This is a simple EarthCache that requires you to visit Telegraph Road in Thurstaston, to answer the questions below at the above co-ordinates. This cache should NOT be done as a drive-by, instead please park in the nearby Thurstaston Common car park, and take the short walk along Telegraph Road. You attempt this EarthCache at your own risk and I would recommend standing on the opposite side of the cuttings, because this is where there is a safe pavement and you are in view of the traffic. If you are bringing young children, please do be careful with them, the same also applies to dogs.
Telegraph Road in Thurstaston, specifically just after Thurstaston Common LNR, is known locally for having beautiful cuttings through the Sandstone rock, to allow the road to pass through. Thurstaston and Irby are underlain by red sandstone formed in the Triassic era (251 to 199 million years ago). As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic were marked by major extinctions. The start of the Triassic period (the 'Lower Triassic') came at the end of the Permian period when up to 96 percent of all marine species and 70 percent of land vertebrate species died out.
The Triassic climate was probably hot and dry. Land was formed together in one mass called by geologists 'Pangea'. Pangea was surrounded by ocean except that one part of the land was deeply indented by a sea called the Tethis Ocean. There does not seem to have been any glacial activity and the whole environment was ideal for the formation of red bed sandstones and mudstones in the ocean and by the action of wind forming sand dunes which later hardened into stone, on land. Because of the mass extinction at the start of the Triassic period there are few fossils in the stone, although fossilised footprints have been found at Hilbre Island and at Storeton Quarry.
The sandstones are red because they include large amounts of Iron Oxide (common rust!) among their constituents (components). Mainly the stone is formed by grains of quartz, which is Silicon Dioxide. Quartz is the most common mineral in the earth's crust.
The Lower Triassic (between 251 and 245 million years ago) sandstones of the Sherwood Sandstone Group form low, but prominent ridges on the Wirral Peninsula. The Sherwood Sandstone Group consists largely of red, yellow, and brown sandstones that often show colour mottling. Pebbles are scattered through much of the rock; the smoothness and roundness of the pebbles shows that they were transported by a large and powerful river system, probably on the edge of an dry, desert mountain range. Where they are close to the surface as at Thurstaston, they are covered by Podzolic or rather poor, well drained soils. In turn this is the most suitable type of soil for heathland vegetation.
To post a Telegram on this page, what I would like you to do is:
1. Name the rock that you can see in this cutting and describe its texture
2. Describe the colours of the rock that you can see in the cutting and explain why they differ throughout the cutting
3. Estimate from the pavement the length of the elongated hole in the cutting, as labelled in the picture above
4. As an optional extra, include a photo of yourself and/or your GPS at this EarthCache.
Please only attempt to answer these questions from the pavement, as traffic will be able to see you and it is far safer.
Please do not include the answers for the above questions in your Telegram on this page, instead send me a separate Telegram through my profile.
Huge thanks must go to Jane267, who has given permission for me to use some of the Geological History that you see above, from her website. Thank you very much Jane! 