, Points Earned:, 1/1 Your Response:, B 5., You place a granite monument in the cemetery to honor one of your ancestors. If your great-great-great-great-…- great grandchildren were to come back and look at the base of the monument, where is is buried in the soil, they likely would find: , A., Clays and rust were produced by weathering, and hung around to contribute to the soil, while soluble ions dissolved and were washed away toward the ocean. B., The quartz all washed away to the ocean, while the feldspar and dark-mineral grains hung around to make soil. C., No changes whatsoever. D., Clays were produced by weathering, dissolved, and washed away with the water in the rain. E., Soluble ions were produced by weathering, and hung around to help make soil, while clays and rust produced by weathering all washed away rapidly to the ocean. Weathering of granite in Pennsylvania makes some things (clay, rust, and quartz sand) that stay behind to contribute to soil, and other things (soluble ions) that dissolve and wash away very quickly. , Points Earned:, 1/1 Your Response:, A 6., During weathering, iron in minerals typically:, A., Dissolves and washes away to the ocean, to be used in shells. B., Washes away as chunks, which react with hot sea-floor rocks at spreading ridges to change the composition of the mantle.C., Dissolves and washes away to the ocean, to react with sea-floor rocks at spreading ridges.D., Rusts, becoming part of the soil, later to be transported as solid particles to contribute to sediment in the ocean.E., Is unchanged; the iron-rich minerals break out of the rocks and then form sand particles in the soil. Iron does rust. If no oxygen were present, then the iron would dissolve and wash away; and indeed, the presence of very old iron ores that formed in oceans suggests that the early Earth lacked free oxygen in the atmosphere but had oxygen-producing bacteria in the ocean, so the iron washed into the ocean, met the iron there, rusted and fell to the bottom. But with our modern, oxygenated atmosphere, iron rusts, contributes to soil, and later is transported to oceans to make sediment there. , Points Earned:, 1/1 Your Response:, D 7., Clay consists of new minerals commonly formed by: , A., Chemical weathering of quartz (quartz is pure silica) B., Evaporation of water leaving the salts it was carrying C., Combination of iron with water and oxygen D., Chemical weathering of feldspar (feldspar contains silica, aluminum, potassium and other things) E., None of the previous choices are accurate
When weathering attacks feldspar, some things are washed away, water is added, there is a little rearrangement of the chemicals, and clay results. Quartz, which is pure silica, mostly just sits around not doing much. Weathering usually dissolves a little bit of quartz, but this leaves a smaller piece of quartz and doesn’t make anything new. Hence, when weathering attacks granite, the quartz pieces in the granite become quartz sand in the soil that is formed.
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