Field notes on some Broadland churches in the Wroxham area, Norfolk

Field notes on some Broadland churches in the Wroxham area, Norfolk.

Ruth Siddall, January 2019.

 The building stones of Broadland Churches visited by Ruth Siddall and Tim Atkinson on 12 January 2019. Please regard these as field notes; they are not intended to be exhaustive or complete records of the fabric of the churches described below. 

St Peter’s, Belaugh

TG 2890 1841

12thCentury with 15thCentury alterations and 19thCentury restoration by Butterfield & Phipson.

Rubble Masonry: Coarse flint, ferricrete, Wroxham Crag[1]component (minor), beach flints (minor).

Course flints retain cortices and may be very large > 30 cm long-axis single flints (NB very large flints are also used as gate posts in the village).

Ferricrete (very dark brown – almost black, pebbly [angular, moderately sorted], friable and rarer pieces of rust-red pebbly variety, with stratified pebbles). The dark ferricrete is used for quoins on NE corner and for (filled) window dressings on the north wall and as squared blocks in the lower part of this wall. These are probably from the 12thCentury phase and the ferricretes blocks are possibly reused. Ferricrete blocks have developed a pale green-white encrusting limestone.

Wroxham Crag component: white vein quartz cobble (south wall, close to door).

15thCentury rubble masonry includes a few slabs of Barnack Stone on west wall. Clipsham Stone dressings on windows of this period?

19thCentury – Knapped flint work with Ancaster Stone dressings. Uncoursed, coarse flint with cortices. Some Conulussp. echinoids. Some coursed, square-knapped flint work on buttresses.

Interior: Font (12thCentury) – grey green, fine grained limestone with a few white bivalve fossils. Unidentified stone.

North facing wall of St Peter’s Church, Belaugh showing several phases of construction and restoration and the distinctive, almost black blocks of ferricrete.

Knapped flints from the south facing wall containing a Conulus sp. Echinoid.

Blocks of ferricrete along with unknapped, uncoursed flints in the south wall of St Peter’s Church, Belaugh. These stones have been recycled into restoration phases.

Ferricrete used as quoins and ashlar on the NE corner of the church.

 

St Helen’s, Ranworth

Woodbastwick Road, Ranworth, Norfolk NR13 6HS

TG 3560 1476

First phase 1290-1350, Second Phase (Perpendicular-style alterations) up to 1530. Rood Screen 1419. North side of the church is much colonised by lichen.

Carved plinths (lamb of God, shields) on buttresses – Clipsham or possibly Barnack Stone.

Quoins, tracery and other dressings: Clipsham Stone

Rubble Masonry: Coarse flint, ferricrete (bright red-orange), Greensand (minor), Wroxham Crag component (vein quartz, Triassic quartzites, chatter-marked flints).

Flints – coarse with intact cortices, some knapped. Probably some are field flints. Upper parts of the building, including the tower have a large amount of red-orange flints. A circular, red flint in the tower (south side, c. 12 m up) is a paramoudra. Square, knapped, coursed flint work on foundations and buttresses.

Red-stained flints on the tower at St Helen’s, Ranworth including a ring-shaped paramoudra from the local chalk

Red-stained flint with fossil echinoid.

Ferricrete is a bright orange red cemented gravel with rounded to sub-rounded, poorly sorted, flint pebbles up to 4 cm long axis. Some blocks are of a gritty sand with sparse pebbles.

Blocks of ferricrete at St Helen’s Church, Ranworth.

The ferricrete has variable texture and clast size/distribution. However, it is notably a bright. Brick red in colour.

Wroxham Crag component: cobbles of vein quartz and red-pink Triassic Bunter pebbles (fist size) are common within the fabric, as are rounded, chatter-marked beach flints.

   Vein quartz cobbles from the Wroxham Crag at St Helen’s, Ranworth.

Spolia: a few rough fragments of Barnack Stone and a fine-grained Caen Stone pilaster. Greensands (possibly Kentish Rag) occur in a few squared blocks. These are possibly spolia or ballast.

Small pillar of Caen Stone spolia.

Greensand block, probably spolia or ballast.

Interior: grave slab of Green Purbeck Marble (with Uniosp.) flanked by smaller slabs of Red Purbeck Marble. Also slabs of 18thCentury of black Lower Carboniferous limestone with small white rugose corals, sparse brachiopods and a gastropod. This is probably Belgian or Irish in origin.

