An introduction to Precambrian basins: their characteristics and genesis

• Published in: Sedimentary geology 2001-06, Vol.141 (1-4), p.1-35
• Main Authors: Eriksson, P.G, Martins-Neto, M.A, Nelson, D.R, Aspler, L.B, Chiarenzelli, J.R, Catuneanu, O, Sarkar, S, Altermann, W, Rautenbach, C.J.de W
• Format: Article
• Language: English
• Subjects: Eustasy and palaeoclimate; Magmatism; Precambrian basins; Rates of change; Tectonism
• ISSN: 0037-0738; 1879-0968
• DOI: 10.1016/S0037-0738(01)00066-5

Precambrian and younger basins reflect the interaction of sediment supply and subsidence; the latter is generally ascribed to tectonic, magmatic and related thermal processes. The interplay of supply and subsidence is further modified by eustasy and palaeoclimate. Problems and enigmas inherent in analysis of Precambrian basin-fills include: a spectrum of ideas on the maximum age of Phanerozoic-style plate tectonics in the rock record; Archaean heat flow up to two to three times present values; changes in magmatism over time (including global magmatic events); the evolution of atmospheric composition and of life and their influence on weathering, erosion and sediment supply rates; degree of preservation, deformation and metamorphism, and preservational bias (especially of intracratonic basins which would lack evidence for early plate tectonics); a limited rock record; poor age constraints, inherent errors in geochronological techniques and difficulty in dating the time of deposition of sedimentary rocks. Major influences on Precambrian basin formation are assumed to include magmatism, plate tectonics, eustasy and palaeoclimate, all of which interacted. Models for greenstone belt evolution include plate tectonic intra-oceanic generation, plume-generated oceanic plateau, and global catastrophic magmatic events that may have been transitional to a plate tectonic regime over several hundred million years. The latter transition may have included the onset of the supercontinent cycle. Insignificant preservation of Precambrian ocean floor makes evaluation of these models problematic. Eustasy was intrinsically related to continental crustal growth rates, continental freeboard and the hypsometric curves of emerging cratons. Possible maximum crustal growth rates near the Archaean–Proterozoic boundary led to globally elevated sea levels, and the formation of enormous carbonate-banded iron formation platforms where cyanobacterial mats, which produced oxygen, flourished. The combination of changes in cratonic growth rates, thermal elevation of cratons, eustasy, weathering and palaeo-atmosphere composition may have combined to produce the first global glaciation at ca. 2.4–2.2 Ga. Examples of basins discussed here emphasise the interaction of tectonism, magmatism, eustasy and palaeoclimate in their evolution. For the Neoarchaean Witwatersrand basin (Kaapvaal craton, South Africa), evidence for all these factors is preserved in the basin-fill, whereas for the Neoproterozo