Today I visited the mantle

Cyprus is one of the few places where rocks from the mantle crop out at the surface. They are not part of the mantle anymore, of course, but they were during the formation. Seeing mantle rocks and walking through moho (boundary between the crust and the mantle) should definitely be in every geologists lifetime list. I am very glad I did it today.

http://picasaweb.google.com/107509377372007544953/Cyprus#5736497097636994738
Me holding a piece of the mantle (harzburgite) in my hand.
http://picasaweb.google.com/107509377372007544953/Cyprus#5736497007440923922
Harzburgite is the main rock type of the deepest exposed sections. Harzburgite is a peridotite (ultramafic rock) that is composed of olivine (brown) and orthopyroxene (greenish brown reflective crystals) with minor chromite. Harzburgite is a residue of partial melting (take basalt or gabbro out of the mantle and harzburgite is what remains).
http://picasaweb.google.com/107509377372007544953/Cyprus#5736496960203772226
Dunite is an ultramafic rock that is composed almost exclusively of olivine. Dunites here usually contain some orthopyroxene as well and there seems to be a gradational transition from dunite to harzburgite.
http://picasaweb.google.com/107509377372007544953/Cyprus#5736496967181919954
Orthopyroxenite (ultramafic rock that contains almost only orthopyroxene) forms layers in dunite and harzburgite. Here is orthopyroxenite layer on top of dunite block.
http://picasaweb.google.com/107509377372007544953/Cyprus#5736497050092795026
Littlebit higher (stratigraphically but also topographically) there is a boundary between the crust and the mantle (moho) which is represented by layered cumulates.
http://picasaweb.google.com/107509377372007544953/Cyprus#5736496998177608402
All the rock types are partly hydrothermally altered (serpentinized). Here is a block of serpentinite on top of harzburgite.


3 comments to Today I visited the mantle

  • Howard

    This is a great “virtual field trip”! Thanks for bringing us along. How did you know where to go? Were you following a field trip guidebook? Or were you just exploring on your own?

  • I am in most part following a guidebook. The book is titled „Cyprus“, it is a part of a „Classic Geology in Europe“ series. Highly recommended!

  • A. Tenkaten

    Do not forget to visit the geology museum when you are up in the mountains. It is near the abandoned asbestos mine. Lovely geology here; tried to figure out the nature of the Mamonia complex, the museum proved a key to this.

Leave a Reply

You can use these HTML tags

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>