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Graymont Dolime (OH) Inc. Quarry (GenLime Group L. P. Quarry; U. S. Gypsum Quarry; Genoa Quarry), Genoa, Ottawa Co., Ohio, USAi
Regional Level Types
Graymont Dolime (OH) Inc. Quarry (GenLime Group L. P. Quarry; U. S. Gypsum Quarry; Genoa Quarry)Quarry
Genoa- not defined -
Ottawa Co.County

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Lock Map
Latitude & Longitude (WGS84): 41° 30' 24'' North , 83° 21' 14'' West
Latitude & Longitude (decimal): 41.50694,-83.35389
GeoHash:G#: dpksphpe3
Locality type:Quarry
Köppen climate type:Dfa : Hot-summer humid continental climate
Nearest Settlements:
Genoa2,306 (2017)1.3km
Elmore1,393 (2017)5.9km
Woodville2,083 (2017)6.2km
Clay Center283 (2017)6.3km
Millbury1,249 (2017)8.8km

The Genoa Quarry is an active quarry for building stone and aggregate located in the W 1/2 of Section 3, Genoa, Clay Township, Ottawa County. The rocks exposed in the quarry are identified as part of the Lockport Dolomite.

Edward Orton (1888, p. 732) was the first geologist to describe the geology and quarrying of limestone at Genoa. Orton observed that there were three quarries with multiple kilns in the immediate area: Wyman, Gregg & Co. and A.L. Newman both owned three kilns each and William Habbeler had two kilns. These quarries were shallow with the deepest quarry only being 20 feet.

Carlson (1990, p. 524, 1991, p. 98, 2015, p. 166) noted in that Orton (1888, p. 735) had reported that the mineral baryte (which was often referred to as heavy spar) had been encountered at Genoa or from a subsequent abandoned pit nearby. (Carlson, 1990, p. 524). A further analysis of the literature reveals that although Orton had indeed misidentified the mineral celestine for baryte, which is commonly encountered at the Genoa Quarry, the locality that Orton mentions in his report that the “heavy spar” was found was at Clay Center and not Genoa.

In 1915, the United States Gypsum Company purchased 25 acres of land at Genoa with the prospect of getting into the lime industry. Rock Products and Building Materials (1915, p. 42) magazine reported:

The new constructed lime plant consists of nine kilns, a hydrator, automatic sacking machines and other machinery used in hydrating plants. Three additional units of nine kilns each will be added to the plant from time to time as the demand for product requires. The plant is built of concrete and steel throughout. The machinery is electrically driven with individual motors.

The method of getting the rock from the quarry to the kilns differs from the usual practice in this locality, in that instead of the long incline from the top of the kilns to the bottom of the quarry, the rock is hoisted direct from the quarry and dropped into the top of the kilns by a large traveling “Gantry” crane. This crane is also to be utilized in unloading coal and placing it through proper chutes on the kiln floors for burning the lime. The plant was completed and placed in operation on Dec. 1.

A crushed rock plant is now being built for crushing various size rock for road-making and ballast work.

By the early 1990s, the quarry began operations under the GenLime Group L.P. Company from U.S. Gypsum and in 1998, Graymont Dolime (OH) Inc., a subsidiary of Graymont acquired both the Bellefonte Lime Co. in Pennsylvania and the GenLime Group L.P. of Genoa. The quarry is still owned and operated by Graymont today.

Regions containing this locality

North America PlateTectonic Plate

Select Mineral List Type

Standard Detailed Strunz Dana Chemical Elements

Commodity List

This is a list of exploitable or exploited mineral commodities recorded at this locality.

Mineral List

8 valid minerals.

Detailed Mineral List:

Formula: CaCO3
Reference: Minerals of Ohio Bull. 69 ODNR
Formula: SrSO4
Reference: Minerals of Ohio Bull. 69 ODNR
Formula: CaMg(CO3)2
Reference: Minerals of Ohio Bull. 69 ODNR
Formula: CaF2
Reference: Minerals of Ohio Bull. 69 ODNR
Formula: PbS
Reference: Minerals of Ohio Bull. 69 ODNR
Formula: FeS2
Reference: Minerals of Ohio Bull. 69 ODNR
Formula: FeS2
Reference: Minerals of Ohio Bull. 69 ODNR
Formula: ZnS
Reference: Minerals of Ohio Bull. 69 ODNR

List of minerals arranged by Strunz 10th Edition classification

Group 2 - Sulphides and Sulfosalts
Group 3 - Halides
Group 5 - Nitrates and Carbonates
Group 7 - Sulphates, Chromates, Molybdates and Tungstates

List of minerals arranged by Dana 8th Edition classification

Group 2 - SULFIDES
AmXp, with m:p = 1:1
AmBnXp, with (m+n):p = 1:2

List of minerals for each chemical element

C CalciteCaCO3
C DolomiteCaMg(CO3)2
O CalciteCaCO3
O CelestineSrSO4
O DolomiteCaMg(CO3)2
F FluoriteCaF2
Mg DolomiteCaMg(CO3)2
S CelestineSrSO4
S SphaleriteZnS
S GalenaPbS
S MarcasiteFeS2
S PyriteFeS2
Ca CalciteCaCO3
Ca FluoriteCaF2
Ca DolomiteCaMg(CO3)2
Fe MarcasiteFeS2
Fe PyriteFeS2
Zn SphaleriteZnS
Sr CelestineSrSO4
Pb GalenaPbS

Regional Geology

This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.

