Multiple sulfur isotopes constraints on origin and evolution of the Neoarchean and Paleoproterozoic Cu-Au systems from the Carajás Domain, Amazonian Craton, Brazil
Érika Suellen Barbosa SantiagoRoberto Perez XavierSteffen HagemannLena Virgínia Soares MonteiroJohn Cliff
7
Citation
88
Reference
10
Related Paper
Citation Trend
Keywords:
Metallogeny
Mass-independent fractionation
<p>In a geodynamic, geological and geophysical review of global Archean cratons, we find that the survival of Archean cratons depends on the initial conditions of their formation, as well as the tectonic processes to which they were exposed.&#160; In a sense, we must consider both their nature and how they were nurtured.&#160; In a review of existing literature and models, we use stability regime diagrams to understand the factors that contribute to the intrinsic strength of a craton: buoyancy, viscosity, and relative integrated yield strength. We find that cratons formed in the Archean when thermal conditions enhanced extraction of large melt fractions and early cratonization promoted the formation of stable Archean cratonic lithosphere.&#160; In terms of the cratons' nurturing, processes that may have modified and weaken cratonic lithosphere include subduction and slab rollback, rifting, and mantle plumes, as these processes introduced materials and conditions that warmed and metasomatized the lithosphere.&#160; Examining four Archean cratons that are more stable, and four that are categorized as modified or destroyed, we note that continental lithosphere that was cratonized prior to the end of the Archean has more potential to survive deformation during the last 500 My. Although, the survivability of these cratons is highly dependent on their unique positions relative to larger scale tectonic processes, such as subduction.&#160;&#160; We also observe that once an Archean craton begins to undergo even a small amount of modification, it is more likely to continue to be modified, as it loses the preservation advantage that it had upon birth.<br><br></p>
Cite
Citations (0)
Metallogeny
Cite
Citations (5)
Metallogeny
Orogeny
Cite
Citations (263)
Metallogeny
Mantle plume
Hotspot (geology)
Cite
Citations (0)
The original connections of Archean cratons are becoming traceable due to an increasing amount of paleomagnetic data and refined magmatic barcodes. The Uauá block of the northern São Francisco craton may represent a fragment of a major Archean craton. Here, we report new paleomagnetic data from the 2.62 Ga Uauá tholeiitic mafic dyke swarm of the Uauá block in the northern São Francisco craton, Eastern Brazil. Our paleomagnetic results confirm the earlier results for these units, but our interpretation differs. We suggest that the obtained characteristic remanent magnetization for the 2.62 Ga swarm is of primary origin, supported by a provisionally-positive baked contact test. The corresponding paleomagnetic pole (25.2°N, 330.5°E, A95 = 8.1°, N = 20) takes the present northern part of the São Francisco craton to moderate latitudes. Based on the comparison of the paleolatitudes of cratons with high-quality paleomagnetic data and magmatic barcodes, we suggest that the northern part of the São Francisco craton could have been part of the proposed Supervaalbara supercraton during the Archean. Supervaalbara is proposed as including (but not limited to) the part of the São Francisco craton as well as the Superior, Wyoming, Kola + Karelia, Zimbabwe, Kaapvaal, Tanzania, Yilgarn, and Pilbara cratons.
Yilgarn Craton
Greenstone belt
Cite
Citations (21)
Radiogenic nuclide
Indian Shield
Cite
Citations (47)
Supercontinent
Dharwar Craton
Cite
Citations (711)