We are privileged to publish this interim report on the discovery of open settlement sites of the early Palaeolithic in the Paris basin. The early occupation areas were defined beside the river Yonne at Soucy during gravel-quarrying, which were to produce flint bifaces and débitage and the bones of elephant, rhinoceros, horse and a wealth of other mammals. The sites differed from each other, both in their assemblages and in their location with respect to the old river channels. In the author's analysis this demonstrates signs of subsistence strategy and spatial organisation in the buried valley between 365 and 345 000 years ago.