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’.

Travels of an Urban Geologist: Building Bavaria

IMG_3810Bavaria is a huge province of modern Germany. Recently I visited the southern parts, the Allgäu and Upper Bavaria regions, out on the Molasse Basin of the northern Alpine Foreland, staying in the town of Memmingen. The countryside looks like a picture-book, full of toy farms with green manicured grasslands spotted with white, plastered houses with red tile roofs (right). What is noticeable is there is less of the slate and stone seen in the French and Italian Alpine forelands. However in the few towns and villages I visited, churches and modern shop fronts featured stone masonry or cladding. The building stones used were striking in being predominantly fairly recent looking breccias and tufas. I just assumed they were from the Molasse. I pointed one out to my (non-geological) friends and Amira, a local, immediately said ‘my Dad will know exactly what this is’. Amira’s Dad did know, he told us it was ‘Biberstein’ and it was related to the Ice Ages. Dads always know these things. So I started to look into this a little bit more.

Now, I have spent many years studying and teaching Alpine Geology, but have pretty much managed to ignore the Ice Age geology of the region. Somewhere deep I recall the mantra of Günz, Mindel, Riss and Würm, the original glacial periods devised by Alpine geomorphologists and geologists at the turn of the 19th Century. During the glaciations which define the Pleistocene Stage of the Quaternary, the Alps were covered by a huge ice cap, with enormous glaciers descending towards the southern and northern forelands. In Upper Bavaria, large lobate piedmont glaciers coalesced to form the Inn-Chiemsee Glacier, which was at its greatest extent during the last glacial maximum around 21 thousand years ago (ka). This ice body excavated the famous moraine field around the town of Rosenheim and when it retreated, left behind the enormous glacial Lake Rosenheim, the remnants of which are the present day Simsee and Chiemsee. However this was the last of at least four major glaciations, the Würm. The Victorian glacial chronology has been considerably refined over the last century, but the terminology remains essentially the same. The four main glaciations, Günz, Mindel, Riss and Würm each lasted around 100 thousand years, separated by warm periods of similar lengths.

IMG_3820Glacial Lake Chiemsee, with the Bavarian Alps behind

Quaternary deposits from the Bavarian-Austrian Alpine foreland have been used as building materials since the Roman period. The most famous and most widely used are the Brannenburg Nagelfluh, the Hötting Breccia and the calcareous tufa deposits worked between the Inn Valley and Vorarlberg. A major advantage of these stones, compared with the bedrock of the Alpine series, is that they are soft and easy to quarry, hardening on surface exposure. Despite their young geological age, these Quaternary deposits have been surprisingly resilient to weathering and erosion. They often display large porosity, which, far from being detrimental, has contributed to the resistance to decay; the stones dry out more quickly rather than preserving water in small pore spaces. Having formed at the Earth’s surface and not having undergone major periods of burial or diagenesis, they are at ‘equilibrium with their environment’ (Mirwald et al., 2012). They have been use since at least the Roman period, and some still continue to be quarried today.

A locally sourced and much used stone is the wonderfully named Brannenburger Nagelfluh from Brannenburg am Inn, in the Inn Valley of Southern Bavaria, south of the town of Rosenheim. This is Amira’s father’s ‘Biberstein’ named from the Biber hill near the quarries, and Biberstein is the colloquial name for this stone. The word ‘Nagelfluh’ is used in the German geological literature to refer to young (Tertiary or Quaternary) formations of conglomerate. Nagel means nail, and the name refers to the fact that in outcrop, the rock surface appears to have large nails hammered into it, so that only the heads are seen. Brannenburger Nagelfluh is a (just) coast supported, polymict conglomerate with a ratio of clasts:matrix of 50:50. The clasts are moderately sorted, up to around 10 cm across and composed of a variety of rock types derived from the Alps; limestone, sandstone, gneiss, amphibolite schist, dolerite and quartz. Brannenburger Nagelfluh formed on the shores of the Rissian Lake Rosenheim, and they represent a series of deltaic deposits, which are exposed in the quarries around Brannenburg and Flintsbach (Herz et al., 2014). These sediments were deposited at around 150 ka. The topsets are exposed in the Anton Huber Quarry and foresets are exposed in the Grad Nagelfluhwerk quarry. Grey and yellow varieties are observed in photographs of the quarries published in Herz et al. (2014).

