In-Situ K-Ar Dating Based on UV-Laser Ablation Coupled with a LIBS-QMS System Development, Calibration and Application

Absolute age determination isnecessary to check and calibratethe relative Martian chronologypresently available from meteoriticcrater counting

Prodigious submarine landslides during the inception and early growth of volcanic islands

Volcanic island inception applies large stresses as the ocean crust domes in response to magma ascension and is loaded by eruption of lavas. There is currently limited information on when volcanic islands are initiated on the seafloor, and no information regarding the seafloor instabilities island inception may cause. The deep sea Madeira Abyssal Plain contains a 43 million year history of turbidites among which many originate from mass movements in the Canary Islands. Here, we investigate the composition and timing of a distinctive group of turbidites that we suggest represent a new unique record of large-volume submarine landslides triggered during the inception, submarine shield growth, and final subaerial emergence of the Canary Islands. These slides are predominantly multi-stage and yet represent among the largest mass movements on the Earth’s surface up to three or more-times larger than subaerial Canary Islands flank collapses. Thus whilst these deposits provide invaluable information on ocean island geodynamics they also represent a significant, and as yet unaccounted, marine geohazard

Le volcanisme et les grandes crises géologiques de la biodiversité. 11ème colloque "Biodiversité : de la molécule à l'écosystème", le 11 mars 2010 à Orsay

Magazine "Plein Sud" de l'Université Paris-Sud X

Trace elements and Sr, Nd, Pb isotopic study of K-Ar dated lava flows from Basse Terre, Guadeloupe, Lesser Antilles Arc

International audienc

Geomorphological evolution through time of southern Basse-Terre volcanoes inferred from DEM-based reconstructions as estimations to the construction rates and magma production

International audienc

Causal link between Quaternary paleoclimatic changes and volcanic islands evolution.

International audienc

Construction and destruction of Mont Pelee volcano: Volumes and rates constrained from a geomorphological model of evolution

International audienceThis study presents long-term volumes and construction rates for the Mont Conil-Mont Pelée volcano and rate estimates at which volcanic activity creates relief. An algorithm, ShapeVolc, is used to numerically model topographic surfaces. Volcano morphology is analyzed using current digital elevation model in combination with mapped geology to produce 10 paleotopographies at the end of four constructional stages and three destructional events. Volumes of each constructional stage were estimated at about 35.2 km3, 26.2 km3, 8.3 km3, and 2.5 km3 for a total cumulative erupted volume of 72.2 km3. We estimate that Mont Pelée accounted for about 10% of the Lesser Antilles arc production in the last 100 kyr. The volcano has been built at an average rate of 0.13 km3/kyr during the last 550 kyr. During that time, construction rates varied by a factor of 15, from 0.04 km3/kyr in early stages up to 0.52 km3/kyr after the second flank collapse. Volumes displaced by each flank collapse were estimated at 14.7 km3, 8.8 km3, and 3.5 km3, thus about 37% of the total constructed volume. Integrated over the volcano's lifetime, the rate at which flank collapses removed material off the island is 0.15 km3/kyr. In contrast, long-term erosion rates outside collapsed areas are estimated at about 0.05 ± 0.7 km3/kyr, or ~11 km3 of material removed. This latter rate is not negligible, which strengthens the importance of taking into account recurrent small erosional events on the geomorphological evolution of a volcanic island in a tropical context