Abundance of planktonic foraminifera from IODP Hole 339-U1386C

• Main Authors: Ducassou, Emmanuelle, Fournier, L A, Sierro, Francisco Javier, Alvarez Zarikian, Carlos A, Lofi, Johanna, Flores, José-Abel, Roque, C
• Format: Dataset
• Language: English
• Published: PANGAEA 2017
• Subjects: 339-U1386C; Abundance estimate; Beella digitata; Dentoglobigerina altispira; Dentoglobigerina baroemoenensis; DEPTH; sediment/rock; Description; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Exp339; Foraminifera; planktic indeterminata; Globigerina apertura; Globigerina bulloides; Globigerina calida; Globigerina falconensis; Globigerina obesa; Globigerinella aequilateralis; Globigerinella siphonifera; Globigerinita glutinata; Globigerinoides conglobatus; Globigerinoides extremus; Globigerinoides immaturus; Globigerinoides ruber white; Globigerinoides sacculifer; Globorotalia cf. crassula; Globorotalia crassaformis; Globorotalia hirsuta dextral; Globorotalia hirsuta sinistral; Globorotalia inflata dextral; Globorotalia inflata sinistral; Globorotalia margaritae; Globorotalia menardii; Globorotalia miocenica; Globorotalia puncticulata dextral; Globorotalia puncticulata sinistral; Globorotalia scitula dextral; Globorotalia scitula sinistral; Globorotalia truncatulinoides dextral; Globorotalia truncatulinoides sinistral; Globoturborotalita rubescens; Globoturborotalita tenella; Integrated Ocean Drilling Program / International Ocean Discovery Program; IODP; Joides Resolution; Lithologic unit/sequence; Mediterranean Outflow; Neogloboquadrina atlantica dextral; Planktonic foraminifera
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.870711; https://doi.org/10.1594/PANGAEA.870711

The base of the Faro contouritic drift (IODP Site U1386) on the northern margin of the Gulf of Cádiz (Algarve margin) is characterized by two sequences of frequent gravity deposits with different ages and compositions. Among these gravity deposits, several relatively thick debrites (up to 12 m) have been observed and studied in detail. Sedimentological analyses have been performed and because of non-turbulent behavior of debris flows, detailed micropaleontological studies could be realized. Planktonic foraminifera thus allowed establishing a detailed biostratigraphy of these deposits. Benthic foraminifer and ostracod assemblageswere used to evaluate the origin of the sediment composing these debris flows and estimate their run-out distance. These debrites are dated fromEarly Pliocene and early Pleistocene, andwere deposited in amesobathyal environment. They comprise silty mud clasts and matrixes with sand content up to 34%. The Early Pliocene debrites are bioclast-rich whereas the Early Pleistocene debrite is enriched in terrigenous particles. The data indicates that these debrites were triggered on the continental shelf and traveled less than 100 km, eroding the seafloor all along their path for the Early Pliocene debrites and only the first part of their path for the early Pleistocene debrite.Matrixes originate fromfailure areaswhereas eroded sediments along the flow pathway are incorporated into the flow as clasts. High abundance of shelf fauna during the Early Pliocene and great supply of terrigenous particles from rivers during the early Pleistocene in the south-western Iberian margin have favored gravity flows fromthe continental shelf to the slope. The contouritic paleo-moat of the Faro drift has been a determining channeling feature for gravity flows along the Algarve margin during the early Pleistocene, testifying of the strong interaction between MOW circulation and down-slope processes. Tectonic and diapiric activities were significant during Early Pliocene and early Pleistocene on the Algarve margin ...