Sedimentology

The main aim of our re­se­arch is to bet­ter un­der­stand the pro­ces­ses con­trol­ling re­cent se­di­men­ta­ti­on in coastal and deep-wa­ter en­vi­ron­ments in or­der to im­pro­ve pa­leo­cea­no­gra­phic and pa­leo­en­vi­ron­men­tal re­con­struc­tions ba­sed on se­di­men­ta­ry ar­chi­ves. Our group has three main li­nes of re­se­arch:

Sediment dynamics in deep-water environments: This line of re­se­arch stu­dies the se­di­men­ta­ry pro­ces­ses that con­trol seaf­loor mor­pho­lo­gy and se­di­ment dis­tri­bu­ti­on in the deep sea, with a spe­cial fo­cus on de­po­sits ge­ne­ra­ted by ocea­nic cur­rents. We are also in­te­rested in the se­di­men­ta­ry pro­ces­ses trans­porting se­di­ments from the con­ti­nent to the deep sea and the ef­fect of ocea­nic cir­cu­la­ti­on in this trans­fer of se­di­ment. For in­stan­ce, we stu­dy how ocea­nic cur­rents in­ter­act with tur­bi­di­ty cur­rents and af­fect the mor­pho­lo­gy and evo­lu­ti­on of sub­ma­ri­ne chan­nels. We use a mul­ti­di­sci­pli­na­ry ap­proach to stu­dy se­di­men­ta­ry pro­ces­ses in the deep sea that com­bi­nes ob­ser­va­tions of na­tu­ral sys­tems using geo­phy­si­cal data, se­di­ment co­res and ocea­no­gra­phic data; with hydro­dy­na­mic mo­del­ling and flu­me-tank ex­pe­ri­ments.

Bedform fields - hydrodynamics, sediment transport and geomorphology: Bedforms (ripples, dunes, sand waves) are ubiquitous in shallow water sandy environments. They form from the interaction between hydrodynamics (river, tidal and wind or wave-related currents and waves) and a mobile bed. Bedforms are active morphodynamic elements which both reflect and influence hydrodynamic, sediment transport and geomorphology at various spatiotemporal scales. The study of their presence, size, movement and interactions with hydrodynamics is directly relevant for a wide range of fundamental and applied research. We study bedforms (mainly dunes) in a variety of environments (river, estuarine, tidal and marine) using a range of techniques (field measurements, flume experiments and numerical modelling).

Coccolithophores ecology and climate proxies: Coc­co­li­tho­pho­res are a group of ma­ri­ne, unicel­lu­lar al­gae. Their mor­pho­lo­gy is cha­rac­te­ri­zed by an exo­s­ke­le­ton com­po­sed of nu­merous mi­nu­te cal­ci­te plate­lets - the coc­co­liths - that are rea­di­ly pre­ser­ved in the se­di­men­ta­ry re­cord. Coc­co­li­tho­pho­res are one of the main groups of ma­ri­ne phy­to­plank­ton play­ing key ro­les in the ma­ri­ne eco­sys­tem as pri­ma­ry pro­du­cers and in ma­ri­ne bio­geo­che­mis­try, and pre­ser­ve the com­po­si­ti­on of the over­ly­ing wa­ter mass con­di­ti­ons. Sin­ce coc­co­liths are pheno­me­n­al­ly ab­un­dant in sea-floor se­di­ments, they are va­luable in­di­ca­tors of the pa­leo­en­vi­ron­ment and of cli­ma­te-in­du­ced pa­leo­pro­duc­tivi­ty chan­ges.