Scent of a supercontinent: Gondwana's ores as chemical tracers—tin, tungsten and the Neoproterozoic Laurentia-Gondwana connection

Continental velocity through Precambrian times: The link to magmatism, crustal accretion and episodes of global cooling

“…The transition from 'A' to 'B' was probably concentrated during widespread w1.1 Ga Grenville orogenesis (see text) although the supercontinent continued to be constrained to the low order and symmetric hemispheric form within a single hemisphere until continental break-up during Ediacaran times at w0.6e0.55 Ga. (a) Illustrates the distribution of the rapakivi graniteanorthosite magmatic event unique to Mesoproterozoic and Early Neoproterozoic times (w1.7e1.0 Ga); ages of these intrusions become generally younger towards the instep of the crescent and dashed chrontour lines embrace emplacement ages limits to highlight this trend (after Piper, 1980 updated with age data summarised by Vigneresse, 2005); results from the Gondwana wing of Palaeopangaea are too few and dispersed to suggest age trends but mostly appear to fall within the older part of this interval. Tin-wolfram orefields form a single axial province on the Palaeopangaean reconstruction and are unique to this sector of the crust; although ages are unknown and reworked examples occur in PanAfrican and Andean belts; they are probably of primary Precambrian age (De Wit et al, 1999). (b) Shows global distribution of the w1.1 Ga Grenville mobile/orogenic belts with the concentration of arc and subduction-related magmatism in the instep of the supercontinent crescent between w1.0 and 0.6 Ga.…”

The geodynamic setting of the Phanerozoic basins of Africa

“…The Mozambique Belt here possibly represents a full-Wilson cycle, though evidence for initial rifting is scarce. Pan-African ages have also been determined in the south west of Madagascar, where the characteristic north-south foliation trend and Petters, 1991;Unrug, 1997;De Wit et al, 1999). the paleoposition of Madagascar adjacent to the East coast of Africa within Gondwana, may suggest that a portion of the Mozambique mobile belt outcrops on the island (Fig.…”

Protopangaea: Palaeomagnetic definition of Earth's oldest (mid-Archaean-Palaeoproterozoic) supercontinent

“…'Arctica' and 'Atlantica' by Rogers (1996) and Rogers and Santosh (2004) are indicated but note that Atlantica had not fully consolidated by the time period considered here. The distribution of straight belts is after Watson (1973) and the mineral distributions are generalised after Petrasheck (1973), Watson (1978), Berry (1980) andde Wit et al (1999). Note the concentration of gold and economic pegmatites within the oldest protocontinent of Ur with a second belt of gold emplacement running through Atlantica, whilst the broad zones of Tin and Tungsten are exclusive to Atlantica and comprise broad belts conforming to the form of the supercontinent.…”

“…The former are embraced by the interval considered here. Whilst the heterogeneous distribution of metallogenesis in the crust has usefully been linked to Plate Tectonic processes from several decades of study, it has become apparent that these distributions frequently reflect the products of older, and often Archaean and Palaeoproterozoic, deposition so that they can provide key tracers of continental growth (de Wit et al, 1999). One of the most striking is the concentration of tin and tungsten within long zones running through Atlantica ( Fig.…”