We introduce a modification to the current IUGS classification system for igneous rocks to include ultramafic lamprophyres, which are currently entirely omitted. This is done by including a new step in the sequential system, ...

In order to constrain the role of fluid phases during metasomatic processes in the upper mantle, trace element partition coefficients for Ba, Sr, Pb, Nb, Ta, Zr, Hf, Ti, La, Ce, Sm, Tb, and Yb between aqueous fluids and ...

Liquidus phase relations in the system diopside–kalsilite–forsterite–quartz with 3 wt% F were examined at 1 bar and the locations of important invariant points were determined at 18 kbar. At all pressures within this range ...

Fractionation of some or all of the high field strength elements (HFSE) Nb, Ta, Zr, Hf, and Ti relative to other trace elements occurs in igneous rocks from convergent margins and in the average continental crust, and is ...

Olivine leucitites from the Gaussberg volcano, Antarctica are primitive members of the lamproite group of ultrapotassic rocks. They are glass rich, have an Mg number of around 70, and carry spinel lherzolite xenoliths. ...

A definition for ultrapotassic rocks is introduced using the chemical screens K2O > 3 wt.%, MgO > 3 wt.% and K2O/Na2O > 2 for whole-rock analyses. On this basis a data base of more than 800 analyses was retrieved by a ...