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in 1820, Platteville
Limestone was abundant and nearby. The fort site lay atop a great deposit of the material. It is an easy stone to quarry, as it breaks readily. Soldiers built almost the entire original fort, from foundations to the round tower, out of Platteville stone. It remains the largest
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As a building stone, Platteville's chief attraction was its availability; in Saint Paul and
Minneapolis it was often simply quarried on site. But it had limits. Coarse and crumbly, it could not be carved or polished to a smooth finish, and its gray color had limited appeal. With the spread of
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Like almost all limestones, the
Platteville variety is a marine creation. Platteville Limestone formed between 488 and 436 million years ago, when what became southeastern Minnesota and southwestern Wisconsin lay beneath an ancient sea. This sea was heavily populated by shellfish and other
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was built atop a
Platteville shelf. Once the city moved beyond its early stage of flimsy and flammable wooden buildings, the local limestone came into heavy use. The first quarry went into operation in 1856. The Original Coney Island (1858), the
510:, though less of it survived there into the 21st century. Quarrying began in 1864 and builders used it for the original Customs House and City Hall (both 1873) and the original Central High School (1878). The most conspicuous survivor is the
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invertebrates. As they died, their shells and other hard parts, made of calcium carbonate, fell to the ocean floor. Over the centuries, the weight of these deposits crushed the shell fragments and compressed them into stone.
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About 100 million years later, geologic forces raised southeastern
Minnesota above the ocean surface. In the area that became Twin Cities metropolitan region, the limestone was covered by thin deposits of
499:(1874) were all built partly or entirely from the local stone. Several fine examples of Platteville limestone's use in private houses can be found in Saint Paul's Summit Hill district, including the
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430:, and the Mississippi River bluffs in most of the Twin Cities area. Sea life was abundant during the Ordovician Period and a large number of marine fossils including corals,
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covered this region from 75,000 to about 12,000 years ago. When they finally melted, between 14,000 and 12,000 years ago, the released water carved the channels of the
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466:. The Platteville Limestone is the less-eroded, layered unit that constitutes the majority of the photo. Below it is a thin, dark layer of
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were also made of
Platteville. (The stone in this area tends to be a paler gray, often stained with light brown patches.)
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that were more attractive and easier to work with. Builders rarely used
Platteville for major projects after the 1880s.
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can be found in the limestone sediments at several areas along the
Mississippi River in the Twin Cities.
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340:
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railroads in the 1870s, other, finer materials became available and affordable, including the red
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680:"Minnesota at a Glance: Minnesota Geological Survey: Fossil Collecting in the Twin Cities Area"
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336:
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633:"RI-33 Sedimentology of the Middle Ordovician Platteville Formation Southeastern Minnesota"
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pattern; this dolotimization occurred after deposition but prior to the development of
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331:. It is characterized by its gray color, rough texture, and numerous fossils. Its
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703:
Griffin, Robert H. (1942). "Dolomitic
Mottling in the Platteville Limestone".
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In
Illinois, the formation is elevated to group status and referred to as the
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building, built in 1881; its walls all Platteville stone quarried on site.
419:, and smaller rivers through the layers of limestone, exposing some of it.
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This shell from the limestone is the holotype specimen of the nautiloid
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339:. It was heavily used in the early decades of the building of
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Creative Commons Attribution-ShareAlike 3.0 Unported License
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formation in the sedimentary sequence characteristic of the
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Mossler, J.H.; S. Benson; A.C. Runkel (December 2018).
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The Platteville stone was quarried and used also in
525:(1872), was built of Platteville stone quarried at
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117:Paleozoic Stratigraphy of the Upper Midwest, USA
422:This difficult-to-erode unit forms the cap of
52:Platteville Limestone exposed in Decorah, Iowa
483:complex of Platteville structures ever made.
