“Nidaros: The Portland Cement Cathedral” (Baker Memorial Lecture)

Posted on September 10, 2017 by
The newly restored choir at Nidaros Cathedral in the 1880s (left) and 1994 (right), before the last restoration early 2000s. All the white calcite crusts are a result of leaching of calcium hydroxide from Portland Cement used in the 1880s. Photos by the Nidaros Restoration Workshop and Per Storemyr.

The medieval choir at Nidaros Cathedral just after reconstruction in the 1880s (left) and 1994 (right), before the last restoration in the early 2000s. All the white calcite crusts are a result of leaching of calcium hydroxide from Portland Cement used in the 1880s, and particularly during a restoration by 1920. Photos by the Nidaros Restoration Workshop and Per Storemyr.

This week I attended the international conference “Rediscovering Traditional Mortars” in Trondheim. The conference was hosted by the Nidaros Cathedral Workshop and it was part of the annual conferences organised by the British Building Limes Forum and its Nordic counterpart.

I was lucky to be invited to deliver two lectures, one on the experimental lime burning in Hyllestad earlier this year, and the Baker Memorial Lecture during the gala dinner. A very great honour to keep this traditional lecture for more than 230 delegates! I concentrated the lecture on the use of Portland Cement during the restoration of Nidaros Cathedral from 1869 on. Read on to get a glimpse of all the problems it has caused! Continue reading →

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Forvitring av kleberstein på middelalderkirker – to videoer

Posted on August 17, 2017 by
Hvorfor forvitrer kleberstein? Foredrag om den gotiske vestportalen på Utstein kloster i 2017. Screenshot AM-UiS

Hvorfor forvitrer kleberstein? Foredrag om den gotiske vestportalen på Utstein kloster i 2017. Screenshot AM-UiS

Tidligere i år holdt jeg to foredrag om forvitring av kleberstein sett i lys av bygnings- og restaureringshistorie. Det dreide seg om portaler fra norsk middelalder og foredragene ble holdt på «Portalseminaret» i regi av «Domkirken 2025»; miljøet som nå restaurerer Stavanger domkirke og som jeg også er en liten del av. Alle foredragene fra seminaret (og mange andre interessante saker om restaureringen) er nå lagt ut på YouTube.

Kanskje kan mine to foredrag være til hjelp for folk som sliter med å forstå hvorfor kleberstein forvitrer. Veldig mye dreier seg om hva bygningene har vært utsatt for av forandringer og restaureringer gjennom tidene. Men noe av forvitringen kan også knyttes til steinkvalitet, tidligere luftforurensning og ikke minst vann! Rett og slett lekkasjer! Innholdet i foredragene er i stor grad basert på min gamle doktoravhandling The Stones of Nidaros fra 1997 og mange artikler om forvitringshistorie, bl.a. Weathering of soapstone in a historical perspective. SE VIDEOER!

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Experimental archaeology: Building a “classic”, intermittent limekiln and burning marble at Millstone Park, Hyllestad, Western Norway

Posted on July 13, 2017 by
The freshly built, classic limekiln at Hyllestad in operation, june 2017.

The freshly built, classic limekiln at Hyllestad. In operation, June 2017.

It took us about six months: Building a cylindrical, intermittent limekiln of the classic Roman/Medieval type with local materials only – stone rubble and clay. In June this year (2017), we built the firing chamber, filled the kiln with 2.5 tons of local marble and started burning. A week, night and day, with much of the local community involved! Here’s an extended photo story of the project – the first of its kind in Norway. Media was interested! A national radio story here, a local newspaper story here (in Norwegian).

