Introduction: Several types of magnesian highlands rocks occur in the lunar samples including the mafic Mg-suite rocks, magnesian feldpathic granulites, and magnesian anorthosites. Some mafic magnesian rocks are easily accommodated into the magma ocean model, as large variations in Mg/Fe are expected as the magma ocean crystallizes, forming source regions for magnesian melts. The origin of othe...

Eoarchean [3.6 to 4.0 billion years ago (Ga)] tonalite-trondhjemite-granodiorite (TTG) is the major component of Earth's oldest remnant continental crust, thereby holding the key to understanding how continental crust originated and when plate tectonics started in the early Earth. TTGs are mostly generated by partial melting of hydrated mafic rocks at different depths, but whether this requires...

Igneous sheet-complexes transport magma through the crust, but most studies have focused on single segments of magma-transport-system or low resolution. In Jameson Land Basin in East Greenland, reflection-seismic data and extensive outcrops give unparalleled constraints mafic intrusions down to 15 km. This dataset shows how sill-complexes develop is transported from mantle sedimentary basins. T...

In the Palaeoproterozoic Nagssugtoqidian orogen of West Greenland reworked Archaean and juvenile Proterozoic orthogneisses occur side by side and are difficult to differentiate in the field. Archaean gneisses have tonalitic to trondhjemitic compositions with relatively low Al2O3 and Sr, and may have been derived from magmas formed by melting of basaltic or amphibolitic rocks at moderate pressur...

Abstract Mafic magma intrusions into silica-rich magmatic reservoirs are commonly proposed to drive the eruptions of andesitic hybrid magmas that characterise many arc volcanoes. However, interactions between contrasting involve large gradients physical and chemical properties change over time, details such processes have proven difficult constrain. In this paper we investigate dynamics minglin...

Introduction: Defining the mineralogy and composition of martian mantle source regions has proved to be a difficult task because: (1) the martian sample set does not include samples of the mantle, and (2) many of the samples are either cumulates or are highly fractionated and therefore not in equilibrium with the mantle. Despite these complexities, isotopic evidence suggests that Mars had a mag...

The Von Damm Vent Field (VDVF) is located on the flanks of the Mid-Cayman Spreading Centre, 13 km west of the axial rift, within a gabbro and peridotite basement. Unlike any other active vent field, hydrothermal precipitates at the VDVF comprise 85-90% by volume of the magnesium silicate mineral, talc. Hydrothermal fluids vent from a 3-m high, 1-m diameter chimney and other orifices at up to 21...

ONE petrological approach to upper mant le studies is to determine which ultramafic rocks represent mantle material. Ultramafic rocks occur in a variety of field and petrographic associations : in recent reviews, Wyllie [1967b, 1968] outlined eleven petrographic associations, some with subdivisions. In this summary, it is convenient to consider these in four larger groups: (1) layered, stratifo...