Mineral Evolution Database

Created and maintained by the Mineral Evolution Project in partnership with RRUFF and mindat.

Mineral locality data provided by mindat.org

The Mineral Evolution database is currently under development.

The goal of this page is to present localities at which the mineral is found, and estimates of the oldest possible geologic age of the minerals at these localities.

Locality Name:
Baltimore Co., Maryland, USA

Oldest recorded age at locality: 774.4
Youngest recorded age at locality: 470

mindat Locality ID: 23520
mindat URL: http://www.mindat.org/loc-23520.html

Tectonic Settings:

Total number of sublocalities beneath "Baltimore Co., Maryland, USA": 184
Total number of bottom-level sublocalities: 164

Number of Child Localities: 147
Child Localities:
Alberton Quarry
Arbutus Canyon Siderite Locality
Arundel Quarry
August Sandusky Quarry
Bare Hills
Bethke Ore Bank
Bishop Ore Bank
Blowhorn Ore Banks
Bonaparte Quarry
Bosley And Ensor Ore Banks
Brian Ore Banks
Brown Ore Banks
Cambria
Carney
Chew Ore Bank
Cochran Prospect
Cockeysville
Cook Ore Banks
Coursey Ore Bank
Cross Ore Bank
Delight
Dietz Quarry
Dolfield Placer (Rose Placer)
During Ore Bank
East Baltimore Ore Banks
East Lutherville Ore Bank
Ellicott City
Ender Ore Bank
Excelsior Brick And Pottery Company Bank
Feeney And Atherton Company Quarries
French Quarry
Furstenburg Mine
Gay Shore Prospect
Geist Ore Bank
Gerst Ore Bank
Gilmor Quarry
Glyndon Occurrence
Gore Placer
Gorsuch Point Mine
Granite (Waltersville)
Green Springs Valley
Guilford & Waltersville Quarry
Gwynn Quarry
Hamilton Quarries
Harris Mine
Hengemihle Ore Bank
Herman Ore Bank
Hernwood
Hilton Quarry
Hofmeister Ore Bank
Holbrook
Hollofield
Hollofield Quarries
Humphrey Quarry
James Peach Quarry
Jenkins Ore Bank
Jones Quarry
Kahler Ore Bank
Kaufman Ore Bank
Kemp Quarries
Kennedy Ore Bank
Kern Ore Bank
King Ore Bank
Kline's Brickyard Ore Bank
Kraft Ore Banks
Leitschuh Ore Bank
Lepper Ore Bank
Link Pits
Loch Raven Reservoir
Lohman Ore Banks
Lutz Chromite Placer
Mase Ore Banks
Matthews Ore Bank
Milford Quarry
Miller Ore Banks
Minckins Quarry
Minebank Ore Bank
Mohr Ore Bank
Myers Ore Bank
Nine Mile Hill Deposit
Nine Number 62
Northeast Halethorpe Ore Banks
Northeast Landsdowne Ore Banks
Northwest Landsdowne Ore Banks
Notch Cliff Quarries
Obrien Ore Banks
Offutt Quarry
Old Triplett Placer
Owings Mills
Patapsco Quarry (Patapsco Natural Stone Quarries Inc)
Patterson Quarries
Pearce Quarry
Picnic Wood Quarries
Pierce Quarry
Pitcher And Creager Brick Company Banks
Pitcher Ore Bank
Poole Farm Quarries
Poplar/White Marsh (Cyprus Mines Corp.; United Sierra; Div)
Pot Springs Ore Banks
Randle Ore Bank
Reddington Ore Bank
Reich Ore Bank
Rheinhardt Ore Bank
Rice Ore Bank
Rider Ore Bank
Ridgely Ore Bank
Riemschneider Ore Bank
Ring Ore Bank
Rittenhouse Ore Bank
Rockland
Roeder Ore Bank
Rohe Ore Bank
Rossville Pit (Baltimore Brick Company; Rosedale Pit)
Rupp Quarries
Schmidtman Ore Bank
Smith Ore Bank
Solomon Ore Bank
South Granite Quarries
South Mine & Mill
Southeast Landsdowne Ore Banks
Stapleton Ore Banks
Taylor Ore Bank
Texas
Texas Maryland Quarry Number 2
The Caves Ore Banks
Toboll Ore Bank
Townsend Ore Bank
Tremper Ore Banks
Triplett Placer
Turner Ore Banks
U. F. Peach Quarries
Unnamed Quarry
Virginia Ore Banks
Von Kapff Ore Bank
Wagonfere Ore Bank
Waranch Prospect (Patapsco State Park Prospect)
Weaver Stone Company Quarry (Butler Quarry; C. E. Weaver Stone Company)
Westerman Ore Bank
Westport Paving Brick Company Bank
Whitaker Ore Banks
William Speigel & Son Quarry
Wilson Bank
Wilt Quarry
Windsor Farm Ore Bank
Woodensburg-Cardiff District
Worthington Quarries
Zinkand Ore Bank

