Soil Micromorphology

During the 2010 excavations, soil samples were taken both from the trenches and a series of small test pits dug by Kate Boulden [Link to Kate’s ‘Meet the Team’ page?]. The test pits were spaced out in a line between our two main excavation areas, in the process crossing from the Undifferentiated Head to the Upper Chalk. Taking the samples from the sides of the trenches dug across Pegasus Barrow was a particularly amusing process – at least, it was for those of us who watched. Sun-baked Undifferentiated Head is not the easiest of soils to push a sampling container in to. 

Kate and Scott join forces to take a sample from a reluctant Pegasus Barrow.

Kate and Scott join forces to take a sample from a reluctant Pegasus Barrow.

 The samples were taken back to the McBurney Laboratory for Geoarchaeology at the University of Cambridge, and mounted on slides for analysis under a microscope. The slides were then examined for evidence of human activity, especially those taken from the Pegasus Barrow samples. The analysis proved a success, the slides showing a complex history of land development in the area of our trenches.

Some of Kate’s test pits, as viewed from Pegasus Barrow, with the Area E trench in the distance.

Some of Kate’s test pits, as viewed from Pegasus Barrow, with the Area E trench in the distance.

Prior to the construction of Pegasus Barrow – which we estimate to have occurred nearly 6,000 years ago – the area of the mound was wooded, but at some point this woodland was cleared by burning. Then, in this clearing, the clay from the surrounding area was scooped and heaped up into a low mound, enhancing the natural promontory on which it stood – the mound may never originally have been very substantial at all, certainly nowhere near as substantial as Dampney Barrow. 

Activity seems to have been quite short-lived on this hill, but down the slope, towards Area E, things picked up in the Bronze Age as evidenced by the various ditches which  were probably some form of land boundary. The valley bottom in particular seems to have been open grassland from the Neolithic, and by the Bronze Age was well-established pasture. The ditches themselves seem to have existed for quite some time, gradually filling in as nature took hold.

One of Kate’s thin sections, in all its glory.

One of Kate’s thin sections, in all its glory.

The charcoal samples recovered during excavation indicate the presence of oak prior to the construction of the Pegasus Barrow mound. Hopefully further analysis of the bulk samples taken during the course of the excavations at both Pegasus Barrow and in Area E will allow us to create an even more detailed picture of the landscape and environment before, during and after the construction and use of these monuments. Area E will provide us with added insight into the past environment through the presence of molluscan remains – snail shells. Snails are remarkably fussy about where they live, and particular species give an excellent indication of the localised environment. Unfortunately, snail shells do not survive at all on more acidic soils, such as the Undifferentiated Head occupied by Pegasus Barrow.