In a booklet published by the British Geological Society called 'Britain beneath our feet' these is a curious map on page 72 entitled 'Flooding in the recent geological past'.
|BGS Map of the post glacial Flooding|
The Section from the book (page 72) states quite clearly that:
"Flooding is the major and most frequent recurring natural disaster in Britain. But it is not a new phenomenon and geological information shows where it has happened in recent geological past - in the last 10 000 years. BGS holds data that show where the floodplains occur - the alluvial deposits that compose clay , silt sand and gravel left behind in previous inundations"
To repeat - IT HAS HAPPENED IN THE RECENT GEOLOGICAL PAST - IN THE LAST 10 000 YEARS and take a closer look at the area of interest in my book Stonehenge.
|BGS map of Wiltshire showing Post Glacial Flooding|
Digital geological data which shows the extent of alluvial deposits are available at 1:50 000 scale for virtually the whole of Britain; they delineate not only the wide floodplains of major rivers and streams, but also the flat ground that floors all of the smaller tributary valleys and gullies."
Again in the text is the answer and confirmation of my hypothesis on post glacial flooding: THEY DELINEATE NOT ONLY THE WIDE FLOODPLAINS OF MAJOR RIVERS AND STREAMS, BUT ALSO THE FLAT GROUND THAT FLOORS ALL THE SMALLER TRIBUTARY VALLEYS AND GULLIES
In other words the post glacial flooding (less than 10 000 years ago) not only flooded the rivers to create new flood plans but the streams and the tributary valleys and gullies were also flooded such as Stonehenge Bottom, which is a dry river (tributary) valley that has sand, silt and pebbles under the top soil . To date archaeologists have maintained this valley was dry for hundreds of thousands of years - they are wrong and the BGS are telling us that the entire region was flooded less than 10,000 years ago.
So when we now look at the post holes in the Visitors Car Park at Stonehenge and see that they are dated to be 10,000 years old 8500BCE we know now that this area was flooded and the post holes were placed at the shorelines of this post glacial flooding - not only I say so, moreover, so does the British Geological Society!!
The confusion in the past has come from geologists that call this river evidence 'head' and that it is formed from hill-wash - that clearly is complete nonsense!!
When you see what makes up 'head' compared to 'alluvium' you can see how they got themselves into this complete mess as BOTH deposits contains clay, sand, silt and gravel. But alluvium is only used if found by an existing river - they never understood in the past that these rivers were ten times larger in post glacial Britain so these gullies and tributary valleys were also free flowing rivers and should have been termed alluvium not head for accuracy.
Now we have sorted that geological mess - the next blog will be about the launch of my new map series that show these (post glacial) features to a much higher degree than the map here or even BGS's 1:50 000 series which is from borehole data and is therefore somewhat lacking in detail or accuracy.
I will be providing 1:25 000 scale detailed maps including ALL ancient sites (past and present) - stay tuned as the big launch date is just 10 days away.