Which do you think will weather at a faster rate, sandstone or granite? Why?

1 Answer
Jun 29, 2016

Sandstone will weather faster than granite.


We classify sandstone as sedimentary rock, this means that the rock is composed of sand-sized minerals or rocks that have been "smooshed" (that's a science term) together. These grains of rock are very loosely compacted in comparison to other rocks. Below is an image of red sandstone at Lower Antelope Canyon:

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Image Courtesy: Moondigger (Wikipedia user); Obtained from: https://en.wikipedia.org/wiki/Sandstone; Reused under: CC BY-SA 2.5

Granite, by contrast, is classified as igneous rock which is formed from the cooling and solidification of magma (from volcanoes). When the magma cools it crystallizes creating a densely packed, interwoven structure of rock. Here's a picture of a granite pinnacle formation in Chile's Torres del Paine National Park:

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Image Courtesy: Xlboy~commonswiki (Wikipedia user); Obtained from: https://en.wikipedia.org/wiki/Granite#Rock_climbing; Reused under:CC BY-SA 3.0

Granite is packed much more densely than sandstone therefore granite is less susceptible to the weather than sandstone.

I hope this helps!