The Earth Story

Scattered by cones

Volcanic cones (150 in total) on Marion Island almost appear are spots on a teenagers face. In addition a large portion of the island is covered in A'a and pahoehoe flows, the vegetated ones could be less than 100 years old. Marion is one of the peaks of a large submarine shield volcano that rises 500m from the bottom of the sea. Mascarin peak, the highest point on Marion is 1242m high. Eruptions have occurred in 1980 and 2004. It’s South Africa’s only historically known active volcano. Together with smaller neighbor Prince Edward Island Marion is collectively known as the Prince Edward islands and is located 1769 km from the South African mainland and a little bit further away from Antarctica. On average it rains 320 days a year. Thus Marion is rightly known as one of the cloudiest places in the world. Due to the wetness of the climate the island is covered with bog, lichen and other subarctic vegetation. There is not much difference between winter and summer on the island, it is always wet, with threat of snow and frost. The strong westerly winds that roam the island are branded the Roaring Forties

Marion was discovered by the Dutch ship Maerseveen in 1663, however it was not until 1772 that someone actually sat foot on it. Frenchman Joseph Marion du Fresne was in the preconception that he had made it to Antarctica. It took him 5 days to discover he was on two small islands. Again in 1803 the island was visited by sealers. In 1947 South Africa annexed the island and based a meteorological station there. There are no permanent inhabitants.

The introduction of cats on the island (in the first place brought here to deal with the problem of mice) caused the grey petrel to become extinct. Supposedly the cats managed to eat about half a million birds in 1975 alone. The cat eradication programme finally managed to get rid of the cats in 1991.

-OW-

Image: NASA Erath Observatory.

References: http://www.sanap.ac.za/sanap_marion/sanap_marion.html http://www.volcano.si.edu/volcano.cfm?vn=234070

THE GEOLOGY OF KITTY LITTER -OR- MINERALOGY FOR CATS

Since 78% of Social Media posts appear to involve kitties, who are we at The Earth Story to disagree? We love kitties, too! 

And yes, there is a real geologic basis behind the mineralogy of kitty litter. There are, of course, many kinds of kitty litter (including silica dehydrates, recycled newspapers, synthetic pine chips, etc), but the kind we will discuss today is the classic clay-based litter.

Many of you (including fellow geologists who frequent our site) sort of assume that most of us walk around with the swagger that announces that we move tectonic plates for a living, shift climatic barriers to benefit humankind, or explore for exceedingly wonderful precious minerals like gold, silver, copper, even chromite. But there is a class of scientists among us who work in a geologic field called -- “Industrial Minerals.”

Industrial Minerals are earth resources that are non-fuel, non-metallic minerals that are mined (usually in bulk) for – money. Lots of money. Among these are the geologic deposits that make cement, road fill, ceramics, and … kitty litter. Doesn't sound very exciting compared to lunar exploration or discovering a new kind of dinosaur, but where would the human race be without cement or kitty litter?

Attapulgite (do not blame some abstruse Greek source for this word: the name of this mineral comes from a type-locality in Attapulgus, Georgia, USA) is a clay mineral that has the property that it can absorb a great amount of water without swelling in size, as does bentonite. Because of this property, it is an excellent material for use as cat litter, unless you want your cat litter to enlarge in volume whenever the cat uses it. It also, thank gods, has the ability to absorb unpleasant odors. I have a piece of it from a nearby attapulgite mine which, if I touch it to my tongue, adheres as if I stuck my tongue against ice (I chose not to use a photo of myself demonstrating this phenomena by dangling a piece of it from my tongue for this post). It is one of several clay minerals grouped together in a non-technical group of minerals called “fullers’ earth,” called so because fullers (traditional makers of cloth) used it to remove impurities and animal stench from their woolens.

All such clay minerals in this class are characterized as having a high magnesium content, and because of this, they are relatively rare in bulk amounts where they can be economically exploited. Clays are secondary minerals, formed by the alteration of primary minerals to better fit the conditions on the earth’s surface. Thus, to create a lot of Mg-rich clays, you need primary rocks that are also rich in Mg. In my area, tremendous deposits of attapulgite and associated “fullers’ earth” clay minerals are present because of the weathering of rocks from the earth’s mantle, rich in olivine and pyroxene, which are rich in Mg, and which are unstable in normal atmospheric conditions. They alter to serpentines, weather into soils, and in thick quantities become large deposits of “kitty litter.” From the earth’s mantle, to your litter box…

Attapulgite has many uses that don’t concern kitties directly: a small amount is probably included in the diarrhea medicine sitting in the back of your medicine cabinet; modern cosmetics incorporate attapulgite to retain moisture; fertilizers last longer with additions of attapulgite (they release nutrients at a slower more stable rate). Another property of attapulgite is that it is thixotropic (tremendous word!), meaning that when attapulgite muds are shaken or vibrated, they becomes more fluid – this makes it very useful as drilling mud, but totally irritating when your Land Rover gets stuck in it. When you stop spinning your wheels, the thixotropic substance will reverse to a more viscous state again.

Industrial minerals – may not sound like a very exciting field of geoscience, but believe me, industrial mineralogists (including those who specialize in cat litter), are literally raking it in.

Annie R.

Photo: I downloaded this kitty swimming in cat litter from: http://livingyearspets.wordpress.com/2010/04/18/comfortable-in-kitty-litter/ Who attribute it to the discontinued blog: http://www.catmas.com/

Further reading required for all cats viewing this post: http://www.clays.org/journal/archive/volume%2010/10-1-284.pdf http://www.geohellas.com/ http://www.youtube.com/watch?v=w8eyvgMQ_TU http://www.technology.org/2013/01/11/ingredient-in-diarrhea-medicine-leads-to-sustainable-new-farm-fertilizer-2/ http://www.reade.com/products/12-minerals-clays/38-polygorskite-salt-gel-fullers-earth-attapulgite-clay-activated-natural-012174-11-7-8031-18-3