How to use this Page

FreshPlans checked out Strataca, a museum at a working salt mine in Hutchinson, Kansas. We had the opportunity to go 650 feet down below the surface and see part of the mine. We learned a lot about salt!

There are still salt miners working in Hutchison, mining salt used on icy roads. This part of the mining industry, the nonmetallic mineral mining and quarrying industry, is not expected to grow in the future, but it’s essential work right now and an important part of the history of Hutchinson.

In fact, it’s an important part of the history of the Midwest, way back when it was under water. If your school is located in the middle of North America, chances are good that the land where it sits was once under the Permian Sea.

Is your school’s location on this map? Does it look as though the land where your school sits used to be under the sea?

If so, you might have salt somewhere in your neighborhood, too.

The salt mine in Hutchinson, Kansas, is part of the Permian Wellington Formation, formed about 275 million years ago when the Permian Sea dried up. At 27,000 square miles, this is one of the world’s largest salt deposits.

The deposit was discovered in 1887 by a prospector who was looking for oil. He didn’t find oil, but he did find salt. By 1923, the salt mine we visited was producing salt commercially. It still turns out about 500,000 tons of rock salt each year.

It’s called “rock salt” because the salt is in rocks.

This giant piece of salt is fun to touch. The walls and ceilings in the salt mine are also made of salt. We got to ride in a little train through a part of the salt mine that is no longer in use. There we had a chance to see the places where the miners worked, the miners’ bathroom, and even a part of the mine where layers of salt had fallen from the ceiling to the floor. It was interesting to think about what it might have been like to work in a salt mine.

The Kansas Salt Museum at Strataca has some great resources for educators.

Here are some more online resources for a study of salt in the context of basic chemistry:

• A lesson on dissolving salt in water from PBS provides hands-on experience with ideas about solvents, solutes, and solutions, with study materials for high school students.
• Study Ladder has a whiteboard presentation on the subject of salt production.
• ScienceNetLinks has a lesson that uses salt to work with magnification. If you’ve got magnifying glasses and microscopes on hand, this lesson gives you a simple way to put them to work.
• The University of Colorado offers a Java simulation with lots of resources on salt and sugar solutions.

If you have a chance to visit Strataca, you should. If not, think about our field trip and spend a little time exploring salt in your classroom. Lunch will never be the same!

The post FreshPlans Visits a Salt Mine appeared first on FreshPlans.

The study of minerals is the most fundamental aspect of the Earth and environmental sciences. Minerals existed long before any forms of life. They have played an important role in the origin and evolution of life and interact with biological systems in ways we are only now beginning to understand.

One of the most rapidly developing areas in what is now called ‘geobiology’ concerns the role of microbes in processes both of mineral formation and destruction. For example, the ‘geobacter’ bacteria, shown in the accompanying picture taken in an electron microscope, are not just sitting on an iron oxide mineral surface but interacting with it because it is their method of ‘respiration’ (just as breathing oxygen is ours).

A transfer of electrons between the microbe and the mineral in this case brings about a change in the chemical state of the iron (its ‘reduction’) which also causes the mineral to dissolve. Interactions of this type are now known to play important roles in the release and movement of metals and other elements, including pollutants such as arsenic, at the Earth’s surface.

A very different story linking minerals and the living world concerns the ways that many organisms form minerals to fulfil a particular function, such as providing an external skeleton (shell).

For example, the chalk rock responsible for the ‘White Cliffs of Dover’ in the south of England are almost entirely composed of the remains of microscopic plates of calcite derived from a protective armour around unicellular planktonic algae (‘coccolithophorids’). In many cases the products of such processes of ‘biomineralisation’ are delicate structures of great beauty.

A good example is provided by the (as illustrated) ‘radiolaria’, free-floating single celled organisms found in the upper regions of the water column in the oceans, and  which have skeletons of poorly crystalline (‘opaline’) silica.

Amongst the most remarkable examples of organisms producing a mineral to serve a specific function are the ‘magnetotactic bacteria’. Here the bacterium concerned produces a chain of perfect crystals (see illustration of magnetite crystals), most commonly of magnetite, which make use of the magnetic properties of that mineral. It seems that these organisms use magnetite to become aligned in relation to the Earth’s magnetic field and therefore in the most advantageous position in relation to the sediment-water interface.

One of the most challenging questions in all of science is: ‘How did life on Earth originate’? It is now widely believed that minerals played a key role as catalysts for biochemical reactions and templates for the emergence of the complex biomolecules needed for life. Many different routes have been proposed for the emergence of the first living organisms, almost all have major roles for minerals. These roles may have been in providing catalysts through biomolecule sized cavities in their crystal structures or weathered surfaces. Other routes involve clay minerals as substrates aiding in the formation of the first self-replicating genetic molecules, or look to the environments at, or near, mid-ocean ridges where hot fluids emerge releasing a stream of metal sulphide mineral particles. At the present day, both micro- and macro-organisms utilise chemical energy available in these environments for their metabolisms. Iron sulphide minerals are suggested as the key catalysts in these models.

There are challenging questions in all of these areas, whether it be understanding the electron transfer processes involved when bacteria interact with minerals, the mechanisms involved in biomineral formation, or the complex roles probably played by minerals in the emergence of life on Earth.

In these and many other cases, it is the processes at mineral surfaces which are critically important. Only in recent years has it been possible to study mineral surfaces at a molecular scale. Today, we are at the threshold of a new understanding of the processes taking place at the surface of the Earth which integrates the mineralogical, geochemical and biological realms at the molecular scale. Understanding what happens at surfaces and interfaces at scales from global to molecular is key to that understanding. Here, the emergent field of ‘molecular environmental science’ should provide new insights into the way our planet ‘works’ comparable to the revolutionary advances seen in human biology associated with the genetic code.

Featured image credit: Didimocrytus tetrathalamus, by Tim Evanson. CC-BY-SA-2.0 via Wikimedia Commons.

The post Minerals, molecules, and microbes appeared first on OUPblog.

        

Related Stories

• Discovering microbiology
• A very short trivia quiz
• Stardust making homes in space