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Newsletter No. 202

The Black Country Geological Society

August 2010

west to the coast we would be able to see the Aberystwyth Grits, (see photograph above) a sequence of alternating sandstones and mudstones. It has been generally accepted that you can only find sandstone where there is energy to move the grains, and the shales are formed in quiet, deep water. This means that there must have been several changes in sea level to give shallow water for the sandstone and deep water for the mudstones.

Silurian stratigraphical terminology has been changed, as have many of the fossil names; Omphyma is now called Ketophyllum. Plate tectonics was about to emerge as sea floor exploration and sophisticated geophysics developed. Similarly the electron microscope was waiting to have its enormous impact on identifying both rocks and fossils, particularly the organic nature of the Chalk. It would also open up the research into Precambrian sediments and the organic material therein and radiometric dating would become more accurate, allowing the age of the start of the Cambrian to be revised several times. The concept of a geosyncline is not entirely redundant, there will always be thick sedimentary basins; the breakthrough paper interpreting the Aberystwyth Grits as a turbidite deposit appeared in February 1957. There are several anachronisms here, but for convenience I have put developments over a brief period into one hypothetical time slot.

There are so many ideas that have been reinterpreted because of new evidence. You may know of others, or you may have other comments to make. Please do so through the Members’ Forum. The only problem is that by doing so you are revealing your relative, even if not absolute, age. ■

Bill Groves

Members' Forum

Letters/emails

The Bushbury & Bognop Glacial Erratics

Following on from the field trip to West Park, Wolverhampton earlier this year, here are some details on how to find further examples of the extensive glacial erratics to be found to the north of the City.

Bushbury Church

Follow the Stafford Road (A449) north from the City Centre looking out for the crematorium signs which will lead directly to Bushbury. The church is on your right hand side immediately past Bushbury Nursery School. Plenty of parking spaces are available outside the church and the erratics are obvious in the middle of the grassed area. Also look along the stone walls immediately opposite this little green as further erratics

have

been

incorporated into the stonework, the majority of which is made up of Permo-Triassic dressed blocks, presumably from the long closed Bushbury Hill quarries.

Old Warstones Lane

This site is some 6 miles from Bushbury Church but is easy to find by turning right out of the churchyard and following Bushbury Lane until the first turning on the right, Underhill Lane, immediately identifiable by Northicote Park Farm buildings on the corner. Continue along Underhill Lane to the junction with the Cannock Road (A460). Turn left and proceed along the A460, under the M54 until Shareshill sign is seen on the left. Take the next right turn, Hilton Lane, also signposted Hilton Hall. Carry on along Hilton Lane, and after passing over the M6, look for the next turning on the left which is Old Warstones Lane. It is possible to park alongside a small field entrance on ►

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