IMG_3586 IMG_3590 Above: Shop fronts in Memmingen

IMG_3929 IMG_3910Brannenburger Nagelfluh used in Ludwig II’s crazy fountains at Schloss Herrenchiemsee

A superficially similar stone is the Hötting Breccia. This is an alluvial fan and talus slope deposit, developed on the Northern Calcareous Alps basement. The breccias outcrop around Innsbruck, and are dated between 100-70 ka (Spötl & Mangini, 2006). They are therefore associated with the Riss-Würm interglacial period. Petrologically, they are carbonate-cemented breccias, with poorly-sorted clasts of the underlying Triassic limestones. Local concentrations of red Permian sandstones (Alpiner Buntsandstein) stain the lowest deposits of the Hötting Breccia yellow and red. These are up to 40 m in thickness. The overlying White Hötting Breccia does not contain Buntsandstein, and has only limestone clasts, however this was less well consolidated and was not used for building (Unterwurzacher et al., 2010). Several quarries operated near Innsbruck until the early 20th Century, the largest of which was Mayr (below). Transportation both north and south along the river Inn was favourable in the distribution of this stone and it is the main building stone in Innsbruck, where it was used for the Cathedral and other examples of civic architecture (Mirwald, 2012, Unterwurzacher et al., 2010).

MayrQuarry2

Many modern buildings are clad with a grey matrix-supported breccia. We need to travel to the southern Alpine foreland to source this stone. This is ‘Ceppo’ from the shores of Lago di Iseo in the Italian Lake District. The Ceppo di Poltragno Conglomerate is a grey, carbonate-cemented breccia. Quarries are located in the Adda and Brembo valleys (Vola et al., 2009). Ceppo is a Quaternary fluvial-glacial conglomerate. It was deposited during the lower to middle Pleistocene (1.8 – 0.125 Ma) as diamictites and colluvial scree deposits. The clasts are matrix supported and are derived from the Triassic dolomites in the Carnic Alps (Forcella et al., 2012).

IMG_3569 IMG_3570 Above: Cladding on the ground floor of an office building in Memmingen

Ceppo has been quarried since the Roman period and is actively quarried today, used as cladding and as paving. Vola et al. (2009) have described its use in Bergamo and Bugini & Folli (2008) have described its use in Milan. Varieties known as Ceppo Gentile, Ceppo Gré and Ceppo Poltragno are marketed. Vola et al., (2009) list the following quarries; Camerata Cornello, San Pellegrino and Brembate Sotto (inactive) and Poltragno, Pianico, Grè (at Solto Collina on the lake shore) and Castro (active). The stone is exported throughout southern and central Europe and is widely used in southern Germany.

Back in Austria and Bavaria, tufa limestone occurs commonly across the Northern Calcareous Alps, found in association with cool spring activity, where waters are supersaturated with calcium carbonate. Important quarry sites are at Thiersee, in the Inn Valley south of Brannenburg and at Andelsbuch in the Vorarlberg of westernmost Austria. It could be relatively easily exported to the Allgäu region of Bavaria (Kempten and Memmingen) from this latter locality, along the River Iller. The stone is both strong and light in weight. Like many tufas and also large porosity stones such as the Portland Roach and the Florida Coquina, these stones are extremely effective in the constructions of fortifications as their properties allow them to absorb impacts (of cannon balls etc.) well. Thiersee Tufa was used to construct the Kufstein Fort in the Tirol (Mirwald et al., 2012). However there is good evidence that these stones have been won since the Roman period; they are used in the villa at Rankweil in the Vorarlberg (see Unterwurzacher et al., 2010). It is probably Andelsbuch Tufa that is used in the church at Memmingen (below).

