My first post, thanks for having me. So who's my goto Geology member then?
Took a morning walk up Bidston Hill and was thinking about it's ice age past, and why there doesn't seem to be large igneous boulders deposited across it. Surely there would be some dotted across Wirral left over from the last ice age when the ice shelf receeded? Are there any?
I'm not a geologist but I am old. I would think that glacial erratics if left on the tops of sandstone ridges would gradually be move to lower ground over time so would no longer be visible.
I have seen only one for certain. That was in the foundations of the old A & E section of Victoria Central Hospital in Croxteth Ave Wallasey back in the 1950's. The excavation deep into the boulder clay had cut through and exposed a large erratic boulder embedded in the clay.
There is one possible one on the surface in Central Park Wallasey assuming it is still there. When I last saw it it was about 4 ft high well rounded and looked like a dark grey granite - definitely not sandstone. GoogleEarth view attached.
I should have mentioned that the boulder clay cliffs at Thurstaston erode out erratic boulders stones etc. and these can be seen along the beach below the Visitors Centre on the Wirral Way.
The link put up by DiggingDeeper looks very interesting, but Ye Gods I wish the person writing it had used paragraphs! They make text much more digestible. My (totally amateur) idea on the lack of glacial erratics on Bidston Hill is that, being a high area, it would have been scoured clear and any deposition would have been on lower-lying areas. Smaller ones lying around might later have been used for building or walling. There is a rich variety of erratics (mostly small) eroding out of the cliffs at Thurstaston, well worth exploring.
