Age and geochemistry of Cambaí Complex, Sao Gabriel Terrane, Brazil: Arc-related TTG-like rocks

The Cambai Complex TTG-like rock assemblage representing a Neoproterozoic juvenile magmatic arc is part of the Sa similar to o Gabriel Terrane that crops out in the SW domain of the Dom Feliciano Belt in S-Brazil. Geochemistry of dioritic, tonalitic, trondhjemitic, and granodioritic rocks of this complex indicate their low-medium-K calcalkaline geochemical affinity being metaluminous and with fractional crystallization as the main magmatic process of formation. Whole-rock geochemistry enrichment in LILE as Sr and Ba in relations to HFSE as Y and Zr, with flat patterns in an REE spider diagram, with enrichment to chondrite ((La/Yb) N = 1.3 to 17.2) and low Eu anomaly (Eu/Eu* = 1.2), with 87Sr/86Sr(i) from 0.704260 to 0.706430, 143Nd/144Nd(t) from 0.512070 to 0.512080, Nd-TDM model age from 820 to 852 Ma, epsilon Nd(t) from 3.9 to 4.2 and 207Pb/204Pb and 206Pb/204Pb ranged from 15.5040 to 15.5776 and 17.5313 to 18.5696, suggest an immature magmatic arc-related rock setting. Geochronology U-Pb LA-ICP-MS in zircons from diorites shown Tonian crystallization ages (745 +/- 4 Ma, 748 +/- 5 Ma, 752 +/- 4 Ma). Any model proposed to explain the history of the evolution of the West Gondwana Supercontinent needs to consider the accretion of juvenile crust from primitive mantle source with minor crustal contamination in this segment of the orogenic collage during the Neoproterozoic.

Automated summary

The Cambai Complex TTG-like rock assemblage represents a Neoproterozoic juvenile magmatic arc with calcalkaline geochemical affinity, showing an immature magmatic arc-related rock setting. The rocks indicate low-medium-K calcalkaline geochemical characteristics and suggest a juvenile crust accretion with minor crustal contamination during the Neoproterozoic in the SW domain of the Dom Feliciano Belt in S-Brazil.