The quicklime (burnt marble) will be tested at Selja medieval monastery and other restoration projects in Norway. Big thanks to all, 30-40 volunteers and paid people (see list at the end) and support from The ruin restoration programme of the Norwegian Directorate for Cultural Heritage, as well as Hyllestad Municipality! The project was carried out by The Norwegian Millstone Centre/The Museums in Sogn og Fjordane County. Continue reading →

Posted in Marble, Monument conservation, New projects, Norway | Tagged , , , , , , | 4 Comments

Update after long absence – follow on facebook

Posted on June 28, 2017 by

Over the last six months I’ve been immersed in practical and scientific works and so I’ve been unable to write sensible blog posts on this website. I guess most bloggers experience something similar once in a while. If you want to get an idea of what I’ve been up to, please follow me on my personal facebook profile. There you can find brief news about e.g. building and running a “medieval” limekiln at Hyllestad in Western Norway, and various projects across Norway; from rock art in Finnmark county up north to stone conservation at Stavanger cathedral in the south.

Now I’m on a combined study tour and holiday in Ireland and Northern Ireland, focusing on geoparks and heritage, and having just visited Giants Causeway:

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Happy New Year from the most beautiful old quarry in Western Norway!

Posted on December 31, 2016 by
A medieval millstone quarry taken over by a creek in rainy Western Norway: At Hyllestad, the largest Viking Age and Medieval quarry landscape in Northern Europe. Photo by Per Storemyr

A medieval millstone quarry taken over by a creek in rainy Western Norway: At Hyllestad, within the largest Viking Age and Medieval quarry landscape in Northern Europe. Photo by Per Storemyr

With a picture, taken today, of a splendid little old quarry in Western Norway, I wish all my clients, partners, colleagues – and those who read my blog and website – a Happy New Year! Continue reading →

Posted in Archaeology, Norway, Old quarries | Tagged , , | 2 Comments

Geoarchaeology of the famous ancient amethyst mines in Wadi el-Hudi, Egypt: Desert heritage at risk

Posted on December 29, 2016 by
A fading raw amethyst from Wadi el-Hudi, Egypt. The purple variety of quartz. Photo by Per Storemyr

A fading raw amethyst from Wadi el-Hudi, Egypt. The purple variety of quartz. Photo by Per Storemyr

This fall I joined the Wadi el-Hudi expedition to the famous Middle Kingdom amethyst gemstone mines in the Eastern Desert south-east of Aswan. The expedition is led by Dr. Kate Liszka of California State University San Bernardino (US), and over the last few seasons it has excavated and documented the ancient mining settlements in very high detail. My task was to take a closer look at the geoarchaeology – to try and understand relationships between geology and mining. It is hugely important to document what is left, for the ancient mining area is now at high risk from looting, modern gold mining and stone quarrying. Continue reading →

Posted in Ancient Egypt, Archaeology, Heritage destruction, New projects, Old mines, Ruins | Tagged , , , , | 3 Comments

Værnes: Norges mest komplette sandsteinskirke fra middelalderen

Posted on December 4, 2016 by
Sørportalen på Værnes kirke da pussen på kirken var hogd vekk på 1990-tallet. Her er det sandstein i murene! Og grønnskifer i portalen. Foto: Per Storemyr

Sørportalen på Værnes kirke da pussen var hogd vekk på 1990-tallet. Her er det sandstein i murene! Og klorittskifer i portalen… Foto: Per Storemyr

Den er dekorert med elementer av kleberstein og klorittskifer, men ellers er det sandstein så langt øyet kan se: Værnes er Norges mest komplette sandsteinskirke fra middelalderen! Den rager i størrelse og volum av brukt sandstein langt over middelalderbyggverk i tilsvarende stein i andre deler av landet! Her er et sammendrag av min artikkel til boken «Værnes kirke – en kulturskatt i stein og tre» som ble utgitt for et par uker siden (november 2016). Det er Grubleseminaret som står bak, med Morten Stige og Kjell Erik Pettersson som fantastiske redaktører av boken! Continue reading →

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Fra Aswan til Hyllestad. Hva er et steinbruddlandskap?

