We just started a Planet Earth unit in science and I am on the Types of Rocks unit. I got a worksheet after the first day and I know the answers to all the question except for this one because I couldn't find anything in my textbook;
Pumice is formed by gasses trapped inside of lava and has a light density, letting it float in water. Although, Scoria, which is formed by basaltic lava, is similar to Pumice in texture but does not float in water. Why do you think this happens? Give a possible explanation.
Pumice is formed by gasses trapped inside of lava and has a light density, letting it float in water. Although, Scoria, which is formed by basaltic lava, is similar to Pumice in texture but does not float in water. Why do you think this happens? Give a possible explanation.
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In pumice, a greater proportion of the rock consists of gas bubbles than scoria. Also the minerals that makes up scoria is much denser than those that make up pumice
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"but in contrast to pumice, all scoria has a specific gravity greater than 1, and sinks in water " http://en.wikipedia.org/wiki/Scoria
fewer bubbles, thicker walls from higher viscosity (thicker) lava
fewer bubbles, thicker walls from higher viscosity (thicker) lava