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:
Bunker Mine (Bunker Mines; Blue Bird Mine [1880's]; Bay Tree Prospect; Sunnyside Occurrence), Sage Hill, Michigan Bluff District (Michigan Bluff Deposit), Placer Co., California, USA

Oldest recorded age at locality: 388
Youngest recorded age at locality: 388

mindat Locality ID: 85152
mindat URL: http://www.mindat.org/loc-85152.html

Tectonic Settings: Oceanic Arc (Subduction)

Total number of sublocalities beneath "Bunker Mine (Bunker Mines; Blue Bird Mine [1880's]; Bay Tree Prospect; Sunnyside Occurrence), Sage Hill, Michigan Bluff District (Michigan Bluff Deposit), Placer Co., California, USA": 1
Total number of bottom-level sublocalities: 1

Number of Child Localities: 1
Child Localities:
Coal Pit

Latitude: 39°2'16"N
Longitude: 120°46'15"W
Decimal Degree (lat, lon): 39.037777777778,-120.77083333333

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.

Clay	Garnet	None	Serpentine	Spinel

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: Ca Cr Fe H Mg O Si

Elements from minerals reported directly at this locality: Ca Cr Fe H Mg O Si

Structural Groups for minerals in this locality:
Clay Garnet None Serpentine Spinel

4 IMA Minerals at location:

Antigorite ()*	Magnesiochromite ()*	Magnetite ()*	Uvarovite ()*

Mineral name	Structural Groups	IMA Formula	Max Age (Ma)	Min Age (Ma)	# of localities containing mineral
Antigorite ()*	Serpentine Clay	Mg₃Si₂O₅(OH)₄	388	388	708
Magnesiochromite ()*	Spinel	MgCr₂O₄	388	388	311
Magnetite ()*	Spinel	Fe²⁺Fe³⁺₂O₄	388	388	14899
Uvarovite ()*	Garnet	Ca₃Cr₂(SiO₄)₃	388	388	212

1 Ages assigned to this locality:

	Excel ID	Max Age (Ma)	Min Age (Ma)	Age as listed in reference	Dating Method	Age Interpret	Prioritized?	Sample Source	Sample Num	Run Num	Age from other Locality	Dated Mineral	Minerals explicitely stated as having this age	Age applies to these Elements	MinDat Locality ID	Dated Locality (Max Age)	Location as listed in reference	Reference	Reference DOI	Reference ID	Age Notes
	podchrome-00152	388	388	pre-Early Devonian-Jurassic (388±17 Ma U-Pb zircon from felsic igneous rocks; 174 Ma K-Ar white mica from blueschists)										Cr	85152	Bunker Mine (Bunker Mines; Blue Bird Mine [1880's]; Bay Tree Prospect; Sunnyside Occurrence), Sage Hill, Michigan Bluff District (Michigan Bluff Deposit), Placer Co., California, USA	Bunker (main)	Moiser et al. (2012)		USGSSIR2012_5157

Sample	Source Locality	Reference URL

All locality data graciously provided by mindat.org

All age data...