Posted on May 16, 2016 by
Aswan, Egypt. For et par år tilbake. Transport av stein slik det ble gjort for tusenvis av år siden. I et landskap der steinbrytning tok til allerede i eldre steinalder. Foto: Per Storemyr

Aswan, Egypt. For et par år tilbake. Transport av stein slik det ble gjort for tusenvis av år siden. I et landskap der steinbrytning tok til allerede i eldre steinalder. Foto: Per Storemyr

Menneskene har brutt stein til alle mulige formål siden tidenes morgen. Men hva er et steinbruddlandskap? Hva kan vi si om alle de millioner av steder der folk har tatt ut stein? Fra den tidligste steinalder til i dag? Det var temaet jeg fikk til et foredrag på det 14. Hyllestadseminaret i slutten av april 2016, i regi av Norsk Kvernsteinsenter. Dessuten skulle jeg snakke om hvordan steinbruddlandskap kan formidles. Jeg innså raskt at oppgaven var helt umulig. Continue reading →

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Gneiss for the Pharaoh: Geology of the Third Millennium BCE Chephren’s Quarries in Southern Egypt

Posted on April 18, 2016 by
Located far south in the Egyptian Western Desert, Chephren's Quarry is the world's oldest large-scale quarry for sculpture and stone vessels. Photo by Per Storemyr

Located far south in the Egyptian Western Desert, Chephren’s Quarry is the world’s oldest large-scale quarry for sculpture and stone vessels. Photo by Per Storemyr

Chephren’s Quarry. A name imbued with splendour. It was not the first quarry from which stone vessels and sculpture were provided in Ancient Egypt, but it was definitely the most spectaular one. Work started here, far south in the Western Desert of Egypt, already by the Predynastic period or earlier. By the Old Kingdom, 4500 years ago, it was a huge work site, comprising 700 quarry pits in the flat desert, covering an area of some 50 square kilometres. With Tom Heldal as the lead author, Ian Shaw, Elizabeth Bloxam and I have now written an account of how geology shaped Chephren’s Quarry. It is a story spanning millions of years, explaining the beauty of this hard, bluish stone – and how it could be exploited. Continue reading →

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Gamle steinbrudd som UNESCO-verdensarv? En analyse

Posted on March 13, 2016 by
"Dronninggruva" i kvernsteinslandskapet i Hyllestad, Ytre Sogn. Her er ICOMOS på besøk i nominasjonsprosessen mot verdensarvsted i 2014; man blir vist rundt av godt trente unge guider fra Hyllestad skule. Men verdensarv-prosessen er nå på vent og veien videre høyst uklar. Foto: Per Storemyr

“Dronninggruva” i kvernsteinslandskapet i Hyllestad, Ytre Sogn. Her er ICOMOS på besøk i nominasjonsprosessen mot verdensarvsted i 2014; man blir vist rundt av godt trente unge guider fra Hyllestad skule. Men verdensarv-prosessen er nå på vent og veien videre høyst uklar. Foto: Per Storemyr

Det er nesten ingen gamle steinbrudd på UNESCOs verdensarvliste. Det er ikke bra, for steinbruddene var helt sentrale produksjonssteder for verktøy, husgeråd, våpen, boliger, kunst, monumenter, arkitektur, skulptur. Kort sagt en vesentlig del av hva som var viktig i gamle samfunn – og i dag: Store deler av verdens kulturarv er jo basert på brytning av stein. Spørsmålet er: Hvor går veien videre for gamle steinbrudd som verdensarvsteder? Kanskje Norge burde fremme en egen steinbruddsnominasjon? Eller kanskje dette rike landet burde hjelpe mindre bemidlede nasjoner med å få eldgamle steinbrudd inn på verdensarvlisten? Man kunne jo starte i Egypt, landet med den største konsentrasjonen av gamle steinbrudd i verden. Continue reading →

Posted in Archaeology, Old quarries | Tagged , , | 4 Comments