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Magri, Donatella
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- PublicationOpen AccessThe 4.2 ka BP Event in the Mediterranean region: an overview(2019)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;; ; ; ; ; ; ; ; ; ; ; ;The Mediterranean region and the Levant have returned some of the clearest evidence of a climatically dry period occurring around 4200 years ago. However, some regional evidence is controversial and contradictory, and issues remain regarding timing, progression, and regional articulation of this event. In this paper, we review the evidence from selected proxies (sea-surface temperature, precipitation, and temperature reconstructed from pollen, 18O on speleothems, and 18O on lacustrine carbonate) over the Mediterranean Basin to infer possible regional climate patterns during the interval between 4.3 and 3.8 ka. The values and limitations of these proxies are discussed, and their potential for furnishing information on seasonality is also explored. Despite the chronological uncertainties, which are the main limitations for disentangling details of the climatic conditions, the data suggest that winter over the Mediterranean involved drier conditions, in addition to already dry summers. However, some exceptions to this prevail – where wetter conditions seem to have persisted – suggesting regional heterogeneity in climate patterns. Temperature data, even if sparse, also suggest a cooling anomaly, even if this is not uniform. The most common paradigm to interpret the precipitation regime in the Mediterranean – a North Atlantic Oscillation-like pattern – is not completely satisfactory to interpret the selected data.220 32 - PublicationRestrictedA 4500 year record of palaeomagnetic secular variation and relative palaeointensity from the Tyrrhenian Sea(Geological Society of London, 2020-07-27)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; A marine sediment core from the western Mediterranean provides a new high-resolution 4500 year record of palaeomagnetic secular variation and relative palaeointensity. In 2013, the 7.1 m C5 core was recovered from the Tyrrhenian Sea as part of the NextData climate data project. The coring site, 15 km offshore from the Volturno river mouth, is well located to record combined marine and terrestrial palaeoclimatic influences, and the fine-grained, rapidly deposited sediments are effective palaeomagnetic recorders. We investigate the palaeomagnetic field direction and strength recorded in the core, which provide a valuable high-resolution record of Holocene geomagnetic variation in the area. Using rock magnetic techniques, we constrain the magnetic mineralogy of the studied sediments and confirm their suitability for palaeomagnetic analysis. Palaeomagnetic declination and inclination records were determined by stepwise alternating-field demagnetization, and relative palaeointensity estimates were obtained based on normalization to anhysterestic and isothermal remanent magnetization and to magnetic susceptibility. The age of the core is well constrained with a tephra and biostratigraphic age model, and its magnetic records are compared with relevant core and model data for the region, demonstrating that our record is compatible with previous results from the area. An automated curve matching approach is applied to assess the compatibility of our data with the existing secular variation path for the Mediterranean area.56 2 - PublicationOpen AccessMarine response to climate changes during the last five millennia in the central Mediterranean Sea(2016)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; We present a high-resolution paleoclimatic and paleoenvironmental reconstruction of the last five millennia from a shallow water marine sedimentary record from the central Tyrrhenian Sea (Gulf of Gaeta) using planktonic foraminifera, pollen, oxygen stable isotope, tephrostratigrapy and magnetostratigrapy. This multiproxy approach allows to evidence and characterize nine time intervals associated with archaeological/cultural periods: Eneolithic (base of the core–ca. 2410 BCE), Early Bronze Age (ca. 2410 BCE–ca. 1900 BCE), Middle Bronze Age–Iron Age (ca. 1900 BCE–ca. 500 BCE), Roman Period (ca. 500 BCE–ca. 550 CE), Dark Age (ca. 550 CE–ca. 860 CE), Medieval Climate Anomaly (ca. 860 CE–ca. 1250 CE), Little Ice Age (ca. 1250 CE–ca. 1850 CE), Industrial Period (ca. 1850 CE–ca. 1950 CE), Modern Warm Period (ca. 1950 CE–present day). The reconstructed climatic evolution in the investigated sedimentary succession is coherent with the short-term climate variability documented at the Mediterranean scale. By integrating the planktonic foraminiferal turnover from carnivorous to herbivorous–opportunistic species, the oxygen isotope record and the pollen distribution, we document important modification from the onset of the Roman Period to the present-day. From ca. 500 CE upwards the documentation of the cooling trend punctuated by climate variability at secular scale evidenced by the short-term δ18O is very detailed. We hypothesise that the present day warm conditions started from the end of cold Maunder event. Additionally, we provide that the North Atlantic Oscillation (NAO) directly affected the central Mediterranean region during the investigated time interval.310 113 - PublicationOpen AccessLate Holocene forest dynamics in the Gulf of Gaeta (Central Mediterranean) in relation to NAO variabilty and human impact.