It is getting towards the end of the dig now, and we can tell that we have dug ourselves down to sea level.  The deposits are getting wetter and wetter and pumping is becoming a routine part of the day.   We should not really complain about the water table; if the mere had not been permanently waterlogged since the Bronze Age we would not be able to gather the data that we have.

          three grown men making mud pies!

Even the pollens that had fallen in the lake have been preserved and have helped us build up a picture of not just what was living in the lake, but also in the surrounding landscape.

It is clear from the boreholes that one of the earliest forms of the mere was a wet but woody landscape.  Alder Carr was frequently found in the lowest deposits (Bronze Age) along with willow, oak, hazel and a few other native species.  Then we can see a silty layer that was deposited: the first real formation of the mere.  By the Iron Age, the mere started to dry out and turn to fen.  The trees are replaced by mosses, reeds, sedge and other wetland species, which we can see in the pollen types. 

          sorting the Bronze-Age wood samples

In the Roman period, however, this changes again, when the Car Dyke was built and a large earth ridge created.  This acts as a dam and creates a large, deep lake.  It was at least 5m deep and would have been full of fish.  There is even a possibility that the Romans used it as a harbour and that it connected to Car Dyke.  We are hoping that in the future we will get the chance to carry out a geophysical survey to establish if this was the case.  This deep lake is represented in our sequence of deposits by lake marl - a pale soil created by algae.  Until recently this was very obvious as a large white spread covering the length of three fields. 

We have now excavated through most of the layers and tomorrow (10 June) we will be removing the last of the organic deposits before starting to back fill.

          I hope these boots were removed before going into the house last night!

Guest blogger: Hayley Roberts