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nHenwent from Prussia to Russia as he studied rocks and minerals.
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nnBornnon this date in 1719, Lehmann was a German geologist. He studiednmining practices in the German states of Saxony and Prussia, and heneventually became a professor of chemistry in Russia, where he alsondirected the imperial museum.
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nnButnLehmann is best known as one of the founders of stratigraphy.
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nnManynrocks are formed in shallow seas and lakes, as sand and claynparticles, tiny rocks, bones and shells of dead creatures, and othernsediments sink to the bottom of still or slow-moving water. Over thenyears, these sediments are crushed together by the weight of newernparticles and, of course, the water itself—crushed together so hardnthat the sediments form a rock.
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nnExamplesnof such sedimentary rocks include:
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nsandstone,
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nnlimestone,nn
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nnandnconglomerate.
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nnLehmannnand other pioneers of stratigraphy were able to study and describenvarious layers of rock, which can give rock a striped look.nSedimentary rocks have since become very important in determiningntime scales and figuring out what was happening on the earth, bothnwith landforms and lifeforms, in the far, far past. n
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| Striped rocks=beautiful rocks. The Grand Canyon is made from eroded sedimentary rock. |
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nAlsonon this date:
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nCoast Guard Day in the USA
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nConstitution Day in Cook Islands