 Green Purbeck Marble grave slab with thick walled, Unio sp. Bivalves inside St Helen’s Church, Ranworth.

 

St Mary’s, South Walsham

23, The Street, South Walsham NR13 6DQ

TG 3653 1325

First phase 12th-13thCentury but much is 13th-14thCentury. Tower and porch are 15thCentury. Heritage Norfolk states ‘This church has a large quantity of lava incorporated into the walls along with reused masonry.’ I have no idea what the ‘lava’ refers to!

Lower courses (C12-13) of coarse flints with cortices intact, roughly coursed. Upper parts of knapped, uncoursed flint with spolia. The latter is composed of slabs of Purbeck Marble (much weathered, but with clear Viviparussp., 10 cm thick, c. 30 cm long) occur about 1 m up from foundations in the south and east chancel walls. Also, a fragment of carved, spoliated capital in Caen Stone or Clunch to the west of the down pipe of the buttress between the nave and chancel on the south side.

Exotic pebbles: sub-angular, brown, quartz arenites. These may be derived from the Crag or tills or could be ballast. Possibly striation on one example suggests till.

Porch: Square knapped, coursed flint flushwork with Clipsham Stone dressings (15thCentury).

Unknapped, beach flints have been added to the top of the walls of the north porch, probably in in the 19thCentury.

Knapped, coarse flints with boulders of brown arenaceous sandstone at St Mary’s, South Walsham.

The photo above shows a boulder which may show evidence of glacial striae.

St Mary’s Church, South Walsham. Fragment of carved capital in Caen Stone used as spolia in the church’s fabric.

Slabs of Purbeck stone, weathering in are laid in a line across the centre of the photograph.

 

St Lawrence’s, South Walsham

The Street, South Walsham NR13 6DQ, located next door to St Mary’s (above)

A 14thCentury Church restored in 1992. This building was visited very briefly.

Knapped, uncoursed flint work with Clipsham Stone dressings.

Stonework at St Lawrence’s, South Walsham; detail of Clipsham Stone dressings; this cross-bedded calcarenite is packed with shell fragments.

Knapped flint cobbles.

 

All Saints, Hemblington

Church Lane NR13 4EF

TG 35 11

Saxon-Norman Round Tower, chancel c. 1300, nave c. 1400 with 15thCentury roof and wall-paintings (of St Christopher).

Walls are predominantly of unknapped, coursed flint with cortices intact. Some (faint) herringbone coursing. Some knapped flint.

Exotic cobbles: Abundant, well-rounded quartzite (Triassic) pebbles and also sub-rounded to sub-angular cobbles of brown arenaceous sandstones, probably from Wroxham Crag and related deposits. Also a few one-off finds i.e. Hertfordshire Puddingstone sarsen, a medium-grained diorite.

Abundant spolia in Caen Stone is present. The Tudor brick window on the tower is cut into what was probably a spoliated window sill in Caen Stone. There is also a large amount of brick and tile incorporated into the walls.

Flushwork, knapped flint crosses on either side of the south porch entrance.

Dressings on buttresses in Lincolnshire Limestone (not fully observed).

The east end of All Saints Church, Hemblington showing at least two phases of construction.

Flushwork flint crosses in the brick-built south porch.

Carved spolia and rough flints in the walls.

Carved spolia in Caen stone. This is the remains of a window sill which has been cut into by Tudor brick work (on the left of the image).

Detail of stones at All Saints Church, Hemblington. Triassic quartzite split pebble.

A medium grained diorite of unknown origin.

Hertfordshire puddingstone, a form of sarsen.

Knapped flint with the trace of a fossil echinoid.

Download these notes as a pdf

Bibliography

Candy, I., Lee, J. R. & Harrison, A. M. (Eds.), 2008, The Quaternary of northern East Anglia., Quaternary Research Association., 263 pp.

Hart, S., 2000, Flint architecture of East Anglia., Giles de la Mare Publishers Ltd., London., 150 pp.

Norfolk Heritage Explorer

[1]According to Candy et al. (2008), the pre-Anglian Wroxham Crag and associated Bytham Gravel Beds contain a clastic component dominated by pebbles and cobbles of vein quartz, Triassic quartzite, ‘schorl’, Carboniferous chert, RhaxellaChert, flint and chatter-marked flint. The Bytham River flowed from the English Midlands, eastwards into the North Sea and provided a sediment source for the Wroxham Crag. The Wroxham Crag is differentiated from the underlying Norwich Crag by the presence of these ‘far travelled pebbles’.