470:. Below the shale is a thin, white stripe of
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717:10.1306/D4269148-2B26-11D7-8648000102C1865D
762:Ordovician southern paleotropical deposits
478:When the United States Army began work on
458:The Platteville Limestone cropping out in
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737:Limestone formations of the United States
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705:SEPM Journal of Sedimentary Research
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568:This article incorporates text from
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757:Ordovician System of North America
537:and most of the main buildings of
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531:Cathedral of Our Merciful Saviour
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742:Ordovician geology of Wisconsin
501:Burbank–Livingston–Griggs House
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613:. Minnesota Historical Society
329:upper Midwestern United States
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1:
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521:'s first permanent building,
517:Outside of the Twin Cities,
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7:
605:Nelson, Paul (2016-08-10).
383:, which overlies the thick
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387:. It is shot through with
685:. University of Minnesota
631:Mossler, John H. (1985).
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767:Ordovician United States
497:Church of the Assumption
607:"Platteville Limestone"
547:Lake Superior Sandstone
656:Cite journal requires
493:Alexander Ramsey House
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449:
372:
369:Actinoceras beloitense
341:Minneapolis–Saint Paul
337:Platteville, Wisconsin
549:and the buff-colored
539:Shattuck-Saint Mary's
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379:It overlies the thin
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318:Platteville Limestone
276:Mount Simon Sandstone
168:Platteville Limestone
30:Platteville Limestone
18:Platteville Formation
752:Ordovician Minnesota
529:. In Faribault, the
486:Like Fort Snelling,
345:Faribault, Minnesota
269:Eau Claire Formation
262:Galesville Sandstone
747:Ordovician Illinois
488:downtown Saint Paul
472:St. Peter Sandstone
424:Saint Anthony Falls
385:St. Peter Sandstone
252:Franconia Formation
184:St. Peter Sandstone
152:Wise Lake Formation
36:Stratigraphic range
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242:Munising Formation
82:Glenwood Formation
535:Bethlehem Academy
527:Dundas, Minnesota
438:, clams, snails,
352:Platteville Group
314:
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257:Ironton Sandstone
237:Potsdam Sandstone
217:Shakopee Dolomite
192:Knox Unconformity
146:Dubuque Formation
122:Dates approximate
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16:(Redirected from
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551:Kasota limestone
519:Carleton College
512:Pillsbury A-Mill
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227:Jordan Sandstone
212:Everton Dolomite
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428:Minnehaha Falls
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247:Davis Formation
232:Potosi Dolomite
222:Oneota Dolomite
200:Knox Supergroup
128:Maquoketa Group
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468:Glenwood Shale
460:Minnehaha Park
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391:mottles in an
381:Glenwood Shale
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203:(~497-~470 Ma)
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194:(~470-~459 Ma)
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186:(~459–~455 Ma)
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176:Glenwood Shale
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154:(449.4–447 Ma)
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480:Fort Snelling
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399:in the rock.
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158:Decorah Shale
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107:Upper Midwest
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97:United States
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687:. Retrieved
649:cite journal
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615:. Retrieved
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505:
495:(1868), and
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349:
317:
315:
202:
170:(455–454 Ma)
167:
160:(454–452 Ma)
148:(447–446 Ma)
138:(454–446 Ma)
136:Galena Group
130:(446–440 Ma)
641:11299/60754
572:, which is
523:Willis Hall
508:Minneapolis
464:Minneapolis
440:cephalopods
436:brachiopods
413:Mississippi
731:Categories
689:2019-05-24
617:2019-05-24
576:under the
557:References
444:trilobites
407:and soil.
393:anastomose
322:Ordovician
40:Ordovician
432:bryozoans
417:Minnesota
389:dolomitic
358:Formation
325:limestone
178:(~455 Ma)
68:Underlies
62:Formation
611:MNopedia
574:licensed
570:MNopedia
503:(1862).
409:Glaciers
88:Location
78:Overlies
320:is the
93:Country
442:, and
397:joints
103:Extent
683:(PDF)
405:shale
662:help
533:and
343:and
316:The
58:Type
713:doi
637:hdl
450:Use
347:.
335:is
733::
711:.
709:12
707:.
670:^
653::
651:}}
647:{{
635:.
609:.
589:^
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38::
719:.
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660:(
643:.
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620:.
580:.
305:e
298:t
291:v
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
