New Crustal Framework in the Amazon Craton Based on Geophysical Data: Evidences of Deep East-West Trending Suture Zones

Author(s)

Carneiro, Cleyton de C. ^[1] ; Juliani, Caetano ^[2] ; Carreiro-Araujo, Saulo A. ^[3] ; Monteiro, Lena Virginia S. ^[2] ; Crosta, Alvaro P. ^[4] ; Fernandes, Carlos Marcello D. ^[5]

Affiliation

^[1] Univ Sao Paulo, Mine & Petr Engn Dept, Escola Politecn, BR-05508010 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Dept Geol Sedimentar & Ambiental, Inst Geociencias, BR-05508010 Sao Paulo - Brazil

^[3] Exploracao & Prod Petroleo Brasileiro SA, PETROBRAS, BR-20031170 Rio De Janeiro - Brazil

^[4] Univ Estadual Campinas, Dept Geol & Recursos Nat, BR-13083970 Campinas, SP - Brazil

^[5] Univ Fed Para, Inst Geociencias, BR-66075110 Belem, Para - Brazil

• Document type: Journal article
• Source: IEEE Geoscience and Remote Sensing Letters; v. 16, n. 1, p. 20-24, JAN 2019.
• Web of Science Citations: 0

Abstract

The Tapajos mineral province (TMP), in the Brazilian Amazon Craton, comprises NW-SE Paleoproterozoic insular magmatic arcs accreted to the Carajas Archean Province (CAP). We present new geological and geophysical data pointing toward a different evolutionary model for the TMP. Results obtained from magnetic data indicate that NNW-SSE trending structures occur at shallow crustal levels. Furthermore, an E-W structural framework shows up at 15.4 km depth, in disagreement with the accreted island arc orientation. These E-W structures are associated with north-dipping blocks, reflecting ductile compressive tectonics, similar to the tectonic setting found in the CAP. We interpret these E-W structures of the TMP as the continuity westwards of similar structures from the CAP, under the Paleoproterozoic volcanic rocks of the Uatuma Supergroup. Based on this evidence, we propose that Paleoproterozoic arcs have been formed in an Archean active continental margin, instead of in island arcs. This novel tectonic setting for the TMP has significant implications for the tectonic evolution and the metallogenic potential of the southern portion of the Amazon craton, particularly for Paleoproterozoic magmatic-hydrothermal (epithermal and porphyry) precious and base metal systems. (AU)

• FAPESP's process: 10/10498-8 - GEOLOGY AND GOLD METALLOGENY OF THE TAPAJOS PROVINCE, ITAITUBA REGION, PARA STATE, BRAZIL: APPROACH BASED IN AEROGEOPHYSICAL MAGNETOMETRY AND GAMMASPECTROMETRY IMAGES.
• Grantee: Cleyton de Carvalho Carneiro
• Support Opportunities: Scholarships in Brazil - Post-Doctoral