Initially, a number of samples from five faults (Mattinata Fault-Italy, Rodopos fault in Crete-Greece, Arkitsa fault zone-Central Greece, Nojima Fault-Japan, Asano Fault-Japan and Arima Fault-Japan) were collected, as these faults represent different characteristics in relation to the material developed in their brittle zones which in turn affect the mechanical strength and stability of faults differently. Following this step, the collected fault zone materials were characterized, by perfoming microstructural, mineralogical and chemical analyses. Petrographic thin sections were prepared and the microstructural characteristics of the bulk brittle material samples were observed by Scanning Electron Microscope (SEM). Quantitative chemical analyses on polished thin sections were made using Energy-Dispersive Spectrometry (EDS). Mineralogical analyses by X-ray diffraction (XRD) were made to observe different mineral structures. This gave the opportunity to identify and characterize brittle fault zone materials that contain suitable minerals for luminescence dating (e.g. quartz and feldspar). This also gave the opportunity to examine the thermal history (as a result of faulting) of the samples as minerals illite and chlorite undergo changes on heating.
Assessment of the zeroing potential of the luminescence signal of minerals contained in materials found on faults zone was a crucial step towards achieving the aim of the project. To this end, stress-simulations in the laboratory were performed using a shear High-Velocity Rotary Friction (HVRF) machine, to investigate the frictional processes and the dynamic strength of the samples, and also the mechanical results and the developing microstructures, within the brittle material layer. Experiments were conducted at varying slip rates, displacements, normal stresses and ambient conditions, to test the dependence of the strain distribution. Mechanical data as well as the temperature close to the slip surface were recorded during the experiments. Following the stress-simulation experiments, samples were chemically treated to isolate the minerals suitable for luminescence measurements (quartz and feldspar) and their luminescence signals were measured using a number of different luminescence techniques (OSL, ITL, IRSL). Luminescence investigated “zeroing” of the luminescence signals, as a result of the different stress simulation conditions.
The next step of the project was the development of methodological procedures on the use of luminescence dating techniques, suitable specifically for deformed geological formations and the establishment of palaeoerthquake ages of selected faults. To achieve this, luminescence measurements were employed on samples of selected faults and experimental approaches were followed to establish the appropriate parameters for luminescence dating, suitable specifically for deformed geological formations.
A necessary step to validate the dating results of the project was to perform a number of cross-checks of the luminescence-dated samples. ESR dating was performed on a number of samples used in luminescence dating and results were compared with the luminescence ages obtained. Additionally, luminescence ages of selected faults were judged against the available historical information on previous activations.
The SMR project systematically disseminated the research results and methods to the scientific community and general public through different channels including notes, participation in various international conferences, talks and lectures in educational bodies, websites and publications in peer-reviewed international journals. The dissemination of the research results enabled their exploitation by the scientific/academic community, leading to new research possibilities and new collaborations between research centres.
