Browsing by Author "Jiménez-Espejo, Francisco J."
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- Earliest known use of marine resources by NeanderthalsPublication . Cortés-Sanchez, Miguel; Morales-Muñiz, Arturo; Simón-Vallejo, María D.; Lozano-Francisco, María C.; Vera-Peláez, José L.; Finlayson, Clive; Rodríguez-Vidal, Joaquín; Delgado-Huertas, Antonio; Jiménez-Espejo, Francisco J.; Martínez-Ruiz, Francisca; Aranzazu Martinez-Aguirre, M.; Pascual-Granged, Arturo J.; Merce Bergada-Zapata, M.; Gibaja-Bao, Juan F.; Riquelme-Cantal, José A.; Antonio López-Saez, J.; Rodrigo-Gamiz, Marta; Sakai, Saburo; Sugisaki, Saiko; Finlayson, Geraldine; Fa, Darren A.; Bicho, Nuno Gonçalo Viana Pereira FerreiraNumerous studies along the northern Mediterranean borderland have documented the use of shellfish by Neanderthals but none of these finds are prior to Marine Isotopic Stage 3 (MIS 3). In this paper we present evidence that gathering and consumption of mollusks can now be traced back to the lowest level of the archaeological sequence at Bajondillo Cave (Malaga, Spain), dated during the MIS 6. The paper describes the taxonomical and taphonomical features of the mollusk assemblages from this level Bj(19) and briefly touches upon those retrieved in levels Bj(18) (MIS 5) and Bj(17) (MIS 4), evidencing a continuity of the shellfishing activity that reaches to MIS 3. This evidence is substantiated on 29 datings through radiocarbon, thermoluminescence and U series methods. Obtained dates and paleoenvironmental records from the cave include isotopic, pollen, lithostratigraphic and sedimentological analyses and they are fully coherent with paleoclimate conditions expected for the different stages. We conclude that described use of shellfish resources by Neanderthals (H. neanderthalensis) in Southern Spain started similar to 150 ka and were almost contemporaneous to Pinnacle Point (South Africa), when shellfishing is first documented in archaic modern humans.
- Mediterranean Outflow and surface water variability off southern Portugal during the early Pleistocene: A snapshot at Marine Isotope Stages 29 to 34 (1020-1135 ka)Publication . Voelker, Antje H. L.; Salgueiro, Emilia; Rodrigues, Teresa; Jiménez-Espejo, Francisco J.; Bahr, Andre; Alberto, Ana; Loureiro, Isabel; Padilha, Maria; Rebotim, Andreia; Roehl, UrsulaCentennial-to-millennial scale records from IODP Site U1387, drilled during IODP Expedition 339 into the Faro Drift at 558 m water depth, now allow evaluating the climatic history of the upper core of the Mediterranean Outflow (MOW) and of the surface waters in the northern Gulf of Cadiz during the early Pleistocene. This study focuses on the period from Marine Isotope Stages (MIS) 29 to 34, i.e. the interval surrounding extreme interglacial MIS 31. Conditions in the upper MOW reflect obliquity, precession and millennial-scale variations. The benthic delta O-18 signal follows obliquity with the exception of an additional, smaller delta O-18 peak that marks the MIS 32/31 transition. Insolation maxima (precession minima) led to poor ventilation and a sluggish upper MOW core, whereas insolation minima were associated with enhanced ventilation and often also increased bottom current velocity. Millennial-scale periods of colder sea-surface temperatures (SST) were associated with short-term maxima in flow velocity and better ventilation, reminiscent of conditions known from MIS 3.A prominent contourite layer, coinciding with insolation cycle 100, was formed during MIS 31 and represents one of the few contourites developing within an interglacial period. MIS 31 surface water conditions were characterized by an extended period (1065-1091 ka) of warm SST, but SST were not much warmer than during MIS 33. Interglacial to glacial transitions experienced 2 to 3 stadial/interstadial cycles, just like their mid-to-late Pleistocene counterparts. Glacial MIS 30 and 32 recorded periods of extremely cold (<12 degrees C) SST that in their climatic impact were comparable with the Heinrich events of the mid and late Pleistocene. Glacial MIS 34, on the other hand, was a relative warm glacial period off southern Portugal. Overall, surface water and MOW conditions at Site U1387 show a strong congruence with Mediterranean climate, whereas millennial-scale variations are closely linked to North Atlantic circulation changes. (C) 2015 Elsevier B.V. All rights reserved.
