Late Gauss to Early Matuyama invasions of Neogloboquadrina Atlantica in the Mediterranean and associated record of climatic change

Abstract

A well‐dated, high‐resolution record of climatic change is presented for the late Pliocene Mediterranean. Principal component analysis on abundances of 14 planktonic foraminiferal species reveals a series of late Gauss to early Matuyama surface water cooling events which can be correlated with North Atlantic glacial isotope stages 108 to 94. The abundance record of the benthic foraminifer Trifarina angulosa suggests lowered bottom water temperatures at times of surface water cooling. The record of surface water oxygen and carbon isotopes shows an inverse pattern with δ18O maxima and δ13C minima at times of cool sea surface temperature conditions. Concomitant decrease in P/B value and increased admixtures of clastic material suggest that late Gauss to early Matuyama surface water cooling events in the Mediterranean are accompanied with glacioeustatic sea level low‐stands. Major surface water cooling events are associated with invasions of Neogloboquadrina atlantica. This North Atlantic mid‐ to high‐latitude species is at 2.55 Ma close to the Gibraltar portal whereafter it could invade the Mediterranean repeatedly during periods of climatic cooling until it disappears from all over the North Atlantic and Mediterranean at the end of glacial stage 96.

Integrated magnetostratigraphy and biostratigraphy of the upper Pliocene-lower Pleistocene from the Monte Singa and Crotone areas in Calabria, Italy

“…Three more influxes occur in the thick homogeneous interval between the A and B sapropel clusters. These successive occurrences of N. atlantica have been correlated to glacial isotope stages 108, 106, 104, 100, 98 and 96 in DSDP Site 607 [7]. An even older influx of this species has recently been found slightly below the A1 in the Punta Piccola section on Sicily and correlates with stage 110 [24].…”

“…An even older influx of this species has recently been found slightly below the A1 in the Punta Piccola section on Sicily and correlates with stage 110 [24]. The last occurrence (LO) of N. atlantica in the Mediterranean is marked by the influx of this species at isotopic stage 96 and is synchronous with the final extinction of the species in the North Atlantic [7,25].…”

“…The long reversed polarity zones both below and above the relatively short interval with normal polarities identifies this central normal zone as representing the Olduvai subchron. The lowermost normal polarity zone in the upper Singa section has been correlated previously to the youngest part of the Gauss chron [7].…”

“…In the middle of the Pliocene, however, a substantial part is missing: a hiatus of approximately 1 Ma corresponds to the interval of the uppermost part of the Gilbert Chron and a major part of the Gauss Chron [2,7]. The sequence below the hiatus (lower Singa) includes the M/P boundary and has been the subject of a study by Zijderveld et al [2].…”

“…The Miocene-Pliocene (M/P) boundary has been studied by various authors [2][3][4] and now has an age, according to the conventional radiometric time scale, of 4.86 Ma, slightly below the Thvera subchron. The early Pliocene and early late Pliocene have been the subject of detailed magnetostratigraphic and biostratigraphic research by Langereis and Hilgen [5] and Zachariasse et al [6,7].…”