Figure 2
From: Bilateral geochemical asymmetry in the Karoo large igneous province
Relative abundances of Nb, Zr, and Y in Karoo CFBs. (a) Variation of Zr/Y and Nb/Y in Karoo CFBs relative to depleted MORB and Icelandic plume-derived volcanic rocks. Plausible parental magma types with MORB-like (D-picrites23 and Ahlmannryggen (AR)29 dykes for South Karoo CFBs; P-dykes44,48 for North Karoo CFBs) and SCLM-like (E-picrites18,20,25,28 for South Karoo) characteristics are indicated and compositions of OIB-like South Karoo dykes23,29 are shown for comparison. The deviation of Nb/Y from the lower limit of the Icelandic array is quantified using a ΔNb parameter31 and TA error indicates estimated total analytical error (Methods). (b) Frequency distribution, average and standard deviation of ΔNb values. MORB data from http://georoc.mpch-mainz.gwdg.de/georoc/ and Icelandic array from ref.31.