Click on geological units on the map for more information. Click here to view full-screen map on

251.902 - 541 Ma

ID: 3187973
Paleozoic sedimentary rocks

Age: Phanerozoic (251.902 - 541 Ma)

Lithology: Sedimentary rocks

Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529. [154]

Ludlow - Llandovery
423 - 443.8 Ma

ID: 2720013
Lockport Dolomite

Age: Silurian (423 - 443.8 Ma)

Stratigraphic Name: Lockport Dolomite

Description: Dolomite, shades of white to medium gray, medium to massive bedded, fine to coarse crystalline; fossiliferous; vuggy.

Comments: Secondary unit description from USGS Lexicon website (ref. OH017) and OH005:Rock units forming the bedrock in the Maumee, Lucas Co., OH, and that crop out in the walls of a quarry are the Lockport Dolomite and the Greenfield Dolomite. The two form a thick reef complex roughly 600 m in diameter and about 68 m thick. The Lockport contains multistory stromatolite, thrombolite, and coral-microbialite reefs that were probably formed in a subtidal setting within a hypersaline lagoon. Lockport may be Wenlockian or Llandoverian to Ludlovian. In contrast to the mostly massive Lockport, the Greenfield at Maumee quarry is well bedded. It is Wenlockian, according to Shaver (1991), but fig. 16 of this report (after Howell, 1993) depicts the Greenfield as Llandoverian with a significant hiatus between deposition of the two units (Kahle, 1994). Original map source: Slucher, E.R., (principal compiler), Swinford, E.M., Larsen, G.E., and others, with GIS production and cartography by Powers, D.M., 2006, Bedrock geologic map of Ohio: Ohio Division of Geological Survey Map BG-1, version 6.0, scale 1:500,000.

Lithology: Major:{dolostone}

Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052. [133]

Data and map coding provided by, used under Creative Commons Attribution 4.0 License


Sort by

Year (asc) Year (desc) Author (A-Z) Author (Z-A)
Orton, E. (1888) The production of lime in Ohio. Report of the Geological Survey of Ohio, Economic Geology: 6: 732-733.
Various authors (1915) U.S.G. Co. Manufacturing Lime. Rock Products and Building Materials: 17(4): 42.
Stout, W.E. (1941) Dolomites and limestones of western Ohio. Geological Survey of Ohio, Fourth Series, Bulletin 42: 413-414.
Harness, C.L. (1942) Strontium minerals. United States Bureau of Mines Information Circular 7200: 414.
Schreck, A.E. and Arundale, J.C. (1959) Strontium, a materials survey. United States Bureau of Mines Information Circular 7933: 18, 39.
Sparling, D.R. (1965) Geology of Ottawa County, Ohio. The Ohio State University, Columbus, Ohio, Ph.D. dissertation: 171, 236-237.
Strogonoff, R.F. (1966) The common minerals of northwestern Ohio and their geologic occurrence: Bowling Green State University, Bowling Green, Ohio, M.A. thesis: 16, 18-19.
Floyd, J.C. (1971) Depositional environments of some Silurian rocks, northern Ohio. Bowling Green State University, Bowling Green, Ohio, M.A. thesis: 99-101, 167, 170.
Forsyth, J.L. (1971) Geology of the Lake Erie islands and adjacent shores. Michigan Basin Geologyal Society Guidebook for Annual Field Excursion, Ann Arbor, Michigan: 15-16.
Botoman, G. (1975) Precambrian and Paleozoic stratigraphy and potential mineral deposits along the Cincinnati Arch of Ohio. The Ohio State University, Columbus, Ohio, M.S. thesis: 45.
Fisher, H.H. (1977) Ohio celestine: Rocks & Minerals: 52(8): 414.
Mychovsky, G. (1978) The origin of fluorite, sulfate and sulfide minerals in northwestern, Ohio. Kent State University, Kent, Ohio, M.A. thesis: 33, 42.
Lanz, R.C. (1979) Development of Lockport (Niagaran) carbonate buildups and associated rocks at Genoa, Ohio: Bowling Green State University, Bowling Green, Ohio, M.A. thesis: 118 p.
Carlson, E.H. (1983) The occurrence of Mississippi Valley-type mineralization in northwestern Ohio, in Kisvarsanyi, G., Grant, S.K., Pratt, W.P., and Koenig, J.W., eds., International Conference on Mississippi Valley Type Lead-Zinc Deposits, Proceedings, University of Missouri-Rolla Press, Rolla, Missouri: 425, 427, 429-430.
Carlson, E.H. (1986) Localization of Sr-F-Zn-Pb mineralization in Lockport mound structures, northwestern Ohio, in Coogan, A.H., Field Trip Guidebook, Geological Society of America North-Central Section Annual Meeting, Kent State University, Kent, Ohio: 4-13.
Carlson, E.H. (1990) Ohio mineral locality index. Findlay Arch and Serpent Mound Districts. Rocks & Minerals: 65(6): 524-525.
Carlson, E.H. (1991) Minerals of Ohio: Ohio Department of Natural Resources, Bulletin 69, First Edition: 93-94, 98, 103, 106, 108, 118, 127, 139.
Carlson, E.H. (1994) Geologic, fluid inclusion, and isotopic studies of the Findlay Arch District, northwestern Ohio. Economic Geology: 89(1): 88.
Carlson, E.H. (2015) Minerals of Ohio: Ohio Department of Natural Resources, Bulletin 69, Second Edition: 157, 166, 178, 185, 190, 216, 233, 259.
Vasichko, J.W. (2018) Fluorite of the Findlay Arch Mineral District, Ohio, Michigan and Indiana. Rocks and Minerals: 93(2): 113-121.

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