Category: Stories in Stone Blog

Curb Your Enthusiasm

What’s the most common use for granite dimension stone in the US? Curiously, it is often curbs? Yes, regular old street curbing. For instance in 2010, 154,000 tons of granite was used for curbing versus 103,000 for buildings. In 2009, curbing hit 138,000 tons compared with 133,000 tons for monumental uses. Crazy.

I would have thought in this modern age that the abundance and quality of concrete would have lead to much less granite use. Of course, I don’t have the statistic on how much concrete goes into curbing. I suspect there is far more concrete curbing than granite but the amount of granite curbing still surprises me. And, of note, this reflects only how domestic stone is used.  I couldn’t locate comparable statistics for international stone but the use of imported stone dwarfs the use of domestic stone in the building trade. (Brazil is the largest importer.)

I do know that the National Park Service uses granite curbing regularly. They do so for the reasons that others do, too. Granite lasts longer than concrete, is far better looking, and far more grand. If money was no object I am sure that most builders would use granite.

Granite is not the only stone used for curbs. I have seen marble curbs in Carrara, Italy; basalt curbs in Hilo, Hawaii; and gneiss curbs in Morton, Minnesota. These latter curbs are pretty nifty because the stone is 3.54 billion years old. And, with the basalt curbs probably no older than a few thousand years, if not much younger, that’s a pretty good age spread of stone.

[nggallery id=23]When I do my building stone tour in Seattle, I like to point out the curbs in the downtown area. (I know, I lead a pretty exciting life!) Seattle builders initially curbed its streets with the local granite, a 32-million-year old salt and pepper stone from Index. It looks quite similar to concrete. After the granite, they turned to concrete though it seems that it was not very high quality. On many streets, you can still find the steel railings that were used to protect the concrete. With better concrete, steel was no longer needed.

In fact, it’s sort of a nifty way to age date one’s neighborhood in Seattle. Older ones still retain some granite. Younger have the steel railing and the youngest neither steel nor granite.

And one final use for granite curbing, from my pal Dave Tucker at NW Geology Field Trips. He sent me this great photo of adaptive reuse of an old granite curb in Bellingham. The title is “Days Go By” by Brian Goldbloom. He completed it in 1987 from curbstone removed in 1982 “to make way for modernization.” I like it!

Confession of a basalt addict

They say the first step in addiction is to admit it. Okay, I like basalt. I like to travel to see it. I like to know how it has influenced our planetary history. I like how it creates such wonderful scenery so rich in color and texture. I like how it shows that nature bats first, and in many places last and clean-up. In essence I am what you might call a basaltophile.

I realized this recently on a vacation to Hawaii’s big island. This was the second time in less than a year that I spent time on an island of basalt. The first was last year on a trip to Iceland. In each place, basalt dominated the landscape. I don’t use dominated lightly. I mean it in the dictionary definition of “to bear rule over, control, sway; to have a commanding influence on.”

When you travel in Hawaii and Iceland, you quickly learn that basalt is what rules these islands. Drive down a road and you will discover how it weaves through lava flows, unless, of course, it simply disappears under the lava. Read stories about the islands’ histories and you will learn how basalt has shaped the actions of where and how people lived. Look at tourist brochures and you will see how promoters exploit the splendor of basalt to draw in visitors.

[nggallery id=22]Part of the attraction is the beauty of the basalt, but part of it is the raw nature of the rock. On Iceland and Hawaii, you feel the primal personality of the planet. Exploding geysers, bubbling hot springs, oozing molten rock, this is how Earth was in its earliest days. It was a harsh and dangerous place, and yet seeing how life has taken root on these islands, it takes little imagination to envision some form of existence starting to evolve and flourish those billions of years ago.

Because of the youth of the basalt—on Hawaii we saw flows less than a year or so old—both islands have a dynamic feel. On Iceland, we experienced the eruption of Grimsvötn, which shut down the airport and curtailed our travel plans. On Hawaii, the ongoing spewing of toxic gases from Halema’uma’u crater prevented us from hiking several trails. Where else would you see signs that read “Stay on trail. Dangerous earth cracks in park area”?

That dynamic also gives Iceland and Hawaii a raw and unformed feel. The islands are in a constant state of change, growing with new lava flows and disemboweling themselves with eruptions. Hiking around Iceland, I was struck by how moss was often the lone plant life, as if only primitive vegetation veneered a primitive land. Hawaii does have its tropical rainforests, which at times made the island seem far older, but I also saw huge areas devoid of any plant, or even any animal. When driving, I found you could not always trust a map, as some geologic disaster might have simply erased a road or bridge.

The story of basalt is one that stretches back to the earliest days of Earth and continues unabated to the present. It is a story that shapes our planet and our species. It is a story that shows that geology is alive and well, and often kicking some butt. What more could a basaltophile want?