THE SITE, GEOLOGY AND TOPOGRAPHY
The topography, geology and soils of an area have an important bearing on the presence, character and survival of archaeological remains.
The site is located at a height of c. 45-48 m AOD, on a low rise in the Cretaceous Lower Greensand ridge, some 0.75 km south east of the centre of Gamlingay village. To the west, an abrupt break of slope, enhanced by dumped material from a ploughed-out farm track (J. Brown, pers. comm., Murray 1996a) marks the limit of the former floodplain of Millbridge Brook, at the time delineated by a line of overhead electricity cables. To the north the development area is bounded by Station Road, believed to be mediaeval in origin (Stubbert 1993), and created in association with establishment of Merton Manor probably in the 13th century. Land to the east of the site has been developed in recent years for factory and light industrial use. To the south the site is defined by the course of the dismantled former Bedford-Cambridge railway. Beyond this the ground surface drops gently to a former small tributary of Millbridge Brook, now taken into cultivation. Examination of the surface of the site revealed no upstanding earthworks to be evident on the site prior to the archaeological excavations taking place.
Prior to the excavation the site was used as arable farmland. Evidence for deep ploughing was recorded (including displacement of skeletons and feature fills), but no farrow scars were found associated with the ridge and farrow field systems suggested by the Langdon map of 1602 (Stubbert, 1993, 16, Murray 1996a).
The village lies on the edge of the Greensand ridge, which runs generally from the south west around Leighton Buzzard to Sandy, marking the limits of the Jurassic and Cretaceous rocks. The clays and loams of the valleys in the area of the Greensand ridge are generally very fertile, though the acidic, sandy heathland soils in the region are less so.
The Millbridge Brook runs through the village, some 60 m to the west of the site. The brook has a substantial floodplain and steep, abrupt terrace in the vicinity of the site, and would have been a sizeable watercourse in prehistoric times, and almost certainly a more dominant feature during the Saxon period than today.
The sandy, easily worked soils were clearly attractive to early occupation, reflected in the widespread scatters of prehistoric lithic material along the valley of the Millbridge/Potton Brook. Prehistoric settlement of the region is well attested from the known river valley evidence, though increasing documentation from Hertfordshire and Essex suggests that the boulder clay plateaux were being more densely settled from at least the Bronze Age.
Assessment of aerial photographs was undertaken on behalf of HAT as part of the desk-based assessment of the site (Murray 1996a). This disclosed a number of ditches and enclosures of unknown date on the site, in addition to a wide circular enclosure cropmark. The latter had an elongated internal pit to the south-east of the site, adjacent to the former Gamlingay Station. The possible features were revealed on only two air photographs from Summer 1962, held by the Cambridgeshire County Record Office. Other air photos consulted recorded nothing on the site itself (though revealed features in the surrounding fields), and indeed aerial survey in the vicinity, undertaken over five years by Air Photo Services, recorded nothing. This illustrates the unpredictable nature of the appearance of crop marks in the presence of buried features, dependent upon the coincidence of a number of environmental and agricultural variables. The excavations examined the nature of these features and verified that some were spurious, others were geological and a number were of archaeological origin.