File:Gneiss with mafic enclave (Archean; Norris South roadcut, Madison County, Montana, USA) 2 (44803636724).jpg

From Wikimedia Commons, the free media repository
Jump to navigation Jump to search

Original file (4,000 × 3,000 pixels, file size: 7.11 MB, MIME type: image/jpeg)

Captions

Captions

Add a one-line explanation of what this file represents

Summary

[edit]
Description

Gneiss in the Precambrian of Montana, USA.

Gneiss is a high-grade, foliated metamorphic rock. It forms principally by metamorphism of schist, granite, or granite-like rocks. The foliation in gneiss is obvious and consists of alternating bands of light and dark minerals.

Geologic unit & age: unit Agg of Kellogg (1994) - plagioclase-microcline-quartz-biotite gneiss, Archean, probably 3.1 to 3.2 Ga (= age of peak metamorphism during intrusion of Spanish Peaks area trondhjemites and tonalites)

Locality: roadcut on the eastern side of Route 287, Burnt Creek-Bradley Creek Valley, south of the town of Norris, northern Madison County, southwestern Montana, USA (45° 31' 29.67" North latitude, 111° 41' 50.54" West longitude)

Reference cited:

Kellogg (1994) - Geologic map of the Norris quadrangle, Madison County, Montana. United States Geological Survey Geologic Quadrangle Map GQ-1738.
Date
Source Gneiss with mafic enclave (Archean; Norris South roadcut, Madison County, Montana, USA) 2
Author James St. John

Licensing

[edit]
w:en:Creative Commons
attribution
This file is licensed under the Creative Commons Attribution 2.0 Generic license.
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 James St. John at https://flickr.com/photos/47445767@N05/44803636724. It was reviewed on 7 November 2018 by FlickreviewR 2 and was confirmed to be licensed under the terms of the cc-by-2.0.

7 November 2018

James St. John

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeThumbnailDimensionsUserComment
current00:28, 7 November 2018Thumbnail for version as of 00:28, 7 November 20184,000 × 3,000 (7.11 MB)Lu Brito (talk | contribs)Transferred from Flickr via #flickr2commons

You cannot overwrite this file.

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.

Retrieved from "https://commons.wikimedia.org/w/index.php?title=File:Gneiss_with_mafic_enclave_(Archean;_Norris_South_roadcut,_Madison_County,_Montana,_USA)_2_(44803636724).jpg&oldid=934793563"