Benthic foraminiferal fossil assemblages of the St. Peter’s Pool section, south-eastern part of the Malta Island, were analyzed for the first time. The St. Peter’s Pool section (MMi4a-MMi4b planktonic foraminiferal biozonal scheme of Di Stefano et al., 2008 emended by Iaccarino et al., submitted) that outcrops at Delimara Peninsula, belongs to the Upper Globigerina Limestone, the youngest member of the Globigerina Limestone formation. The sedimentary record is characterized by cyclic alternations of calcareous marl, marly limestone and jutting bioturbated hardened limestone. Taxonomic and quantitative analyses were carried out on benthic foraminiferal species in order to obtain paleoenvironmental information. Multivariate analyses were performed on some selected benthic foraminiferal species in order to demonstrate the linkage between taxa distribution and paleoenvironmental gradients. St. Peter’s Pool section is characterized by a highly diverse benthic foraminiferal assemblage with epifaunal as well as infaunal morphogroups typical of an upper-bathyal water-depth (e.g., Murray 1991, Schmiedl et al. 2003). The continuous and significant presence of the species Bolivina spathulata, Cassidulina laevigata and Cibicidoides pseudoungerianus with the contemporaneous presence of Siphonina reticulata, and the absence of taxa typical of shallow-water environments, also confirm the deposition in a relatively deep sedimentary basin. Throughout the section the benthic foraminiferal assemblage is characterized by a number of common and abundant species such as B, spathulata, C. laevigata, Cibicidoides dutemplei, C. pseudoungerianus, Gyroidina spp., Hanzawaia boueana, Lenticulina spp. and Melonis pompiloides; and by the presence of several species which show a scattered distribution as Uvigerina costata, well represented in the lowermost part of the section (from the base up to 13.90 m) and Uvigerina peregrina which is common from its appearance at ~6 m up to the top of the section. Paleoenvironmental implications of each epifaunal and infaunal morphogroups and their stratigraphic distribution suggest that oxygenation and trophic conditions are the most important factors that control the community structure of the benthic foraminiferal fauna. The temporal increase in the proportion of infaunal benthic foraminifera recorded between 10 and 13 m and between 19 and 21 m, reveals interval of reduced bottom-water oxygenation and relatively large nutrient availability.

(2011). Diversity abundance trends of benthic Foraminifera from the St. Peter's Pool Section, South-eastern part of Malta Island. In Joint RCMNS - RCANS Interim Colloquium, - Climate changes, bioevents and geochronology in the Atlantic and Mediterranean over the last 23 Myr (pp.107-108). Salamanca : F.J. Sierro & J.A.González-Delgado (eds.).

Diversity abundance trends of benthic Foraminifera from the St. Peter's Pool Section, South-eastern part of Malta Island

Foresi, L. M.;Mazzei, R.;Salvatorini, G.
2011

Abstract

Benthic foraminiferal fossil assemblages of the St. Peter’s Pool section, south-eastern part of the Malta Island, were analyzed for the first time. The St. Peter’s Pool section (MMi4a-MMi4b planktonic foraminiferal biozonal scheme of Di Stefano et al., 2008 emended by Iaccarino et al., submitted) that outcrops at Delimara Peninsula, belongs to the Upper Globigerina Limestone, the youngest member of the Globigerina Limestone formation. The sedimentary record is characterized by cyclic alternations of calcareous marl, marly limestone and jutting bioturbated hardened limestone. Taxonomic and quantitative analyses were carried out on benthic foraminiferal species in order to obtain paleoenvironmental information. Multivariate analyses were performed on some selected benthic foraminiferal species in order to demonstrate the linkage between taxa distribution and paleoenvironmental gradients. St. Peter’s Pool section is characterized by a highly diverse benthic foraminiferal assemblage with epifaunal as well as infaunal morphogroups typical of an upper-bathyal water-depth (e.g., Murray 1991, Schmiedl et al. 2003). The continuous and significant presence of the species Bolivina spathulata, Cassidulina laevigata and Cibicidoides pseudoungerianus with the contemporaneous presence of Siphonina reticulata, and the absence of taxa typical of shallow-water environments, also confirm the deposition in a relatively deep sedimentary basin. Throughout the section the benthic foraminiferal assemblage is characterized by a number of common and abundant species such as B, spathulata, C. laevigata, Cibicidoides dutemplei, C. pseudoungerianus, Gyroidina spp., Hanzawaia boueana, Lenticulina spp. and Melonis pompiloides; and by the presence of several species which show a scattered distribution as Uvigerina costata, well represented in the lowermost part of the section (from the base up to 13.90 m) and Uvigerina peregrina which is common from its appearance at ~6 m up to the top of the section. Paleoenvironmental implications of each epifaunal and infaunal morphogroups and their stratigraphic distribution suggest that oxygenation and trophic conditions are the most important factors that control the community structure of the benthic foraminiferal fauna. The temporal increase in the proportion of infaunal benthic foraminifera recorded between 10 and 13 m and between 19 and 21 m, reveals interval of reduced bottom-water oxygenation and relatively large nutrient availability.
(2011). Diversity abundance trends of benthic Foraminifera from the St. Peter's Pool Section, South-eastern part of Malta Island. In Joint RCMNS - RCANS Interim Colloquium, - Climate changes, bioevents and geochronology in the Atlantic and Mediterranean over the last 23 Myr (pp.107-108). Salamanca : F.J. Sierro & J.A.González-Delgado (eds.).
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11365/386897
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