Latitude: 39°21'35"N
Longitude: 76°38'21"W
Decimal Degree (lat, lon): 39.359722222222,-76.639166666667

A	This mineral is Anthropogenic.
G	This mineral is directly dated.
B	This mineral is reported as having this age.
Y	This mineral is using an age reported as an element mineralization period.
O	This mineral is using an age calculated from all data at the locality.
R	The age displayed for this mineral originates from a different, non-child locality.
P	The age displayed for this mineral is the range of ages for this mineral at all of this locality's children.
	This mineral's age has not yet been recorded.

Allophane	Amorphous	Amphibole	Analcime	Aragonite	Baryte	Beryl	Brucite	Calcite	Chalcanthite
Chalcopyrite	Chlorite	Clay	Clinozoisite	Copper	Corundum	Covellite	Diaspore	Epidote	Feldspar
Fluorite	Garnet	Gypsum	Kaolinite	Malachite	Marcasite	Melanterite	Mica	Millerite	Molybdenite
Natrolite	Nickeline	None	Not in a structural group	Prehnite	Pyrite	Pyroxene	Quartz	Rocksalt	Rutile
Serpentine	Smectite-vermiculite	Sphalerite	Spinel	Staurolite	Stibnite	Talc	Titanite	Tourmaline	Wollastonite
Zircon

This Mineral list contains entries from this locality, including sub-localities. Minerals in bold are reported by mindat.org as occurring directly at this locality, and do not occur at any children (sublocalities) of this locality.

Elements at this locality, including sub-localities: Al Au B Ba Be C Ca Co Cr Cu F Fe H K Mg Mo Na Ni O Pb S Sb Si Ti Zn Zr

Elements from minerals reported directly at this locality: Au

Structural Groups for minerals in this locality:
Allophane Amorphous Amphibole Analcime Aragonite Baryte Beryl Brucite Calcite Chalcanthite
Chalcopyrite Chlorite Clay Clinozoisite Copper Corundum Covellite Diaspore Epidote Feldspar
Fluorite Garnet Gypsum Kaolinite Malachite Marcasite Melanterite Mica Millerite Molybdenite
Natrolite Nickeline None Not in a structural group Prehnite Pyrite Pyroxene Quartz Rocksalt Rutile
Serpentine Smectite-vermiculite Sphalerite Spinel Staurolite Stibnite Talc Titanite Tourmaline Wollastonite
Zircon

76 IMA Minerals at location:

Actinolite ()*	Albite ()*	Almandine ()*	Analcime ()*	Anthophyllite ()*
Antigorite ()*	Aragonite ()*	Augite ()*	Azurite ()*	Baryte ()*
Beryl ()*	Bornite ()*	Brucite ()*	Calcite ()*	Carrollite ()*
Chalcanthite ()*	Chalcocite ()*	Chalcopyrite ()*	Chromite ()*	Chrysocolla ()*
Chrysotile ()*	Clinochlore ()*	Clinozoisite ()*	Covellite ()*	Cummingtonite ()*
Cuprite ()*	Diopside ()*	Dolomite ()*	Dravite ()*	Enstatite ()*
Epidote ()*	Ferro-hornblende ()*	Fluorite ()*	Galena ()*	Goethite ()*
Gold ()*	Graphite ()*	Gypsum ()*	Hematite ()*	Hydromagnesite ()*
Ilmenite ()*	Kaolinite ()*	Laumontite ()*	Lizardite ()*	Magnesite ()*
Magnetite ()*	Malachite ()*	Marcasite ()*	Margarite ()*	Melanterite ()*
Microcline ()*	Millerite ()*	Molybdenite ()*	Muscovite ()*	Natrolite ()*
Opal ()*	Orthoclase ()*	Phlogopite ()*	Prehnite ()*	Pyrite ()*
Pyrrhotite ()*	Quartz ()*	Rutile ()*	Schorl ()*	Scolecite ()*
Siderite ()*	Sphalerite ()*	Staurolite ()*	Stibnite ()*	Talc ()*
Titanite ()*	Tremolite ()*	Vermiculite ()*	Wollastonite ()*	Zircon ()*
Zoisite ()*

