe, a professor in UW’s Department of Geology and Geophysics, led a research group that found that climate and erosion levels strongly regulate the importance of physical subsurface weather and chemical saprolite, the zone of weathered rock that maintains the relative mineral mineral conditions of the parent bedrock and lies between the soil level and harder rock beneath. Saprolite is very similar to the granite we wear found on the flat areas around Vedauwoo hard granite.
“Our work shows that body weight can no longer be ignored in studies of subsurface weather. It’s not just a chemical process. It’s also physical,” Riebe says. “What we have found is that anisovolumetric weather is much more common than previously thought, and that changes in this process can be explained by climate and erosion.”
Riebe is the lead author of a paper, titled “Anisovolumetric Weather in Granitic Saprolite Controlled by Climate Rates and Erosion Rates,” published in Jan. magazine. 12 de Geology. The journal publishes timely, innovative and inspiring articles relevant to its international audience, representing research from all areas of the geosciences.
The study looked at three sites – with different climates and elevations of granite rock – of the Sierra Nevada, a mountain range in California.
In lingo geochemists, it is assumed that the weather is “isovolumetric,” meaning without a change in volume caused by body weight.
“Our work shows, in contrast, that the weather is usually‘ anisovolumetric, ’meaning that pressure from physical weather is important,” Riebe says.
Riebe credits some of the tools and instruments purchased from the Wyoming Center WyCoR project for Environmental Hydrology and Geophysics (WyCEHG) (Established Program to Promote Competitive Research) that ended a few years on back as the reason his team was able to measure both physically and chemically. weather at several sites in California.
“The reason it was difficult to measure weather in the past is that you have to be able to get to the deep subtext and sample it without being disturbed,” Riebe explains. “You need a Geoprobe push coring system, which is basically a drilling rig set up on a track, to do this.
“It’s an expensive job, especially if you don’t happen to have Geoprobe and you have to hire someone to do the work,” he continues. “Fortunately, we have access to this equipment and the experience to run through Wyoming ‘s Near Surface Geophysics facility, which is possibly managed by Brad Carr, one of the study’ s co – authors. “
The research was funded by grants from the National Science Foundation (NSF), NASA and the Canadian Natural Sciences and Engineering Research Council.
Riebe says there is a direct link between the research in this paper and the $ 5.33 million NSF grant he received in September last year. The grant focuses on connections between rock, water and life at the Earth’s surface.
“This research is partly supported by that grant and helped to motivate it,” Riebe says.
Study examining how rock expands near the earth’s surface in Southern Sierra Nevada
Clifford S. Riebe et al, Anisovolumetric precipitation in granitic saprolite controlled by climatic and erosion levels Geology (2021) doi.org/10.1130/G48191.1
Presented by the University of Wyoming
Citation: A study found that physical weather of rock breaking is more important than previously recognized (2021, January 13) retrieved January 13, 2021 from https://phys.org/news/2021-01-physical-weathering-breakdown- important-previous.html
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