A palynological investigation of the glaciogenic sediments of Clipsham Quarry, Rutland

Abstract

Jurassic palynomorphs dominate samples 1, 3-6 and 10; these are virtually all of Callovian-Oxfordian age. Some minor evidence of Carboniferous and Toarcian reworking was also observed. Exclusively Callovian and Oxfordian index species are common, and forms that are indicative of the late Callovian-early Oxfordian interval are especially abundant. This indicates the incorporation of significant levels of the Oxford Clay Formation. Smaller levels of recycling from the Cornbrash and Kellaways formations are also present. These lithostratigraphical assessments indicate that this Jurassic input was local, and probably derived from the Spalding-Sleaford area of south Lincolnshire to the north-east. Sample 2 yielded a sparse palynoflora, indicating some input from probable marine Quaternary sediments; no evidence of the reworking of Palaeozoic or Mesozoic strata is present. Sample 7 produced a sparse palynoflora indicating input from Carboniferous, Jurassic/?Cretaceous and probable terrestrial Quaternary strata. Sample 8 comprises isolated chalk pebbles from a chalky till and produced a sparse palynoflora. No stratigraphically diagnostic taxa were encountered. The sparseness of the dinoflagellate cyst associations indicates that the Chalk in this sample is not from the Upper Chalk. Sample 9 produced an abundant palynoflora that is dominated by Jurassic miospores; no marine Jurassic microplankton were observed. Low numbers of ?Rugospora spp., a Lower Carboniferous spore, and indeterminate dinoflagellate cysts were also observed. The presence of forms such as Leptolepidites spp. and Neoraistrickia gristhorpensis indicates that this sample was derived from Middle Jurassic strata deposited in a terrestrial/freshwater regime. The source is most likely to be the Rutland Formation, a Bathonian heterolithic, rhythmic unit. The Rutland Formation outcrop is local to Clipsham Quarry. Sample 9 is significantly different to samples 1, 3-6 and 10, which are characterised by younger Jurassic material