GeoJournal 48: 337–340, 1999.© 2000Kluwer Academic Publishers. Printed in the Netherlands.

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Research note

Geocultural activity in seventeenth and eighteenth century Malta

L. BiancoInstitute of Masonry and Construction Research University of Malta, Tal-Qroqq, Msida, Malta

Received 25 April 1999; Accepted 16 July 1999

Throughout history any rock material used as dimensionstone in the building industry had a special significance tomankind. However, it is difficult to objectively determinewhether the relationship between man and stone came aboutthrough accident or by design. Certainly the implicationsof such a bond are far reaching. Stone was the handmaidto civilization for millennia. “Man spent many generationsperfecting the technique of grinding stone, acquiring re-markable skill and achieving admirable results. . . . Stone wasthe material he used to build houses and other structures; hebartered with it, fought with it, used it to indicate his socialstatus” (Kukal et al., 1989).

As in several other cultures, the Maltese building tradi-tion has centred around local limestone since time immemo-rial. Numerous remains and buildings illustrate that theirbuilders differentiate clearly between limestone formations.No written records of the skills and knowledge known to theNeolithic builders exist. Builders of the prehistoric ‘temples’noticed the variability in the quality of local limestone. Theydistinguished between the harder, more durable CorallineLimestone Formations and the softer, less durable Globige-rina Limestone Formation. The former was used for externalwalls. These walls are bare from carvings. Limestone fromthe Globigerina Limestone Formation was carved and usedfor interiors. The carvings present are difficult to make onthe harder limestone even with contemporary machinery.

An equally, more elaborate growing sophistication in theuse and exploitation of local limestone was present duringthe stay of the Knights of the Order of St John (1530–1798 A.D.). The Order had a number of both local andforeign experts. In the late eighteenth century Guy S. Tan-crède de Dolomieu, a French Knight, was such a person(Schermerhorn, 1929).

The geology of industrial minerals used in the buildingindustry

All industrial minerals of Malta are marine sedimentary inorigin, of Oligo-Miocene age. The main industrial mineral islimestone (Bianco, 1995). It constitutes Malta’s landscape,both natural and man-made. Limestone occurs in three for-mations: Upper Coralline, Globigerina and Lower Coralline.Coralline Limestone, whether Upper or Lower, is locallyreferred to as ‘zonqor’ while Globigerina Limestone is re-

ferred to as ‘franka’. Each of these limestone formations hasa number of members as stated, in decreasing age, in Table 1.

Quarrying activity and local workforce

By 1530 local quarries produced onlyfranka, the main andmost common building stone on the island (Blouet, 1964).It was quarried from the Lower Globigerina LimestoneMember and not from the Middle Globigerina LimestoneMember. Francesco Laparelli da Cortona, a military engi-neer sent to Malta by Pope Pius IV, recommended that thequarrying season should last all summer when the build-ing works would come to a halt because the heat dried themortar and thus rendered the construction less durable. He“advised against building in June until August. . . In thesemonths when actual construction was not possible, stonecould, however, be cut and other materials stockpiled so thatwork could start immediately the weather was favourable”(Hoppen, 1979).

During the early stay of the Knights, limestone from theCoralline Limestone Formations was used in small workssuch as in the production of millstones (Abela, 1647). Atabout one mile east of Birgu there was a quarry workingthis limestone (Abela, 1647). The quarry could potentiallyhave been working either one of the following three mem-bers occurring in the Lower Coralline Limestone Formation:II-Mara, Xlendi or Attard Member. In the late seventeenthcentury there was a drive to exploit the advantages offeredby the Coralline Limestone Formations over the Globige-rina Limestone Formation. It was during this period thatthe Lower Coralline Limestone started to be used on sitesexposed to sea-spray (Hoppen, 1979).

In the construction of fortifications the main expensewas building material. Labour force was relatively cheapcompared to building materials. Mortar, pozzolana, woodand iron were some of the materials imported. Due to easeand generous local supply, negligible costs were incurredin importing building stone. It was a common practice thatbuilders providedfranka themselves.Zonqorwas suppliedby the Order (Hoppen, 1979). Despite the abundance oflimestone, shortage ofzonqoron site was sometimes a prob-lem. The building of a low platform at St Christopher’sBastion in Valletta was delayed because there was a delayin obtainingzonqor(Hoppen, 1979).

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Figure 1.