Tyndall Stone: An Iconic Canadian Building Stone

Tyndall Stone is one of Canada’s iconic building stones. Derived from near Garson, Manitoba, it is used in a great number of buildings in Winnipeg. However it shows up all over the place as a high quality and attractive stone, suitable for both exterior and interior use with honed, bush-hammered or a polished surface. With a compressive strength of 62.8 MPa, it is a very strong and durable construction limestone.

Tyndall Stone-clad portico of the Fairmont Chateau Lake Louise in Banff National Park, Alberta

Tyndall Stone is extracted from the Selkirk Formation of the Red River Group of the Williston Basin. Tyndall Stone is quarried at Gillis Quarry in south western Manitoba, but extends westwards into Saskatchewan where the lateral equivalent is known as the Yeoman Formation. These formations are overlain by evaporite deposits. Gillis Quarry exposes a 43 m thick unit of massive, metre-thick beds and have allowed excellent exposures for 3D scientific study of this stone. The rock is of Upper Ordovician (Katian, 445-453 Ma) age.

The Gillis Quarry is located around 40 km northeast of Winnipeg (see Google Maps). Most sources seem to agree that the first use of this stone was at Lower Fort Garry built in the 1830s. Gillis Quarries were brought into commercial production in 1910 and have remained in the same family ever since. The stone lends itself well to both traditional and modernist architectural styles, with finishes ranging from rough, quarry-dressed blocks to smooth, honed or polished ashlars.

Tyndall Stone is a limestone, but with a significant dolomite content.

The most striking thing about this stone – and its main decorative feature – is that it is pervasively riddled with Thalassinoides trace fossils. These are branching burrows, with T- or Y-shaped junctions made by creatures tunnelling through the soft sediment, which are typically 1 to 2.5 cm wide. These show up brown in contrast to the cream-coloured limestone matrix, this is because the burrows backfilled with dolomite. It is not known what made these burrows during the Upper Ordovician, but modern Thalassinoides burrows are made by the shrimp Callianassa so a similar crustacean is a reasonable guess (Jin et al., 2012).

Thalassinoides burrows. Tyndall Stone Cladding on the Terminal City Club, Vancouver.

Weathered Thalassinoides burrows at the Fairmont Banff Springs Hotel.

Many other fossils are present and abundant in these strata and have been described by Jin et al. (2012). The Receptaculitid Fisherites reticulatus (Finney & Nitecki, 1979) is a spectacular component of this rock, and if it were needed, a distinguishing feature of Tyndall Stone. Up to 25 cm or so in diameter, these are circular fossils with a scaly appearance, appearing like the seed head of a sunflower. They are assumed to be fossilised calcareous algae.

Fisherites at the Terminal City Club (West Cordova Street facade) in Vancouver

Fisherites on the Terminal City Club in Vancouver

A section through Fisherites on the terrace at the Fairmont Banff Springs Hotel

Also present are very large Nautiloids. These include orthocones as thick as my arm and indeed called Armenoceras. This genus along with Endoceras can be over a metre in length.

Large orthoceras sections on book matched slabs at the Fairmont Chateau Lake Louise

Orthoceras on the terrace of the Fairmont Banff Springs Hotel

The coiled Nautiloid Wilsonoceras which can reach diameters of 40 cm is also present.

Section through the chambers of a coiled Nautilus

Section through a coiled Nautilus

These cephalopods are diagnostic of the so-called ‘Arctic Cephalopod Fauna’ and are typical of these late Ordovician carbonate platforms.

Other molluscs include gastropods, such as the planispiral Maclurina and the cone-spiralled Hormotoma.

Tyndall Stone with Thalassinoides at the Fairmont Chateau Lake Louise. A possible planispiral gastropod can be seen at bottom right.

Sections through a gastropod on slabs paving the lobby of the Fairmont Banff Springs Hotel

Corals are also present. This is probably the tabulate coral Catenipora.

Fairmont Chateau Lake Louise

Rugose corals include the varieties Grewingkia, Crenulites and Palaeophyllum.

Rugose Coral on the Terminal City Club, Vancouver

Other reef-forming organisms in addition to corals and Receptaculitids are stromatoporoids of which I found only fragments.

