in memoriam - Dr. Dominique Righi (1943-2010)
D. Righi, research scientist at HydrASA CNRS – University of Poitiers , passed away in the evening on March 7. He was born on 1943, January 19th at La Rochelle where he grew up, then married Annick and had two children, Quantin and Nicolas. He was graduated in agricultural science and he got his PhD in 1977 and started working at the ‘Laboratoire de P’dologie’ of the University of Poitiers with professor Jacques Dupuis. During the nineties, this laboratory evolved to a composite research team focussed on clay minerals. This was especially important for him because he could deeply interact with other scientists having a very different background and aims. In that context he was capable to create a very fruitful interaction contributing in importing and exporting data, methodologies and approaches between the clay mineralogy and the soil science communities.
The basics of his approach embrace two point of reference: a multi-facets studying of soil (fine) clay aiming to understand soils and the use of soil forming factors sequences. Indeed Dominique gave an enormous importance in analysing the soil system by employing chrono-, topo- and lito-sequences concepts as a mean of disentangling and understanding the soil complexity. Then the analysis of such complexity was challenged by integrating soil morphology with chemical, spectroscopic and ultramicroscopic approaches of clay minerals.
In the first part of his carrier Dominique became a leading scientist on podzol and podzolization processes. Then as his carrier moved towards the study of clay minerals he became a leading international authority on soil clay mineralogy and its relationship with soil type and soil morphology. He produces outstanding results concerning clay formation during podzol development. On Swiss soils, he was able to highlight phyllosilicates evolution by linking geology, time and soil horizonation proving that smectite is the end-product of mica alteration in strongly leached and acidified E horizons. He also demonstrated that the end-products of the weathering processes in either the A or the Bw horizons appeared to be quite different. More recently he established that eluvial pedogenic smectites of Finnish podzols change over time with soil evolution, in terms of clay assemblage, chemistry and interlayer charge. Dominique gave an outstanding contribution by studying factor time of pedogenesis throughout the rate of clay minerals change (smectite + mica = illite + mixed-layer minerals) in a chronosequence of polders where the progress of reaction in time appeared to be non-linear. His cutting-edge research has also advanced the world’s knowledge on the evolution of clay minerals in Vertisols. He proved the pedogenic formation of new clay minerals in toposequences of Vertisols in accordance to soil horizons and environmental settings. For instance, he demonstrated the neogenesis of kaolinite-smectite mixed layers in toposequences developed from basaltic parent material ( Italy ) and related this finding to the drainage conditions induced by the slope, demonstrating that the pedogenic formation of high-charge beidellite are in connection with the unstability of montmorillonitic layers in subalkaline soil environment. Then his findings largely dismantled classical pedological theories concerning whole soil homogeneization and montmorillonite stability in Vertisols. He has also given important contribution in understanding the importance of expandable phyllosilicate in the clay fraction for explaining organic matter complexes resistant to oxidation, in reviewing halloysite formation in soils, demonstrating the role of fulvic and humic acids in Oxisol-Spodosol toposequence ( Brazil ) and finally showing examples of the effect of agricultural activities on the mineralogy of soil clays.
He has also pioneered some important methodologies in soils including high-gradient magnetic separation techniques, the estimate of layer charge of smectites using infrared spectroscopy and, most importantly, the pioneer soil science applications of XRD patterns decomposition. To this respect he definitively proved that the decomposition of XRD patterns gave realistic data, after having directly measured clay crystals size on HRTEM images. Moreover he proved the important influence of microsystems on clay mineralogy by analysing weathering sequences of rock-forming minerals in serpentinite and basalt.
Dominique has successfully trained and inspired more than 20 PhD and MSc students and postdoctoral fellows, and hosted numerous international visiting scientists.
Dominique was the head of HydrASA laboratory during the 2002-06 period. He has served on numerous national and international scientific and academic committees. He also has served in the Editorial Board of Clay Minerals and as referee for many international Soil Science and Clay Science journals.
Dominique was an eminent scientist, a great educator, appreciated teacher and passionate soil scientist. He was indeed a man combining the rigour of his research activities with humbleness, kindness and deep understanding of human being regardless whether students, young scientists, technicians or senior colleagues. He had a passion for soil science and most of his students and colleagues have been affected by this passion producing a decisive influence on their careers.
Thank you, Dominique, from your friends and colleagues.