Sedimentation in the adjacencies of a southwestern Atlantic giant carbonate ridge
Although carbonate mounds have been investigated for 100 years, few studies focus on the giant variety. The Alpha Crucis Carbonate Ridge (ACCR), a ~17 x 12-km ring-shaped ridge formed by hundreds of mounded structures, located between the 300 and 800-m isobaths and reaching a maximum height of 340 m...
Main Authors: | , , , , , , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Instituto Oceanográfico - Universidade de São Paulo
2022
|
Subjects: | |
Online Access: | https://revistas.usp.br/ocr/article/view/204781 |
id |
ftunivsaopojs:oai:revistas.usp.br:article/204781 |
---|---|
record_format |
openpolar |
spelling |
ftunivsaopojs:oai:revistas.usp.br:article/204781 2024-04-28T08:02:09+00:00 Sedimentation in the adjacencies of a southwestern Atlantic giant carbonate ridge Santos, Rosangela Felicio dos Kim, Bianca Sung Mi Trevizani, Tailisi Hoppe Oliveira, Rodrigo Udenal de Maly, Mascimiliano Ramos, Raissa Basti Figueira, Rubens Cesar Lopes Mahiques, Michel Michaelovitch de 2022-11-23 https://revistas.usp.br/ocr/article/view/204781 eng eng Instituto Oceanográfico - Universidade de São Paulo https://revistas.usp.br/ocr/article/view/204781/188411 https://revistas.usp.br/ocr/article/view/204781 Copyright (c) 2022 Ocean and Coastal Research Ocean and Coastal Research; Vol. 70 No. Suppl. 2 (2022): Biology and Geochemistry of seabed pockmark and carbonate mound habitats Ocean and Coastal Research; v. 70 n. Suppl. 2 (2022): Biology and Geochemistry of seabed pockmark and carbonate mound habitats 2675-2824 Carbonate mound Sedimentation SW Atlantic Continental slope info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Original Article 2022 ftunivsaopojs 2024-04-01T14:09:40Z Although carbonate mounds have been investigated for 100 years, few studies focus on the giant variety. The Alpha Crucis Carbonate Ridge (ACCR), a ~17 x 12-km ring-shaped ridge formed by hundreds of mounded structures, located between the 300 and 800-m isobaths and reaching a maximum height of 340 meters above the adjacent seafloor, is the first giant carbonate mounded feature described for the SW Atlantic margin. This study provides the first multiproxy approach to investigate sediments covering the ACCR and its adjacencies. Most of the area is located under the Intermediate Western Boundary Current (IWBC) flow, which carries the nutrient-rich Antarctic Intermediate Water (AAIW). Radiocarbon aging shows pronounced differences for the shallow layers (MIS3 for the top of the mounds and late Holocene for the adjacencies). Grain size data indicate the prevalence of sandy fractions on top of the mounds and muddy sediments in the adjacent areas. Fe/Ca and Ti/Ca proxies allowed for identifying mainly biogenic sedimentation in the area. However, the input of allochthonous terrigenous sediment is necessary for mound buildup, and values of Fe and Ti collected on the top of the mounds are significant. End-Members distributions and metal concentrations also allowed for recognition of distinct sources of sediment. εNd and Ln(Fe/K) indicated two primary terrigenous sources, the Precambrian rocks of the Brazilian shield (Cabo Frio end-member) and the multiple lithologies drained by the Rio de la Plata basin. Redox condition proxies indicated that the area is submitted to oxic conditions, probably reflecting the action of the IWBC. This work provides the first insight into an integrated grain-size and geochemical characterization of the Alpha Crucis Carbonate Ridge (southwestern Atlantic margin). Article in Journal/Newspaper Antarc* Antarctic Universidade de São Paulo: Portal de Revistas da USP |
institution |
Open Polar |
collection |
Universidade de São Paulo: Portal de Revistas da USP |
op_collection_id |
ftunivsaopojs |
language |
English |
topic |
Carbonate mound Sedimentation SW Atlantic Continental slope |
spellingShingle |
