Bull. not. Hist. Mus. Land. (Geol.) 58(supp): 51-58 



Issued 26 June 2003 



Gough's Cave, Cheddar, Somerset: 

 Microstratigraphy of the Late Pleistocene/ 

 earliest Holocene sediments 



RICHARD I. MACPHAIL 



Institute of Archaeology, University College London, 31-34, Gordon Sq., London, WC1H OPY, UK 



PAUL GOLDBERG 



Department of Archaeology, Boston University, 675, Commonwealth Ave., Boston, Mass. 02215, USA 



SYNOPSIS. Eleven thin sections of Late-glacial and early Holocene sediments from Gough's Cave were investigated by soil 

 micromorphology in order to complement analyses of contemporary faunal and human remains. Despite the paucity of continuous 

 vertical and lateral stratigraphic sequences, which were the result of cave exploitation during the first half of the twentieth century, 

 we were able to elucidate site formation processes relating to both Late-Glacial environmental conditions and the burial 

 environment affecting human remains. 



INTRODUCTION 



During 1987-1989 the Late Pleistocene (c. 12 ka bp) to earliest 

 Holocene cave sediments at Gough's Cave, Cheddar, Somerset, were 

 studied in conjunction with archaeological, human bone and faunal 

 studies by R. Jacobi, A. Currant, and C. Stringer (Natural History 

 Museum)(Jacobi, 1985, 1991; Currant et al., 1989; Stringer, 1990, 

 2000; Currant, 1991). Sedimentological investigations, like the ex- 

 cavations, suffered from having only relict and fragmentary deposits 

 to study, on account of the general removal of most of the cave fill 

 during the opening up of the cavern during the first part of the 

 twentieth century (Donovan, 1955). We therefore focused our atten- 

 tion upon extant sediment sequences dispersed within the upper part 

 of the cave with Late Pleistocene deposits: i) Areas I and III of the 

 North Wall of the cave, ii) the 'Skeleton Rift', iii) a cemented, early 

 Holocene stalagmite on the 'South Wall' , and iv ) an earliest Holocene 

 sequence in the 'Sand Hole'. 



METHODS 



Field 



Undisturbed samples were collected during the excavations from 

 North Wall Areas I (samples 44 and 59, G and H) and III (sample E), 

 the 'Skeleton Rift' (sample D), cemented (Holocene) stalagmite on 

 the 'South Wall' (sample F), and an earliest Holocene sequence in the 

 'Sand Hole' (samples A, B and C)(Table 1; Fig. 1). Samples were 

 impregnated with an epoxy resin and manufactured into ~8 x 6 cm 

 size thin sections at the Natural History Museum, London. 



Eleven thin sections were made from Gough's Cave and were 

 described according to Bullock etal. ( 1 985) and Courty etal. (1989). 

 They were viewed at a number of magnifications ranging from x 1 , up 

 to x400 under a polarising microscope, employing plane polarised 

 light (PPL), crossed polarised light (XPL), oblique incident light 

 (OIL), and ultra-violet (blue) light (UVL) (cf. Stoops, 1996). The 

 combined use of these different types of illumination permit a large 

 number of identifications, such as apatite (bone, guano and coprolites) 

 which autofluoresce under UVL. The authors also made use of 

 comparative material of Pleistocene cave sediments (e.g., Courty et 



al., 1989), including nearby Middle Pleistocene Westbury-sub- 

 Mendip (Somerset) and Late Pleistocene King Arthur's Cave in the 

 Wye Valley (ApSimon et al., 1992; Macphail and Goldberg, 1999). 

 In addition, the number of soil micromorphological investigations of 

 palaeosols dating to the Dimlington Stadial, Windermere Interstadial 

 and Loch Lomond Stadial has increased greatly since this original 

 work was done at Gough's Cave. These include a number of chalky 

 colluvial Aller0d palaeosols (Rendzinas) from Kent (Macphail and 

 Scaife 1987, Fig. 2.4;Preecee?a/., 1995), a ranker from West Sussex 

 (Macphail 1995) and a palaeosol formed in scree outside King 

 Arthur's Cave (Macphail et al. 1999). 



RESULTS AND INTERPRETATIONS 



Soil micromorphological descriptions and findings are summarised 

 in Table 1 and illustrated in Figs 1-7. In order to simplify presenta- 

 tion of the findings we have grouped the results and associated 

 interpretations. 



Pleistocene Deposits 



Pleistocene deposits overlying the widespread, unfossiliferous, ba- 

 sal conglomerate are composed of gravels overlain by silt-rich 

 sediments (Fig. 1 ) that represent an identifiable depositional/post- 

 depositional sequence. We can broadly refine these characterisations 

 as follows: 1) bedded silts, sands and gravels; 2) the formation of 

 banded fabrics with associated link cappings; and 3) reworked and 

 disrupted silts and sands; 4) minor biological reworking by roots and 

 fauna, and 5) inwashing of silts and dusty clay. 



Bedded silts (Fig. 2), sands and gravels (Fig. 4) are broadly related 

 to an upward fining sequence associated with phreatic flow within 

 the main chamber of the cave (cf. Gillieson, 1996, Fig. 5.3). These 

 depositional episodes are tied to fluctuating/diminishing water flow 

 events within the overall karstic system that give rise to a sequence 

 of cobbles (e.g., the basal conglomerate; not sampled here), gravels 

 (sample 59, Table 1 ), sand (samples G, H, D, E, I and 59), and mud 

 (samples B and C). Very thick phreatic sands and gravels also typify 

 the Middle Pleistocene basal fill at Westbury-sub-Mendip Cave 

 (Macphail and Goldberg, 1999) and comparable karstic settings 

 (e.g., Goldberg and Sherwood, 1994). 



© The Natural History Museum. 2003 



