Sand . . . sand is on Earth, with few exceptions, almost everywhere - it can be found in deserts, on beaches, at the bottom of seas, lakes, rivers, in the soil. Scientists estimate that there are 100000000000000000000 [one hundred thousand quadrillion] grains of sand on the globe. We often complain that the wind pours sand in our eyes, sand grinds in our teeth, oppresses in the shoe . . . And yet life on our planet without sand would be practically impossible. And yet without sand our general way of life would be impossible. Sand is necessary for the production of glass, plastic and electronics. Sand is the main component of concrete and beton. Sand is used in all areas of our lives. After water and air, sand is the third most used resource by poeple.. Every year, 40 billion tons are used in the world, or about 15 billion cubic meters.
Where does the sand come from?
Sand forms as a result of complex and lengthy processes. Sand can be found in many locations, it comes from many sources and environments. Sand forms when rocks break down from weathering and eroding over thousands and even millions of years. The type of rock the sediment originated from and the intensity of the environment give different compositions of sand. The most common rock to form sand is granite. Rocks erode or weathere for a long time. They crack and break down into smaller and smaller fragments.
The main factors causing the erosion [destruction] of rocks are:
- wind; it lifts small grains and hits them against rocks that are subject to abrasion. This natural form of sandblasting makes layers of rocks up to several hundred meters thick weathered away
- water; erosion occurs, for example, as a result of the destructive activity of the waves in the ocean. Waves are constantly crashing against coastal cliffs, loosening and tearing off rock debris that fall into the foamy water. This, in turn, grinds their sharp edges, as a result of which pebbles are formed. In the seething, the pebbles are gradually crushed and rubbed into small pebbles, and then into even smaller particles-sand.
- temperature; in the rock crevices, water freezes, ice wedges crush the rocks. These divisions continue continuously: large blocks of rock break down into smaller and smaller pieces, from which sand is eventually formed.
Often rocks flow down rivers and streams, constantly disintegrating. When they reach the ocean, they continue to erode under the influence of the constant action of waves and tides, until they become fine grains. These grains, depending on their diameter, are eligible for silts, sands and gravels. The exact definition of sand varies. The scientific Unified Soil Classification System used in engineering and geology corresponds to US Standard Sieves, and defines sand as particles with a diameter of between 0.074 and 4.75 millimeters. If the average particle size is smaller, it is considered to be silt or clay, and if the average particle size is larger, it is garden variety gravel.
The process of erosion, depending on the rock, can last from hundreds of years up to hundreds of millions of years.
Sand can accumulate in aquatic and terrestrial environments. Sand forms a variety of accumulation forms; deserts, beaches, patches, dunes, Along with other components it forms soils.
By going through several successive cycles of transport and deposition [sedimentation], sand grains acquire specific characteristics, such as a specific shape and size, degree of rolling and smoothing of the surface, given to them by individual environments.
In terms of mineral composition, sands are distinguished:
- quartz; the main ingredient is quartz.
- limestone or carbonate; the main component is calcite, less often aragonite
- polymineral; a mixture of different minerals, for example, the products of weathering different rocks
- volcanic (main component: volcanic ash and ash, enamel crumbs
The most widespread, due to the relatively high chemical and mechanical resistance, are quartz sands.
In the sands there may be various admixtures; for example, miki (syndics), chlorites, glauconite, carbon, humic substances, etc.
And it is the admixtures that can cause surprising colors of sand: red [admixture of iron oxides], green [admixture of olivine], pink [admixture of organisms from coral reefs]. You can also find white sand formed from the fragmentation of marine limestone rocks, as well as black sand formed from igneous rocks formed from volcanic lava. The most popular colors are any shades of beige, yellow, golden, gray.
A variety of sand admixtures can cause sand to acquire interesting properties. For example, the presence of magnetite causes sand to have little magnetic properties. The content of clay particles makes the sand stick to the body.
To claim this EarthCache you will need to find answers to these tasks and either email or message me via my profile. You may log at time of visit.
TASK 1
Look around you. Describe the color of the sand and write whether it is homogeneous [the same everywhere], or is it possible to distinguish places with different shades of color ? [Remember that dry sand and wet sand have different shades].
TASK 2
Put the dry part of the body [foot, hand] to the sand. Does the sand stick to the skin, or does it fall off, does it fall off? Why?
Grains of sand can be transparent or not, they can be coated or with sharp edges. Sand can be loose or clayey, thick or dusty, soft or rough, dull or glossy, loose or sticky.
TASK 3
Using the terms above, using a magnifying glass or magnifying glass, describe what sand is under your feet. [If you don't have a magnifying glass with you, take a small sample of sand home.]
TASK 4
Write your login in the sand, take a photo and attach when logging in EC. Other photos also welcome. But please do not take any of the sand.
Developed on the basis of:
- own observations and knowledge
- https://oceanservice.noaa.gov/facts/sand.html
- www.wol.jw.org/pl - www.rp.pl
- www.polityka.pl/tygodnikpolityka
- www.kruszywa-warszawa.pl
- wikipedia
- https://podroze.onet.pl/plaze/
- www.nadbaltykiem.pl
- www.focus.pl
- karnet.up.wroc.pl
- internet
