The paper reports the preliminary results from the short season of fieldwork that the Cyrenaican Prehistory Project was able to undertake with a small Anglo-Libyan team in September 2013. The work concentrated on continuing the excavation of Trench M down the southern side of the Middle Trench and of Trench D on the southern side of the Deep Sounding below it, the eventual objective being to link these so as to provide a high quality dataset of sedimentary and cultural data from the top to the bottom of the Pleistocene occupation deposit (some 12 m). The ~1 m of sediments investigated in Trench M in the 2013 fieldwork includes carbonate crusts possibly formed in oscillating sub-humid to arid climatic pulses, perhaps likely during Marine Isotope Stage (MIS) 4, around 60,000–70,000 years ago. One of these crusts formed the base on which a hearth-like structure had been built. In Trench D evidence for human occupation appears to decline moving up the profile, coinciding with sedimentary evidence of more frequent disruptive climatic events possibly associated with latter stages of MIS 5.