This quiz was first posted on Twitter over the New Year Weekend of 2017-2018. If you missed it, both questions and answers are given here. Scroll down for answers.
Q1. Where do these coloured marbles come from?
A. Tuscany, Italy
B. Derbyshire, England
C. Devon, England
D. Namur, Belgium
Q2. Which is the main building stone of the British Museum?
A. Bath Stone
B. Lincolnshire Limestone
C. Portland Stone
Q3. This well known building stone is a rapakivi granite called Baltic Brown. Where is it quarried?
Q4. When were the Carrara Marble quarries first worked?
B. Roman Period
D. 19th Century
Q5. This is a very well-known building stone called Larvikite because its found in Larvik, Norway. Noted for its iridescent feldspars, what kind of rock is it?
Q6. What type of granite is this?
A. Rubislaw Granite
B. Shap Granite
C. Dartmoor Granite
D. Sardinian Granite
Q7. These two stones have been used on the Titanic and for St Peter’s Throne in the Vatican. In which mountain range are they quarried?
A. Atlas Mountains
Q8. This fossiliferous stone is currently very fashionable, used for exterior cladding as well as paving in malls and stations. Where is it from?
A. Paris Basin
B. French Jura
C. Bavarian Jura
Q9. These two porphyries were the main stones used in a Medieval paving technique called ‘Cosmati Work’. At the time they were looted from Roman ruins, but where were they originally quarried?
A. Italy and France
B. France and Turkey
C. Turkey and Greece
D. Greece and Egypt
Q10. How much granite was used in the construction of London’s Victoria Embankment?
A. 500,000 m3
B. 1 million m3
C. 1.5 million m3
D. 2 million m3
Q1: Devon, England.
These colourful limestones were quarried around Torquay, Plymouth and Ashburton in Devon and were popularly used for decorative items made by the English pietra dura industry during the 19th Century. The black limestone in which they were set is from Derbyshire.
So called ‘Devon Marbles’ were worked small-scale from the Frasnian-Givetian age Tamar Group Limestones of south Devon. You can find out more about the geology of these stones and there use in decorative works in Gordon Walkden’s books published by the Geologists’ Association.
Walkden, G., 2015, Devonshire Marbles: their geology, history and uses. Volume 1. Understanding the marbles. Geologists’ Association Guide no. 72., The Geologists’ Association, London.,1-232.
Walkden, G., 2015, Devonshire Marbles: their geology, history and uses. Volume 2. Recognising the marbles. Geologists’ Association Guide no. 72., The Geologists’ Association, London., 233-484.
Q2. Portland Stone.
Like many of London’s great civic buildings of the 18th and 19th Centuries, The British Museum is built from Upper Jurassic Portland Stone. Find out more on London Pavement Geology.
Bath Stone and Lincolnshire Limestone are also important British, Jurassic, oolitic limestones which are important building stones, however, the introduction of Portland Stone after the Great Fire of London in 1666 eclipsed their use in the capital.
This stone is quarried from the enormous Vyborg (Wiborg) Batholith which straddles the Finnish-Russian border. The stone shown in the photo and exported globally is quarried in Finland from several quarries near Lappeenranta in the SE of the country. It is a variety of rapakivi granite (‘rapakivi’ is a Finnish word meaning rotten rock) called a wiborgite. This rock has the distinctive ‘ovoid’ zoned feldspar megacrysts. Find out more in Axel Muller’s article in Geology Today.
Q4. Roman Period
Although it is probably the case that pre-Roman societies used field stones from the Massa e Carrara region for small scale use, ‘quarrying’ as we understand that term today began during the Roman period. The Romans quarried several marbles from the Carrara region including the white variety which they called ‘Luna’.
Larvikite is a monzonite, a plutonic igneous rock containing no (or very minor) quartz and equal amounts of plagioclase and K-feldspar. The iridescent (‘schillerescent’) feldspars are antiperthites with an oligoclase host and K-feldspar blebs. Find out more about the geology and use of this famous building stone here:
Heldal, T., Meyer, G. B. & Dahl, R., 2014, Global stone heritage: Larvikite, Norway., in: Pereira, D., Marker, B. R., Kramar, S., Cooper, B. J. & Schouenborg, B. E. (eds) Global Heritage Stone: Towards International Recognition of Building and Ornamental Stones. Geological Society, London, Special Publications, 407, 14 pp.
Q6. Dartmoor Granite
This is ‘Giant Granite’ from Dartmoor, so-called because of the large megacrysts present in this rock. There are several ‘megacrystic’ granites used in the building stone trade because they are both strong and decorative. A ‘megacryst’ is a phenocryst in a granite which is bigger than 1-2 cm. The megacrysts in Dartmoor ‘Giant Granite’ can be 10-15 cm long. Rubislaw Granite (from Aberdeen) does not contain megacrysts. Shap Granite and some varieties of Sardinian Granite are megacrystic, but usually the megacryst are on the small size. The give-away here are the lace-like blobs of black tourmaline which is characteristic of the Dartmoor Granite facies quarried around Princeton and elsewhere in the north of the pluton. The example in the photos is from Fishmongers’ Hall in London.
A number of very decorative tectonic breccias have been quarried in the Pyrenees since the Roman period. Shown here is the pink-grey variety Sarrancolin which was used in the dining room of the Titanic (designed by Charles Fitzroy Doll who also designed the Russell Hotel, where this stone is also used). The black and white stone is generally called Grand Antique. It was first quarried by the Romans and has been worked on and off since. The quarries have recently been brought back into production by Carrieres Plo. This stone has been much favoured by the Catholic Church. It is used for the plinth of the statue of St Peter Enthroned in the Vatican and this statue (including the stones used) has been much replicated.
Q8. Bavarian Jura
This stone is known as ‘Jura Marble’ in the building trade. Geologically it is from the Kimmeridgian Treuchtlingen Formation and it is quarried in the Altmühltal Naturpark, Southern Frankonian Alb, Bavaria, Germany.
Q9. Greece and Egypt
The green porphyry is called Lapis Lacedaemonium and it was quarried near the village of Krokeai near Sparta (Spartí), Greece. This is an altered Triassic basalt. It was worked from the Bronze Age until the Byzantine Period (5th Century AD).
The purple porphyry is the ‘original’ porphyry, named by the Romans because of its colour. It comes from the Roman Quarries of Mons Porphyrites in the Eastern Desert of Egypt which were in operation from (probably) the 3rd Century BC to the 5th Century AD. The rock is an andesite from the Neoproterozoic Dokhan Volcanics. It contains the epidote mineral piedmontite which is partially responsible for imparting the purple colouration.
Q10. 500,000 m3
Did you get lucky here? Half a million metres cubed of granite were used in embanking the Thames, the bulk of the material used was earth to backfill the new land reclaimed from the river.
Surprisingly little is written about this incredible feat of engineering. Find out more here:
Siddall, R. & Clements, D., 2015, Never in the field of urban geology have so many granites been looked at by so few! A stroll along the Victoria Embankment from Charing Cross to Westminster & Blackfriars Bridge., Urban Geology in London No. 21, 19 pp.
How did you do?
>8/10 You are a building stone expert! But here’s a #toptip – don’t give up your day job!
5-8/10 Pretty good! You have some sound stone skills!
3-5/10 OK, but definitely room for improvement …
< 3/10 Better luck next time!
Happy New Year and thanks for participating the #UrbanGeologyQuiz!