Monthly Archives: September 2013

Classification of Sedimentary Rocks

Sedimentary rocks are classified by their genesis: how they formed. All sedimentary rocks are made from the components of other, pre-existing rocks, that have been broken down, transported, and reassembled into new rocks. The classification of the rock gives information … Continue reading

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Quartz Arenites

Detail the general characteristics of quartz arenites and describe an environment where you might expect them to be particularly common. Arenites contain less than 15% matrix (<15% material that is <30µm). Quartz arenite is a quartz sandstone (>95% quartz) held … Continue reading

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Evaporites

If you evaporate a 1000m column of sea water only 1.5m of evaporites are produced. Given this, how would you account for the 2km thickness of Permian Zechstein deposits? In your answer make reference to the sequence of minerals you … Continue reading

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Oxygen Isotopes

How are oxygen isotopes used in the correlation of Quaternary sediments? Chemostratigraphy is using stable isotopes in determining stratigraphic ages. Isotopes are variations in the number of neutrons of a particular element. Some isotopes, like oxygen ¹⁶O and ¹⁸O, have … Continue reading

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Accretionary Wedge: Guidebooks Galore!

For the August 2013 Accretionary Wedge #59, I asked anyone who reads geology guides, goes on geotourism adventures, or collects fieldtrips to review their books for the good, the bad, and the downright handy. Hollis Marriott of In the Company … Continue reading

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