Tuesday, June 16, 2009

The Most Beautiful Building Stone in the Country

My favorite liquor store in the country is in Morton, Minnesota. It’s an odd sort of store, mostly bar, with a small section up front where one can buy bottles. I, of course, don’t like it for its alcohol selection, but for its architecture, or more particularly its cladding. I am guessing but feel confident that no other liquor store in the country, perhaps in the world, is built with older stone. The rock that covers the liquor store is the 3.5-billion-year old Morton Gneiss, what one geologist calls “the most beautiful building stone in the country.”

Rectangular, two stories tall, and clad partially in brick, the Morton liquor store has a practical appearance, though it does incorporate some semblance of an aesthetic with the cornice and frieze. They have a pattern of outlined squares atop two, horizontal rows of raised bricks, which rest on another row of inverted, stepped pyramids. A faded red awning adds another touch of character, boldly proclaiming in large white letters, MORTON LIQUOR.

The gneiss starts below the cornice. Pink and black layers swirl around each other as if they are still fluid. Other layers look stretched and torn like taffy. Four inch-wide eyes of black minerals, complete with white eyebrows, dot the variegated layers. I cannot imagine trying to contemplate this wall of stone after spending a few hours partaking of the goods sold within.

Known in the trade as Rainbow Granite, the stone has been quarried in Morton since 1884. Cold Spring Granite has longed owned the quarry, which is opened on a limited basis. Because of the stone’s unusual color and patterns, it was a popular building material during the 1920s and 1930s, when Art Deco architecture was all the rage.

The Qwest Building in Minneapolis, originally the Northwestern Bell Telephone Building, built 1930-1932

Morton clad structures can be found around the country. The tallest is in New York, the 952-foot high AIG building (formerly Cities Service). The most northern is in Seattle, the Seattle Exchange Building. The closest to John Wayne’s birthplace in Winterset, Iowa, is in Des Moines, the Bankers Life Insurance Building. The most recently converted to lofts is in Birmingham, Alabama, the Watts Building.

Up close with the Morton Gneiss

Geologists had long known that the Morton Gneiss was very old but not until 1956 when Samuel Goldich and three other geologists published a crystallization date of 2.4 billion years did geologists learn how old. Previously, geologists had simply used undated terms such as primitive, Huronian, and Archean. Seven years after Goldich’s discovery, Ed Catanzaro pushed the date back to 3.2 billion years, the oldest age so far determined on this continent. Not to be outdone, Goldich reanalyzed the Morton and came up with a date of 3.55 billion years. In November 1974, the rock became even older when Goldich reported the Morton was 3.8 billion years old, not just the oldest rocks on North America but the oldest rocks on Earth. As one can imagine there was much rejoicing.

The Morton Gneiss Quarry, in Morton

Fame was fleeting though. By 1980, the age of the Morton had dropped back to 3.5 billion years. In 2006, Pat Bickford, emeritus professor of petrology at Syracuse University, led a team of researchers who obtained the Morton’s most up to date age of 3,524 million years. Although the Morton is but a babe compared to the oldest rocks on Earth, it is still the oldest, most commonly used building stone in the world. And, in my opinion, one of the best looking.


Silver Fox said...

Ooh, that is pretty gneiss, indeed - and how fancy can you get for a liquor store!

Unknown said...

It would be interesting to know the history of the liquor store building. Clearly it's an older building, remodeled -- I would guess -- after WW2, but when? I can't imagine the angled front being pre-WW2. Aesthetically I don't think it works at all.

But boy, that stone sure is beautiful. It's used most appropriately in the Qwest Building. I am moving to Chicago (from NYC) later on this year, and see that I have some touristing to do.

David B. Williams said...

Unfortunately, I didn't have time to check out the history of the building. It is a funky structure. When you get to Chicago, go check out the Adler Auditorium, which is clad in the Morton stone.

Dave19128 said...

Here's an alternative model for gneiss formation that suggests gneiss is an authigenic rock formed in an aqueous setting in microgravity. The microgravity explains the large, precipitated mineral-grain size and the aqueous setting explains the sedimentary layering.

The sharp isoclinal folding of comet rock occurs when differentiated Outer Oort Cloud (OOC) comet cores shrink during diagenesis, causing 'circumferential folding' which is not found in terrestrial sedimentary rock. Heat and temperature of metamorphism only converts hydrous minerals to their anhydrous counterparts but has no effect on the layering or folding (except in the case of massive granite and massive gneiss which has melted and is therefore plutonic).

Mantled gneiss domes are comet cores formed from authigenic rock (formed by precipitation of mineral grains) such as gneiss and quartzite and hydrothermal rock like schist and dolomite formed from hydrothermal fluids expelled during diagenesis of the underlying gneiss.

Core collapse of comet clusters create larger compound comets from comet mergers of multiple gneiss-dome comet cores, and smaller-grained authigenic shale forms in the higher gravity of the larger compound comet cores. The Appalachian province 'platform' is an example of a compound comet core from the OOC.

The Black Hills is a granite-greenstone compound-comet core from the Inner Oort Cloud which is a second comet reservoir which is volatile-enriched.

Rich H. said...

And it makes good rail road track ballast once crushed down.

Rich H. said...

Makes great rail road track ballast once crushed down.