Pliocene to Pleistocene carbonate systems of the Guadeloupe archipelago, French Lesser Antilles: a land and sea study (the KaShallow project)

Abstract

This work presents a synthesis of the present-day knowledge on both emerged and submerged carbonate platforms of the Guadeloupe archipelago. Onshore and offshore data acquired during the KaShallow project are presented. Since the early Zanclean, some isolated platforms developed onto a Jurassic to Tortonian basement which displayed reliefs inherited from a major extensional tectonic episode dated from −8 to −5 Ma. Marie-Galante, Grande Terre and the southern shelf of Grande-Terre show strong similarities with Zanclean to Gelasian red-algal facies upward changing into early Calabrian coral facies. A major erosional unconformity (SB2) was recognized and allows to distinguish two early Calabrian formations (Calcaires à Agaricia Formation and Calcaires à Acropora Formation). The final emersion of these platforms is late Calabrian. The La Désirade platform displays Zanclean to early Piacenzian red-algal facies upward changing into coral facies. This platform emerged as soon as in the late Piacenzian. The island subsided again in relation with later extensional tectonic episode and early Calabrian reef platform then unconformably deposited. The Colombie bank deposits comprise Pliocene basinal deposits overlain by late Calabrian coral reefs. The Flandre bank might have emerged synchronously with La Désirade but was drowned only in the late Pleistocene-Holocene interval. Four extensional tectonic episodes have been identified in the late Miocene-Recent interval. Their effects depend on the location of the platforms within the fore-arc.

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

“…U S7 displays low amplitude to transparent facies (F2 -Table 1 and see seismic section of Fig. 6 in Münch et al, 2013). Such geometries of the latest submerged deposits along ancient platforms margins have been described elsewhere in the Guadeloupe Archipelago and were interpreted as reefal terraces of the last Holocene sea level rise (Leclerc et al, 2014).…”

“…Progradations infill paleovalleys of the basement and are directed to the bank margins (see seismic section of Fig. 6 in Münch et al, 2013; U S6 is correlated to FB1). At the top, the surface SB6 truncates the prograding lobes of U S6 .…”

“…Albeit mostly conformable in NAP and CAP, SB3 is clearly of tectonic origin in SAP. Moreover, in the Marie-Galante island a late Miocene unconformity is known, related to SB3 (De Min, 2014;Münch et al, 2013). Thus, SB3 is a major sequence boundary of the spur.…”

La Désirade island (Guadeloupe, French West Indies): a key target for deciphering the role of reactivated tectonic structures in Lesser Antilles arc building

“…As littoral deposits onlap the basement in the lower part of the Pliocene table, the topography of the basement was made under aerial conditions. By comparison with MarieGalante, this emersion surface was probably created during the latest Miocene to early Zanclean time-span [Münch et al, 2013]. Then, La Désirade suffered a drowning during the Zanclean.…”

“…1), the island of La Désirade exhibits the oldest rocks of the Lesser Antilles arc and the eastern Caribbean plate and represents the exhumed base of the active Lesser Antilles volcanic arc on which only indirect information is available. Moreover, recent investigations have clearly shown the importance of lower Cretaceous thrust tectonics as well as Pliocene extensional tectonics in the structural evolution of this island [Léticée, 2008;Cordey and Cornée, 2009;Corsini et al, 2011;Münch et al, 2013]. The latter represents therefore a key target for understanding the role of inherited structures for the development of current tectonic setting of the Lesser Antilles arc.…”