*popular aria from The Bohemian Girl, an 1843 opera by Michael William Balfe
From: Urban Geology in London No. 7:
“The foyer of the Hotel Russell is famous for it’s ‘sumptuous’ marble decoration and it makes for a fine display of primarily French decorative stones. Doll was famous for such interiors and this gave us the colloquialism ‘dolled up’ (see recent posts) for lavish decoration. Identification of the marbles by this author has been much aided by the works of Renwick (1909) and Elsden & Howe (1923). Both writers saw the hotel as a prime example of a fin de siècle interior decoration and gave the names of the stones used in its construction. Although the stones used here are described as ‘marbles’ very few of the examples used in the foyer of the Hotel Russell fit this description geologically. A true marble is a limestone which has been transformed and recrystallised by the actions of an increase in temperature and pressure. This process is called metamorphism and it erases the original features of limestones, such as fossils. However many limestones are capable of displaying a range of colours and able to take a good polish and they are thus termed ‘marbles’ by the building trade. Whether or not they have been metamorphosed, many of the rocks seen here have been deformed by tectonic processes active in the Earth’s crust. These include movement along faults and the formations of folds in strata, both ultimately driven by plate tectonics. In brittle rocks such as limestones these process can cause the rock to fracture and break up to form ‘breccias’. The jumbled and cemented rock fragments that have formed as a result of these process have produced many of the decorative stones seen in the Hotel Russell foyer…
…Sarrancolin comes from several quarries near the hamlet of Beyréde-de-Jumet, just south of the village of Sarrancolin in the French Pyrenées. The quarries were worked from the 17th – 18th Centuries, particularly for stone for the French Royal Court. They were abandoned in the 18th century but reopened again in 1823. This marble has been particularly popular for making fire surrounds, but its use in the Hotel Russell dining room is one of its most extensive architecturally. The craftsmanship is breathtaking. The walls are clad with panels that have been ‘book-matched’; that is with slabs that have been cut from the same block and opened like a book to provide mirror images of the slabs. More remarkable are the ‘quarry-matched’ slabs cladding the pillars and pilasters. To give the impression of monolithic columns, the cladding has been applied as it would have appeared in natural outcrop with veins and geological features traceable along the length of the pillars. This work requires a great deal of organization and skill with blocks being carefully numbered at the point of extraction and this being carried through the slabbing, polishing, cutting, transportation and application, with information being passed on via the series of artisans employed in these processes.
The decorative quality of the stone from Sarrancolin is derived from the red, pink and orange coloured, laminated infillings and breccias in fissures in massive and brecciated mid-Cretaceous, grey, limestones. Clasts include yellow-colored laminated mudstones, brown, microbrecciated, gravelly deposits and carbonates, red clays are common in the matrix. The rock is cross-cut by white veins and tension gashes. There is some controversy over the age and formation mechanisms of the Sarrancolin ‘Marbles’; Canérot (2007) makes a convincing argument for them being post-tectonic continental deposits whereas earlier authors have speculated on a latest Mesozoic marine origin. In outcrop they are vertically bedded mid-Cretaceous limestones which host karst infill in fractures in their upper surfaces; these are not pervasive to depth and so are interpreted as being post-tectonic (later than Middle – Upper Eocene). The fractures are hydraulic and later fractures have reworked the fill of earlier ones. Canérot (2007) interprets these as Oligocene-Neogene continental exokarsts. However, tension gashes clearly post-date the karst infill indicating that there must have been tectonism subsequent to the karst deposits.”
Dr Ruth Siddall, University College London, Gower Street, London WC1E 6BT: Geologists’ Association trip on 9th July 2013. (And see Seven questions with Dr Ruth Siddall)