The landscape surrounding Thurlow is the result of the joint effects of past glaciation and the agricultural alteration of the land by its inhabitants. The cross-section of Little Thurlow (Fig. 1) shows the village in a wide shallow valley cut into the East Anglian plateau which gently dips toward the south – south east (Fig. 2). This valley feature is the result of the advances and retreat of a glacier.
The last great glacial period to affect the British Isles was divided into five main periods when ice was piled upon the land, separated by times when the ice retreated and warmer conditions prevailed.
The first and the second of these glacial periods had very little effect on the landscape of East Anglia. The third (fig. 3a), however, happened approximately 780,000 years ago and lasted for some 90,000 years; and between this time and that of the last great glaciation to affect this area (the fourth, fig 3b), which took place between 235 and 360 thousand years ago, the area was covered by a vast blanket of chalky boulder clay. This material was the result of the glaciers grinding away at the material they þowed over, which was picked up, carried by the glaciers and then deposited once the glaciers melted. This covered a very large area in front of the glaciers and varied in thickness, usually between 30 and 50 metres, but in the south west of Suffolk thicknesses between 50 and 75 metres have been recorded, though you can’t tell that from the surface.
Fig 3. Direction of Ice movement: A Lowestoft and B Gipping.
— Ice Front
When the glaciers melted vast amounts of water were released, generally following the route of the streams and rivers that we see today. During this period the sea level was some 200 metres lower than it is today. This large amount of water had a great erosive power, carrying a vast quantity of debris and flowing beneath the glacier under high pressure, to produce tunnel valleys. Since these valleys were confined by the ice this caused the water to pass along deep incised water routes with irregular bases, before rising at the glacier snout to flow from the edge of the ice sheet as outwash or meltwater streams.
The movement of the water followed the lie of the land and the movement of the ice from the north west toward the south east. Undoubtedly the tunnel streams began on the plateau, though there is some evidence that they tended to retreat with the melting ice sheet.
Glacial sands and gravel are present the whole length of the River Stour. Bedrock in Thurlow is some 20 metres below the present river level, the infill being mainly boulder clay with approximately 4 metres of glacial sands and gravel. The same tunnel valley that þowed through Thurlow can be seen at Wixoe (fig. 4), where its lowest point is approximately 40 metres below the present sea level, while at Clare it is as far as 110 metres below our present sea level. Except for the tunnel valleys it is probable that the ice sheet, which produced the chalky boulder clay, rolled upon a bed of glacial sand and gravel, producing the general flattened character of the area which we see today.
It was the presence of the boulder clay, with its thickness and its ability to be watertight when ‘puddled’, which persuaded the National River Authority (Anglian) to present a feasibility report in 1993 for a reservoir to be built at Great Bradley. But after opposition from all the local villages this proposal was rescinded in September 1995.
Beneath the boulder clay which dominates the area lies the chalk. This was originally quarried where it came to the surface, and was either burned to produce agricultural lime which was used as a top dressing or was mixed with sand, quarried locally, for mortar used in building. Clay lump was another use of boulder clay, and wattle-and-daub cottages had to be protected by a coating of lime plaster produced from the chalk.
Generally, the most important necessity for living, and the one which often decided the site of a village, was water. Thurlow was probably no exception. It must have been sited where it is for two reasons. First, it was close to the river, which was likely to have been drinkable during the initial settlement; and secondly, the river here was shallow enough for people to cross, as it still is today. It is probable that the two villages of Great and Little Thurlow grew round two main families, who occupied the sites of both Great and Little Thurlow Hall but wished to live separately.
There is evidence that people lived close to the glaciers as early as the period between the second and third glaciations, but it is not until the change in climate at the end of the last period of glaciation, at about 5,000 years ago, that agriculture as we know it came into being. There was extensive clearing of the area by the Anglo Saxons who maintained an agricultural economy similar to our own, with sheep, pigs and horses as well as arable crops. In mediaeval times the wealth of East Anglia was brought about by the wool trade. This wealth can be seen in the existence of many fine churches in the area such as those at Clare, Long Melford and Lavenham, and of course also the Cathedral at Bury St. Edmunds (though the building is earlier, its wealth continued).
The area also has a long tradition of arable farming, and root crops were introduced in the 17th century. During the Napoleonic wars, owing to the increase in grain prices, many Suffolk farmers ploughed their land to grow cereals and at this time 80% of the farmed land in Suffolk was ploughed land. And despite the fall in the cereals market in the 1830s, agreements between farmers and stock dealers meant that land was still ploughed rather than put to pasture.The boulder clay soils traditionally supported a rotation of wheat, roots, barley, beans or clover, but this changed for two main reasons: first the effect of World War Two, with the government’s insistence that more cereal crops be grown, and secondly the change in emphasis from horse to tractor.
River Stour (from the Drift)
Since 1939 cereal crops in the area have grown from 228,000 acres to over 400,000 acres, with fodder food such as mangels rarely grown now. Meanwhile the total number of farms has been reduced from 10,000 to below 6,000, as smaller farms have been absorbed into larger ones. The total number of the population employed in agriculture has been reduced by at least threequarters, from just over 30,000 in 1939 to some 9,500 at the present day, not taking into account the large additional number who were employed only on a casual basis. This has, of course, greatly altered the structure of the village population and the lifestyle of its inhabitants.