A fragment of a stromatoporoid at the Fairmont Chateau Lake Louise

The Tyndall Stone-type of Thalassinoides facies is regionally widespread throughout the Upper Ordovician strata of Laurentia, with very similar formations existing in Greenland (Børglum River Formation), as well as in Canada and the USA (i.e. Bighorn Dolomite of Wyoming; see Jin et al., 2012; Gingras et al., 2004; Sheehan & Schiefelbein, 1984).

As a good quality freestone, Tyndall Stone has also been used for carving by a number of artists and it even gets a mention in literature. Canadian author Carol Shields described Tyndall Stone in her, perhaps predictably titled, novel ‘The Stone Diaries’; “Some folks call it tapestry stone, and they prize, especially, its random fossils: gastropods, brachiopods, trilobites, corals and snails. As the flesh of these once-living creatures decayed, a limey mud filled the casings and hardened to rock

Urban Geology guides and descriptions of Tyndall stone buildings in Winnipeg are available by Thorsteinson (2013) and on Donna Janke’s Blog ‘Destinations, Detours & Dreams’.

Tyndall Stone is widely used throughout Canada, but as far as I know, has yet to make it to the UK … I looked at the following buildings during my recent trip to Vancouver and Banff National Park.

In Vancouver, the Tyndall Stone-clad Terminal City Club is on West Hasting’s street and the same building occupied by the Lion’s Pub fronting onto West Cordova Street.

In Banff National Park, the Fairmont Chateau Lake Louise has Tyndall Stone cladding on the ground floor and the Fairmont Banff Springs uses polished Tyndall Stone as paving, cladding and dressings in the impressive entrance hall.

My Sister, thrilled at finding the Receptaculitid Fisherites on the Terminal City Club in Vancouver. It is on the slab above the right side of the porch.

All photos used here are by Ruth Siddall and should be cited as such.


To cite this article:

Siddall, R., 2017, Tyndall Stone: An Iconic Canadian Building Stone., Orpiment Blog, published 09/09/2017: http://wp.me/p53QQu-bC


References and further reading

Finney, S. C. & Nitecki, M. H., 1979, Fisherites n. gen. reticulatus (Owen, 1844), a New Name for Receptaculites oweni Hall, 1861., Journal of Paleontology., 53 (3), 750-753.

Gingras, M. K., Pemberton, S. G., Muelenbachs, K. & Machel, H., 2004, Conceptual models for burrow-related, selective dolomitization with textural and isotopic evidence from the Tyndall Stone, Canada., Geobiology, 2, 21–30.

Janke, D., 2017, Winnipeg and Tyndall Stone: Fossils and Architecture., Destinations, Detours & Dreams.

Jin, J., Harper, D. A. T., Rasmussen, J. A. & Sheehan, P. M., 2012, Late Ordovician massive-bedded Thalassinoides ichnofacies along the palaeoequator of Laurentia., Palaeogeography, Palaeoclimatology, Palaeoecology 367–368 (2012) 73–88.

Kendall, A.C., 1977. Origin of dolomite mottling in Ordovician limestones from Saskatchewan and Manitoba. Bulletin of Canadian Petroleum Geology, v. 25, p. 480-504.

McCracken, A.D., Macey, E., Monro Gray, J.M. & Nowlan, G. S., 2007, Tyndall Stone., Natural Resources Canada.

Sheehan, P.M. and Schiefelbein, D.R.J., 1984. The trace fossil Thalassinoides from the Upper Ordovician of the eastern Great Basin: deep burrowing in the early Paleozoic. Journal of Paleontology, v. 58, p. 440-447.

Shields, C., 1993, The Stone Diaries., Fourth Estate., 361 pp.

Thorsteinson, J., 2013, Tyndall Stone., Winnipeg Architecture Foundation Inc., 13 pp.

Gillis Quarries

 

 

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First I was afraid, I was petrified … A short history of scary silicified log cabins

This is urban geology at the extreme; petrified wood is not exactly a common building stone, though it is becoming more frequently seen as a decorative stone, used for interior feature walls and even chopping boards and coasters. However it does have a place as a building stone, albeit mostly for novelty purposes … and only in America. Or at least this is the case as far as I am aware.

