Field images from the studied part of the Chinese Tianshan metamorphoc belt a) Blueschist-facies pillow basalt with eclogite-facies rims along the pillow margins. b) Blueschist- to eclogite-facies veins of omphacite-quartz (OQ), glaucophane-quartz (GQ), ankerite (A) and calcite (Cc). c) Thick veins of quartz and ankerite in an eclogite. d) Decimetric veins of quartz in a high-pressure metapelite indicating Si-rich fluid circulation. Note that the veins show deformation structures similar to the metapelites, implying their formation before or during deformation.
Scan of the polished sample of fracture upper plate material (field of view 5 cm). The black veins correspond to ancient pseudotachylite veins that are interpreted as the record of subduction zone earthquakes rooted in the hanging wall.
Optical microscope picture of a fine grained foliated cataclastic structure (field of view 6 mm) from the base of the Dent Blanche nappe, in southern Switzerland (Moiry region, depth 40 km). Note the heterogeneous clast size distribution and the presence of quartz-rich mylonitic fragments from the initial orthogneiss.
Tectonic plates sinking over millions of years? Megaearth-quakes & tsunamis? Global fluxes of elements?… How do stresses and energy release, via earth-quakes and fluid-mediated mass transfer, interact on such varied spatial and temporal scales (from 10-4 to 106-7 yr)? Time to ZIP (Zoom In between Plates), into the subduction plate interface!
The 4th ZIP newsletter is dedicated to Evguenii Burov, who passed away on the way to the ZIP Consolidator field trip in Chile on the 9th of October 2015. An obituary on the first page shall honour his life and work. May you rest in peace, Evguenii!
The newsletter covers two major ZIP events in 2015:
1. The ZIP Starter I cruise on geophysical data acquisition in the Tyrrhenian and Ionian Sea in July 2015. Fellows accompanied the team of the CSIC (Barcelona) for approximately 10 days during their geophysical data acquisition campaign onboard the “B/O Sarmiento de Gamboa”.
2. The ZIP Consolidator field trip and associated short courses in Chile during October 2015 that addressed the monitoring and understanding of an active subduction zone.
Today, the underlying mechanisms that generate earthquakes at greater depth, i.e. deeper than 60 km, are still unknown. These earthquakes cannot be explained in the same way as shallow earthquakes, because pressure and temperature conditions are different. Due to better seismic imaging methods it is possible to localize even smaller and deeper earthquakes… read more
The new year has already been on its way for a while now and fellows are working hard. A year packed with training activities, workshops, field trips and meetings is entering the hot phase. We are pleased to welcome Paraskevi Ioannidi (GFZ Potsdam), the last missing fellow: Welcome to ZIP, Io!
The newsletter starts with a look back into 2014 at the scientific short-course on “Active seismic data processing and inversion” in Barcelona (November 24-28 2014). The coverage on upcoming ZIP activities include the short-course on “Analytical Geochemistry” in Bern (May 18-22), the Mid-Term-Review in Paris (June 2) and the associated private mini-workshop organized in Rueil-Malmaison by our associate partner IFP-EN (June 4-5), the ZIP Starter 1 cruise (July 4-23), several activities in conjunction with the ZIP consolidator in Antofagasta, Chile (October 5-17) and the short-course on “Rock mechanics and experimental rheology” in Paris (October 26-30).