Jump to content

File:Madocite (tourmaline-pyrite metamorphite), Madoc Ontario.jpg

Page contents not supported in other languages.
This is a file from the Wikimedia Commons
From Wikipedia, the free encyclopedia

Original file (3,008 × 2,000 pixels, file size: 2.37 MB, MIME type: image/jpeg)

Summary

Description

“Madocite” (field of view ~2.7 cm across) from the Precambrian of Ontario.


Here’s a rock from Ontario having a mineral combination you don’t see very often. This sample is from a metamorphosed mafic dike that intrudes tremolite-talc schists hosted in dolomitic marble. The metamorphism has converted the original mafic igneous minerals into a mixture dominated by tourmaline (black) and pyrite (brassy gold). Some of the small bright white patches are talc. Tourmaline-pyrite metamorphic rocks lack a formal name, so the term “madocite” has been used by some geologists. Published mineral analysis indicates that “madocite” contains tourmaline, pyrite, tremolite, and some phlogopite mica.

Age of metamorphism - probably ~1.24 billion years, during the Mesoproterozoic. Subsequent metamorphism occurred at ~1.1 billion years, during assembly of the Rodinia supercontinent.

Initial metamorphic agent - probably emplacement of the nearby Deloro Granite.

Locality: Canada Talc Limited mine at Madoc, south-central Hastings County, southeastern Ontario, southeastern Canada.


Most info. from:

Dunn (1998) - Formation of dolomite-hosted massive talc at Madoc, Ontario. Geological Society of America Abstracts with Programs 30(7): 229-230.
Date
Source Madocite (tourmaline-pyrite metamorphite) (Precambrian; Canada Talc Limited Mine, Madoc, south-central Hasting County, se Ontario, se Canada)
Author James St. John

Licensing

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 jsj1771 at https://www.flickr.com/photos/47445767@N05/14874133400. It was reviewed on 31 August 2014 by FlickreviewR and was confirmed to be licensed under the terms of the cc-by-2.0.

31 August 2014

Captions

Add a one-line explanation of what this file represents

Items portrayed in this file

depicts

29 September 2007

File history

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

Date/TimeThumbnailDimensionsUserComment
current21:18, 31 August 2014Thumbnail for version as of 21:18, 31 August 20143,008 × 2,000 (2.37 MB)TillmanTransferred from Flickr via Flickr2commons

The following page uses this file:

Global file usage

The following other wikis use this file:

Metadata