Silicified or petrified wood is relatively common and always an attractive fossil, with excellent preservation of the wood structure down to cell level. Identification of wood down to species level is often possible from microscopic observation of preserved cell structure. Trees have been around since the Carboniferous but are often much ignored in earth history. They are the background to what are perceived to be more interesting events. Here is an Upper Cretaceous scene whereby a right porker of a Tyrannosaurus is bringing down a green skinny lizard as an amuse bouche, whilst being eyed by circling Pterosaurs. These trees in the background are probably Araucaria sp.

7TyranosaurusRex

The process of silicification of wood is frequently closely associated with local volcanism. Silica is leached from decaying volcanic ash and carried in groundwaters and stream waters where it can permeate logs and branches. This works particularly well if the logs are buried in ash. Many fossil forest deposits represent preserved log jams in river systems and tree debris becomes silicified in anoxic environments (see Sigleo , 1979). Colours are imparted by trace elements; iron, copper, manganese, even uranium. Black is produced by carbon or finely disseminated pyrite.

Silicified wood deposits are known from Chemnitz in Germany from the Permian Leukersdorf Formation (Luthard et al., 2016) where the coloured stones were used as decorative inlay and as semi-precious gemstones. Also in Europe, deposits occur in Lesvos in Greece (Miocene; see Vasileiadou & Zouros, 2012). Worldwide, silicified wood is known from China (i.e. the Cretaceous ‘Jehol Biota’; see Ding et al., 2016) and exceptionally well-preserved, Pliocene trees are found in Java, Indonesia and Triassic trees occur in Madagascar, and these regions are the origin of most silicified woods on the decorative stone market today (Mandang & Kagemori, 2004; Yoon & Kim 2008). Recent discoveries petrified trees have been made in Brazil (Lower Permian tree ferns; see Maria da Conceiçao et al., 2016) and Turkey (Miocene willows, junipers and oaks; see Akkemik et al., 2016).

IMG_9263Silicified wood panelling supplied by the Emperors of Stone Bling, Maer Charme.          Photo by Ruth Siddall.

There are a large number of deposits of various ages in the USA and it is here that fossil trees have largely been used for building. Deposits are known from the Dakotas, Colorado, Oklahoma, Texas etc. The best known deposit is in the Upper Triassic Chinle Formation represents continental facies and outcrops throughout the southwestern USA. These famous fossil conifer deposits occur in the Lower and Upper Petrified Forest Members of Carnian-Norian age. Conifer logs are also found in the intervening Sonsela Member, representative of an alluvial floodplain (see Ash, 1992; Trendell, 2013). However, there are many other examples through the West and Midwest. Many of these deposits have been raided for garden ornaments and other small-scale structures.

A well-known and rather American Gothic building constructed from petrified wood is the (former) gas station in Lamar, Colorado, described by David Williams in his book ‘Stories in Stone’ and also illustrated in his blog. The gas station was built by one William Brown in the 1930s. The Colorado trees are of Cretaceous age but the precise age of strata of origin is unknown. The ‘logs’ were found in fluvial outwash in farmland around 25 miles south of Lamar.

DSC00947Lamar Gas Station; photo from Geologywriter.com

And then there is Petrified Wood Park in Lemmon, South Dakota, also constructed in the 1930s. This is a truly terrifying place; cones, pinnacles, pyramids and creepy-looking grotto-like buildings are built from petrified wood as well as dinosaur and mammoth bones. The park occupies a whole block of the town and was built by amateur geologist and ‘visonary’ Ole S. Quammen. To be fair his intention was altruistic, it was to provide work for 50 or so otherwise unemployed men during the depression era West. Quammen’s heirs donated the park to the grateful town of Lemmon in 1954 where it remains ‘the world’s largest petrified wood park of its kind’. Obviously. An on-site museum once house a collection of stuffed animals playing musical instruments. Sadly, these are no longer on display. The petrified wood was sourced locally, potentially from several strata. The Early Cretaceous Lakota Sandstone Formation outcrops in the eastern Black Hills and has fossilised logs of cypress, palm and cycads. The Hell Creek Formation of South Dakota also has petrified Late Cretaceous cypress (and dinosaurs). The Palaeocene petrified wood is found in the Badlands of South Dakota where conifers and broadleaf tree trunks and branches are preserved (Teachout, 1995).

