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:
Jarretsville-Dublin District, Harford Co., Maryland, USA

Oldest recorded age at locality: 510
Youngest recorded age at locality: 470

mindat Locality ID: 307378
mindat URL: http://www.mindat.org/loc-307378.html

Tectonic Settings:

Total number of sublocalities beneath "Jarretsville-Dublin District, Harford Co., Maryland, USA": 16
Total number of bottom-level sublocalities: 14

Number of Child Localities: 12
Child Localities:
Ayres Mine
Birdseye Mine (Birdseye Pit)
Cherry Hill Chrome Sand Placer (Yinger Farm Prospect; Road Pit)
Cherry Hill Mine
Cherry Hill Ore Banks
Dublin
Irrigation Well Prospect
Reed Mine
Rocks Quarry (Air's Quarry)
Scarboro Quarry
Whiteford
Wilkins Mine (Wilkens Mine; John W. Carman Property)

Latitude: 39°38'0"N
Longitude: 76°22'39"W
Decimal Degree (lat, lon): 39.633333333333,-76.3775

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.

Amphibole	Brucite	Calcite	Chlorite	Clay	None	Quartz	Serpentine	Smectite-vermiculite	Spinel
Talc

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 C Ca Cr Fe H Mg O Si

Elements from minerals reported directly at this locality:

Structural Groups for minerals in this locality:
Amphibole Brucite Calcite Chlorite Clay None Quartz Serpentine Smectite-vermiculite Spinel
Talc

12 IMA Minerals at location:

Ankerite ()*	Anthophyllite ()*	Antigorite ()*	Brucite ()*	Chromite ()*
Chrysotile ()*	Clinochlore ()*	Magnesite ()*	Magnetite ()*	Quartz ()*
Talc ()*	Vermiculite ()*

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
Ankerite ()*	None	Ca(Fe²⁺,Mg)(CO₃)₂			1	218794	3092
Anthophyllite ()*	Amphibole	Mg₂Mg₅Si₈O₂₂(OH)₂			1	218795	718
Antigorite ()*	Serpentine Clay	Mg₃Si₂O₅(OH)₄	510	470	3	218791,218797,218803	708
Brucite ()*	Brucite	Mg(OH)₂	510	470	1	218797	462
Chromite ()*	Spinel	Fe²⁺Cr₂O₄	510	470	6	218788,218789,218790,218791,218797,218803	3902
Chrysotile ()*	Serpentine Clay	Mg₃Si₂O₅(OH)₄	510	470	1	218797	951
Clinochlore ()*	Chlorite Clay	Mg₅Al(AlSi₃O₁₀)(OH)₈	510	470	4	218788,218797,218801,218803	1756
Magnesite ()*	Calcite	Mg(CO₃)	510	470	3	218795,218797,218801	1487
Magnetite ()*	Spinel	Fe²⁺Fe³⁺₂O₄			3	218792,218794,218801	14899
Quartz ()*	Quartz	SiO₂	510	470	2	218794,218797	61156
Talc ()*	Clay Talc	Mg₃Si₄O₁₀(OH)₂	510	470	5	218794,218795,218797,218798,218801	3337
Vermiculite ()*	Clay Smectite-vermiculite	Mg_0.7(Mg,Fe,Al)₆(Si,Al)₈O₂₀(OH)₄·8H₂O			2	218794,218795	652

3 Ages assigned to this locality:

Excel ID	Max Age (Ma)	Min Age (Ma)	Age as listed in reference	Age applies to these Elements	MinDat Locality ID	Dated Locality (Max Age)	Location as listed in reference	Reference	Reference ID
podchrome-00407	490	490	Lower Ordovician (490±20 Ma)	Cr	142724	Ayres Mine, Jarretsville-Dublin District, Harford Co., Maryland, USA	Ayres	Moiser et al. (2012)	USGSSIR2012_5157
podchrome-00502	510	470	Lower Ordovician (490±20 Ma)	Cr	142771	Cherry Hill Mine, Jarretsville-Dublin District, Harford Co., Maryland, USA	Cherry Hill	Moiser et al. (2012)	USGSSIR2012_5157
podchrome-00497	510	470	Lower Ordovician (490±20 Ma)	Cr	143059	Reed Mine, Jarretsville-Dublin District, Harford Co., Maryland, USA	Reed	Moiser et al. (2012)	USGSSIR2012_5157

Sample	Source Locality	Reference URL

All locality data graciously provided by mindat.org

All age data...