Green Geology

Normally, visiting a geological location shows you at least something of the geological history of the area in question, but when you are looking at building stone you often see the history of another area writ large.  As well as the more exotic stone of the Canadian and Australian war memorials, in the case of London’s Green Park the Tube Station, the Bomber Command Memorial, the Wellington Arch and other structures have been built from Portland stone.


The Portland Beds are limestones that were laid down in warm, clear waters during the Jurassic in a series of strata which have been shown to excellent effect at Green Park tube station which has recently been upgraded.  The street-level building, designed by John Maine RA, is a permanent artwork – Sea Strata.  It is floored with granites and Larvikite and clad with Portland stone including the fossiliferous Roach Stone, stuffed with Portland Screw Aptyxiella portlandica and Trigoniid bivalves.  Other Portland stone used here comes from the Whitbed, the shelly Grove Whitbed, and Basebed.  Wonderful large-scale carvings of the fossils in the Roach stone have been created in panels of Basebed as part of the artwork, placed directly above panels of the Roach stone itself.


The Bomber Command Memorial, along the periphery of the park near Marble Arch, is built from vast quantities of Jordan’s Whitbed and Basebed – this was a new edifice in 2012 and, like the tube station, the exposures are very fresh and sharp here.  The plinth of the statue of the aircrew at the heart of the memorial is a red porphyry from Egypt.


The Wellington Arch, built in the 1820s, has been there long enough to show the effects of long-term weathering of the Portland stone it is built from, which makes the fossils it contains stand out proud from the surface.  There is a clear algal mat on the southwest side and there are some good Thalassinoides burrows visible on the south side.


The Memorial Gates, commemorating Indian, African and Caribbean countries that took part in the two World Wars, were a Millennium Project, and like many other such projects they have not fared well, with some of the plinths weathering badly.


Text and photographs:  Naomi Stevenson

Text and photography (c):

Naomi Stevenson


Page updated June 2013

Green Park, London - Portland Stone

Click to enlarge

Sea Strata