|
|
|
|
|
Basile, Christophe; Girault, Igor; Paquette, Jean-louis; Agranier, Arnaud; Loncke, Lies; Heuret, Arnauld; Poetisi, Ewald. |
We report the discovery of 173.4 Ma hotspot-related magmatic rocks in the basement of the Demerara Plateau, offshore French Guiana and Suriname. According to plate reconstructions, a single hotspot may be responsible for the magmatic formation of (1) both the Demerara Plateau (between 180 and 170 Ma) and the Guinea Plateau (circa 165 Ma) during the end of the Jurassic rifting of the Central Atlantic; (2) both Sierra Leone and Ceara Rises (mainly from 76 to 68 Ma) during the upper Cretaceous oceanic spreading of the Equatorial Atlantic ocean; (3) the Bathymetrists seamount chain since the upper Cretaceous. The present-day location of the inferred Sierra Leone hotspot should be 100 km west of the Knipovich Seamount. |
Tipo: Text |
|
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00628/74034/73363.pdf |
| |
|
|
Mercier De Lepinay, Marion; Loncke, Lies; Basile, Christophe; Roest, Walter; Patriat, Martin; Maillard, Agnes; De Clarens, Philippe. |
We present a global inventory of transform continental margins, based on both a worldwide comparison of continent-ocean boundary identifications with oceanic fracture zones traces, and a compilation of published regional studies. This inventory increases the number of identified transform margins from 29 to 78. These margins represent 16% of continental margins in cumulative length and 31% of non-convergent margins. We include morphological data, published upper crustal sections, continent to ocean transition locations and published Moho shape data in the new database. This review confirms that continent to ocean transitions are sharper at transform margins than at divergent margins. It also emphasizes the structural diversity of transform margins.... |
Tipo: Text |
Palavras-chave: Transform margin; Continental margin physiography; Marginal ridge; Marginal plateau. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00343/45372/44868.pdf |
| |
|
| |
|
|
|