Gravity and Magnetic Constraints on the Crustal Structure of the Ceara Plateau, Brazilian Equatorial Margin

Author(s)

de Moura, Denise Silva ^{[1, 2]} ; Molina, Eder Cassola ^[1] ; Marangoni, Yara Regina ^[1] ; Jovane, Luigi ^[2]

Affiliation

^[1] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, Inst Oceanog, Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: Frontiers in Earth Science; v. 7, DEC 4 2019.
• Web of Science Citations: 0

Abstract

The Brazilian Equatorial Margin (BEM) is a transform passive margin with long fracture zones and several seamounts, including the largest one, the Ceara Plateau (CP). This is a complex and poorly studied area, with few available geophysical data. Gravity and magnetic data from the Equant I Project, seismic published lines and other previous studies are used to make several models and analyses. We related the basement, internally comprised of two magmatic highs, to gravity and magnetic anomalies since there are a positive density and susceptibility contrast between sedimentary and basement rocks. Through gravity and magnetic forward modeling, we estimated the basement surface between 800 and 6000 m and the Mohorovicic discontinuity about 22-23 km below the CP. We also present and discuss the position of the continent-ocean boundary 40 km away from the continental shelf, placing the plateau at the oceanic crust domain, and the area of the transitional crust, with an extension of 40-50 km, formed during the rifting phase of the Atlantic Ocean opening. (AU)

• FAPESP's process: 16/24946-9 - Sea-level changes and Global Monsoon System: clues from marine cores in Brazil
• Grantee: Luigi Jovane
• Support Opportunities: Research Program on Global Climate Change - Thematic Grants
• FAPESP's process: 16/15854-3 - Gravimetric and magnetic modelling of the Ceará plateau, Brazilian equatorial margin
• Grantee: Denise Silva de Moura
• Support Opportunities: Scholarships in Brazil - Master