Petrified-Wood-Park-Lemmon-SD-800x500_c-1Lemmon Petrified Wood Park sign; photo from SouthDakota.com

According to Snider (2012), Texas is the state for construction in petrified wood, and she cites Austin, Huntville, Decatur (which also has a petrified wood gas station) and Stephenville as all having buildings incorporating this unexpected stone. However, the town of Glen Rose in Somerville County has over 40 buildings and other structures constructed of silicified wood. It was once known as ‘The Petrified City’. The post office, several houses, fountains, a (now disused and ruined) speakeasy and the bandstand are all built from petrified wood. The bandstand also incorporates slabs with spectacular dinosaur footprints too.

glen-rose-tx-petrified-houseThe ruins of Glen Rose’s speakeasy; photo by Tui Snider (2013)

glen rose bandstandBandstand, Glen Rose, Texas; photo by Tui Snider (2012)

texas-dinosaur-tui-sniderDetail of dinosaur footprint in Glen Rose’s bandstand; photo by Tui Snider (2012)

The origin of this Texan petrified wood building spree, which occurred in the 1920s and 30s was a unexpected consequence of the mechanisation of agricultural machinery. Farmers were able to dig deeper into their soils than before and they hit a petrified wood motherlode in the local fields. The logs were hauled out and used to build the town.

Finally, the most attractive structure built from petrified wood is not all scary. It is Agate House, located in the Petrified Forest National Park, Arizona. It was originally constructed between 1050 and 1300 AD by Ancestral Puebloans from Triassic Chinle Formation petrified trees. Other examples of structures built from petrified wood have also been excavated in the surrounding region, since the 1930s. The excavation of Agate House and its subsequent reconstruction was overseen by archaeologist Cornelius Burton Cosgrove Jr. (1906 – 1999). Petrified wood was also used for arrowheads and similar artefacts by the Ancestral Puebloans.

agate-house-1[6]Above, Agate House; photo by Amusing Planet

agate-house-wall-of-petrified-woodAbove, the wall of Agate House; photo by NotsofastinBoulder’s Blog.

More petrified wood buildings in the USA …

Gas Station, Decatur, Texas

Carter County Museum, Montana – does anyone have a photo of this? It is partially built of Hell Creek Formation wood.

Petrified wood and petrified wood buildings in Oklahoma

Outside the USA …

The town of Mata – “Cidade da Pedra que foi madeira” (“The city of rocks that once were wood.”) – in Rio Brande do Sul, Brazil. Petrified wood from the Upper Triassic Caturrita Formation is used to build several buildings and can be seen in the Palaeobotanical Garden. The fossils were collected by priest and palaeontologist Daniel Cargnin.

Thanks to Christian Kammerer  for this information and photos.

 

If anyone knows of any more structures built of petrified wood outside the US, do let me know …

 

How to cite this blog:

Siddall, R., 2017, First I was afraid, I was petrified … A short history of scary silicified log cabins., Orpiment Blog https://orpiment.wordpress.com/2017/04/13/first-i-was-afraid-i-was-petrified-a-short-history-of-scary-silicified-log-cabins/

 

References

Akkemik, Ü., Arslan, M., Poole, I., Tosun, S., Köse, N., Kiliç, N. K. & Aydin, A., 2016, Silicified woods from two previously undescribed early Miocene forest sites near Seben, northwest Turkey., Review of Palaeobotany and Palynology 235., 31–50.

Ash, S.R. and Creber, G.T., 1992. Palaeoclimatic interpretation of the wood structures of the trees in the Chinle Formation (Upper Triassic), Petrified Forest National Park, Arizona, USA. Palaeogeogr., Palaeoclimatol., Palaeoecol., 96:299 317.

Ding, Q., Tain, N., Wang, Y., Jiang, Z., Chen, S., Wang, D., Zhang, W., Zheng, S., Xie, A., Zhang, G. & Liu, Z., 2016, Fossil coniferous wood from the Early Cretaceous Jehol Biota in western Liaoning, NE China: New material and palaeoclimate implications., Cretaceous Research, 61, 57-70.

Mandang, Y. I. & Kagemori, N., 2004, A Fossil Wood of Dipterocarpaceae from Pliocene Deposit in the West Region of Java Island, Indonesia., Biodiversitas, 5(1), 28-35.

Maria da Conceiçao, D., Saturnino de Andrade, L., Cisneros, J. C., Iannuzzi, R., Pereira, A. A. & Machado, F. C., 2016, New petrified forest in Maranhao, Permian (Cisuralian) of the Parnaíba Basin, Brazil., Journal of South American Earth Sciences 70, 308-323.

Petrified Wood Park, Lemmon, South Dakota.

