In:
Geology, Geological Society of America, Vol. 47, No. 10 ( 2019-10-01), p. 923-927
Abstract:
Thermomechanical models of mantle convection and melting in an inferred hotter Archean Earth show the emergence of pressure-temperature (P-T) regimes that resemble present-day plate tectonic environments yet developed within a non–plate tectonics regime. The models’ P-T gradients are compatible with those inferred from evolving tonalite-trondhjemite-granodiorite series rocks and the paired metamorphic belt record, supporting the feasibility of divergent and convergent tectonics within a mobilized, yet laterally continuous, lithospheric lid. “Hot” P-T gradients of 10–20 °C km–1 form along asymmetric lithospheric drips, then migrate to areas of deep lithospheric downwelling within ∼300–500 m.y., where they are overprinted by high-pressure warm and, later, cold geothermal signatures, up to ∼8 °C km–1. Comparisons with the crustal production and reworking record suggest that this regime emerged in the Hadean.
Type of Medium:
Online Resource
ISSN:
0091-7613
,
1943-2682
Language:
English
Publisher:
Geological Society of America
Publication Date:
2019
detail.hit.zdb_id:
184929-3
detail.hit.zdb_id:
2041152-2
SSG:
13
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