Late Neoarchaean-Palaeoproterozoic supracrustal basin-fills of the Kaapvaal craton: Relevance of the supercontinent cycle, the "Great Oxidation Event" and "Snowball Earth"?

Abstract

The application of the onset of supercontinentality, the "Great Oxidation Event" (GOE) and the first global-scale glaciation in the Neoarchaean-Palaeoproterozoic as panacea-like events providing a framework or even chronological piercing points in Earth's history at this time, is questioned. There is no solid evidence that the Kaapvaal craton was part of a larger amalgamation at this time, and its glacigenic record is dominated by deposits supporting the operation of an active hydrological cycle in parallel with glaciation, thereby arguing against the "Snowball Earth Hypothesis". While the Palaeoproterozoic geological record of Kaapvaal does broadly support the GOE, this postulate itself is being questioned on the basis of isotopic data used as oxygen-proxies, and sedimentological data from extant river systems on the craton argue for a prolongation of the greenhouse palaeo-atmosphere (possibly in parallel with a relative elevation of oxygen levels) which presumably preceded the GOE. The possibility that these widespread events may have been diachronous at the global scale is debated.

A review of the inferred geodynamic evolution of the Dharwar craton over the ca. 3.5–2.5 Ga period, and possible implications for global tectonics

“…The Wilson Cycle can be seen as an integral part of the larger concept of the supercontinent cycle. When supercontinental dynamics are traced back into the deep geological past, as for the Proterozoic or even possibly the Archaean, it is clear that the relatively simple scenario of rifting of a large continental mass, separation of the relatively large daughter fragments on either side of a growing ocean, and eventual ocean closure together with reassembly of the earlier rifted margins in approximately similar mutual relationship (as implicit in Wilson's 1966 cycle derived from the Atlantic ocean example), becomes much more complex (e.g., Bleeker 2003;Eriksson et al 2011aEriksson et al , 2011b. Proterozoic supercontinents fragmented into many daughter components, and reassembly of the subsequent supercontinent several hundred million years later, encompassed a reassembly of fragments in a plethora of new relative orientations, reflecting multiple rotations and complex plate movements within a veritably Byzantine amalgamation history (e.g., Hartnady 1986;Hoffman 1991;Dalziel 1991;Moores 1991).…”

“…While the supercontinent cycle is widely accepted as a fundamental concept in geology, and is generally seen as one of the major controls on Earth's geological, palaeoclimatic, and biological evolution (e.g., Rogers and Santosh 2002), its antiquity, plates making up a specific supercontinent, and genesis (including relationship with mantle convective and plume processes) have generated much more debate (e.g., Unrug 1992;Rogers 1996;Dalziel 1997;Condie et al 2001;Meert 2002;Bleeker 2003;Personen et al 2003;Condie 2004aCondie , 2004bEriksson et al 2004Eriksson et al , 2009Eriksson et al , 2011aZhong et al 2007;Hou et al 2008;Nelson 2008). Supercontinents extended to at least 2 Ga (Miall 1997) and most likely to the Neoarchaean (e.g., Aspler and Chiarenzelli 1998).…”

“…Recently also, a comparison of the geological evolution of the Singhbhum (India) and Kaapvaal cratons was made (Mazumder et al 2012) which argued against any amalgamation of these cratons in the Palaeoproterozoic. Eriksson et al (2009Eriksson et al ( , 2011a examined the supercontinental affinities of the Kaapvaal craton more generally, including possible assembly with Dharwar; they argued against the latter assembly, citing several reasons such as poor age data from the Indian terrane.…”

“…3.5-2.5 Ga, and will attempt to interpret commonalities and distinctions arising with Kaapvaal geodynamic history as a subordinate aim. The geo-dynamic evolution of Kaapvaal has been summarized in a number of recent papers (e.g., Eriksson et al 2006aEriksson et al , 2006bEriksson et al , 2011aBumby et al 2012;Mazumder et al 2012;Eriksson and Condie 2013) and is thus not repeated here except for a summary figure (Fig. 2).…”

Secular changes in sedimentation systems and sequence stratigraphy

“…Kirschvink, 1992, or not), it is possible that diachroneity of influences and products was a more likely scenario (e.g., Eriksson et al, 2011b). Some unique events may also have intervened in the Earth's secular history, such as the possible "magmatic slowdown" (ca.…”