The Alpha Crucis Carbonate Ridge (ACC R): Discovery of a giant ringshaped carbonate complex on the SW Atlantic margin Maly, Mascimiliano Lobo, Francisco José Recently acquired bathymetric and high-resolution seismic data from the upper slope of Santos Basin, southern Brazilian margin, reveal a major geomorphological feature in the SW Atlantic that is interpreted as a carbonate ridge - the Alpha Crucis Carbonate Ridge (ACCR). The ACCR is the first megastructure of this type described on the SW Atlantic margin. The ~17 × 11-km-wide ring-shaped ACC R features tens of >100-m-high steep-sided carbonate mounds protruding from the surrounding seabed and flanked by elongated depressions. Comet-like marks downstream of the mound structures indicate that the area is presently influenced by the northward flow of the Intermediate Western Boundary Current (IWBC), a branch of the Subtropical Gyre that transports Antarctic Intermediate Water. Abundant carbonate sands and gravels cover the mounds and are overlain by a biologically significant community of living and dead ramified corals and associated invertebrates. The IWBC acts as a hydrodynamic factor that is responsible for both shaping the bottom and transporting coral larvae. We contend that the ACCR was formed by upward fluid flow along active sub-surface faults and fractures that formed by lateral extension generated by the ascending movement of salt diapirs at depth. The ACC R provides an important modern and accessible analogue for a seabed carbonate build-up related to sub-surface hydrocarbon systems. 2020-01-09T13:47:11Z 2020-01-09T13:47:11Z 2019 journal article Maly, M., Schattner, U., Lobo, F. J., Dias, R. J. S., Ramos, R. B., de Matos Couto, D., ... & de Mahiques, M. M. (2019). The Alpha Crucis Carbonate Ridge (ACCR): Discovery of a giant ring-shaped carbonate complex on the SW Atlantic margin. Scientific Reports, 9(1), 1-10. http://hdl.handle.net/10481/58600 10.1038/s41598-019-55226-3 eng http://creativecommons.org/licenses/by/3.0/es/ open access Atribución 3.0 España Springer Nature