Mineral name	Structural Groups	IMA Formula	Max Age (Ma)	Min Age (Ma)	# of Sublocalities containing mineral	LOCALITY IDs, not mindat ids	# of localities containing mineral
Actinolite ()*	Amphibole	Ca₂(Mg_4.5-2.5Fe²⁺_0.5-2.5)Si₈O₂₂(OH)₂	510	470	4	218401,218403,218472,218495	3419
Albite ()*	Feldspar	Na(AlSi₃O₈)	774.4	470	4	218401,218440,218466,218495	8803
Almandine ()*	Garnet	Fe²⁺₃Al₂(SiO₄)₃	510	470	1	218401	2353
Analcime ()*	Analcime	Na(AlSi₂O₆)·H₂O			1	218495	1627
Anthophyllite ()*	Amphibole	Mg₂Mg₅Si₈O₂₂(OH)₂	510	470	3	218400,218401,218472	718
Antigorite ()*	Serpentine Clay	Mg₃Si₂O₅(OH)₄	510	470	2	218402,218433	708
Aragonite ()*	Aragonite	Ca(CO₃)	510	470	4	218401,218474,218511,218574	3250
Augite ()*	Pyroxene	(Ca,Mg,Fe)₂Si₂O₆			1	218495	2060
Azurite ()*	Not in a structural group	Cu₃(CO₃)₂(OH)₂	510	470	1	218401	5509
Baryte ()*	Baryte	Ba(SO₄)			1	218550	11547
Beryl ()*	Beryl	Be₃Al₂Si₆O₁₈			1	218397	4286
Bornite ()*	None	Cu₅FeS₄	510	470	1	218401	5516
Brucite ()*	Brucite	Mg(OH)₂	510	470	2	218511,218574	462
Calcite ()*	Calcite	Ca(CO₃)	510	470	17	218401,218404,218417,218418,218420,218424,218431,218433,218449,218461,218465,218470,218474,218490,218495,218550,218559	27770
Carrollite ()*	Spinel	CuCo₂S₄	510	470	1	218401	154
Chalcanthite ()*	Chalcanthite	Cu(SO₄)·5H₂O	510	470	1	218401	925
Chalcocite ()*	None	Cu₂S	510	470	1	218401	5707
Chalcopyrite ()*	Chalcopyrite	CuFeS₂	510	470	4	218401,218404,218465,218495	27198
Chromite ()*	Spinel	Fe²⁺Cr₂O₄	510	470	14	218399,218402,218403,218405,218431,218433,218450,218461,218470,218511,218512,218513,218575,218576	3902
Chrysocolla ()*	Allophane	(Cu_2-xAl_x)H_2-xSi₂O₅(OH)₄·nH₂O	510	470	1	218401	3531
Chrysotile ()*	Serpentine Clay	Mg₃Si₂O₅(OH)₄	510	470	2	218402,218433	951
Clinochlore ()*	Chlorite Clay	Mg₅Al(AlSi₃O₁₀)(OH)₈	510	470	7	218399,218402,218403,218405,218511,218512,218513	1756
Clinozoisite ()*	Clinozoisite Epidote	Ca₂Al₃[Si₂O₇][SiO₄]O(OH)	510	470	1	218404	1025
Covellite ()*	Covellite	CuS	510	470	1	218401	4165
Cummingtonite ()*	Amphibole	Mg₂Mg₅Si₈O₂₂(OH)₂	510	470	1	218401	327
Cuprite ()*	Not in a structural group	Cu₂O	510	470	1	218401	2970
Diopside ()*	Pyroxene	CaMgSi₂O₆			2	218465,218550	4135
Dolomite ()*	None	CaMg(CO₃)₂	510	470	6	218402,218404,218424,218433,218465,218550	9895
Dravite ()*	Tourmaline	NaMg₃Al₆(Si₆O₁₈)(BO₃)₃(OH)₃(OH)	510	470	3	218404,218465,218550	648
Enstatite ()*	Pyroxene	Mg₂Si₂O₆	510	470	2	218401,218474	944
Epidote ()*	Epidote Clinozoisite	Ca₂(Al₂Fe³⁺)[Si₂O₇][SiO₄]O(OH)	774.4	470	6	218397,218401,218404,218440,218466,218495	8173
Ferro-hornblende ()*	Amphibole	Ca₂(Fe²⁺₄Al)(Si₇Al)O₂₂(OH)₂	510	470	1	218401	271
Fluorite ()*	Fluorite	CaF₂			1	218550	9617
Galena ()*	Rocksalt	PbS			1	218550	24243
Goethite ()*	Diaspore	FeO(OH)	510	470	6	218418,218420,218426,218469,218490,218510	7437
Gold ()*	Copper	Au	774.4	470	0		30554
Graphite ()*	None	C	510	470	3	218404,218465,218550	2812
Gypsum ()*	Gypsum	Ca(SO₄)·2H₂O	510	470	1	218401	6890
Hematite ()*	Corundum	Fe₂O₃			1	218417	14640
Hydromagnesite ()*	None	Mg₅(CO₃)₄(OH)₂·4H₂O	510	470	2	218403,218574	341