Carbonate mound Sedimentation SW Atlantic Continental slope Santos, Rosangela Felicio dos Kim, Bianca Sung Mi Trevizani, Tailisi Hoppe Oliveira, Rodrigo Udenal de Maly, Mascimiliano Ramos, Raissa Basti Figueira, Rubens Cesar Lopes Mahiques, Michel Michaelovitch de Sedimentation in the adjacencies of a southwestern Atlantic giant carbonate ridge |
topic_facet |
Carbonate mound Sedimentation SW Atlantic Continental slope |
description |
Although carbonate mounds have been investigated for 100 years, few studies focus on the giant variety. The Alpha Crucis Carbonate Ridge (ACCR), a ~17 x 12-km ring-shaped ridge formed by hundreds of mounded structures, located between the 300 and 800-m isobaths and reaching a maximum height of 340 meters above the adjacent seafloor, is the first giant carbonate mounded feature described for the SW Atlantic margin. This study provides the first multiproxy approach to investigate sediments covering the ACCR and its adjacencies. Most of the area is located under the Intermediate Western Boundary Current (IWBC) flow, which carries the nutrient-rich Antarctic Intermediate Water (AAIW). Radiocarbon aging shows pronounced differences for the shallow layers (MIS3 for the top of the mounds and late Holocene for the adjacencies). Grain size data indicate the prevalence of sandy fractions on top of the mounds and muddy sediments in the adjacent areas. Fe/Ca and Ti/Ca proxies allowed for identifying mainly biogenic sedimentation in the area. However, the input of allochthonous terrigenous sediment is necessary for mound buildup, and values of Fe and Ti collected on the top of the mounds are significant. End-Members distributions and metal concentrations also allowed for recognition of distinct sources of sediment. εNd and Ln(Fe/K) indicated two primary terrigenous sources, the Precambrian rocks of the Brazilian shield (Cabo Frio end-member) and the multiple lithologies drained by the Rio de la Plata basin. Redox condition proxies indicated that the area is submitted to oxic conditions, probably reflecting the action of the IWBC. This work provides the first insight into an integrated grain-size and geochemical characterization of the Alpha Crucis Carbonate Ridge (southwestern Atlantic margin). |
format |
Article in Journal/Newspaper |
author |
Santos, Rosangela Felicio dos Kim, Bianca Sung Mi Trevizani, Tailisi Hoppe Oliveira, Rodrigo Udenal de Maly, Mascimiliano Ramos, Raissa Basti Figueira, Rubens Cesar Lopes Mahiques, Michel Michaelovitch de |
author_facet |
Santos, Rosangela Felicio dos Kim, Bianca Sung Mi Trevizani, Tailisi Hoppe Oliveira, Rodrigo Udenal de Maly, Mascimiliano Ramos, Raissa Basti Figueira, Rubens Cesar Lopes Mahiques, Michel Michaelovitch de |
author_sort |
Santos, Rosangela Felicio dos |
title |
Sedimentation in the adjacencies of a southwestern Atlantic giant carbonate ridge |
title_short |
Sedimentation in the adjacencies of a southwestern Atlantic giant carbonate ridge |
title_full |
Sedimentation in the adjacencies of a southwestern Atlantic giant carbonate ridge |
title_fullStr |
Sedimentation in the adjacencies of a southwestern Atlantic giant carbonate ridge |
title_full_unstemmed |
Sedimentation in the adjacencies of a southwestern Atlantic giant carbonate ridge |
title_sort |
sedimentation in the adjacencies of a southwestern atlantic giant carbonate ridge |
publisher |
Instituto Oceanográfico - Universidade de São Paulo |
publishDate |
2022 |
url |
https://revistas.usp.br/ocr/article/view/204781 |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Ocean and Coastal Research; Vol. 70 No. Suppl. 2 (2022): Biology and Geochemistry of seabed pockmark and carbonate mound habitats Ocean and Coastal Research; v. 70 n. Suppl. 2 (2022): Biology and Geochemistry of seabed pockmark and carbonate mound habitats 2675-2824 |
op_relation |
https://revistas.usp.br/ocr/article/view/204781/188411 https://revistas.usp.br/ocr/article/view/204781 |
op_rights |
Copyright (c) 2022 Ocean and Coastal Research |
_version_ |
1797573598528929792 |