News | Publications

| Abstract |

The coticule, or razor hone, and the slate both contributed for centuries to the ‘Pays de Salm’ prosperity. Known for its outstanding qualities in metal sharpening, the unique Belgian razor hone has been exported worldwide. From the everyday object to the architectural design, the slate is everywhere and is a part of the daily life: slate can be shaped anyhow! These factories, still in business, left a permanent mark on the ‘Pays de Salm’.

Over 20 researchers in history, botanic, zoology and geology tell us about the geological formation of slate and razor hone, the history of the workshops, the several steps of the stone extraction from surface quarries, the transport through the underground tunnels, to the transformation process in finished product in the workshops. The technological progress and the living conditions of the workers follow the evolution of the society and European borders.

Nowadays, an amazing fauna and flora has settled in the underground cavities, the rock walls, and the waste rock piles. Many of these sites are classified as nature reserve and others should be worth getting this designation! The slate and the coticule are part of our present through our museums and the beauty of our architectural heritage, but also through the pursuance of the traditional extraction, an inheritance of our elder workmanship and its adaptation to present-day needs and tastes.

The multidisciplinary book is fully illustrated with old and recent photographs along with a lot of unpublished documents. It brings back memories and pays tribute to the work and know-how of men, women, industrialists and kids of the ‘Pays de Salm’.

2008 was the International Year of Planet Earth. This book contributes to celebrate this event by reminding us of its exceptional uniqueness. Its ambition is to pass down a piece of the past to the younger generation in order to confer a future to their history.

More information, see the following page "GEOSCIENCES" where one chapter of the book can be downloaded freely.

| Abstract |

Most beautiful rocks of Wallonia - Geology and small history. Certain rocks form part of the cultural inheritance of Wallonia. But how many people know the nature and the age of the rocks which compose them, how they settled, in which circumstances they were folded or fractured? Many sites are also impressed with a history or legends.

The work wishes to inform a large audience on these various aspects which were not treated yet in a total way. It invites the reader to go up time on more than 500 million years by visiting 78 remarkable rock sites described according to an approach identical going from 4 to 6 headings.

Basing itself on a rigorous scientific work, the authors tackled the subject in a didactitic way by privileging the photographs and the sketches compared to the text, to facilitate the reading of it.

This book should find a place of choice in the libraries of experts in love with nature and their area.

More information, see the following page "GEOSCIENCES" where one chapter of the book can be downloaded freely.

| Abstract of the articles |

A survey of East Flemish building stone. The few stony layers intercalated within an essentially unconsolidated sediment sequence underlying the province of East-Flanders have been systematically and intensively quarried for building stones. Nowadays, the built environment is the best, sometimes only place to view these local stones. They testify of both a long geological past and rich building history. Every rock type possesses characteristics which make it suitable for a particular use. Moreover, occurrence in the built landscape matches the occurence in the geological substrate and its possible outward move. We therefore pay most attention to the local building stones, originating from the east-flemish subsoil and to the historically significant Tournai limestone.

Tournai limestone, a building stone since Roman times, unique among the Belgian marbles. Tournai limestones have been quarried since Roman times. Nowadays, quarrymen distinguish the grey beds quarried below a volcanic ash layer called Gras-délit and the blue beds from above. The Tournai black marble is produced from the blue beds. These limestones occur in the Upper Tournaisian strata (Mississippian) exposed on both sides of the River Scheldt. The general chemical composition of these limestones is close to the ideal Portland Cement and most of the quarries have switched to current production. After the fall of the Roman Empire; the stone industry disappeared almost completely from our regions. Tournai will be the first city to reopen the quarries in order to build the local cathedral (1110-1171), the main romanesque monument of the country. An important craft industry arose and hundreds of churches and civil buildings in Flanders, the Netherlands, France, Great Britain and farther away are proud of their Tournai marble fonts, tombstones or other architectural elements. The Gothic period contributed to the emergence of other building stones lighter and easier to sculpt. Along the Scheldt River, in Flanders as well as in the Netherlands, the use of Tournai limestones will last longer but the decline will continue and the trade activities will stop at the end of the XVth century. During the reign of Louis XIV, the urban development stimulated the recurrence of Tournai stone as decorative element of the façades. The fashion of whitewashing the buildings which started during the reign of Louis XVI and further increased during the Empire restricted the use of limestone for the basement of local buildings. The reign of the Portland cement could then start.

