Tectonic and sedimentary architecture of the Karukéra spur: A record of the Lesser Antilles fore-arc deformations since the Neogene

Forearc structure in the Lesser Antilles inferred from depth to the Curie temperature and thermo-mechanical simulations

“…9c) that has also been related to the subduction of sediments beneath the backstop [Christeson et al, 2003]. This is moreover consistent with basal erosion processes, suggested by Münch et al De Min et al [2015], rather than with frontal accretion. Indeed, Bangs et al…”

“…In detail, the discrepancies between observed and modeled data are reliable to the fact that we focus on the regional deep sources without studying the local shallow structures. De Min et al [2015] showed that the inner fore-arc at the latitude of the Guadeloupe archipelago is subsident since the late Paleogene-early Miocene, consistently with the negative gravimetric anomaly . This subsidence was related to four main extensional tectonic episodes since the early Miocene with various directions of extension.…”

“…This approach will help characterizing the regional thermal structures of the LAA but also better constraining the very complex structure of the fore-arc domain in its northern part where: (1) almost no heat flow data are available [synthesis in Manga et al, 2012], (2) an oligocene-miocene remnant arc is present East of the present-day active volcanic arc, thus in a fore-arc setting [e.g., Bouysse, 1979;Bouysse et al, 1985Bouysse et al, , 1988Bouysse and Westercamp, 1988] and (3) extensional tectonics is active since at least the early Miocene [Münch et al, 2014;De Min et al, 2015]. One of the main goals of this study is therefore to better understand the origin of magnetic anomalies along the LAA subduction zone.…”

“…the CPD determination and the thermomechanical modeling, have several fundamental implications on the LAA structure, particularly in the vicinity of the Guadeloupe archipelago. There, the structure of the fore-arc has been extensively studied concerning its deep parts [Bangs et al, 2003;Christeson et al, 2003;Evain et al, 2013;Kopp et al, 2011;Ruiz et al, 2013;Laigle et al, 2013a] and its shallow sedimentary cover [De Min et al, 2015;Laigle et al, 2013b;Münch et al, 2014].…”

“…This subsidence was related to four main extensional tectonic episodes since the early Miocene with various directions of extension. According to De Min et al [2015], such configuration and tectonic regime of the central Lesser Antilles fore-arc domain suggest that the subduction is erosive in this part of the LAA. Therefore the extensional and subsiding setting of the inner fore-arc basin since at least ~30 Ma is inconsistent with the assumed homogeneous crustal thickness of Kopp et al [2011].…”