- The Mesolithic-Neolithic transition in southern IberiaPublication . Cortes Sanchez, Miguel; Jiménez-Espejo, Francisco J.; Simon Vallejo, Maria D.; Gibaja Bao, Juan; Carvalho, António Faustino; Martinez-Ruiz, Francisca; Rodrigo Gamiz, Marta; Flores, Jose-Abel; Paytan, Adina; Lopez Saez, Jose A.; Pena-Chocarro, Leonor; Carrion, Jose S.; Morales Muniz, Arturo; Rosello Izquierdo, Eufrasia; Riquelme Cantal, Jose A.; Dean, Rebecca M.; Salgueiro, Emilia; Martinez Sanchez, Rafael M.; De la Rubia de Gracia, Juan J.; Lozano Francisco, Maria C.; Vera Pelaez, Jose L.; Llorente Rodriguez, Laura; Bicho, Nuno Gonçalo Viana Pereira FerreiraNew data and a review of historiographic information from Neolithic sites of the Malaga and Algarve coasts (southern Iberian Peninsula) and from the Maghreb (North Africa) reveal the existence of a Neolithic settlement at least from 7.5 cal ka BP. The agricultural and pastoralist food producing economy of that population rapidly replaced the coastal economies of the Mesolithic populations. The timing of this population and economic turnover coincided with major changes in the continental and marine ecosystems, including upwelling intensity, sea-level changes and increased aridity in the Sahara and along the Iberian coast. These changes likely impacted the subsistence strategies of the Mesolithic populations along the Iberian seascapes and resulted in abandonments manifested as sedimentary hiatuses in some areas during the Mesolithic-Neolithic transition. The rapid expansion and area of dispersal of the early Neolithic traits suggest the use of marine technology. Different evidences for a Maghrebian origin for the first colonists have been summarized. The recognition of an early North-African Neolithic influence in Southern Iberia and the Maghreb is vital for understanding the appearance and development of the Neolithic in Western Europe. Our review suggests links between climate change, resource allocation, and population turnover. (C) 2011 University of Washington. Published by Elsevier Inc. All rights reserved.
- Unexpected weak seasonal climate in the western Mediterranean region during MIS 31, a high-insolation forced interglacialPublication . Oliveira, Dulce; Goni, Maria F. Sanchez; Naughton, Filipa; Polanco-Martinez, J. M.; Jiménez-Espejo, Francisco J.; Grimalt, Joan O.; Martrat, Belen; Voelker, Antje; Trigo, Ricardo; Hodell, David; Abrantes, Fatima; Desprat, StephanieMarine Isotope Stage 31 (MIS 31) is an important analogue for ongoing and projected global warming, yet key questions remain about the regional signature of its extreme orbital forcing and intra-interglacial variability. Based on a new direct land-sea comparison in SW Iberian margin IODP Site U1385 we examine the climatic variability between 1100 and 1050 ka including the "super interglacial" MIS 31, a period dominated by the 41-ky obliquity periodicity. Pollen and biomarker analyses at centennial-scale resolution provide new insights into the regional vegetation, precipitation regime and atmospheric and oceanic temperature variability on orbital and suborbital timescales. Our study reveals that atmospheric and SST warmth during MIS 31 was not exceptional in this region highly sensitive to precession. Unexpectedly, this warm stage stands out as a prolonged interval of a temperate and humid climate regime with reduced seasonality, despite the high insolation (precession minima values) forcing. We find that the dominant forcing on the long-term temperate forest development was obliquity, which may have induced a decrease in summer dryness and associated reduction in seasonal precipitation contrast. Moreover, this study provides the first evidence for persistent atmospheric millennial-scale variability during this interval with multiple forest decline events reflecting repeated cooling and drying episodes in SW Iberia. Our direct land-sea comparison shows that the expression of the suborbital cooling events on SW Iberian ecosystems is modulated by the predominance of high or low-latitude forcing depending on the glacial/interglacial baseline climate states. Severe dryness and air-sea cooling is detected under the larger ice volume during glacial MIS 32 and MIS 30. The extreme episodes, which in their climatic imprint are similar to the Heinrich events, are likely related to northern latitude ice-sheet instability and a disruption of the Atlantic Meridional Overturning Circulation (AMOC). In contrast, forest declines during MIS 31 are associated to neither SST cooling nor high-latitude freshwater forcing. Time-series analysis reveals a dominant cyclicity of about 6 ky in the temperate forest record, which points to a potential link with the fourth harmonic of precession and thus low-latitude insolation forcing. (C) 2017 Elsevier Ltd. All rights reserved.