Sand. Sand is all around, but we love it most when it’s fine and white. It looks almost like flour. This is due to its texture and color. Also, because it appears uniform, it’s almost as if it were one substance. It is not.
It is misleading to call it that, since it only refers to the form in which rocks, minerals, and organic materials take: small, loose grains ranging from 1/16th to 2 millimeters in size. Silt is made up of granules that are smaller than this size, and gravel is made up of larger ones. Sand can be found in deserts as well as riverbeds and oceans. Its main component is silicon dioxide, which can be found in the form quartz. This is because silicon and oxygen are the most prevalent elements in the earth’s crust. Quartz is also the most important mineral on the earth’s surface. Sand, feldspars are a group of aluminosilicates that contain potassium, sodium, and calcium.
There are many more elements. Sand can include skeletal remains from various organisms. These include complete shells of some small molluscs and fragments of granitic, oceanic volcanic, sedimentary and clastic rock fragments (agglomerations or clasts containing other rocks and minerals), chunks coral and many more.
Sand can be found in many different places and environments. Sand is formed by the disintegration of rocks due to weathering over thousands or even millions of years. Every grain of sand is a traveler. It has traveled thousands upon thousands of kilometers from the time it was separated from its parent rock during the time of dinosaurs. From the moment it reached us, it traveled in rivers and began to disintegrate due to weather and water. Wind, waves, tides and the actions of animals or plants.
Quartz that makes up most of the sand is white, yellowish, or reddish depending on the amount of iron oxide it contains. Feldspars are typically shades of pink or brown, but there are also gray, white and blue. Black sand is made from volcanic rocks like lava and basalt that have been eroded. It can be found near active volcanoes, such as Hawaii, the Aleutian Islands and Canary Islands.
There are beaches that are pinker than others, like Bermuda’s. This is because of the shells unicellular organisms called Foraminifera. The white beaches of Hawaii are almost entirely made up of quartz. They are formed by the depositions parrot fish. These fish bite the rocks and corals and take their nutrients. They also excrete the calcium carbonate which forms the skeleton for the corals.
A handful of sand can be put under the microscope. This is an amazing adventure that everyone should have, no matter their age. You can see the diversity of colors and sizes, as well as the uniqueness of each grain, which gives you a glimpse into the vast biological, chemical, and geological history of our planet.
Specialists, known as arenologists (a division of Geology), use clues such as the size, shape, and composition of the sand grains to determine the environmental conditions of each sample. In general, acting as forensic scientist who can read every tiny piece of information.
Curtin School of Earth and Planetary Sciences are able to determine the age distribution footprint of mineral zirconia from a sand sample. This allows for a better understanding of our planet’s surface evolution. Planet over billions and years. They explain that the chemical elements in zirconia grains enable arenologists to reconstruct the conditions for the formation of this mineral in a similar manner to how demographers monitor the evolution of nations. This technique allows you to determine the age of the zirconia grain samples, as each one is different in composition and was created at different geological times. According to Dr. Chris Kirkland of the group that developed this system, it is easy to identify the sediments on the eastern and western coasts of South America. The sediments on the western coast were formed from the earth’s crust, which subducted beneath the continent. This caused earthquakes and volcanoes to occur in the Andes. On the Atlantic coast, however, “everything seems relatively calm from a geological perspective and there are a mixture of old and new grains, sourced from a wide variety of rocks in Amazon Basin.”
The physics aspect of sand is not only important for its chemical properties, but also for the study of its physical characteristics. The first is the shape. A grain of sand that has a more rounded appearance indicates that it has been exposed to greater erosion. This tells us not only its antiquity, but also the forces it has been exposed to and how far it has traveled from the point it separated from the bedrock. A smaller size allows for greater mobility, while a larger arena keeps it closer to its source, statistically.
Physics studies the movement and replenishment of sand to forecast the future. The movement of dunes in deserts is also important, as it can cause damage to the land’s ability to be used for agriculture, human habitation, transportation, and roads. Satellite images are used to track and predict the movements of the dunes to take preventive actions.
There are many types of sand that make up the concrete used in modern times. It is used as a raw material in almost all industrially produced glass, as well as for the production of asphalt, paper and toothpaste. About 50,000 million tonnes of sand is used annually in the industry.
These scientific perspectives give us a fresh perspective on how we use sand. It is a great exercise in geology and the deepest histories of the planet.
