Precise paleoclimatic information from Northern Peru is still very scarce. Several paleoclimatic and paleoecologic interpretations which have been proposed in the last 20 years relie on a limited set of data, and were sometimes elaborated on groundless assumptions. The geographical location of NW Peru and the predominant control exerted on the coastal climate by oceanographic parameters (warm and cool oceanographic currents, upwelling and "El Nino' phenomena) partly explain the difficulty of interpreting the Late Quaternary climatic evolution, but at the same time plainly justify a renewed interest on this topic. -from English summary