This study documents the sediments, pollen, seeds, molluscs, vertebrates and mineral magnetism of deposits found in an abandoned water supply system at gasr Mm 10 in the Wadi Mimoun in the pre-desert of Tripolitania. These new data suggest (1) at or close to an episode of probable abandonment of that gasr, the growth of cereals (and perhaps general agricultural activity) still occurred on the wadi catchment upstream of the gasr, and (2) the vegetation of the adjacent wadi floor was richer in species (which included olive) than occurs today.