Holocene Coastal Evolution and Facies Model of the Bragança Macrotidal Flat on the Amazon Mangrove Coast, Northern Brazil.

SOUZA FILHO, PEDRO WALFIR; COHEN, MARCELO; LARA, RUBÉN JOSÉ; LESSA. G. C.; KOCH, BORIS; BEHLING, HERMANN

JOURNAL OF COASTAL RESEARCH

CERF

Lugar: Florida; Año: 2006 p. 306 - 310

0749-0208

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:DE; mso-fareast-language:DE;} p.MsoBodyTextIndent, li.MsoBodyTextIndent, div.MsoBodyTextIndent {margin-top:0cm; margin-right:0cm; margin-bottom:0cm; margin-left:35.45pt; margin-bottom:.0001pt; text-align:justify; text-indent:-35.45pt; mso-pagination:widow-orphan; font-size:12.0pt; mso-bidi-font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-GB; mso-fareast-language:DE;} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} /* List Definitions */ @list l0 {mso-list-id:694115011; mso-list-type:hybrid; mso-list-template-ids:1179174070 67567631 67567641 67567643 67567631 67567641 67567643 67567631 67567641 67567643;} @list l0:level1 {mso-level-tab-stop:36.0pt; mso-level-number-position:left; text-indent:-18.0pt;} ol {margin-bottom:0cm;} ul {margin-bottom:0cm;} -->  <!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} p.abstract, li.abstract, div.abstract {mso-style-name:abstract; margin-top:12.0pt; margin-right:0cm; margin-bottom:14.2pt; margin-left:0cm; text-align:justify; mso-pagination:widow-orphan; font-size:9.0pt; mso-bidi-font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:Arial; color:black; mso-fareast-language:PT-BR;} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> The Bragança coastal plain is large macrotidal flat with barrier-beach ridge association located in Northern Brazil. This setting is a characteristic part of one of largest mangrove system in the world with approximately 8,900 km2. Data derived from surface sediment samples, vibra and percussion-cores, radiocarbon dating, and pollen analysis, provide a detailed stratigraphic interpretation and the reconstruction of paleo-environmental changes in the Bragança mangrove coastal plain. On the basis of lithology, sedimentary structures, texture, color, elevation and bounding surfaces, sixteen sedimentary facies were identified. A cross-normal morphostratigraphic profile situated between the coastal plateau and the recent barrier shows a steep paleo-cliff carved in the Barreiras Group, in direct contact with Quaternary deposits. The coastal evolution during the last 5100 yr B.P., is marked by relative sea-level close to the modern one, with macrotidal-dominated coastal environments associated to transgressive barrier-dune-beach ridges. Old mangrove deposits are probably associated with barriers from 5115 yr BP to 3412 yr BP. After 2100 yr B.P., a high-stand relative sea-level occurred, which was responsible for the muddy-mangrove development for more than 20 km seaward.