Abstract

Geologic transect across the Grenville orogen of Ontario and New York

“…2, a, b). The Karelian Craton and the Belomorian Province, that extends along the craton's eastern boundary, embrace the major in size and geological significance domains of the continental crust in the Fennoscandian Shield [Mints et al, 2015]. The crust was largely formed by the onset of the Neoarchaean and then underwent tectonic and metamorphic reworking during the Neoarchaean and Palaeoproterozoic.…”

“…Rocks of the Tipasjärvi-Kuhmo-Suomussalmi suture are dated at 2.81-2.74 Ga. According to geological data and interpretation of seismic crustal images along CMP profiles 1-EU, 4B, FIRE-1 and FIRE-3-3A, all the three sutures plunge in the eastern and northeastern directions and are traced down to the crust-mantle boundary [Mints et al, 2009[Mints et al, , 2015. The younger belts of the second group, which are primarily composed of epicontinental metasedimentary and metavolcanic rocks, are dated at 2.75-2.73 Ga.…”

“…Reflection seismic methods yield widely variable seismic images of the crust-mantle boundary at the base of Precambrian crust, and specific features of such images suggest a dependence on structure and formation history of the crust [BABEL Working Group, 1990;Abramovitz et al, 1997;White et al, 2000;Van der Velden, Cook, 2005;Kukkonen, Lahtinen, 2006;Mints et al, 2009Mints et al, , 2015Cook et al, 2010;Hammer et al, 2010;Mints, 2011]. It is assumed that beneath the Precambrian cratons, as a rule, this boundary is rather distinctly expressed in the replacement of the moderately or intensely reflecting lower crust by the mantle domain that is acoustically transparent.…”

“…It characterizes relationships between P-wave velocity, density, heat generation, and thermal conductivity of rocks, which determine gravity field, surficial heat flow, and internal fields of temperature and lithostatic pressure Glaznev, 2003]. Seismic images of the crust along detailed 4B, FIRE-1, FIRE-3-3A CMP profiles and corresponding geological interpretation sections [Kukkonen, Lahtinen, 2006;Mints et al, 2009Mints et al, , 2015Mints, 2011] are used as the second independent model. The efficient modern methods for 3D geophysical (petrophysical) modeling of the Earth's crust are based on the criteria-target-oriented approach [Strakhov, Romanyuk, 1984;Golizdra, 1988], which assumes a combination of the solutions obtained using a complex of geophysical methods within a certain coherent presentation of interpretational petrophysical parameters characterizing the geological medium [Glaznev, 1987[Glaznev, , 2003Glaznev et al, 1989Glaznev et al, , 1996Glaznev et al, , 2008Buyanov et al, 1995;Romanyuk, 1995;Romanyuk et al, 2001;Tiberi et al, 2003;Kozlovskaya et al, 2004;Artemieva et al, 2006;Kobrunov, 2008;Tikhotsky, Achauer, 2008].…”

Crustal Architecture of the Inverted Central Lapland Rift Along the HUKKA 2007 Profile

“…2; POLAR, SVEKA81, BALTIC, FIRE1, FIRE4) or revealing the internal architecture of the Archean (EU1, 4B, KostomukshaPechenga) or Paleoproterozoic (EGT/FENNOLORA, FINLAP7) (LUOSTO et al 1990;GUGGISBERG et al 1991;SHAROV 1993;MINTS et al 2004a;MINTS et al 2004b;GRAD and LUOSTO 1987;LUOSTO et al 1989;KUKKONEN et al 2006;PATISON et al 2006;JANIK et al 2009). Nevertheless, neither the lateral change along the strike of the terranes nor the more gradual NW-SE change from Archean to Paleoproterozoic dominated areas, is well understood.…”