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We present a continuous ∼6.2 Ma long record of explosive activity from the Northwest Pacific volcanic arcs based on a composite tephra sequence derived from Ocean Drilling Program Sites 882A and 884B, and core MD01‐2416 on the Detroit Seamount. Geochemical fingerprinting of tephra glass using major and trace element analyses and correlations of tephra layers between the three cores allowed the identification of 119 unique tephras, suggesting eruptions of magnitude (M) of 5.8–7.8. Age estimates for all the identified eruptions were obtained with the help of published and further refined age models for the studied cores, direct 40 Ar/ 39 Ar dating of four ash layers, and Bayesian age modeling. The glass compositions vary from low‐ to high‐K 2 O basaltic andesite to rhyolite and exhibit typical subduction‐related affinity. The majority of the tephras originated from Kamchatka, only a few tephras—from the neighboring Kuril and Aleutian arcs. The glass compositions revealed no temporal trends but made it possible to identify their source volcanic zones in Kamchatka and, in some cases, to determine their source eruptive centers. Our data indicates episodes of explosive activity recorded in the Detroit tephra sequence at ∼6,200, 5,600–5,000, 4,300–3,700 ka, and almost continuous activity since ∼3,000 ka. Within the latter episode, the most active intervals can be identified at 1,700–1,600, 1,150–1,050, and 600–50 ka. Geochemically fingerprinted and dated Detroit tephra sequence form a framework for dating and correlating diverse paleoenvironmental archives across the Northwest Pacific and for studies of geochemical evolution of the adjacent volcanic arcs. Plain Language Summary Explosive volcanic eruptions produce defragmented material named tephra, which can be spread over large distances and form layers in sediments on ocean floor and continents. Long continuous tephra sequences preserved in marine sediments provide one of the best chronicles of the explosive eruptions

The Fucino Basin, central Italy, with its long and continuous history of Quaternary sediment accumulation, is one of the richest Mediterranean Middle Pleistocene tephra records. Here, we present a new detailed investigation of tephra layers (tephras) of the 250–170 thousand years before present (ka) interval, corresponding to the entire Marine Isotope Stage (MIS) 7 and parts of the MIS 8 and MIS 6. The investigated tephras have been characterised in terms of major, minor and trace elements, Sr–Nd isotopic compositions and 40Ar/39Ar ages. For correlation purposes, glass compositions and several new 40Ar/39Ar ages of selected proximal pyroclastic units spanning the same temporal interval from Vulsini (Latera Volcanic Complex), Sabatini, and Vico volcanic systems, central Italy, were measured. The late MIS 8-early MIS 6 Fucino tephras were backtracked to their corresponding volcanic sources, which include the Vulsini, Vico, Sabatini, Roccamonfina, Ischia and Campi Flegrei volcanic systems. While some of these tephras have been correlated to specific eruption units, other layers are currently not documented or described in near-vent sections, thus highlighting previously unrecognised events generated by these volcanic systems. Furthermore, the new high precision 40Ar/39Ar ages provide improved temporal constraints for Fucino making it one of the most detailed and chronologically best constrained tephra records for central Mediterranean MIS 7 tephrochronology. The Fucino record thus provides new integrative information for reconstructing the explosive history of Italian volcanoes during the investigated time interval. Furthermore, the geochronological constraints provide the basis for future paleoclimatic investigations at local and regional scale.

The present study focuses on the morphotectonic evolution of the axial portion of the Southern Apennine chain between the lower Calore River valley and the northern Camposauro mountain front (Campania Region). A multidisciplinary approach was used, including geomorphological, field-geology, stratigraphical, morphotectonic, structural, Ar-40/Ar-39 and tephrostratigraphical data. Results indicate that, from the Lower Pleistocene onwards, this sector of the chain was affected by extensional tectonics responsible for the onset of the sedimentation of Quaternary fluvial, alluvial fan and slope deposits. Fault systems are mainly composed of NW-SE, NE-SW and W-E trending strike-slip and normal faults, associated to NW-SE and NE-SW oriented extensions. Fault scarps, stratigraphical and structural data and morphotectonic indicators suggest that these faults affected the wide piedmont area of the northern Camposauro mountain front in the Lower Pleistocene-Upper Pleistocene time span. Faults affected both the oldest Quaternary slope deposits (Laiano Synthem, Lower Pleistocene) and the overlying alluvial fan system deposits constrained between the late Middle Pleistocene and the Holocene. The latter are geomorphologically and chrono-stratigraphically grouped into four generations, I generation: late Middle Pleistocene-early Upper Pleistocene, with tephra layers Ar-40/Ar-39 dated to 158 +/- 6 and 113 +/- 7 ka; II generation: Upper Pleistocene, with tephra layers correlated with the Campanian Ignimbrite (39ka) and with the slightly older Campi Flegrei activity (Ar-40/Ar-39 age 48 +/- 7 ka); III generation: late Upper Pleistocene-Lower Holocene, with tephra layers correlated with the Neapolitan Yellow Tuff (15ka); IV generation: Holocene in age. The evolution of the first three generations was controlled by Middle Pleistocene extensional tectonics, while Holocene fans do not show evidence of tectonic activity. Nevertheless, considering the moderate to high magnitude historical sei

