The Rum Layered Suite

Experimental petrology constraints on the recycling of mafic cumulate: a focus on Cr-spinel from the Rum Eastern Layered Intrusion, Scotland

“…Each unit is formed of peridotite (olivine-rich cumulate) overlain by plagioclase-bearing cumulate (troctolite, gabbro and poikilitic gabbro, in variable proportions; known collectively as allivalite). The sill complex was fed by new magma injections along the Central Zone fault originating from a magma source at a depth of several kilometres (Emeleus et al, 1996). The intrusive units were thought originally to have formed by fractionation of individual batches of olivine-phyric picrite melts (Brown, 1956;Upton et al, 2002).…”

“…Lateral variations may be explained by local accumulation of high temperature crystals and the segregation of interstitial melt that will fractionate down-temperature. Also gravity currents (Emeleus et al, 1996;Tepley and Davidson, 2003;O'Driscoll et al, 2007) may transport and juxtapose grains crystallized at different conditions.…”

Geophysical Modelling of the Molopo Farms Complex in Southern Botswana; Implications for Its Emplacement Within the 2 Ga Large Igneous Provinces of Southern and Central Africa

“…The overall gently to moderately dipping lopolithic shape of the MFC in southern Botswana identified by previous workers with steeply dipping feeders is typical of layered ultramafic/mafic complexes (e.g. Emeleus et al, 1996). The discontinuous nature of layering within the MFC, in part due to faulting and shearing, coupled with the almost complete absence of exposure means that it is unlikely that laterally extensive PGE mineralization similar to that found in the contemporaneous Bushveld Complex will be found in the MFC.…”

“…However, these ultramafic rocks along with the later (second-stage) mafic rocks also form steeply dipping, dyke-like bodies locally aligned along major, steeply dipping shear zones. It is proposed that these steeply dipping bodies represent solidified feeders to the lobate or lopolithic parts of the MFC, analogous for example, to the model for the emplacement of the Rum Central Complex (Emeleus et al, 1996).…”

Mineral-scale Sr isotope variation in plutonic rocks — a tool for unravelling the evolution of magma systems

“…Thus the isotopic heterogeneity is more consistent with emplacement as multiple 16 sheets rather than a single volume of magma. Emeleus et al, (1996) note that field and petrographic evidence is also consistent with multiple intrusion.…”