Tasty Rocks: salt and friends

Salt — that stuff that melts the ice on sidewalks and makes popcorn taste so yummy — salt is a rock! Well, the kind in your salt shaker is rock-y. There's also salt dissolved in the oceans. It is dissolved rock! A mineral, actually. 

Salt is mined just like rocks too! It takes huge mining equipment like front loader shown in the photo of a salt mine below. 

Is salt the only rock that is tasty?

Big machinery cuts salt out of Iran's gigantic salt mine on the Silk Road in Semnan province.

Well, many rocks do have a taste. OG geologists used to use their taste buds to help identify rocks. Like, for instance, they could ID a rock because it tasted more bitter than its lookalike. Like halite does vs natural sodium chloride (table salt). Of course, tasting rocks is a bit of a gross way to identify them. It's not always safe, either! Some very hard substances can hurt you.

Lead is a harmful but useful rock-like substance. It was used in things like weights, pencils, and even paints. It tastes a little sweet. In fact, one of the old names for lead is "sugar of lead"! Problem is, lead causes brain damage that makes it harder to think. It is not safe to lick lead!

Lead isn't used in paints or pencils anymore. It hurt too many people and animals. Lead isn't used in fishing weights either, now. When people have to work with lead to build things today, they wear a lot of safety equipment to make sure that no lead gets on their skin or in their lungs. (See the lead safety instructions.)

Besides salt, gypsum is a rock we eat. You might know it as drywall, the sheets that make the walls in your house and school. That white crumbly gypsum is used in making beer, flour, ice cream and cheese! It tastes like — well‚ it tastes like drywall!

Here are some other rocky substances that have their very own flavour:

Borax — sweet but works as a cleaner, it is not a food

Chalcanthite — sweet but poisonous

Epsomite — bitter

Glauberite — salty and bitter

Hanksite — salty

Melanterite — sweet, puckery and metallic

Sylvite — bitter

Ulexite — alkaline (more soapy)

Alice E. Wilson: A Pioneer in Geology

By Claire Eamer

Several years ago, I wrote a book about pioneers in science and technology and how they were treated. It is called Before the World Was Ready: Stories of Daring Genius in Science (Annick Press, 2013). A couple of days ago, I had one of those awful authorly moments where you shout (internally, at least), "NO!!! I missed that!!!"

What I missed, or rather who I missed, was Alice E. Wilson, the first woman geologist in the Geological Survey of Canada. I'd never heard of her. And I should have. In fact, all Canadians should hear about her. And she should definitely have been in my book.

In Alice Wilson's case, the world at the beginning of the twentieth century -- most particularly, the Geological Survey of Canada -- was not ready for a woman to be a geologist. Wilson worked for the Geological Survey for 37 years, but only late in her career did she get the recognition (and pay) that would have come automatically to a man many years earlier.

Alice Evelyn Wilson was born in Cobourg, Ontario, in 1881, the daughter of a university professor. She and her two brothers spent much of their childhood hiking, camping, canoeing, and exploring the outdoors. They collected fossils and interesting minerals from the limestone formations around Cobourg, sparking in Alice a lifelong fascination with fossils.

When it came time to go to university, however, Alice chose to study modern languages. She explained later that at that time -- 1901 -- it was acceptable for a young woman to become a teacher, but not a scientist. Just a few classes short of her degree, however, Alice's health broke down, and she had to drop out of university for a long convalescence. 

Dr. Alice E. Wilson

When she recovered, she found a job at the Museum of Mineralogy in Toronto and rediscovered her childhood passion for rocks and fossils. In late 1909, she managed to get a temporary position with the palaeontology section of the Geological Survey of Canada, helping catalogue, organize and label the division's invertebrate fossil collection.

Alice's boss took a liking to her and helped her get a leave of absence to finish her degree. When she returned in 1911, it was as a permanent (if very junior) staff member. She stayed with the Survey until her compulsory retirement in 1946 at the age of 65. It reportedly took five employees to cover all the work she had been doing.

Even after retirement, she kept an office at the Geological Survey and continued her research until a few months before her death in 1964. She also taught palaeontology at Carleton University in Ottawa, led field trips, and wrote scientific papers and books, including an introduction to geology for children, The Earth Beneath Our Feet (Macmillan, 1947).

During all that long career, Alice Wilson faced an ongoing struggle against the limitations placed on her as a woman. And she constantly found ways around those limitations. 

She wasn't allowed to do remote fieldwork as that would mean travelling and living with men. (Scandalous!). So she conducted research in her own backyard, the St. Lawrence Valley, on foot and by bicycle, when the Survey wouldn't provide her with a car as they did for male geologists, and later in a car she bought herself. (A colleague said she was a terrifying driver, constantly talking and even turning around to address passengers in the back seat.)

