Chemical weathering and erosion rates in the Lesser Antilles: An overview in Guadeloupe, Martinique and Dominica

Construction and destruction rates of volcanoes within tropical environment: Examples from the Basse-Terre Island (Guadeloupe, Lesser Antilles)

“…In the Lesser Antilles, the erosion rates of 610 ± 550 and 1350 ± 550 t/km 2 /yr, obtained here for the Monts-Caraïbes and the Beaugendre Valley, respectively, are comparable with those determined for Montserrat Island (0.0125 km 3 /kyr; Le Friant et al, 2004) or Martinique Island (131-2150 t/km 2 /yr; Germa et al, 2010) and with chemical weathering rates obtained for La Dominica (116 to 481 t/km 2 /yr; Rad et al, 2013). However, the erosion rates computed for Basse-Terre Island are lower than those determined on islands characterized by similar climatic and hydrological regimes, such as La Reunion Island with erosion rates of 1200-9100 t/km 2 /yr (Louvat and Allègre, 1997) and, more recently, of 6000-18,000 t/km 2 /yr (Salvany et al, 2012), or Tahiti Island where rates of 3645-8292 t/km 2 /yr have been obtained (Hildenbrand et al, 2008).…”

“…6). The high rate obtained for the Carbet River may be the consequence of the active erosion of the young volcanic formation constituting the watershed (Rad et al, 2013). On the contrary, the much lower erosion rate obtained for Capesterre can be related to its location on the east coast, where the low slope of it watershed suggests a steady state of the river, and hence leads to low erosion rate over a short timescale when obtained by the mass budget method.…”

“…This makes this island an especially suitable place to quantify long-term erosion processes. On this island, estimation of total erosion rate has been previously proposed based on determination of only the present-day chemical erosion rate (Rad et al, 2006;Rad, 2007;Rad et al, 2013). However, in addition to the surprisingly wide range of erosion rates obtained, such an approach constrains the erosion rate only over a very short time interval (on the order of a few years) and does not take into account extreme climatic events like storms and hurricanes regularly affecting Basse-Terre Island, and which, most probably, contribute significantly to the erosion budget.…”

The reef platform of Martinique: Interplay between eustasy, tectonic subsidence and volcanism since Late Pleistocene

“…Terrigenous volcanic materials are also eroded at a high rate in the Lesser Antilles (Rad et al, 2006), especially in the young drainage basins of northern Martinique, and are sporadically brought to the sea by rivers that have torrential hydrodynamic behaviors (Rad et al, 2013). The northern part of the Atlantic coast of Martinique is the wettest (Rad et al, 2013), and therefore the high amount of sediments discharged by rivers and the consecutive increase in turbidity of the water most certainly prevent current reefs to develop along the northern coast of the island.…”

“…The northern part of the Atlantic coast of Martinique is the wettest (Rad et al, 2013), and therefore the high amount of sediments discharged by rivers and the consecutive increase in turbidity of the water most certainly prevent current reefs to develop along the northern coast of the island.…”