Resedimented carbonates from the Jurassic of Mallorca

Abstract

The Cutri Formation of Mallorca consists of sediments which formed during the rifting of the Neotethys Ocean. It comprises thick carbonate turbidite sequences (interbedded with bioturbated marls, calcisilts and Posidonia bivalve coquinas) interpreted to have formed along a line source. The most abundant deposits are oolitic-peloidal grainstones and packstones, with sedimentary structures indicating primary deposition by high-density turbidity flows and debris flows which fed slope and base of slope sediments into a current-swept basin. With continued filling and diminishing sediment supply, a basin-plain association developed, comprising fine-grained and thin-bedded turbidites intercalated with bioturbated marls. A diagenetic history is developed that determined porosity was destroyed very quickly, mainly through compaction. The sedimentological and diagenetic history is compared to examples of resedimented carbonates that do provide good reservoir quality to try and understand the reason for porosity preservation compared to the Cutri Formation.