The Lauzanier area represents the northernmost extension o
f the Annot Sandstone series and contains deposits between 650 and 900 m-thick. This basin was active
from upper Bartonian or lower Priabonian to early Rupelian. It is composed o
f two superposed units separated by a major uncon
formity. The sediment supply is due to channelled
flows coming
from the south. Flow processes include mass
flow to turbidity currents. The size o
f the particles and the absence o
f fine-grained sediment suggest a transport over a short distance. The Lower Unit is made o
f coarse-grained tabular beds interpreted as non-channelled lobe deposits. The Upper Unit is made o
f massive conglomerates interpreted as the channelled part o
f lobes. These lobe deposits settle in a tectonically con
fined basin according to topographic compensation that occurs
from bed scale to unit scale. The abrupt progradation between the lower and the upper unit seems related to a major tectonic upli
ft in the area. This upli
ft is also suggested by a change in the petrographic nature o
f the source and an abrupt coarsening o
f the transported clasts.
This field example allows providing high resolution analysis for depositional sedimentary sequences of terminal lobe deposits in a coarse-grained turbidite system. The outcrop analysis shows the lateral evolution of deposits and the system progradation allows a longitudinal analysis of facies evolution by superposing on the same outcrops the channelled lobe system and the non-channelled lobe system. These results of high-resolution outcrop analysis can be extrapolated to results obtained on sedimentary lobes in recent deep-sea turbidite system that are either restricted to cores, or with a lesser resolution (seismic).