High velocity friction experiments. In this study, new samples recovered by IODP (Integrated Ocean Drilling Program) Exp. 362 from incoming Indian plate sediments will be used to investigate the frictional behavior of these sediments en-route to the plate boundary interface. The UK IODP Moratorium award will be used to achieve 5 Strategic Objectives: SO 1 - identify the characteristics of the sedimentary sections to optimize the sampling strategy for friction experiments based upon onboard sedimentology, petrology, geochemistry and in-situ logging profiles. This objective will benefit from the Exp. 362 Science Party work carried out during the cruise. SO 2 - acquire a quantitative data set of the mineral assemblages, fluid permeability, and porosity for each sample. SO 3 - measure their frictional dependence on slip, slip rate, slip velocity, and normal stress by performing experiments on the collected samples under deformation conditions typical of earthquakes using the high velocity rock friction apparatus SHIVA. SO 4 - monitor gas emission, humidity, and temperature variations during friction experiments using mass spectrometry, temperature and humidity measurements with the sensors installed on the rotary shear apparatus. SO 5 - analyse the experimental fault rock material using a multidisciplinary approach that involves microstructural analysis, mineralogy, and petrology so that proxy records may be reconstructed for plate interface seismic slip. Validate these against the seismological record. The ultimate goal is to incorporate the actual physical properties of the Sumatra-Andaman incoming sedimentary section within an improved theoretical earthquake rupture propagation model. This research will develop a new approach to the assessment of extreme near-trench tsunamogenic slip based on the analysis of incoming plate sediments. This approach is also applicable to other plate-boundary megathrusts (e.g. Japan Trench, Barbados). Future studies can also consider possible lateral variations in the lithological composition of the incoming plate/subduction plate boundary material.
The data include:- sample description file: sample full names, site, hole, depth etc., a quick petrographic description of the sample and the embedding serpentinite mud, and information regarding sample selection for bulk rock chemistry - microprobe analyses of selected samples - bulk rock major and trace elements from 2 labs (SARM, Nancy and VUB, Brussels) - Oxygen Isotopes of both pore fluids and rock samples with estimated temperature equilibrium
120 samples of 57 tephra layers identified at IODP Expedition 350 sites (U1436 and U1437) were used in grain size analysis. Some layers have one grain size measurement, others have multiple measurements throughout the tephra layer.
We provide here Pb isotope data for the basement rocks cored during IODP Expedition 352 (Bonin Forearc). The data are reported as 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios together with their errors. The overall accuracy of the data was determined using international standard NBS SRM 981. Values for this standard achieved during the measurement period were 206Pb/204Pb = 16.9404 ±32,207Pb/204Pb = 15.4969 ±32, 208Pb/204Pb = 36.7149 ±90 (2sd; n=44). The data are separated into four parts one for each drill site that cored basement. Sites 1440B and 1441A both sampled a basalt type known as FAB (Forearc Basalts), whereas Sites 1439C and 1442A both sampled boninites (Mg-rich andesites). Both rock types are typical of the forearc setting and contain information needed to understand the process of subduction initiation. A summary of the Expedition, and hence the petrography and setting of the samples as well as the various scientific objectives for the project to which these analyses contribute) may be found in: Reagan, M.K., Pearce, J.A., and Petronotis, K., Expedition Scientists, 2015, Izu-Bonin-Mariana Fore Arc: Proceedings of the International Ocean Discovery Program, 352. International Ocean Discovery Program, http://dx.doi.org/10.14379/iodp.proc.352.2015.
Data are either (1) depths and spacings between stylolites and faults within Unit IV, (2) images from IODP drill core image logs of the locations of samples observed, (3) photomicrographs and flatbed thin section scans of thin sections cut from samples, (4) SEM BSE or EDS data collected at Cardiff University. These data form the basis of: Leah et al. "Brittle-ductile strain localisation and weakening in pelagic sediments seaward of the Hikurangi margin, New Zealand", Tectonics, Submitted. Images and data from samples collected at IODP Expedition 375 Site U1520 (38°58.1532'S, 179°7.9112'E, 3522.1 mbsl). This is just seaward (east) of the trench of the Hikurangi Margin, New Zealand.