Stratigraphic palynology of the Lake Menindee region, northwest Murray Basin, New South Wales

A number of shallow bores in the marginal marine region of the northwest part of the Murray Basin have yielded pollen and dinof lagellates in the lower dark grey-black clays.The upper red-brown-yellow sediments, showing signs of weathering, are barren.The bores of this area correlate best with the late Oligocene -early Miocene sequence in the Oakvale bore (Truswell et a 1 ., 1985) which is also in the northwest part of the basin.The assemblages may be placed in the upper part of the P.tuberculatus Zone (Stover and Partridge, 1973) and conclusive evidence for the latest early to mid Miocene T. bellus Zone has not been found.Dinof lagellates found in many of the bores are reported here.The spore-pollen palynology of this northwest part shows some differences when compared with the eastern margin of the basin.These differences are consistent with the hypothesis of a climatic gradient parallel to that of today, i.e. drier in the northwest, controlling geographic variation in the vegetation of the time.