Jacobsville Sandstone is a red sandstone common to the Keweenaw Peninsula and north shore of the Upper Peninsula of Michigan.[1][2] The geological formation the rock is present in is known as the Jacobsville Formation[3] and is entirely devoid of fossils.[4]
The sandstone was used as an architectural building stone[5] both locally and around the United States. It is named after Jacobsville, Michigan, a town in which much of the sandstone was quarried.[2] Quarrying occurred throughout the Upper Peninsula approximately between 1870 and 1915. The sandstone was desirable for its durability and aesthetics.
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Until the early 1900s, Jacobsville Sandstone was variously called Lake Superior Sandstone, brownstone, or redstone,[6] and prefixed by the location in which it was quarried, such as Marquette and Portage Entry (e.g., Marquette brownstone). Early geology literature also referred to it as Eastern Sandstone.[1] In 1907, the sandstone was named Jacobsville by A. C. Lane and A. E. Seaman after the town of the same name.[7]
Jacobsville Sandstone is a fluvial sandstone that formed from northward flowing streams that deposited sand and gravel along the southern shore of what is now Lake Superior.[6] It dates to the late Mesoproterozoic Era,[1] between 1.03 and 1.07 billion years ago. However, the lack of fossils makes it difficult to exactly determine its age,[8] and it may date from as recently as Middle Cambrian.[9][10] Jacobsville Sandstone is related to the Bayfield group,[6] a similar sandstone located in northern Wisconsin. Despite their similarity, it is unknown as to whether the two formations are one in the same.[11]
The formation lies southeast of the Keweenaw Fault in the Keweenaw Peninsula, and south of Lake Superior further east in the Upper Peninsula. Jacobsville Sandstone is also present in southwest Ontario near Sault Ste. Marie.[8][12] Due to the highly irregular surface on which it was deposited, the formation varies in thickness between 46 and 1,100 ft (14 and 340 m).[6] The Jacobsville Formation lies unconformably beneath the Munising Formation.[4] Jacobsville Sandstone features prominently in Pictured Rocks National Lakeshore, and is the oldest formation exposed along the lakeshore in the park.[4]
The formation is also a confined aquifer, called the Jacobsville aquifer,[13] that covers an area of 4,363 square miles (11,300 km2).[14] Despite it being a sandstone aquifer, it has a low permeability[15] and water largely moves through cracks and fissures which extend to a depth of about 100 to 150 ft (30 to 46 m).[13] In 1985, 6.5 million US gallons (25,000 m3) of freshwater were withdrawn per day[13] for human use.
Jacobsville Sandstone is generally red, mottled with various pinks, whites and browns. The red coloration is due to small quantities of iron oxides.[16] Spherical light spots are caused by leaching and bleaching, and form sharp boundaries with surrounding colors. Its lithology varies from nearly pure quartzose sandstone (quartz-rich) to arkosic sandstone (feldspar-rich).[1]
The grains of Jacobsville Sandstone range from .25 to .5 mm (0.0098 to 0.020 in) in size.[16] Based on an average from samples taken in Marquette and Alger counties, Jacobsville Sandstone is composed of:[16] 27.4% nonundulatory quartz, 27.0% undulatory quartz, 23.0% potassium feldspar, and 12.3% silicic volcanic clasts. Smaller constituents are 3.8% polycrystalline quartz, 2.4% metamorphic, 1.4% sedimentary, 1.3% opaque, 0.8% mafic volcanic, and 0.1% plagioclase.
Jacobsville Sandstone's heavy mineral suite[16] is 84% ilmenite, 4-5% leucoxene, 4% garnet, 3% apatite, 3% zircon, and 1% tourmaline.
