Discovering the Past

Page 1

DISCOVERING THE PAST* H . E . P . SPENCER, F . G . S .

IN order to interpret the past one has to understand the processes that effect topographic and geographic changes today. For instance reedbeds on estuarine shores and Spartina townsendi build up the shore level, initiating saltings and eventually saltmarsh, though such processes are slow and are often unnoticed. In geological deposits fossil evidence in the form of bones, shell and plant remains and latterly in pollens, proves changes of climate and of environment. The clays and sands of Suffolk yield much material evidence not only of the changes indicated above but of considerable alterations in the topography due to the fluctuations in the level of the sea. Below the bed of the River Gipping there is a buried Channel over a hundred feet deep, forraed some 300,000 years ago: in the upper parts of the deposits are remains of reindeer and other animals belonging to a cooler age than ours. At a higher level fossils of a temperate period, with Red Deer and a south European Tortoise, imply a warmer climate. These periods—interglacials— occurred between very cold periods—ice ages—when ice spread south sometimes as far as the Thames Valley. Düring an earlier stage the level of the land must have been higher. At Hoxne remains of a lake occur at plateau level with new Valleys subsequently formed on either side. Flint implements of prehistoric people of a quarter of a million years ago have been found in the lake clay, along with animal bones. Remains of a great variety of animals, mostly long extinct, occur in the Forest Beds of Norfolk which extend also into north-east Suffolk. At that time there were three types of elephant and a greater variety of deer. One of the elephants lived much earlier in the earliest Pleistocene, the Red and Norwich Crags. After a Century of misapprehension during which the Red Crag, etc., were thought to belong to the Pliocene, owing to the presence of the Crag elephant Archid.iskod.on meridionalis and associated deer, all of which were either overlooked or ignored, it can now be shown that these marine deposits are equated with the Villafranchian of Northern Italy and date back some three million years. [*A S u m m a r y of a talk given to members of the October 28th, 1967. See page 74.]

Society—Ipswich


Turn static files into dynamic content formats.

Create a flipbook
Issuu converts static files into: digital portfolios, online yearbooks, online catalogs, digital photo albums and more. Sign up and create your flipbook.