The Building Stones of Wakefield

 

Richard Bell's Wild West Yorkshire nature diary, Sunday, 4th November, 2007

gabbroWestgateWHEN YOU LOOK closely at these blocks of gabbro (left) in Tammy Hall Street in the centre of Wakefield, you see dark crystals but when you photograph them it’s the reflections of the buildings beyond that are most noticeable. It’s probably to do with the way the eye focuses on surface detail while your brain filters out ‘superfluous’ distractions, such as the reflections.

Gabbro contains black ferro-magnesian rich minerals, known as 'mafics'.

The gabbro and the grey granite and micro-granite setts (cobbles) nearby are new additions to the building stones of the city. The old local sandstone setts that were taken up during the refurbishment have been used to fill the gaps in an adjoining cobbled alley, the George and Crown Yard.

Granites

graniteAt the top of Westgate (top, right), you can see a variety of granites, including one (left) that was probably quarried in Finland, which contains reddish crystals of feldspar.

Rapakivi granite

Portland StoneGranite formed from molten rock at the roots of mountains during continental collisions. In Rapakivi Granite (above), also from Finland, the feldspars have been partially remelted, losing their angular shape, like an ice-cube dipped in water, and have subsequently acquired a rim of greenish plagioclase feldspar.

Rapakivi granite has been dated at over 1,500 million years old, which is ten times as long ago as the heyday of the dinosaurs and 900 million years before complex life first appeared in the fossil record. That makes the shop front of the Southern Chicken takeaway on Westgate the most ancient thing in the city of Wakefield! (unless someone happens to have a chunk of a meteorite, which formed about 4,500 million years ago).

Jurassic Shell Beds

The frontage of the Midland Bank (right) is built of Portland Stone, an oolitic limestone which contains drifts of the shells of bivalves - clams and oysters - of the Jurassic period. Oolitic refers to the texture, which resembles fish roe. As lime accumulated in a tropical sea, it was rolled around by the current; a process that can be observed in parts of the Caribbean today. Portland Stone is quarried at Portland Bill in Dorset. It was shipped to London for the reconstruction of the city after the Great Fire of 1666.

A public house by Kirkgate railway station, at the other side of town, was the first building to be constructed of Portland Cement, which was invented in 1824 by Joseph Aspdin (1778-1855) as an alternative to Portland Stone. Aspdin is buried in St John's churchyard, Wakefield.

The Westgate Run

The Portland Cement pub is unfortunately boarded up at present, like so many local pubs, but, against the trend, the dozens of pubs and wine bars (someone estimated that there are about 40 of them!) on Westgate seem to be thriving, partly as a result of 'the Westgate Run',which starts at the Redoubt at the lower end of the street. This pub crawl was recently made infamous by the anti-social behaviour of the city's Trinity Wildcats rugby league who were out in drag, which must have been quite a sight in itself, celebrating the end of the season. 'Wildcats Night of Shame' was the headline in the local paper.