Questions tagged [igneous]

concerning rocks and processes relating to the cooling and solidification of magma, typically involving temperatures above approximately 800 degrees Celsius for at least some of the rock's history

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Why do felsic materials have lower melting points than mafic?

It is clear from Bowen's reaction series that more felsic minerals have lower melting points than mafic minerals. As far as I know, the same is true of quenched glasses. Felsics have a higher degree ...
foobarbecue's user avatar
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16 votes
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What processes produced the basalt columns of the Giant's Causeway?

The Giant's Causeway is, according to the Wikipedia page was formed during during the Paleogene Period, Antrim was subject to intense volcanic activity, when highly fluid molten basalt intruded ...
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What, if any, paleoclimate data can be derived from igneous rocks?

Paleoclimate data often derives from sedimentary rocks. Metamorphic rocks can also contribute to paleoclimate information in a wide variety of ways. What about igneous rocks? I guess that this can ...
Gimelist's user avatar
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Basalt vs. columnar basalt

I recently visited a cliff on the south coast of Ulva in the Inner Hebrides where there are ~10m thick flows of columnar basalt. The columnar basalt forming most of the cliff is sandwiched between ...
bobg1756's user avatar
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5 votes
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Is it possible to estimate the size of a meteorite from its remains?

I live near this ophiolite (Sasso di San Zanobi, Firenzuola) and they used to say it is a meteorite. There is no evidence of a crater but let's pretend it is the remain of a meteorite: how big would ...
Alessandro Jacopson's user avatar
2 votes
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Are fossil fuels really formed from fossils?

Hydrocarbons have been found in great abundance elsewhere in the solar system where there is unlikely to be evidence for life past or present. No fossils involved. Petroleum and natural gas wells ...
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