Avesnes stone (‘Avendersteen’). A peculiar type of historical building stone, originating from the north of France but initially part of the Low Countries, is highlighted: what kind of material it is, where it is coming from, where it has been used and what we can do to preserve these examples. There exist few documents on the use of Avesnes Stone in the Low Countries. For a long time in the Netherlands the stone was not recognized at all. There wasn’t even a clear name for this material and up till now no definition. After research it became evident that this type of stone was a very important natural building material, especially for sculptures, and that it has been used for a long time, in spite of the fact that it hardly withstands our climate. From the past, different treatments are known to protect the stone against weathering and research is still going on how to conserve cultural heritage made of Avesnes stone. Material investigation and registering examples of its use are of common interest to geologists, conservation workers and art historians. The characteristics of the stone have their influence on the object which is made out of it. Valuation and conservation is impossible without being familiar with these characteristics.

Geodiversity as an intrinsic property of historical monuments: geotouristical value of historical building stone landscapes in Flanders. Northern Belgium (Flanders) consists of generally unconsolidated Mesozoic to Cenozoic strata, practically devoid of exposure. However, most cohesive rocks have been intensely quarried for local use as building stone and the link between the built environment and the geological substrate is evident. The Meso-Cenozoic consolidated beds possess highly variable lithological and petrophysical properties, contributing to the geo-diversity. Buildings containing particular stone types, of which natural outcrops or quarries are no longer known, can be regarded as artificial or virtual quarries. The distribution of historical building stones in the monuments is clearly related to their exploitation areas: cultural diversity follows geo-diversity. Most stone types only occasionally used as building material are not recorded beyond the area of their natural occurrence, whereas stone types of more commercial value extend from stone-rich to stone-poor areas, mostly going downriver. The regional distribution of different stone types allows to define natural stone landscapes which generally consist of one dominant stone type with associated stone types of lesser importance but equally characteristic. The only way to preserve the building stone is to increase public awareness and to provide access to information on the indigenous historical stone types. This public awareness can be triggered by setting up geological walking trails and biking routes, where natural and cultural history are combined in the stories told by the natural stones of a monument.

What can be learned about historical quarrying techniques from traces left in the quarries? The extraction techniques in medieval quarries did not differ considerably from those in use in Greek and Roman times. Traces of medieval quarries were recently discovered in the dry ditches of three medieval castles in the Meuse-valley in Belgium, i.e. the castles Poilvache, Logne and Château-Thierry. Two quarying techniques were in use. In the ditch of the castles Poilvache and Logne and also in the quarry of the Grands Malades in Namur the stone blocks were split from the adjacent rock by cutting of a number of trapezoidal sockets starting from the surface of the exploited stone bank. Iron wedges were driven in those sockets causing a very similar tension in each socket until the stone-block separated itself from the rock. At the same time horizontal sockets were also cut to split the stone-block from the rock below. In the ditch of castle Château-Thierry the blocks to be extracted were first separated laterally from the rock by small grooves which were incised in the upper surface of the stone bank with a special type of pickaxe (Fr. escoude). Probably thereafter these stone-blocks were split from the rock below with iron wedges but no traces of this have been found. The number of sockets in these medieval quarries was usually quite limited which very often caused an irregular splittting of the stoneblock from the rock frequently necessitating a corrective cutting of the irregularities on the vertical quarry-wall.

Why a natural stone loses its skin. In many cases, the skin of natural stone bears the expression desired by an architect, the cutting of a stone mason, (remains of) polychromy and the patina of ages. This skin, however, is often lost by spalling, exfoliation or alveolitization, etc. In this contribution, an overview is given of mechanisms resulting in this loss of skin of natural stone.

Limits to consolidation of weathered stone. Stone like materials exposed to natural weathering suffer from weathering processes leading to a loss of cohesion. A conservation treatment consists of the application of consolidants on superficially degraded materials. In Belgium, mostly products based on ethylsilicate are used for such purposes and which have widely proven their efficiency. Unfortunately, such applications have their limits related to the presence of certain clays, the alteration depth, the detachment of a thin surface layer and/or the size of constituting grains of the stone. In this paper, each of these phenomena is explained by means of a typical case study.

New Technical filing cards for natural stone. In June 2006, the first interactive technical note of BBRI came on-line. This NT 228 “Natural stone”; was prepared by a working group consisting of the federations of the sector and in cooperation with the Technical Committee “Stone & Marbles”, a review of the TV 205 “Natural stone”, which dates from 1997 was developed. Since the publication of the TV 205, there are significant changes occurred in the natural stone industry. Due to the appearance of new European test and product standards for natural stone and the increasing use of imported stone in which the properties are barely known in the Belgian construction industry, the old TV 205 and his technical filing cards needed an update. The TV 228 is built around a database of technical filing cards of stones that are mostly used in Belgium. These cards contain general information about the stone, a macroscopic and microscopic description, technical characteristics and some attention points. It also includes a chapter explaining the tests and criteria, a chapter that describes the different types of stone and a chapter on finishing and hew of stone. This TV 228 seeks to be a reference document for stone for the user in order to help in his choice and to be a guide through the technical features and names.

The abstract of this professional paper does not exist in English.
However you can consult it in another language : In Dutch

Abstract not available.

