File:Homestake Mine gold ore closeup.jpg
Original file (785 × 690 pixels, file size: 279 KB, MIME type: image/jpeg)
Captions
Summary
editDescriptionHomestake Mine gold ore closeup.jpg |
Homestake Mine gold ore (~3.5 cm across) - numerous visible gold blebs in high-grade gold ore sample from the Homestake Mine, town of Lead, northern Black Hills, western South Dakota, USA. The largest gold mine in the Americas was the long-lived Homestake Mine in the town of Lead (pronounced “Leed”), South Dakota, USA. Located in the Lead Window of the northern Black Hills Uplift in western South Dakota, the Homestake Mine produced about 40 million ounces of gold. The gold at Homestake is almost exclusively confined to the Homestake Formation, a Paleoproterozoic (~1.9-2.0 billion years) sedimentary unit that originally consisted of interbedded Mg-rich siderite iron formation and marlstones. The Homestake Formation has been strongly deformed & multiply metamorphosed, and many of the original rocks were converted to greenschists (cummingtonite schists). The gold has been interpreted as having been originally deposited with the iron formation sediments by seafloor volcanogenic exahalative processes. Slight metamorphic gold mobilization and tight structural folding has resulted in the formation of auriferous greenschist pods along fold axes. |
Date | |
Source | Homestake Mine gold ore, town of Lead, northern Black Hills, western South Dakota (1.25 cm acr.) |
Author | James St. John |
Other versions | File:Homestake Mine gold ore, town of Lead, northern Black Hills, western South Dakota (3.6 cm acr.) (14736672692).jpg |
Licensing
edit- You are free:
- to share – to copy, distribute and transmit the work
- to remix – to adapt the work
- Under the following conditions:
- attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
This image was originally posted to Flickr by jsj1771 at https://www.flickr.com/photos/47445767@N05/14736970735. It was reviewed on 1 August 2014 by FlickreviewR and was confirmed to be licensed under the terms of the cc-by-2.0. |
1 August 2014
File history
Click on a date/time to view the file as it appeared at that time.
Date/Time | Thumbnail | Dimensions | User | Comment | |
---|---|---|---|---|---|
current | 20:37, 1 August 2014 | 785 × 690 (279 KB) | Tillman (talk | contribs) | Transferred from Flickr via Flickr2commons |
You cannot overwrite this file.
File usage on Commons
There are no pages that use this file.
Metadata
This file contains additional information such as Exif metadata which may have been added by the digital camera, scanner, or software program used to create or digitize it. If the file has been modified from its original state, some details such as the timestamp may not fully reflect those of the original file. The timestamp is only as accurate as the clock in the camera, and it may be completely wrong.
JPEG file comment | cmp3.10.3.1Lq4 0xf5fffab1 |
---|