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:
China Flat, Downieville District, Sierra Co., California, USA

Oldest recorded age at locality: 4.3
Youngest recorded age at locality: 2

mindat Locality ID: 269490
mindat URL: http://www.mindat.org/loc-269490.html

Tectonic Settings:

Total number of sublocalities beneath "China Flat, Downieville District, Sierra Co., California, USA": 15
Total number of bottom-level sublocalities: 15

Number of Child Localities: 15
Child Localities:
Bep & Jim Placer
Cat's Whiskers Placer
China Placer (China Slide Placer Mine)
Cuba Placer Mine
Elcey Mine (Elcy; Elcay; Buckingham)
Gold Point Mine (Gray Eagle)
Montrose Mining & Development Company Placer Prospect (Montrose Mng & Dev Co.)
Shaughnessy Mine
Sierra Poorman Mine (Blue Jay & Highland; Black Angel; Little Boulder; Big Boulder; Iron Cube)
Sunshine Mine
Unidentified Au Mine [24] (Unnamed Property)
Unidentified Au Mine [25] (Unnamed Property)
Unnamed Au Property [2] (unidentified Workings)
Unnamed Au Prospect [5]
Unnamed Au Prospect [66]

Latitude: 39°33'48"N
Longitude: 120°45'41"W
Decimal Degree (lat, lon): 39.563333333333,-120.76138888889

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.

Copper	None	Quartz

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: Ag Au O Si

Elements from minerals reported directly at this locality:

Structural Groups for minerals in this locality:
Copper None Quartz

3 IMA Minerals at location:

Gold ()*	Quartz ()*	Silver ()*

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
Gold ()*	Copper	Au	4.3	2	10	177456,177457,177458,177459,177461,177462,177463,177464,177465,177466	30554
Quartz ()*	Quartz	SiO₂			7	177458,177459,177461,177462,177464,177465,177466	61156
Silver ()*	Copper	Ag			1	177459	5186

Locality Notes from all Ages at Locality:

Age ID	Locality Notes
Michelle_0076	Liparite, very near Tolfa (192390)
Michelle_0077	Quartz latite
Michelle_0078	Quartz latite
Michelle_0079	Liparite
Michelle_0080	Quartz latite
Michelle_0081	Liparite
Michelle_0082	Monzonitic porphyry
Michelle_0083	Liparite quartz latite

8 Ages assigned to this locality:

Excel ID	Max Age (Ma)	Min Age (Ma)	Age as listed in reference	Dating Method	Age Interpret	Sample Source	Sample Num	Dated Mineral	MinDat Locality ID	Dated Locality (Max Age)	Location as listed in reference	Reference	Reference ID	Age Notes
Michelle_0076	4.3	4.1	4.2±0.1	K-Ar	Age of liparite	feldspar	K13		93202	Cuba Placer Mine, China Flat, Downieville District, Sierra Co., California, USA	Rocca di Tolfa	Fornaseri (1985)	RDSIMF40_73	Age of liparite
Michelle_0077	3.4	2.6	3.0±0.4	K-Ar	Age of quartz latite	biotite	K2		93202	Cuba Placer Mine, China Flat, Downieville District, Sierra Co., California, USA	Sso della Strega	Fornaseri (1985)	RDSIMF40_73	Age of quartz latite
Michelle_0078	3.1	2.7	2.9±0.2	K-Ar	Age of quartz latite	feldspar	K2		93202	Cuba Placer Mine, China Flat, Downieville District, Sierra Co., California, USA	Sso della Strega	Fornaseri (1985)	RDSIMF40_73	Age of quartz latite
Michelle_0079	3.8	3.6	3.7±0.1	K-Ar	Age of liparite	feldspar	K12		93202	Cuba Placer Mine, China Flat, Downieville District, Sierra Co., California, USA	Fso d. Melledra	Fornaseri (1985)	RDSIMF40_73	Age of liparite
Michelle_0080	2.6	2.2	2.4±0.2	K-Ar	Age of quartz latite	feldspar	K5		93202	Cuba Placer Mine, China Flat, Downieville District, Sierra Co., California, USA	La Tolfaccia	Fornaseri (1985)	RDSIMF40_73	Age of quartz latite
Michelle_0081	2.2	2	2.1±0.1	K-Ar	Age of liparite	feldspar	K3		93202	Cuba Placer Mine, China Flat, Downieville District, Sierra Co., California, USA	La Montagnola	Fornaseri (1985)	RDSIMF40_73	Age of liparite
Michelle_0082	3.6	3.4	3.5±0.1	K-Ar	Age of monzonitic porphyry	feldspar	K15		93202	Cuba Placer Mine, China Flat, Downieville District, Sierra Co., California, USA	Pgio della Stella	Fornaseri (1985)	RDSIMF40_73	Age of monzonitic porphyry
Michelle_0083	3.4	3.2	3.3±0.1	K-Ar	Age of Liparite quartz latite	sanidine	K14	Sanidine	93202	Cuba Placer Mine, China Flat, Downieville District, Sierra Co., California, USA	Mt Riccio	Fornaseri (1985)	RDSIMF40_73	Age of liparite quartz latite

Sample	Source Locality	Reference URL

All locality data graciously provided by mindat.org

All age data...