(2018)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; A new high-resolution pollen record, spanning the last five millennia, is presented from the Gulf of Gaeta (Tyrrhenian Sea, central Italy), with the aim of verifying if any vegetation change occurred in the central Mediterranean region in relation to specific well-known global and/or regional climate events, including the 4.2 ka event, the Medieval Climate Anomaly (MCA) and the Little Ice Age (LIA), and to detect possible vegetation changes related to still under-investigated climate signals, for example the so-called "Bond 2" cold event around 2.8 ka BP. The vegetation dynamics of the Gaeta record shows a recurrent pattern of forest increase and decline punctuating the mid-and late Holocene. When the timing of these patterns is compared with the climate proxy data available from the same core (planktonic foraminifera assemblages and oxygen stable isotope record) and with the NAO (North Atlantic Oscillation) index, it clearly appears that the main driver for the forest fluctuations is climate, which may even overshadow the effects of human activity. We have found a clear correspondence between phases with negative NAO index and forest declines. In particular, around 4200 cal BP, a drop in AP (Arboreal Pollen) confirms the clearance recorded in many sites in Italy south of 43 N. Around 2800 cal BP, a vegetation change towards open conditions is found at a time when the NAO index clearly shows negative values. Between 800 and 1000 AD, a remarkable forest decline, coeval with a decrease in the frequencies of both Castanea and Olea, matches a shift in the oxygen isotope record towards positive values, indicating cooler temperatures , and a negative NAO. Between 1400e1850 AD, in the time period chronologically corresponding to the LIA (Little Ice Age), the Gaeta record shows a clear decline of the forest cover, particularly evident after 1550 AD, once again in correspondence with negative NAO index.322 77 - PublicationRestrictedHuman peopling of Italian intramontane basins: The early Middle Pleistocene site of Pagliare di Sassa (L’Aquila, central Italy)(2010)
; ; ; ; ; ; ; ; ; ; ; ;Palombo, M. R.; Dipartimento di Scienze della Terra, Universita` di Roma ‘‘La Sapienza’’, Roma, Italy ;Mussi, M.; Dipartimento di Scienze dell’Antichita`, Universita` di Roma ‘‘La Sapienza’’, Roma, Italy ;Agostini, S.; Soprintendenza per i Beni Archeologici dell’Abruzzo, Chieti, Italy ;Barbieri, M.; CNR, Istituto di Geologia Ambientale e Geoingegneria, Roma, Italy ;Di Canzio, E.; Dipartimento di Scienze della Terra, Universita` di Roma ‘‘La Sapienza’’, Roma, Italy ;Di Rita, F.; Dipartimento di Biologia Vegetale, Universita` di Roma ‘‘La Sapienza’’, Roma, Italy ;Fiore, I.; Via San Rocco, Fiuggi (FR), Italy ;Iacumin, P.; Dipartimento di Scienze della Terra, Universita` degli Studi di Parma, Parma, Italy ;Magri, D.; Dipartimento di Biologia Vegetale, Universita` di Roma ‘‘La Sapienza’’, Roma, Italy ;Speranza, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Tagliacozzo, A.; Museo Nazionale Preistorico-Etnografico ‘‘Luigi Pigorini’’, Roma, Italy; ; ; ; ; ; ; ; ; ; Multidisciplinary investigations at Pagliare di Sassa (L’Aquila, central Italy) suggest that the local succession accumulated from the late Early to the early Middle Pleistocene in a lacustrine environment. In the upper part, clastic sediments are part of an alluvial fan prograding into the lake, grading to a braided fluvial system. The pollen record confirms that a significant glacial phase occurred just before the onset of the Jaramillo inversion. These data, coupled with evidence from the nearby but earlier Madonna della Strada sequence, allow reconstruction of part of the environmental evolution of L’Aquila basin before the Jaramillo Subchron. The mammal species of Pagliare di Sassa include Stephanorhinus hundsheimensis, mostly of open environments, already present at Madonna della Strada. The faunal turnover characterizing the Early to Middle Pleistocene transition is indicated by the appearances of taxa typical of the Italian early to middle Galerian faunas, such as Praemegaceros verticornis, together with Megaloceros savini. The occurrence of Mimomys savini together with Microtus ex gr. Microtus hintonigregaloides suggests that this assemblage is earlier than the Isernia La Pineta fauna. A flint implement and a fragmentary herbivore femur with impact scars probably linked to human activity give evidence of the human peopling of intramontane basins of the Apennine chain since the early Middle Pleistocene.169 31