Harzburgites come from the Earth's mantle and give valuable information on its composition, since it is not readily accessable.
HerkunftThis partially serpentinised harzburgite is from the "Hartsteinwerke Preg" quarry near Kraubath, Austria
- Highly depleted in most trace elements, except for transition metals.
- LILE (Rb, Sr, K, Ba): 0.27 - 100 µg/g.
- HFSE (Zr, Hf, Th, U, Nb, Ta) 0.014 - 0.42 µg/g.
- Transition metals (Sc, V, Cr, Co, Ni, Cu, Zn) 9.00-2710 µg/g.
Ultramafic rocks are characterised by very low silica (SiO2) content of <45 m/m%. and low potassium. Their principal mineralogy is comprised of Mg and Fe-rich minerals such as pyroxenes and olivine. The Earth's mantle consists of ultramafic rocks. Another term used to describe these rocks is ultrabasic, which includes rocks, that have a low silica content, but are not high in Mg and Fe i.e. carbonatites and ultrapotassic igneous rocks.