A palynological investigation of diamictons and tills from northern Caithness, Scotland

The matrices and erratics gave similar palynological signatures. Palaeozoic spores are rare, especially in the matrix. The relatively sparse Middle Devonian spores were sourced locally. The provenance of the rare Carboniferous spores is unclear. It is possible that these spores were sourced from north of the Firth of Forth, from the Outer Moray Firth, and/or are from Jurassic strata (i.e. were reworked from the Carbioniferous during the Jurassic). Miospores of Jurassic aspect are abundant, especially in the matrix. The source of these miospores is likely to be from paralic Middle Jurassic units. The level of input from Upper Jurassic strata is negligible. Lower Cretaceous dinoflagellate cysts are present in significant numbers, again especially in the matrix. Markers are indicative of of Volgian to Ryazanian/earliest Valanginian input. The likely source is the Ryazanian ‘hot/warm shale’ facies of the Kimmeridge Clay Formation. The probable sources of this Mesozoic material is probably offshore, possibly the Inner Moray Firth. It is highly unlikely that the Quaternary pollen is in-situ. The relative abundance of Palaeozoic material in the erratics, and Mesozoic material in the matrix is interpreted as reflecting the hardness and softness respectively of these sediments.