File:Pyritic quartz monzonite (Butte Quartz Monzonite, Late Cretaceous; Continental Pit, Butte, Montana, USA) (31040133400).jpg

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

Original file (2,850 × 2,480 pixels, file size: 5.67 MB, MIME type: image/jpeg)

Captions

Captions

Add a one-line explanation of what this file represents

Summary

[edit]
Description

Pyritic quartz monzonite from the Cretaceous of Montana, USA. (~5.5 cm across along the base)

This rock is from Butte, Montana, known as the “Richest Hill on Earth”. The mineralized rocks at Butte have produced gold, silver, copper, molybdenum, manganese, and other metals. Mineralization is hosted in the Butte Quartz Monzonite, a large Late Cretaceous igneous pluton. These rocks have been intruded & altered by hydrothermal veins containing valuable metallic minerals - principally copper sulfides. Copper mineralization has been dated to 62-66 million years ago, during the latest Maastrichtian Stage (latest Cretaceous) and Danian Stage (Early Paleocene).

This particular specimen is waste rock and not an ore sample. The quartz monzonite is richly pyritized (click on the photo to zoom in and look around). Pyrite is iron sulfide (FeS2) - it has a metallic luster and a brassy gold color.

Geologic unit: Butte Quartz Monzonite (a.k.a. Butte Pluton), Boulder Batholith, mid-Campanian Stage, late Late Cretaceous, 76.3 Ma

Locality: loose piece from rubble pile next to a large tailings pond, above the Continental Pit, town of Butte, Silver Bow County, southwestern Montana, USA
Date
Source Pyritic quartz monzonite (Butte Quartz Monzonite, Late Cretaceous; Continental Pit, Butte, Montana, USA)
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@N05/31040133400 (archive). It was reviewed on 1 December 2019 by FlickreviewR 2 and was confirmed to be licensed under the terms of the cc-by-2.0.

1 December 2019

File history

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

Date/TimeThumbnailDimensionsUserComment
current08:59, 1 December 2019Thumbnail for version as of 08:59, 1 December 20192,850 × 2,480 (5.67 MB)Ser Amantio di Nicolao (talk | contribs)Transferred from Flickr via #flickr2commons

The following page uses this file:

Metadata