© 2014 Societa Geologica Italiana, Roma. New 40Ar/39Ar ages and major and trace element geochemistry of the middle-late Miocene Cabo de Gata volcanic complex, southeast Spain, indicate that the volcanic activity of the Cabo de Gata volcanic zone developed over a short period through several pulses of geochemically and isotopically different parental magmas. The oldest volcanic rocks exposed in the Cabo de Gata volcanic zone are the shoshonite and high-K calc-Alkaline rocks of Bujo group, which cry - stallised from a parental magma transitional from calc-Alkaline to alkaline potassic generated through large degrees of partial melting, and then affected by a minor contribution from metasomatised veins and a larger one from the surrounding mantle wedge, in comparison to ultrapotassic melts. Subsequent partial melting of the mantle source produced typical calc-Alkaline parental magmas belonging to the Rodalquilar and Agua Amarga groups. Sr-Nd-Pb isotope and incompatible trace element distributions of Cabo de Gata rocks are in agreement with a mantle-wedge source affected by a two-fold metasomatism. The data suggested that mild potassic to sub-Alkaline subduction-related parental magmas (i.e., high-K calc-Alkaline and calc-Alkaline) were generated in the Cabo de Gata sector within a mantle wedge metasomatised by a fluid-dominated agent. In contrast, the enrichment in K2O of shoshonitic to ultrapotassic magmas was achieved through recycling of subducted sediments through melts that enriched the mantle wedge in K and related elements. Such a scenario can be easily reconciled with a geodynamic setting at the edge of a destructive plate margin with the subducted slab responsible for the recycling of sediments within the mantle wedge.

The island of Lanzarote, located at the eastern, oldest age of the Canarian hotspot island-chain, has very sparse Holocene rejuvenation volcanism, possibly restricted to the 1824 and 1730 eruptions, in agreement with the mature, post-erosional stage of the island. The dating of the Corona Volcano, possibly the most recent eruptive event in the island before the historic eruptions, gives a mean Ar-40/Ar-39 age of 21 ± 6.5 ka. This age agrees with the geological observations and the study of the Corona Volcano, particularly the large lava tube (7.6 km long, up to 25 m in diameter) formed in the initial stages of the eruption. The last 1.6 km of this lava tube are at present submerged, ending at a depth of at least 80 m below the present sea level. Our interpretation is that the active lava tube could not have reached that depth and, therefore, the submerged part of the tube formed as the lava flowed on a coastal platform at least 1.6 km wider and at least 80 m below the present sea level, a circumstance that could only have been possible coinciding with a period of low sea-level stand related to a maximum glacial, most probably the last one, at about 20 ka. The subsequent rise in sea level left the coastal platform and the end of the lava tube submerged. The age of the Corona Volcano eruption and lava therefore provide clear evidence of changes in sea level in the Canaries in relation to glaciations, and establish important constraints in the volcanic history of the island of Lanzarote., La isla de Lanzarote, situada en el extremo oriental de la alineación del punto caliente de las Canarias, ha tenido escasa actividad eruptiva de rejuvenecimiento en el Holoceno, posiblemente reducida a las erupciones de 1730 y 1824, hecho que concuerda con el avanzado estado post-erosivo de la isla. La datación de la erupción del Volcán Corona, aparentemente el evento volcánico anterior en Lanzarote a las erupciones históricas, ha dado una edad media ponderada 40Ar/39Ar de 21 ± 6,5 ka. Esta edad concuerda con las observaciones geológicas, particularmente las circunstancias de formación del tubo volcánico de 7,6 km de longitud y hasta 25 m de diámetro que se formó en las primeras fases de la erupción. El último tramo de 1,6 km está sumergido, finalizando a una profundidad de > 80 m. Nuestra interpretación es que el tubo volcánico activo no pudo alcanzar esa profundidad circulando por un medio subacuático, sino que fluyó por una plataforma costera al menos 1,6 km más extensa y al menos 80 m más baja que la costa actual, circunstancia que sólo ha podido darse en coincidencia con un pronunciado descenso del nivel marino en un máximo glacial, con toda probabilidad el último, hace unos 20 ka. La subsiguiente transgresión inundó el tubo hasta el nivel actual. La edad de la erupción queda pues limitada por las edades radioisotópicas en 21 ± 6,5 ka y, concordantemente, por el máximo descenso del nivel marino, registrado entre unos 18 y 21 ka. El estudio de la erupción del Corona establece hitos importantes en la historia volcánica de la isla de Lanzarote y aporta evidencia significativa de los cambios del nivel marino ocurridos en las Canarias en relación con las glaciaciones.