Orbitally forced paleoenvironmental and paleoclimate changes in the late postevaporitic Messinian of the central Mediterranean Basin

Abstract

Paleoenvironmental and paleoclimate changes that occurred during the late postevapo ritic stage of the Mediterranean Basin in the Messinian foreland domain of the Adriatic region offer a new perspective on the relationship between orbital forcing and climate response. The magnetic susceptibility record of the Fonte dei Pulcini A section (Maiella Mountains, Italy) allows us to orbitally tune the record between 5.394 and 5.336 Ma and to temporally constrain the paleoenvi ronmental and paleoclimate changes evidenced by quantitative paleontological (palynomorphs, ostracods, and calcareous nannofossils), stable isotope (δ 18 O and δ 13 C), and X-ray diffraction (XRD) analyses. The base of the Fonte dei Pulcini A section is characterized by Paratethyan ostracods and dinocysts, which point to the late Messinian Lago-Mare biofacies (Loxocorniculina djafarovi zone) of the Mediterranean Messinian stratigraphy. From paleontological and geochemical (δ 18 O) analyses, there is no evidence of a marine incursion in the Fontedei Pulcini A section. The major changes in terms of paleodepth, paleosalinity, evaporation versus precipitation, aridity versus humidity, and reworking processes occurred in the upper part of the Fonte dei Pulcini A section, during the last Messinian insolation cycle (i-cycle 511/512), which is characterized by high-amplitude oscillations. In contrast, the lower part of the Fonte dei Pulcini A section, which was deposited during relatively low-amplitude insolation cycles, is characterized by more stable environmental conditions. Comparing summer insolation with the paleoenvironmental changes at the Fonte dei Pulcini A section, we identify delays of several thousands of years between orbital forcing and climate response.

Sea level and climate forcing of the Sr isotope composition of lateMioceneMediterranean marine basins

“…As discussed in section 2, late Miocene glacial periods (insolation minima) tend to be characterized by arid conditions in Northern Africa and the Mediterranean, and conversely insolation maxima are associated with warm, wetter conditions [ Cosentino et al ., ; van der Laan et al ., ; Jiménez‐Moreno et al ., ]. By comparing 87 Sr/ 86 Sr values throughout the astronomically tuned Maiella section with astronomical forcing and δ 18 O records (Figure ), we can explore how global forcing affected the Sr isotope patterns.…”

“…Equivalent changes have been noted in Morocco, where arid and humid conditions were linked respectively to precessional maxima and minima [ van der Laan et al ., ]. Maximum rainfall and runoff during the late Miocene in Spain [ Sierro et al ., ], the central Apennines [ Cosentino et al ., ], and Crete [ Schenau et al ., ] were also associated with precessional minima. Because total insolation is related to eccentricity plus obliquity (tilt) minus precession (i.e., E+T‐P or ETP), the most arid conditions and strongest glacial phases resulted when obliquity minima coincided with precessional maxima, i.e., at ETP minima.…”

Deep-seated hydrocarbons in the seep “Brecciated Limestones” of the Maiella area (Adriatic foreland basin): Evaporitic sealing and oil re-mobilization effects linked to the drawdown of the Messinian Salinity Crisis

“…The MSC, which was responsible for the deposition of the "Primary Lower Gypsum" and the post-evaporitic Lago-Mare succession in the area (Bonarelli, 1951;Di Napoli Alliata, 1964;Crescenti et al, 1969a, b;Catenacci, 1974;Clermontè and Geisler, 1977;Patacca et al, 1992;Cipollari et al, 1999Cipollari et al, , 2003Gliozzi et al, 2002;Crescenti et al, 2002;Centamore and Nisio, 2003;Cosentino et al, 2005Cosentino et al, , 2011Cosentino et al, , 2013Sampalmieri et al, 2008;Sampalmieri et al, 2010;Iadanza et al, 2013;Schildgen et al, 2014), was followed by the Early Pliocene flooding event that marked the end of the crisis and was responsible for the deposition of bathyal clays (MPL1-lower MPL2 biozones; Cipollari et al, 2003).…”

“…Finally, p-ev2 deposits unconformably overlie p-ev1 deposits through a younger erosional surface (MES2, Cosentino et al, 2010;Cipollari et al, 2013) and are overlain by Early Pliocene bathyal clays (Cipollari et al, 2003). P-ev2 deposits in the Maiella area contain rich Lago-Mare fauna with Paratethyan immigrants (Patacca et al, 1992;Cipollari et al, 1999;Gliozzi et al, 2002;Crescenti et al, 2002;Cosentino et al, 2005Gliozzi et al, 2012).…”

Paleoclimate reconstruction during the Messinian evaporative drawdown of the Mediterranean Basin: Insights from microthermometry on halite fluid inclusions

“…Subsequently, the last stage of the MSC witnessed the refilling of the Mediterranean Basin mainly through continental runoff and meteoric water. Evaporite deposition (Upper Evaporites) continued in some parts of the Mediterranean Basin [ Selli , ; Decima and Wezel , ; Schreiber , ], contemporaneously with an upward increase of continental runoff [ Orszag‐Sperber , 2005, and references therein; Roveri et al ., and references therein; Cipollari et al ., ; Gliozzi , ; Cosentino et al ., , ; Bertini , ; Esu and Girotti , ; Grossi et al ., ; Popescu et al ., ; Guerra‐Merchán et al ., ; Sampalmieri et al , ] and more effective connections with the Paratethys. The MSC ended at 5.33 Ma, when the Mediterranean Basin was completely refilled with marine water from the Atlantic Ocean [ Iaccarino and Bossio , ; Iaccarino et al ., ; Orszag‐Sperber , and references therein; Pierre et al ., ; Gennari et al ., ; Cipollari et al ., ].…”