Ilmenite ()*	Corundum	Fe²⁺Ti⁴⁺O₃			1	218495	5433
Kaolinite ()*	Clay Kaolinite	Al₂Si₂O₅(OH)₄			2	218489,218495	5591
Laumontite ()*	Not in a structural group	CaAl₂Si₄O₁₂·4H₂O	510	470	4	218401,218474,218495,218559	1271
Lizardite ()*	Serpentine Clay	Mg₃Si₂O₅(OH)₄			1	218433	359
Magnesite ()*	Calcite	Mg(CO₃)	510	470	8	218402,218403,218405,218431,218433,218511,218512,218513	1487
Magnetite ()*	Spinel	Fe²⁺Fe³⁺₂O₄	510	470	12	218397,218400,218401,218402,218405,218433,218450,218472,218495,218535,218575,218576	14899
Malachite ()*	Malachite	Cu₂(CO₃)(OH)₂	510	470	1	218401	12537
Marcasite ()*	Marcasite	FeS₂			2	218489,218495	5674
Margarite ()*	Mica Clay	CaAl₂Si₂Al₂O₁₀(OH)₂			1	218550	168
Melanterite ()*	Melanterite	Fe(SO₄)·7H₂O	510	470	1	218401	915
Microcline ()*	Feldspar	K(AlSi₃O₈)	774.4	470	11	218397,218401,218404,218417,218420,218440,218465,218466,218471,218473,218550	4924
Millerite ()*	Millerite	NiS			1	218513	1066
Molybdenite ()*	Molybdenite	MoS₂	774.4	514.6	2	218466,218495	5800
Muscovite ()*	Mica Clay	KAl₂(Si₃Al)O₁₀(OH)₂	774.4	470	10	218397,218404,218457,218465,218466,218471,218473,218495,218535,218550	17380
Natrolite ()*	Natrolite	Na₂(Si₃Al₂)O₁₀·2H₂O			1	218495	1236
Opal ()*	Amorphous	SiO₂·nH₂O	510	470	4	218402,218405,218431,218433	2994
Orthoclase ()*	Feldspar	K(AlSi₃O₈)			1	218440	2349
Phlogopite ()*	Mica Clay	KMg₃(AlSi₃O₁₀)(OH)₂	510	470	5	218404,218424,218449,218465,218550	2273
Prehnite ()*	Prehnite	Ca₂Al(Si₃Al)O₁₀(OH)₂			1	218495	1898
Pyrite ()*	Pyrite	FeS₂	774.4	470	9	218397,218401,218404,218465,218466,218474,218495,218550,218559	39462
Pyrrhotite ()*	Nickeline	Fe₇S₈	510	470	5	218404,218465,218474,218495,218550	9056
Quartz ()*	Quartz	SiO₂	510	470	25	218397,218399,218401,218402,218404,218405,218417,218420,218424,218430,218433,218440,218461,218465,218469,218470,218471,218473,218490,218495,218511,218513,218535,218550,218559	61156
Rutile ()*	Rutile	TiO₂	510	470	5	218404,218433,218465,218495,218550	5614
Schorl ()*	Tourmaline	NaFe²⁺₃Al₆(Si₆O₁₈)(BO₃)₃(OH)₃(OH)	774.4	470	11	218397,218401,218404,218417,218424,218457,218465,218466,218471,218490,218495	2705
Scolecite ()*	Natrolite	Ca(Si₃Al₂)O₁₀·3H₂O			1	218495	390
Siderite ()*	Calcite	Fe(CO₃)	774.4	514.6	3	218396,218445,218466	6417
Sphalerite ()*	Sphalerite	ZnS	510	470	2	218404,218550	21482
Staurolite ()*	Staurolite	Fe²⁺₂Al₉Si₄O₂₃(OH)	510	470	2	218399,218535	978
Stibnite ()*	Stibnite	Sb₂S₃			1	218433	3418
Talc ()*	Clay Talc	Mg₃Si₄O₁₀(OH)₂	510	470	13	218400,218401,218403,218404,218405,218461,218465,218470,218472,218495,218511,218550,218574	3337
Titanite ()*	Titanite	CaTi(SiO₄)O	510	470	3	218404,218495,218550	4899
Tremolite ()*	Amphibole	Ca₂(Mg_5.0-4.5Fe²⁺_0.0-0.5)Si₈O₂₂(OH)₂	510	470	11	218401,218404,218417,218418,218419,218420,218424,218449,218465,218472,218550	2562
Vermiculite ()*	Clay Smectite-vermiculite	Mg_0.7(Mg,Fe,Al)₆(Si,Al)₈O₂₀(OH)₄·8H₂O			2	218449,218474	652
Wollastonite ()*	Wollastonite	CaSiO₃			2	218424,218550	1247
Zircon ()*	Zircon	Zr(SiO₄)			1	218440	5251
Zoisite ()*	Epidote	Ca₂Al₃[Si₂O₇][SiO₄]O(OH)			2	218495,218559	1025

