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THE CONCEPT OF CONTINENTAL BASIC SYLLOGENESIS AND THE ROLE OF CONVERGENT-DIVERGENT FEATURES IN CORRECT DIAGNOSTICS OF LAVA PALEOSTREAMS AND SHALLOW SILLS

G. S. Fedoseev

V.S.Sobolev Institute of Geology and Mineralogy SB RAS, Novosibirsk State University, Novosibirsk, Russia

The article initiated by a critical review of G.S.Fedoseev’s scientific publications on the concept of continental basic sillogenesis covers the state of the second phase of an almost century-old discussion of the facies nature of effusive-shaped reservoir basic bodies mapped as part of the Early Devonian deposits of the Minusinsk Trough. It shows that shallow mafic sills and lava paleostreams of similar composition possess not only convergent features that create problems in geological mapping of different scales, but also divergent features that allow a correct field diagnostics of reservoir bodies of the corresponding composition. Direct and indirect consequences of the concept of sillogenesis are noted, which contribute to the refinement of characteristics of some lithostratigraphic units. The antidromic scheme of Early Devonian magmatism in the Minusinsk trough is advocated: first, volcanism of the bulk and acid composition associated with sedimentation appeared, and then the formed deposits of the Byskar series were injected with numerous shallow basic sills.

Keywords: sillogenesis, shallow sills, Byskarian series, Marchengashskaya Formation, convergent and divergent features.

DOI 10.20403/2078-0575-2019-4-105-111-121