Wikimedia Commons

File:Trachyte obsidian (Quaternary; Ol Doinyo Nyukie Volcano, Kenya) 2.jpg

Original file ‎(3,145 × 2,325 pixels, file size: 6.47 MB, MIME type: image/jpeg)

Captions

Captions

Add a one-line explanation of what this file represents

Summary

edit
Description
English: Trachyte obsidian (glassy trachyte) from the Quaternary of Kenya. (7.9 centimeters across)

Obsidian is an uncommon igneous rock that varies in chemistry from felsic to intermediate to mafic to alkaline. Chemical analysis can show whether an obsidian is rhyolitic, dacitic, etc. The rock seen here is a trachyte obsidian from a small volcano in the East African Rift Valley called Ol Doinyo Nyukie (several variant spellings exist). Eastern Africa is being ripped apart by the Afar Hotspot and quite a few volcanoes having unusual lava chemistries are present along the rift zone. Ol Doinyo Nyukie is a Quaternary-aged volcano that has principally erupted phonolites and trachytes - both lithologies are intermediate extrusive igneous rocks that are high in alkali content (sodium and potassium). This rock is almost 100% glass, but there are some small, scattered phenocrysts of feldspar.

Locality: Ol Doinyo Nyukie Volcano, southern side of the Mt. Suswa caldera, southern Kenya, eastern Africa (the volcano is at 01º 09’ South latitude, 36º 21’ East longitude)
Date
Source https://www.flickr.com/photos/47445767@N05/50732153848/
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@N05/50732153848. It was reviewed on 18 December 2020 by FlickreviewR 2 and was confirmed to be licensed under the terms of the cc-by-2.0.

18 December 2020

File history

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

Date/TimeThumbnailDimensionsUserComment
current15:20, 18 December 2020Thumbnail for version as of 15:20, 18 December 20203,145 × 2,325 (6.47 MB)Ser Amantio di Nicolao (talk | contribs)Uploaded a work by James St. John from https://www.flickr.com/photos/47445767@N05/50732153848/ with UploadWizard

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:Trachyte_obsidian_(Quaternary;_Ol_Doinyo_Nyukie_Volcano,_Kenya)_2.jpg&oldid=882892906"