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artículo
Publicado 2018
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The climatic origin of astronomically induced sedimentary cycles in the Mediterranean and adjacent areas during the late Neogene and Quaternary remains puzzling; as cycles have been linked to concomitant but seasonally opposite changes in African summer monsoon precipitation (Eastern Mediterranean sapropels) and Atlantic regulated winter-precipitation (carbonate cycles on the Atlantic side of the Mediterranean). Particularly, little is known about the cyclic sedimentation on orbital time scales in the Western Mediterranean, with the prime exception of the Messinian sapropels from the Sorbas basin (southern Spain). Here we show that regular alternations in Pliocene downhole logs from the industrial drill-site Muchamiel-1, located along the Balearic Promontory in the Western Mediterranean, are related to eccentricity (bundles) and to obliquity and precession cycles (basic meter-scale alter...
2
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Late Neogene evolution of the Peruvian margin and its ecosystems: a synthesis from the Sacaco record
Publicado 2021
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The highly productive waters of the Humboldt Current System (HCS) host a particular temperate ecosystem within the tropics, whose history is still largely unknown. The Pisco Formation, deposited during Mio-Pliocene times in the Peruvian continental margin has yielded an outstanding collection of coastal-marine fossils, providing an opportunity to understand the genesis of the HCS ecosystem. We present a comprehensive review, completed with new results, that integrates geological and paleontological data from the last 10 My, especially focusing on the southern East Pisco Basin (Sacaco area). We discuss the depositional settings of the Pisco Formation and integrate new U/Pb radiometric ages into the chronostratigraphic framework of the Sacaco sub-basin. The last preserved Pisco sediments at Sacaco were deposited ~ 4.5 Ma, while the overlying Caracoles Formation accumulated from ~ 2.7 Ma on...
3
artículo
Publicado 2021
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JAB received funding from the United States Geological Survey , Climate Research and Development Program , for this study. DO was supported by CONCYTEC (Peru) research grants CB ( N° 105-2018 - FONDECYT ) and “Incorporación de Investigadores” ( N° E038-2019-02-FONDECYT-BM ). RE was supported by Geosciences Research Institute grant GRI19-1 . LWS was supported as an employee of the United States Geological Survey during the 1980s. TJD and MU did not receive any grant from funding agencies in the public, commercial, or not-for-profit sectors.
4
artículo
Publicado 2021
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Facial compartmentalization in the skull of extant pygmy whales (Kogiidae) is a unique feature among cetaceans that allows for the housing of a wide array of organs responsible for echolocation. Recent fossil findings indicate a remarkable disparity of the facial bone organization in Miocene kogiids, but the significance of such a rearrangement for the evolution of the clade has been barely explored. Here we describe Kogia danomurai sp. nov., a late Miocene (c. 5.8 Ma) taxon from the Pisco Formation (Peru), based on a partially preserved skull with a new facial bone pattern. Phylogenetic analysis recovers K. danomurai as the most basal representative of the extant genus Kogia, displaying a combination of derived (incipiently developed and excavated sagittal facial crest) and plesiomorphic features (high position of the temporal fossa, and antorbital notch not transformed into a narrow sl...
5
artículo
Publicado 2021
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The Peruvian coast experiences the largest interannual variability of sea surface temperature in the world due to the combined influence of the coastal upwelling and El Niño Southern Oscillation (ENSO). Although biological impacts of El Niño events have been widely reported, their effects on rocky intertidal communities remains largely unknown in Peru. Herein, we analyze the results of two biological surveys of rocky intertidal communities, conducted along 1400 km of the Peruvian coast. The first survey was conducted in 2015 yielding a snapshot of the distribution of rocky intertidal communities after 17 years of stable La Niña-like conditions. The second survey was carried in October 2017, after the 2015-16 and the 2017 El Niño events, which produced warm sea surface temperature (SST) anomalies up to 6 °C on the Peruvian coast. We find no changes throughout the latitudinal transect...
6
artículo
Publicado 2021
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This research has been supported by the JPI-Belmont project PACMEDY (via grant ANR-15-JCLI-0003-01 for MC, PB, ME, OM, TC, and BT). MC, JC, DO, RSG, AP, and PR acknowledge funding from Concejo Nacional de Ciencia y Tecnologia de Peru (grant n° 007-2017-FONDECYT , grant n° 034-2019-FONDECYT-BM ). SPH acknowledges funding from the ERC-funded project GC2.0 Global Change 2.0: Unlocking the past for a clearer future, grant number 694481 and from the JPI-Belmont project PACMEDY (via NERC ). The distribution and analyses of the transient Holocene simulations with the IPSL model benefit from the Institut Pierre Simon Laplace Climate Modeling Centre Infrastructure supported by ANR “Investissements d'avenir” program ANR-11-IDEX-0004-17-EURE-0006 .