Saturday, January 4, 2014

190+ years of Twin Cities geology/paleontology

Investigations of the geology and paleontology of the Twin Cities area of Minnesota go back a surprisingly long time. Several descriptions can be found from the decades before statehood (1858), included as parts of larger surveys (i.e. Keating [1824], Featherstonhaugh [1836], Nicollet [1843], and several publications by David Dale Owen [1847, 1848, 1852]). The earliest report I am familiar with was published by William H. Keating, concerning an 1823 expedition. Keating was something of a polymath who wore a number of different hats during his relatively short life (1799–1840), including three years' work in the schools and mines of Europe (Miles 1959). In 1823 he joined an expedition under the noted explorer Major Stephen H. Long, as the title of his 1824 publication makes clear (this was back when a title was also an abstract and introduction).

In 1823, Minnesota was 35 years from becoming a state. There was no Minneapolis or St. Paul, not even a Pig's Eye. Fort Snelling was known as Fort St. Anthony, and wouldn't acquire its more famous name until 1825. Minnehaha Falls was Brown's Falls. The Minnesota River was the St. Peter River. About the only names we would recognize today are St. Anthony Falls and Lake Calhoun, named for then-Secretary of War John C. Calhoun, who had authorized the fort. Long's expedition had been dispatched by Calhoun for a rapid survey of the Red River/"St. Peter"/Lake Superior region, with an eye to clearing up some issues affecting the lucrative fur trade (Miles 1959). (Also part of the expedition was prominent American naturalist Thomas Say, who unfortunately lost many of his samples as reported by Keating.) The expedition arrived in our neck of the woods in July of 1823 and visited Fort "St. Anthony", "Brown's Falls" (p. 302–303), and St. Anthony Falls, where Keating was temporarily stranded on an island (Hennepin Island?) above the falls (p. 296–297).

Keating was responsible for documenting the expedition. For the modern reader, Keating's work contains valuable descriptions of conditions at the time, including much information about the tribes living in the area. Geologically speaking, the descriptions are a bit lacking, which is unsurprising given the "rapid survey" part of the expedition's mandate. There is one major error that Keating would have doubtless recognized had he more time (and had not been afflicted with a fever, which is how he got stuck on the island and is never conducive to careful observations): he reported that the rocks in the area of the fort included a limestone with fossils, an underlying sandstone formation, and another limestone formation below that. The first two of these can be recognized as the Platteville Formation and St. Peter Sandstone, but the lower limestone was actually enormous fallen blocks of the Platteville Formation, as noted by Featherstonhaugh (1836) and Nicollet (1843). He did make what appears to the first scientific report of fossils from the Twin Cities area of Minnesota: in the limestone, he noted "organic remains abound in it. These are, as far as we saw, exclusively Producti [Productus is a genus of brachiopod], they lie in the rock as thick as possible" (p. 307). For anyone who has spent time looking at the Platteville along the river, this is instantly recognizable as a shell bed loaded with brachiopods, found occasionally, especially in the upper part of the formation.

"...organic remains abound in it. These are, as far as we saw, exclusively Producti, they lie in the rock as thick as possible..."
References:

Featherstonhaugh, G. W. 1836. Report of a geological reconnaissance made in 1835, from the seat of government, by the way of Green Bay and the Wisconsin Territory, to the Coteau de Prairie, and elevated ridge dividing the Missouri from the St. Peter’s River. Gales and Seaton, Washington, D.C.

Keating, W. H. 1824. A narrative of an expedition to the source of St. Peter’s river, lake Winnepeek, lake of the Woods, etc., performed in the year 1823, by the order of the Hon. J. C. Calhoun, Secretary of War; under the command of Stephen H. Long, U. S. T. E. Volume 1. H. C. & I. Lea, Philadelphia, Pennsylvania.

Miles, W. D. 1959. A versatile explorer: a sketch of William H. Keating. Minnesota History 36:294–297.

Nicollet, J. N. 1843. Report intended to illustrate a map of the hydrographical basin of the upper Mississippi river. Blair and Rives, Washington, D.C.

Owen, D. D. 1847. Preliminary report of the geological survey of Wisconsin and Iowa. Pages 160–174 in U.S. General Land Office Report 1847. Washington, D.C. 30th Congress, 1st session, Senate Executive Document 2, Congressional Serial Set Volume 504.

Owen, D. D. 1848. Report of a geological reconnaissance of the Chippewa Land District of Wisconsin, and incidentally of a portion of the Kickapoo country, and of a part of Iowa and of the Minnesota Territory; made under instructions from the United States Treasury Department. Washington, D.C. 30th Congress, 1st session, Senate Executive Document 57.

Owen, D. D. 1852. Report of a geological survey of Wisconsin, Iowa, and Minnesota; and incidentally of a portion of Nebraska Territory. Lippincott, Grambo & Co., Philadelphia, Pennsylvania. Available at http://archive.org/details/mobot31753000174885 (plates not included), https://archive.org/details/aet7123.0001.001.umich.edu (plates) or http://books.google.com/books?id=Y_ZYAAAAYAAJ.

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