Our study aims to reconstruct the palaeogeography of the northern part of the Lesser Antilles in order to analyse whether emerged areas might have existed during the Cenozoic, favouring terrestrial faunal dispersals between South America and the Greater Antilles along the present-day Lesser Antilles arc. The stratigraphy and depositional environments of the islands of Anguilla, St Martin, Tintamarre, St Barthélemy, Barbuda and Antigua are reviewed in association with multichannel reflection seismic data acquired offshore since the 80's in the Saba, Anguilla and Antigua Banks and in the Kalinago Basin, including the most recent academic and industrial surveys. Seven seismic megasequences and seven regional unconformities are defined, and calibrated from deep wells on the Saba Bank and various dredges performed during marine cruises since the 70's in the vicinity of the islands. Onshore and offshore correlations allow us to depict an updated and detailed sedimentary organisation of the northern part of the Lesser Antilles from the late Eocene to the late Pleistocene. Paleogeographic reconstructions reveal sequences of uplift and emergence across hundredswide areas during the late Eocene, the late Oligocene, the early middle-Miocene and the latest Miocene-earliest Pliocene, interspersed by drowning episodes. The ∼200 km-long and ∼20 km-wide Kalinago Basin opened as an intra-arc basin during the late Eocene -early Oligocene. These periods of emergence may have favoured the existence of episodic mega-islands and transient terrestrial connections between the Greater Antilles, the Lesser Antilles and the northern part of the Aves Ridge (Saba Bank). During the Pleistocene, archipelagos and mega-islands formed repeatedly during glacial maximum episodes.

Worldwide, forearc trench-perpendicular basins are interpreted as the result of trench-parallel extension possibly due to either strain partitioning as at the Aleutians (Ryan & Scholl, 1989) and Ryukyu (Nakamura, 2004) Subduction Zones, and/or to increasing margin curvature as at the Marianas (Heeszel et al., 2008) and Hellenic trenches (Angelier, 1978; Mascle & Martin, 1990). In more extreme cases, widespread deformation of forearc domains results from the collision of buoyant crustal features (e.g., oceanic plateaus, seamount chains, or continental fragments) which is prone to generate bending and rotation of subduction zones (e.g., Vogt et al., 1976). Strongly curved convergent plate boundaries are subject to alongstrike variations in subduction obliquity and thus commonly associated with large-scale rigid body rotation