Petrified Woods from the Indonesian Islands of Java and Sumatra.

Saltarelli, M, G., 2009, ‘Irreplaceable Works of Art’: Petrified wood treasures and dinosaur tracks create a paradise of geology.

Sigleo, A.C., 1979. Geochemistry of silicified wood and associated sediments, Petrified Forest National Park, Arizona. Chem. Geol., 26: 151–163.

Snider, T., 2012, Texas Road Trips: From Dinosaurs to Drive-Ins.

Snider, T., 2013, A to Z Texas: P is for Petrified Wood Buildings.

Teachout, G. E., 1995, Petrified wood of South Dakota.

Trendell, A. L., Nordt, L. C., Atchley, S. C., Lebland, S. L. & Dworkin, S. I., 2013, Determining floodplain plant distributions and populations using paleopedology and fossil root traces: Upper Triassic Sonsela Member of the Chinle Formation at Petrified Forest National Park, Arizona., Palaios, 28, 471-490.

University of Arizona, Laboratory of Tree-Ring Research; Fossil Trees or Petrified Wood.

Vasileiadou, K. & Zouros, N., 2012, Early Miocene micromammals from the Lesvos Petrified Forest (Greece): preliminary results., Palaeobio. Palaeoenv., 92, 249–264.

Williams, D. B., 2009, Chapter 7: Pop rocks, pilfered fossils and Phillips Petroleum – Colorado Petrified Wood., Stories in stone: travels through urban geology., Walker Publishing Inc., New York., 133-151. & Blog.

Yoon, C. J. & Kim, K. W., 2008, Anatomical descriptions of silicified woods from Madagascar and Indonesia by scanning electron microscopy., Micron 39, 825–831.

 

Urban Geology in Birmingham

I was invited to come back to Birmingham by Julie Schroder of the Black Country Geological Society to update and expand previous building stone walks of the city created by Julie, Eric Robinson and Paul Shilston. I was very pleased to do this, having graduated in Geology from the University of Birmingham in 1989. The city has changed a lot since then, with a brand new development around the Bull Ring and New Street Station. Julie, myself and fellow Birmingham Geology graduate Laura Hamilton hit the streets in Easter 2016. We have produced three guides to the city centre which can be downloaded as pdf documents here:

1. The Town Hall to the Cathedral

2. Centenary Square to Brindleyplace

3. Around the shops

The pictures below provide a snapshot of the geodiversity of Birmingham’s built environment …

Prehistoric Animals: A series of illustrations by David Roland

I bought this set of postcards when I was a kid in the 1970s. I can’t remember exactly where I bought them, but it was probably Manchester Museum. They were produced by scientific illustrator David Roland for Birmingham Museum and Art Galleries and represent what was then state-of-the-art interpretations of the appearance of dinosaurs and other prehistoric animals, including Dimtetrodon and Pteranodons. All are very green and scaly. What impressed me at the time, though, is that they all fitted together to make a single, continuous panorama. I loved them!

Featured are: Dimetrodon, Stegosaurus, Diplodocus, Brontosaurus, Iguanodon, Pteranodon, a portly Tyrannosaurus Rex and Triceratops.

Portland Bone

There is a lot of Portland Stone in London, so much of it in fact that I almost blank it out. I am trying to change the way I think about it, partly thanks to Gill Hackman’s inspiring book “Stone to build London” and also, whilst working on the London Pavement Geology project, to give this most iconic of London’s buildings stones its rightful coverage.

London is a good place to see all the varieties of Portland Stone quarried today and in the past, and a variety of facies and fossils can be seen in many buildings (see Siddall & Hackman, 2015; Siddall 2015, Hackman 2014). Notable examples are Green Park Underground Station and BBC Broadcasting House. However the bulk of Portland Stone Buildings in London are of fairly standard Whitbed, with little variation in facies and fossils. Typically these are white to pale-grey weathering, oolitic limestones, sometimes showing cross-bedding and with variable fossil content, mainly shells, shell fragments and occassionally pieces of Solenopora algae. The stone used at St Margaret’s Westminster is, on the whole, fairly characteristic of this description.

