A palynological investigation of the Chalky Till of the Marsh House Farm borehole, north Norfolk

This report describes the palynology of four samples of Chalky Till from the Marsh House Farm Borehole, North Norfolk. The palynofloras of the uppermost interval, represented by samples 1 and 2 are both dominated by Carboniferous miospores. The majority of these forms are indicative of the Westphalian and the source is from the north-west. Jurassic material is present in sample 2; the majority of this are Mid-Late Jurassic miospores with small numbers of Jurassic and earliest Cretaceous microplankton. The latter indicate input from the early Toarcian, Oxfordian-early Kimmeridgian, Kimmeridgian and Portlandian-Ryazanian intervals of eastern England. Late Cretaceous dinoflagellate cysts are rare in both samples, despite the fact that the Till is rich in Chalk Group material. It appears likely that the Chalk Group incorporated into this Till is organic lean. Quaternary and non age diagnostic palynomorphs are also present.
Samples 3 and 4 from the lowermost part of the borehole both yielded abundant palynofloras which were overwhelmingly dominated by Pediastrum. These are most likely to have been derived from Quaternary (or possibly Neogene) lacustrine sediments. The ?Happisburgh Till of Norton Subcourse Pit, Norfolk is also rich in Pediastrum. The remainder of the palynofloras comprise Botryococcus, Cyathidites, indeterminate spores, Tasmanites. spp. and undifferentiated Quaternary miospores. No Carboniferous to Cretaceous palynomorphs were observed; no Late Cretaceous palynomorphs are present, despite the Chalky nature of this sediment.