Demise and recovery of Antillean shallow marine carbonate factories adjacent to active submarine volcanoes (Lutetian-Bartonian limestones, St. Bartholomew, French West Indies)

Abstract

Among other parameters, volcanic activity adjacent to shallow marine environments influences the development of ecosystems and their carbonate-producing communities. Volcaniclastic sediment influx in particular has potential to cause rapid and drastic environmental changes affecting biological systems in their composition and activity, and ultimately leading to changes to and breaks in carbonate sedimentation. Such sedimentary breaks that form in response to volcanic processes are rarely described in detail despite the common occurrence of carbonate platforms adjacent to active volcanoes both in the recent and past geological record. The Island of St. Bartholomew (St. Barths), French West Indies, exposes sections of middle Eocene limestones intercalated with thick volcaniclastic deposits and lavas. Theses carbonates provide an example of a low-latitude tropical platform where non-framework building biota were important, if not dominant, sediment contributors. The carbonate system records the repeated collapse and renewal of carbonate production, as a result of episodic volcaniclastic material input. The discontinuous nature of the carbonate sedimentation is reflected in contrasted depositional systems across sedimentary surfaces and gradational contacts. The studied Eocene deposits provide a sedimentary record of how volcanic events impacted warm-water carbonate factories, both in their disturbance, demise and recovery.