Mineral Evolution Database
Created and maintained by the Mineral Evolution Project in partnership with RRUFF and mindat.
Mineral locality data provided by mindat.org

Ages for Graphite at Maryland, USA

The cyan highlights indicate which age entries were selected as the "best" for assigning the mineral an age of 510Ma - 470Ma at this locality

Age range from children

Excel ID	Max Age (Ma)	Min Age (Ma)	Dated Mineral	Minerals explicitely stated as having this age	Age applies to these Elements	Dated Locality ID	Dated Locality	Ref	Ref ID
podchrome-00496	510	470			Cr	3822	Bare Hills, Baltimore Co., Maryland, USA	Moiser et al. (2012)	USGSSIR2012_5157

Locality age

Excel ID	Max Age (Ma)	Min Age (Ma)	Dated Mineral	Minerals explicitely stated as having this age	Age applies to these Elements	Dated Locality ID	Dated Locality	Ref	Ref ID
Emily000556	540	444				24179	Sykesville, Carroll Co., Maryland, USA	Rast and Horton (1989)	GSA288_1
Emily000557	488	470	Zircon	Zircon		24179	Sykesville, Carroll Co., Maryland, USA	Horton et al. (2010)	GSA206_621
podchrome-00407	490	490			Cr	142724	Ayres Mine, Jarretsville-Dublin District, Harford Co., Maryland, USA	Moiser et al. (2012)	USGSSIR2012_5157
podchrome-00495	510	470			Cr	28369	Choate Mine, Owings Mills, Baltimore Co., Maryland, USA	Moiser et al. (2012)	USGSSIR2012_5157
podchrome-00496	510	470			Cr	3822	Bare Hills, Baltimore Co., Maryland, USA	Moiser et al. (2012)	USGSSIR2012_5157
podchrome-00497	510	470			Cr	143059	Reed Mine, Jarretsville-Dublin District, Harford Co., Maryland, USA	Moiser et al. (2012)	USGSSIR2012_5157
podchrome-00500	510	470			Cr	42105	Weir Mine, Holbrook, Baltimore Co., Maryland, USA	Moiser et al. (2012)	USGSSIR2012_5157
podchrome-00501	510	470			Cr	142886	Harris Mine, Baltimore Co., Maryland, USA	Moiser et al. (2012)	USGSSIR2012_5157
podchrome-00502	510	470			Cr	142771	Cherry Hill Mine, Jarretsville-Dublin District, Harford Co., Maryland, USA	Moiser et al. (2012)	USGSSIR2012_5157
USGS-U-Th-Pb-00758_206_238	968	938	Zircon			43888	Woodstock, Howard Co., Maryland, USA	USGS-U-Th-Pb	USGS-U-Th-Pb
USGS-U-Th-Pb-00758_207_206	1231.5	1201.5	Zircon			43888	Woodstock, Howard Co., Maryland, USA	USGS-U-Th-Pb	USGS-U-Th-Pb
USGS-U-Th-Pb-00758_207_235	1051.3	1021.3	Zircon			43888	Woodstock, Howard Co., Maryland, USA	USGS-U-Th-Pb	USGS-U-Th-Pb
USGS-U-Th-Pb-00759_206_238	585.8	555.8	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	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	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	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	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	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	Zircon			142896	Hilton Quarry, Baltimore Co., Maryland, USA	USGS-U-Th-Pb	USGS-U-Th-Pb