The 1998-2001 submarine lava balloon eruption at the Serreta Ridge (Azores archipelago): constraints from volcanic facies architecture, isotope geochemistry and magnetic data

The most recent submarine eruption observed offshore the Azores archipelago occurred between 1998-2001 along the submarine Serreta ridge (SSR), ~4-5 nautical miles WNW of Terceira Island. This submarine eruption delivered abundant basaltic lava balloons floating at the sea surface and significantly changed the bathymetry around the eruption area. Our work combines bathymetry, volcanic facies cartography, petrography, rock magnetism and geochemistry in order to (1) track the possible vent source at seabed, (2) better constrain the Azores magma source(s) sampled through the Serreta submarine volcanic event, and (3) interpret the data within the small-scale mantle source heterogeneity framework that has been demonstrated for the Azores archipelago. Lava balloons sampled at sea surface display a radiogenic signature, which is also correlated with relatively primitive (low) 4He/3He isotopic ratios. Conversely, SSR lavas are characterized by significantly lower radiogenic 87Sr/86Sr, 206Pb/204Pb and 208Pb/204Pb ratios than the lava balloons and the onshore lavas from the Terceira Island. SSR lavas are primitive, but incompatible trace-enriched. Apparent decoupling between the enriched incompatible trace element abundances and depleted radiogenic isotope ratios is best explained by binary mixing of a depleted MORB source and a HIMU­type component into magma batches that evolved by similar shallower processes in their travel to the surface. The collected data suggest that the freshest samples collected in the SSR may correspond to volcanic products of an unnoticed and more recent eruption than the 1998-2001 episode.

Simplified Chinese lacquer techniques and Nanban style decoration on Luso-Asian objects from the late sixteenth or early seventeenth centuries

The meeting of multiple cultures and their mutual influence during the Portuguese expansion in Asia led to the emergence of different types of fusion styles in objects commissioned by the settlers, merchants, and religious orders present in Portuguese India. The east-Asian lacquer coatings of modestly sized wooden objects of various types dating from the sixteenth and early seventeenth centuries have been analyzed as part of the research for a doctoral thesis that aims to establish their cultural and geographical attribution within the context of the Getty Conservation Institute’s lacquer research project. Among the objects were three seventeenthcentury lacquered trays from Portuguese museums and private collections that had previously been classified as Japanese Nanban, Chinese or Ryukyuan lacquers or even as Indo-Portuguese artifacts. The materials and techniques that were identified show close similarities with Chinese techniques mentioned in historic accounts — the only existing Ming Chinese Treatise on lacquering Xiushi lu and the eighteenth-century memoirs of the Jesuit priest d’Incarville. These nearly 400-year-old artifacts are among the first lacquered objects commissioned by Europeans and probably the first of Chinese origin. Their detailed technical study contributes to international lacquer research and complements existing knowledge and perceptions of the lacquering processes that were applied in response to an early European demand for exotic items.