The earliest extraction of the sandstone occurred in Alger County in the 1860s with two companies providing stone to build nearby blast furnaces for the iron industry.[17] The first widespread and commercial quarrying of the sandstone began in the late 1860s[18] near Marquette and Jacobsville. The industry peaked in the early 1890s.[19] About 32 quarries[20] existed over the years, clustered near Jacobsville and Marquette[21] with many others scattered along the Lake Superior coast. The end of the industry occurred variably by location, though finishing around 1915 at the outbreak of World War I.[22]
One of the principal figures in the Jacobsville Sandstone industry was John Henry Jacobs,[20] to which the largest producers in the Jacobsville area were associated.[23] Both the sandstone and the town of Jacobsville are named for him.[3]
The sandstone was quarried as dimension stone, ton stone, and rubble stone; dimension stone being the most marketable and costly.[24] Blocks of dimension stone typically measured 8 by 4 by 2 ft (2.4 by 1.2 by 0.61 m). The byproduct of removing the dimension stone was rubble stone, which was either sold cheaply or discarded entirely.[25] The sandstone was extracted between April and November,[26] as winter could be detrimental to the stone.
When a new quarry was opened, up to 50 ft (15 m) of glacial drift and shale overburden[26] was blasted and removed to access the sandstone beneath. If no cliffs of sandstone existed for a quarry face, long and narrow channels spaced four feet apart[27] were cut to allow quarrying. A key was removed from between the channels, either by wedging or blasting, to create a space for blocks to move to as they were removed. With the key removed, holes were drilled horizontally under the block to be removed, and then cracked open with wedges.[28] These large blocks were then broken down to size with wedges struck by sledgehammers.[28] Once properly sized, the blocks were transported to the docks and loaded on ships.
The World's Columbian Exposition of 1893 in Chicago, with its White City, ushered in a change of style that preferred light-colored marbles and limestones[29] over the dark color of Jacobsville Sandstone. The industry began to decline and many quarries idled as previously mined sandstone was sufficient to meet demand. According to the director of the Michigan Geological and Biological Survey, the decline was caused in part by the Depression of 1893 and the large distance from the quarries to major markets.[30] Michigan's output of sandstone for building stone peaked in 1902 at a rough value of $136,280, falling to $5,682 by 1911.[31] Artificial stone, concrete, and brick had also become popular and inexpensive,[30] displacing all varieties of stone from the market. All the quarries were closed by about 1915.[20]
Despite the demise of the industry, some new construction still used Jacobsville Sandstone several years into the twentieth century. Examples include the Baraga School (1903-06), J H Kaye Hall (1913-15) at Northern State Normal School (now Northern Michigan University), and a statue named the USS Kearsarge constructed in Wolverine by the Works Progress Administration.[32] As the quarries were no longer in operation, the sandstone was often salvaged from other buildings.[32]
Jacobsville Sandstone was popular as a building material because of its strength, durability and aesthetic appeal.[5] In particular, it is resistant to the extremes in temperature of fire and the freeze-thaw cycle of northern climates. The Marquette Mining Journal reported on 20 November 1875 that:[33]
Its fire-proof qualities were thoroughly tested in the great Chicago fire, were Lake Superior brownstone walls...stood intact, without a crack, scale or blemish being caused by the great heat under the influence of which marble fronts crumbled and fell to the ground.
The sandstone was inexpensively obtainable in large quantities[18] and transport by the Great Lakes further reduced costs. It is also easily worked and carved, and could be used throughout a building.[18] The most popular stone was without white blemishes and with uniform coloring.[26] The Richardsonian Romanesque style, which is "particularly suited for expression in colored stone", helped to popularize the sandstone in architecture.[30]
Several buildings in the Upper Peninsula[34] and across the United States incorporate Jacobsville Sandstone in their construction. In the UP, these buildings include The Calumet Theatre[35], Saint Ignatius Loyola Church,[36] and several buildings in the Quincy Street Historic District.[37] Outside the UP, the sandstone was used in the Tribune Building in Chicago (1872), the Germania Bank Building in St. Paul (1888-90), City Hall in Cincinnati (1888-93), the Chamber of Commerce in Detroit (1894-95), and the original Waldorf-Astoria Hotel in New York City.[38]
The rubble stone was commonly used for foundations, cribs, breakwaters and piers.[25]