In 1770 it was proposed that a canal should be built from the River Dee in Chester to the Trent & Mersey Canal at Middlewich, creating a short-cut route between the Potteries and Liverpool. However, due to engineering issues, costs and a lack of support from the Trent & Mersey Canal Company, the Chester Canal terminated at Nantwich.
In 1813, the Ellesmere Canal Company merged with the Chester Canal Company. Then in 1847 the Ellesmere Canal, Birmingham & Liverpool Junction Canal and the Montgomeryshire Canal came together to form the Shropshire Union Railways and Canal Company and the
waterway became known as the Shropshire Union Canal. The canals were nationalised in 1948, and long-distance commercial traffic had all but ended by 1958. Responsibility for the canal passed from British Waterways to the newly formed Canal & River Trust in 2012.
This EarthCache will take you to one of the deepest passages and most awe-inspiring sights of the canal itself, running along the Roman Walls, where you can also appreciate how it was built.
Focus on the wall of rock towards the city centre to complete all your tasks.
TASK 1: what type of rock can you see here?
Bear in mind: recognizing different types of rocks involves observing their unique characteristics.
a) Igneous rocks, formed from cooled magma or lava, typically exhibit a crystalline texture with interlocking mineral grains. They can appear glassy, like obsidian, or coarse-grained, like granite, with visible crystals of minerals such as quartz, feldspar, and mica. Some igneous rocks, like basalt, are fine-grained due to rapid cooling at the Earth's surface.
b) Sedimentary rocks, created from the accumulation and compaction of sediments, often have a layered or stratified appearance and may contain fossils. Common examples include sandstone, shale, and limestone. Look for cross-bedding within these rocks, which appears as inclined layers or sets of layers within the main strata (see picture above). This feature indicates past environments such as river channels, deltas, or wind-blown sand dunes, where changing conditions caused sediment layers to deposit at an angle.
c) Metamorphic rocks, transformed by heat, pressure, or chemically active fluids, display foliation or banding due to the reorientation of minerals under stress. Examples include schist, which has a platy texture, and gneiss, characterized by alternating light and dark mineral bands. These rocks often have a more crystalline and compact texture compared to their sedimentary or igneous origins, reflecting their intense formation conditions.
TASK 2: rub your finger on the rocks: what happens?
TASK 3: based on your previous considerations, do you think this rock would be a good building material? Why/why not?
TASK 4: based on your previous considerations, why do you think they decided to dig the canal through here?
TASK 5: at the posted coordinates, you'll see a small plaque on the rock (about 5 feet, or 1.5 m from the ground): what or whom is it dedicated to?
Send me your answers by email or via the Message Centre. Feel free to log your visit straight away: if there are issues with your answers I'll get in touch with you.
Please, be considerate and don't include answers nor spoilers in your log and/or in the pictures you might want to attach.