Easily overlooked, dwarfed as it is by its next door neighbour, Westminster Abbey, St Margaret’s Westminster is a neat little church clad in Portland Stone Whitbed. Dedicated to Saint Margaret of Antioch, it is the parish church of the House of Commons. There has been a church on this site since the 12th Century. The current building including its Portland Stone cladding dates from the 1730s refurbishment by the architect John James (1673-1746). St Margaret of Antioch was swallowed by a dragon, but was coughed up alive after she had tickled the dragon’s rib cage from the inside with her cross.

In the passage between St Margaret’s and the Abbey, towards the SE corner of the church, a block sits just above eye-level, containing a pen-shaped, brown clast, truncated by the lower edge of the block, but strikingly different from the standard allochems of the Portland Limestone. The preserved piece is around 15 cm long and 3 cm wide and has been eroded into a flattened pebble (below).

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My knowledge of vertebrate palaeontology is scant and more influenced by Ray Harryhausen than anything I learned when an undergraduate. But I guessed this looked more ‘bone’ than ‘stone’. However, I have never before seen bone in Portland Stone. In the Purbeck Beds it is relatively common, but usually preserved as jet black phosphate. Thanks to the fantastic research tool that is social media, I contacted geologist Mark Godden of Portland quarry firm Albion Stone. Mark agreed that this worn pebble of brown stuff was ‘probably’ bone, as these occasionally turn up when quarrying and Mark sent some pictures for comperanda. Certainly confirmed bone from Portland Stone, recognisable as vertebra etc are a similar colour and texture. Other options where that it is an infilled burrow; however, if so, what is it that has infilled it? There is extensive bioturbation in Portland Stone, but it is all infilled with white oolitic limestone or shell fragments. So I am fairly convinced that it is a fragment of a disarticulated, much eroded and fairly large vertebrate skeleton.

According to Delair & Wimbledon (1993), the bones from several vertebrates have been found in the Portland Limestone member and equivalent strata of Tithonian (Upper Jurassic) age; crocodile and turtle bones, as well as those of marine reptiles Ichthyosaurs and Pleiosaurs are not unexpected, but dinosaur bones also occur. These may have been derived from paddling saurischians who subsequently keeled over, or more likely, were washed in from adjacent dry land, where dinosaurs such as Megalosaurus and Iguanodon were knocking around.

Reconstructions of these types animals can be seen at Crystal Palace. These Victorian effigies somewhat dated (to say the least) and are not exactly Jurassic Park. The real things are now interpreted to be the sleeker, more streamlined beasts with which the average film goer is more familiar. Nevertheless, you get the idea!

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Above, left: Crocodiles and Right: Iguanodons at Crystal Palace. Below, a Megalosaurus surveys the scene.

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Other notable bones to be found in St Margaret’s include those of William Caxton, England’s first printer of books, Sir Walter Raleigh and poet John Milton.

St Margaret’s Westminster is listed here on London Pavement Geology.

Many thanks to Mark Godden of Albion Stone.

References & Further Reading

Crystal Palace Dinosaurs: http://cpdinosaurs.org/visitthedinosaurs

Delair, J. B. & Wimbledon, W. A., 1993, Reptilia from the Portland Stone (Upper Jurassic) of England: A preliminary survey of the material and literature., Modern Geology, 18, 331-348.

Dino Directory: Megalosaurus: http://www.nhm.ac.uk/nature-online/life/dinosaurs-other-extinct-creatures/dino-directory/megalosaurus.html

Dino Directory: Iguanodon: http://www.nhm.ac.uk/nature-online/life/dinosaurs-other-extinct-creatures/dino-directory/iguanodon.html

Godden, M., 2012, Portland’s quarries and its stones. http://www.dorsetgeologistsassociation.com/Portland-Stone/Portland_Stone_Document_-_7_June_12.pdf

Hackman, G., 2014, Stone to build London: Portland’s legacy., Folly Books Ltd., Monkton Farleigh., 311 pp.

London Pavement Geology: http://londonpavementgeology.co.uk

Siddall, R., & Hackman, G., 2015, The White Cliffs of St James’s: Portland Stone in London’s Architecture., Urban Geology in London No. 31, http://www.ucl.ac.uk/~ucfbrxs/Homepage/walks/PortlandStJames.pdf

Siddall, R, 2015, An Urban Geologist’s Guide to the Fossils of the Portland Stone., Urban Geology in London No. 30, http://www.ucl.ac.uk/~ucfbrxs/Homepage/walks/PortlandFossils.pdf

St Margaret’s Westminster: https://en.wikipedia.org/wiki/St_Margaret’s,_Westminster