11 Ages assigned to this locality:

Excel ID	Max Age (Ma)	Min Age (Ma)	Age as listed in reference	Dating Method	Sample Source	Dated Mineral	Age applies to these Elements	MinDat Locality ID	Dated Locality (Max Age)	Location as listed in reference	Reference	Reference ID
podchrome-00496	510	470	Lower Ordovician (490±20 Ma)				Cr	3822	Bare Hills, Baltimore Co., Maryland, USA	Bare Hills	Moiser et al. (2012)	USGSSIR2012_5157
podchrome-00501	510	470	Lower Ordovician (490±20 Ma)				Cr	142886	Harris Mine, Baltimore Co., Maryland, USA	Harris	Moiser et al. (2012)	USGSSIR2012_5157
USGS-U-Th-Pb-00759_206_238	585.8	555.8	570.8±15	206_238	zircon	Zircon		142896	Hilton Quarry, Baltimore Co., Maryland, USA		USGS-U-Th-Pb	USGS-U-Th-Pb
USGS-U-Th-Pb-00759_207_206	544.6	514.6	529.6±15	207_206	zircon	Zircon		142896	Hilton Quarry, Baltimore Co., Maryland, USA		USGS-U-Th-Pb	USGS-U-Th-Pb
USGS-U-Th-Pb-00759_207_235	577.6	547.6	562.6±15	207_235	zircon	Zircon		142896	Hilton Quarry, Baltimore Co., Maryland, USA		USGS-U-Th-Pb	USGS-U-Th-Pb
USGS-U-Th-Pb-00760_206_238	774.4	744.4	759.4±15	206_238	zircon	Zircon		142896	Hilton Quarry, Baltimore Co., Maryland, USA		USGS-U-Th-Pb	USGS-U-Th-Pb
USGS-U-Th-Pb-00760_207_206	636.7	606.7	621.7±15	207_206	zircon	Zircon		142896	Hilton Quarry, Baltimore Co., Maryland, USA		USGS-U-Th-Pb	USGS-U-Th-Pb
USGS-U-Th-Pb-00760_207_235	740.4	710.4	725.4±15	207_235	zircon	Zircon		142896	Hilton Quarry, Baltimore Co., Maryland, USA		USGS-U-Th-Pb	USGS-U-Th-Pb
USGS-U-Th-Pb-00761_206_238	749.6	719.6	734.6±15	206_238	zircon	Zircon		142896	Hilton Quarry, Baltimore Co., Maryland, USA		USGS-U-Th-Pb	USGS-U-Th-Pb
podchrome-00500	510	470	Lower Ordovician (490±20 Ma)				Cr	42105	Weir Mine, Holbrook, Baltimore Co., Maryland, USA	Weir	Moiser et al. (2012)	USGSSIR2012_5157
podchrome-00495	510	470	Lower Ordovician (490±20 Ma)				Cr	28369	Choate Mine, Owings Mills, Baltimore Co., Maryland, USA	Choate	Moiser et al. (2012)	USGSSIR2012_5157

Sample	Source Locality	Reference URL

All locality data graciously provided by mindat.org

All age data...