Dr. Wilson waxing enthusiastic!

She applied for leave to pursue a doctoral degree -- a slam-dunk for a male employee -- but was turned down. Repeatedly. Still, every year she applied. Finally, in 1926, the Federation of University Women took up the struggle and embarrassed the Geological Survey into granting her leave. She received her doctorate in 1929.

The promotion that should have happened automatically when she earned her doctorate actually came seven years later when the Geological Survey discovered that their lowly female employee was receiving international recognition, including appointment as a Member of the Order of the British Empire (MBE) and election as a Fellow of the Geological Society of America. Two years later came another first: Alice Wilson was the first woman elected a Fellow of the Royal Society of Canada.

When asked in an interview how she coped with the resistance she met as a woman in science, she said: "If you meet a stone wall you don't pit yourself against it, you go around it and find a weakness." Dr. Alice Wilson found enough weaknesses in the various stone walls she encountered to achieve plenty of recognition in her own lifetime and after: an honorary doctorate from Carleton University; a photostory about her from the National Film Board; articles in major newspapers; and, in 1959, the Geological Survey held a reception to recognize her 50 years in geology, presenting her with bookends and a paper weight made from marble quarried in a marble deposit she had herself discovered.

Since her death, the honours continue. A meeting room at the Geological Survey's headquarters was named Alice Wilson Hall. In 2018, a plaque honouring her was installed in the Canadian Museum of Nature. And the Canadian Federation of University Women manages the annual Dr. Alice E. Wilson Awards, given to women pursuing graduate studies in the sciences.

And I really REALLY wish she were in my book!

Sources:

Alice Evelyn Wilson (1881-1964), on the website of the Chair for Women in Science and Engineering

Ricard, Alicen. Women's History Month: Dr. Alice Wilson, on the website of Westcoast Women in Engineering,Science and Technology, October 1, 2018.

Sarjeant, William A. S. Alice Wilson, first woman geologist with the Geological Survey of Canada, in Earth Sciences History, v. 12, no. 2, 1993, p. 122-128.

Sinclair, G. W. Memorial to Alice E. Wilson (1881-1964), in Bulletin of the Geological Society of America 77 (1966), p. 215-218.

Soldati, Arianna, and Cassie Freund. Meet Alice Wilson, the Canadian geologist who did the work of five people, on the website Massive Science, Feb. 27, 2020. 

Note: Photos retrieved from NRCan and used under the Open Government Licence -- Canada: https://open.canada.ca/en/open-government-licence-canada

 

Newfoundland Rocks!

This summer I visited Newfoundland. I’d heard lots about its attractions - people, music, scenery, food, icebergs, whales, puffins. But I was surprised at what a world-class fascinating place it is for geology. Gros Morne National Park, on the west coast, is a case in point. 

One of the landmarks in the area is the Tablelands mountain range, a reddish lump of rock over 700 meters high, and totally barren of plant life. 

Part of the Tablelands mountain range.

For once, the lack of vegetation isn’t because humans cleared it all. It’s because the rock itself is toxic to plant life. The area is a UNESCO-designated World Heritage Site because it’s unique. The Tablelands consist of rock from the earth’s mantle. This was discovered by geologist Bob Stevens in the 1970’s and it was an important factor in the acceptance at the time of the tectonic plate theory. 

The earth is made up of layers: core, mantle and crust.

Cutaway diagram of Earth's internal structure (to scale) with inset showing detailed breakdown of structure (not to scale)

Everywhere (almost) the mantle is covered by the crust. The Tablelands is unique in exposing a large chunk of the mantle. The mantle contains a lot of metals: iron (accounting for the rust-red colour), magnesium, chrome, mercury, platinum, nickel. And that's why it's toxic to plants.

Over time, the effect of water on the rock creates serpentinite, a lovely texture like – of course – a snake skin. 

Tectonic Plates

This map shows 15 of the largest plates.

This theory was hotly disputed as late as the 1970’s but has now been generally accepted. The earth’s crust consists of a number of plates which slowly float around on the surface of the mantle. Occasionally (very occasionally) they crash into each other and then drift apart again. Right now the North American plate is moving North-West at a rate of about 2.3 cm (not quite an inch) every year.

The plates don’t necessarily stay intact through this process. Newfoundland was formed by two plates colliding. They were more or less the earlier versions of the North American and Eurasian plates. When they drifted apart, the European bit remained stuck to the (new) North American plate. So the Western half of Newfoundland is geologically similar to the rest of North America, and the Eastern half is similar to Ireland in the Eurasian plate.