Peridotite mantle xenoliths in phonotephrite (Peridot Mesa Flow, Middle Pleistocene, 580 ka; Peridot Mesa, San Carlos Volcanic Field, Arizona, USA) 14

            Peridotite mantle xenoliths in phonotephrite from the Pleistocene of Arizona, USA.

Green = peridotite
Gray = phonotephrite host rock

“Peridot” is a gemological term for gem-quality forsterite olivine, but it does not differ in any chemical sense from ordinary olivine.  Gem-quality olivine is known from several places on Earth, including Peridot Mesa in southeastern Arizona, USA.
 
The volcanic rocks making up Peridot Mesa are gray, slightly vesicular phonotephrites (formerly misidentified as basanites) of the Peridot Mesa Flow, a 3 to 35 meter thick lava flow erupted during the Middle Pleistocene (~580,000 years ago).
 
The Peridot Mesa lavas have common greenish-colored xenoliths derived from the mantle.  The xenoliths are ultramafic, crystalline-textured, intrusive igneous rocks principally composed of olivine and/or pyroxene.  Specific Peridot Mesa xenolith lithologies include spinel lherzolite, dunite, harzburgite, clinopyroxenite, websterite, and orthopyroxenite.

The green xenoliths shown here appear to be spinel lherzolite or spinel dunite, dominated by lime green-colored, glassy-lustered forsterite olivine (Mg2SiO4).  Other minerals include bright green chromian diopside pyroxene ((Ca,Cr)MgSi2O6), and black spinel (MgAl2O4).
 
Some of the green olivine crystals in Peridot Mesa mantle xenoliths are large enough, transparent enough, and richly green enough to be gem quality ("peridot").

Stratigraphy: Peridot Mesa Flow, middle Middle Pleistocene, ~580 ka
 
Locality: Peridot Mesa, San Carlos Volcanic Field, San Carlos Apache Reservation, southeastern margin of Gila County, southeastern Arizona, USA

Some rights reserved

Taken on: November 9, 2018

Tags:

olivine

Peridot

Arizona

Pleistocene

phonotephrite

lava

mantle

xenolith

lherzolite

peridotite « less

Sets appears in: • Green Rocks, Minerals, Fossils • Pleistocene Rocks & Fossils more » • Arizona Rocks & Fossils • Peridot Mesa (San Carlos Volcanic Field, southeastern Arizona, USA) « less

Groups appears in: • Earth Science Teaching Resource

Stats: 910 views

go back

close tools panel

Badge creator

Use Flickriver Badge Creator to create a badge linking to your photos, your group or any other Flickriver view.

You can place your badge on your Flickr profile, Blog or Website.

Add to your iGoogle or Netvibes page

Flickriver widget for iGoogle or Netvibes can display almost any Flickriver view - most interesting today, by user, by group, by tag etc. Once added to your personalized homepage, just edit widget settings to select your desired view.

Clickr on one of the buttons below to install:

Embed on your Web site

To embed this view, Copy and Paste the following HTML code:

Black background (preview):

White background (preview):

Firefox and Chrome addons

Adds a 'Flickriver' button to your browser. While viewing any Flickr photos page, click on this button to open the same view on Flickriver.

Install in Firefox
Install in Chrome

Search plugin

Add 'Search on Flickriver' to your browser's search box. Works with Firefox and Internet Explorer. Install search plugin

"View on Flickriver" Greasemonkey script

A Greasemonkey script that adds Flickriver links to various Flickr photo pages - user photos, favorites, pools etc, allowing to quickly open the corresponding Flickriver view.

Also, allows quickly viewing any Flickr photo on black background in large size.

Install "View on Flickriver" script

Bookmarklet

While viewing any Flickr photos page, click on the bookmarklet to open the same view on Flickriver.

To install: drag and drop the following link to your Bookmarks toolbar.
IE users - add the link to your Favorites under the Links folder