Much of Glasgow's buildings are build from sandstone, but have you noticed there are mainly two types?
This earthcache is a good example of the stone side by side. The coordinates place you just a little way South of the top entrance to Buchanan Street station, you should be standing facing the building currently housing a restaurant. Make sure Dundas Lane is behind you.
The right hand side of the building is the former the former Atheneaum Theatre, and in 1909 this was extended to build the Glasgow Liberal Club.
Have a look at the buildings and answer these questions:
1) Have a look at the buildings - describe the differences in the building stones on the left hand and right hand buildings.
2) Which building (left or right) is made of stone formed in the desert? What makes you think that?
3) Which building (left or right) is made of stone formed in rivers? Give a reason for your answer.
4) Which stone was formed longer ago?
5) According to internet research, the building on the left was built in 1909. Give a reason why a different type of sandstone may have been used for the extension rather than the same type at the original building.
6) Take a photo of yourself at GZ, or an identifying item, being careful not to reveal any of the answers to the questions.
Please submit your answers via message though the Geocaching website or by sending me an email - there is no need to wait for a response before logging your find.
Sandstone is a sedimentary rock, which can be formed in different ways. Sedimentary rocks form in deserts through the accumulation and cementation of wind-blown sand particles. In rivers, sedimentary rocks are created as layers of sediment settle and compact over time.
Blonde Sandstone
Blonde sandstone forms in river environments through the deposition and compaction of sand grains carried by flowing water. It typically contains quartz as its primary mineral, along with varying amounts of feldspar and other minerals.
During the 18th and 19th centuries, Blonde Sandstone was extracted from quarries in and around Glasgow, though not on the same scale as modern operations. Quarries were scattered throughout areas like Kelvingrove and Partick in the West End of Glasgow. Most of the blonde sandstone utilized for historical structures in Glasgow originated from nearby quarries in Bishopbriggs and Giffnock before 1890. This particular sandstone, dating back to the Carboniferous (300 to 360 million years ago) period, reflects Scotland's proximity to the equator during that time.
Red Sandstone
The red sandstone dates back to the Permian period, over 270 million years ago. At this time, a vast desert stretched across Scotland, causing huge dunes and incredibly dry conditions. The red sandstone was formed by layers of sand laid on top of each other (occasionally you can see cross bedding in some stones, showing the differing ways the wind blew). This sandstone's distinctive red hue is attributed to an iron-rich coating on the sand grains, akin to the process observed in the Sahara desert.
After 1890, with the railway network firmly established in and around Glasgow, importing sandstone from outside the city became significantly more convenient and economically feasible. The red sandstone was sourced from quarries in Dumfries and Ayrshire.
Comparing the two types of stone
Blonde sandstone typically contains higher proportions of quartz, imparting a lighter colours, while red sandstone often containsiron oxide minerals, contributing to its distinctive red colour. Additionally, blonde sandstone may exhibit fewer mineral impurities compared to red sandstone, resulting in a lighter appearance. However, both types of sandstone share similarities in their sedimentary origins and commonly contain varying proportions of quartz, feldspar, and other minerals.