Historical building stone in use, an excursion guide to three villages in East-Flanders south of Ghent. Dominance of Ledian stone in St.-Annachurch, Bottelare (Merelbeke), romanesque and gothique parts in St.-Gangulfuschurch Paulatem (Zwalm), patchwork of historical building stones in St.-Apolloniachurch of Elst (Brakel).

| Abstract |

The abstract of this professional paper does not exist in English.
However you can consult it in another language : In Dutch

| Content |

• Organization and scientific committees p. 2
• Introduction p. 3
• Programme of the meeting
  • Oral communications p. 7
  • Posters p. 19
• Abstracts of the oral and poster communications p. 27
• The workshops
  • Andrew C. Scott: Charcoal recognition / taphonomy p. 156
  • Mitchell Power: Databases p. 157
  • Freddy Damblon: Association of charcoal research p. 158
• Index and addresses of the authors and participants p. 169
• Sponsors p. 189

| Content |

• Field-guide of the excursion on September 13th 2008, an introduction
  F. DAMBLON, S. PIRSON & P. GERRIENNE
• An overview of the geology of Belgium
  S. PIRSON, P. SPAGNA, J-M. BAELE, F. AMBLON, P. GERRIENNE, Y. VANBRABANT & J. YANS
• 130 years ago: the discovery of the Bernissart iguanodons
  P. GODEFROIT
• Sedimentology of the wealden clays in the Hautrage quarry
  P. SPAGNA, C. DUPUIS & J. YANS
• Palynology of the wealden facies from Hautrage quarry (Mons basin, Belgium)
  J. DEJAX, D. PONS & J. YANS
• Palaeoflora from the wealden facies strata of Belgium - mega- and meso-fossils of Hautrage
  B. GOMEZ, T. GILLOT, V. DAVIERO-GOMEZ, P. SPAGNA & J. YANS
• Wood remains and sporomorphs from the wealden facies of Hautrage (Mons Basin, Belgium): palaeoclimatic and palaeoenvironmental implications
  T. GERARDS, J. YANS, P. SPAGNA & P. GERRIENNE
• new data on geology, anthracology and palynology from the Scladina cave pleistocene sequence: preliminary results
  S. PIRSON, M. COURT-PICON, P. HAESAERTS, D. BONJEAN & F. DAMBLON

| Abstract |

Paleontological observations on Neogene deposits in Belgium, Antwerp Harbour, from 1971 to 2004, between Kallo and Doel, Antwerp Harbour, Left Bank (East-Flanders, Belgium). The Miocene in the Deurganckdok, Doel. This publication reports the first discovery of mangrove remnants (traces of roots and wood) in the Belgian Miocene deposits and its associated ecosystem. They were found west of Antwerp, on the left bank of the Scheldt. The sudden death and disappearance of this living community are described. The greater part of the examined remnants comes from hard stone blocks of different composition, indicated as lithifications. All of them originate from a horizon which could be observed in situ. This level may be considered as a lithostratigraphical unit, a Bed, named Deurganckdok Sandstone.

In these hard blocks the following fossils were found: wood from Rhizophoraceae en Pinaceae, gonioaster-like starfish living in mud, irregular spatangiform sea urchins, a great diversity of often very well preserved ichnofossils, 46 species of molluscs, among which a for Belgium unknown pteropod species and two non-described taxa, and skulls of archeoceta and dolphins. Only the remnants of echinodermata seemed to better withstand the twofold chemical aggression. The anatomy of the wood remains was examined and their systematic position precised (cf. Supplement 1).

The sandstones of this Member are characterised biostratigraphically by the presence of the gastropod taxa Vaginella austriaca Kittl, 1886 and Semicassis (S.) miolaevigatum gliberti nov. subsp. Also the association of the bivalves Glossus lunulatus crassus (Nyst & Westendorp, 1839) and Glossus burdigalensis cypriniformis (Nyst in Dewalque, 1868) is significant. Two taxa, new to science, are described: the bivalve Allogramma miocaenica sp. nov., and the gastropod Semicassis (S.) miolaevigatum gliberti nov. subsp.

Each animal and plant group is systematically examined and the ecology is dealt with, the relevant bibliography each time being mentioned. The molluscs are treated separately in the second part of this issue. The life conditions, the death and the burying of the various groups, the rarity or absence of certain taxa are explained as far as possible.
An interpretation of the subsequent events is put forward. The lithifications are younger than the Edegem Sands and older than the Antwerp Sands and may consequently represent a facies of the Sands of Kiel.
In addition to the regional geological context, the presence of a particular pteropod species and the dinoflagellate association discovered (cf. Supplement 2) confirm this assumption. The relation of the fauna with diverse other European faunas is discussed, in particular that from the Holy Cross Mountains in Poland (Badenian).