The White House is the official residence and workplace of the United States of America**. Why do you think the White House is white?If you answer: "Because it is made of white rock", then you can only say partially. Construction of the White House began in 1792. Its façade is made of sedimentary sandstone. This sandstone has a lot of pores and is easily infiltrated by rainwater. Flooding was common in the early stages of building construction. To stop the destruction of the water, workers covered the sandstone with a mixture of salt, rice, and glue, which gave the White House a distinctive white color.
One person, one sentence trivia Lithification – sediment to sedimentary rock during the burial and compaction process, the sediment will undergo a certain degree of cementation. Cementation refers to the growth of new minerals between sediment particles. These new minerals bind the sediment particles together. One form of cementation is the growth of quartz edges on the surface of pre-existing quartz grains in the sediment.
The growth of this new mineral is the result of the dissolution of water in the pore space and the precipitation of quartz. The second common cemented mineral is hematite, a red or rust-colored iron oxide mineral that precipitates onto sediment particles through a combination of dissolved iron and oxygen in water in the pores. The third common cemented mineral is calcite, which is also precipitated from ions in water dissolved in pores during lithification.
While there are other cemented minerals, quartz, hematite, and calcite are common cemented minerals that grow between or on the surface of primitive sedimentary grains. Some chemically sedimentary rocks become rocks once the sediments are deposited by crystallization of substances dissolved in water on the earth's surface. Examples include rock salt and other evaporite deposits. Sediments of these salt crystals and other minerals form sedimentary rocks without being buried and compacted. When the sediment is buried, the weight of the overlying material exerts pressure, causing the sediment to compaction. This pressure, known as rock static pressure, "squeezes" the rock. Sediments from all sides become smaller volumes. Rock static pressure compacts the sediment particles more tightly and reduces porosity (the space between sediment particles).
The burial phase of lithification involves the deposition of more sedimentary layers on top of the earlier sedimentary layers. In sedimentary basins where sediments are deposited, the basin usually undergoes subsidence (lowering), either because the crust and lithosphere below it sink into the mantle to some extent, or because the surrounding highlands are experiencing uplift relative to the basin, or both. This makes it possible to bury thousands of feet, and in some cases tens of thousands of feet.
Clastic sedimentary rocks are the result of weathering and erosion of source rocks, turning them into fragments of rocks and minerals (detritals). Once they are reduced to fragments, these debris are free to leave their source rock, and they usually do. They are usually transported by water currents and deposited as layers of sediment.