IMG_3613 IMG_3609

At Thiersee, the tufa deposits are up to 10 metres thick and extended laterally, prior to quarrying for several hundred metres. They are primarily ‘moss tufas’ (Unterwurzacher et al., 2010). These deposits are no longer active and the deposits are almost worked out; peak production was in the 18th Century. At Andelsbuch, moss tufa and phytoclastic tufa have formed on top of the Helvetic Nappe and Flysch formations. The deposit is up to 5 metres thick and extends for 100 m. Tufa deposition here is still active (Unterwurzacher et al., 2010).

References and further reading

Bugini, R. & Folli, L., 2008, Piedras de la arquitectura milanesa (Stones used in Milanese architecture)., Materiales de Construcción, 58, (289-290), 33-50.

Ceppo di Gré: http://www.naturalstoneinfo.com/download/bgcamcom.ceppo_gre.pdf

Forcella, F., Bigoni, C., Bini, A, Ferliga, C., Ronchi, A., Rossi, S. et al., 2012, Note Illustrative della Carta Geologica d’Italia 1:50 000; 078 Breno., Servizio Geologica d’Italia., 313 pp. http://www.cartografia.regione.lombardia.it/metadata/carg/doc/Breno_note_illustrative_dicembre_2012.pdf

Herz, M., Knipping, M. & Kroemer, E., 2014, The Rosenheim Basin: Würmian and Pre-Würmian deposits and the Höhenmoos interglacial (MIS 7). in: Kerschner, H., Krainer, K. & Spötl, C., From the foreland to the Central Alps: Field trips to selected sites of Quaternary research in the Tyrolean and Bavarian Alps., Excursion guide of the field trips of the DEUQUA Congress in Innsbruck, Austria, 24–29 September 2014., 6-17.

Huber Quarry: http://www.nagelfluh.de/INFO/GESCHICHTE/tabid/58/Default.aspx

Mirwald, P., Diekamp, A., Unterwurzacher, D. & Obojes, U., 2012, Weathering of sedimentary stone materials formed under Earth surface conditions., 11 pp.

Sanders, D. & Spötl, C., 2014, The Hötting Breccia – a Pleistocene key site near Innsbruck, Tyrol., in: Kerschner, H., Krainer, K. & Spötl, C., From the foreland to the Central Alps: Field trips to selected sites of Quaternary research in the Tyrolean and Bavarian Alps., Excursion guide of the field trips of the DEUQUA Congress in Innsbruck, Austria, 24–29 September 2014., 81-93.

Spötl, C., Mangini, A., 2006, U/Th age constraints on the absence of ice in the central Inn Valley (eastern Alp, Austria) during Marine Isotope Stages 5c to 5a. Quaternary Research, 66, 167-175.

Spötl, C., Starnberger, R. & Barrett, S., 2014, The Quaternary of Baumkirchen (central Inn Valley, Tyrol) and its surroundings., in: Kerschner, H., Krainer, K. & Spötl, C., From the foreland to the Central Alps: Field trips to selected sites of Quaternary research in the Tyrolean and Bavarian Alps., Excursion guide of the field trips of the DEUQUA Congress in Innsbruck, Austria, 24–29 September 2014., 68-80.

Unterwurzacher, D., Obojes, U., Hofer, R. & Mirwald, P., 2010, Petrophysical properties of selected Quaternary building stones in western Austria. In: Prikryl, R. & Török, A.; Natural Stone Resources for Monuments., Geological Society of London, Special Publication, 333, 143-152.

Vola, G., Fiora, L. & Alciati, L., 2009, Stones used in Bergamo architecture., Studia Universitatis Babe-Bolyai, Geologia, 2009, Special Issue, MAEGS – 16, 137-139.

©Ruth Siddall 2015