Table 1. Geological succession of the building stone of theMaltese Islands (based on Pedley, 1978)

Formation Members Age

Lower Maghlak Chattian

Coralline Attard Chattian

Limestone Xlendi Chattian

II-Mara Chattian

Globigerina Lower Globigerina Aquitanian

Limestone Middle Globigerina Burdigalian

Upper Globigerina Burdigalian

Upper Ghajn Melel Tortonian

Coralline Mtarfa Tortonian

Limestone Tal-Pitkal Tortonian

Gebel Imbark Lower Messinian

At the middle of the seventeenth century there was asufficient local workforce to meet the needs of the buildingindustry (Hoppen, 1979). This was partly due to a significantgrowth in the population despite famine and fatalities duringthe Siege of 1565 (Blouet, 1967).

Labour on building sites was either compulsory or hired.The former was engaged to do unskilled work while the lat-ter did skilled work. Quarries relied a great deal on unskilledworkforce especially for work involved in the extraction oflimestone as skilled work labour was not free. Skilled workwas carried out by experienced craftsmen. Contracts of em-ployment were drawn between them and the Order (Hoppen,1979). Maltese masons were respected and held at high es-teem not only by the Order but also by foreign engineers.The Maltese who fled to Sicily prior to 1566 were encour-

aged to return because of their invaluable knowledge of localbuilding materials and methods (Bosio as cited in Hoppen,1979). Also, visiting “engineers were ready to acknowledgethe skill of native masons in working the local stone. When-ever possible, Maltese craftsmen were employed in buildingworks although at times pressure of work necessitated theimportation of foreign labour” (Hoppen, 1979).

Quarries working the San Leonardo Beds

Selection of building stones used has been governed by ex-pediency rather than by scientific principles. It has alwaysbeen the practice of selecting higher quality, more durablestone for buildings of national importance. More durablestone minimizes expenses incurred for repairing and restor-ing buildings. The formations recommended to be exploitedfor durability are the Upper and Lower Coralline LimestoneFormations, since both formations have similar properties.Very durable beds within the Upper Coralline LimestoneFormation are the San Leonardo Beds. These beds occurin the Gebel Imbark Member. The limestone within thismember is cross-stratified, oolithic, pelletoidal and bioclas-tic limestones, showing ripple-marks and festoon-bedding(Pedley et al., 1976).

Outcrops of San Leonardo Beds occur close to Zabbar(Figure 1). The type locality for these beds is the moataround Fort Leonardo, hence their name. San LeonardoBeds consist of channelled packstones containing marinemollusc bioclasts, overlaid by charophyte-rich marls andunfossiliferous wackestones.

The strength of rocks depends on a number of factors.The most significant are the strength of the minerals mak-ing up the rock, the adhesion of the minerals in the rock,

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Figure 2. St Elmo: Weathered dimension stone from San Leonardo Beds.

Figure 3. St Elmo: Weathered dimension stone from San Leonardo Beds.

grain size, structure, and inter- and intra-particle porosity.Limestone from San Leonardo Beds is made up of closetexture casts of small hard shells. It is durable and weatherswell. The fossilized shells are very hard. Macrofossils otherthan Entobia-boredOstreaare absent from San LeonardoBeds (Pedley, 1978). Weathering of this grain supportedpackstone is characterized by loss of cement between thegrains.

Functional and aesthetic use of San Leonardo Beds

Two buildings making use of San Leonardo Beds are StElmo bastions facing Marsamxett Harbour (Figures 2 and3) and the Baroque gateways of the Magisterial Palace(Figures 4 and 5).

St Elmo was redesigned in the late seventeenth centuryby Don Carlos de Grunenburg, a military engineer to theKing of Spain in Sicily. He gave detailed specificationsfor building materials to be used. Aware of the higher re-sistance thanfranka to weathering when exposed to seaspray, Grunenburg proposed to construct the exterior wallsof zonqorinstead (Hoppen, 1979). Furthermore, mortar andpozzolana were to be used for pointing in the more exposedparts of the bastions (Hoppen, 1979). Upper Coralline Lime-stone from San Leonardo’s Beds was used for the lower partof these bastions.

Figure 4. Magisterial Palace: Detail of column base.

Figure 5. Magisterial Palace: Detail of column.

The Baroque gateways of the Magisterial Palace, over-looking Palace Square, were added in the mid-eighteenthcentury during the Grandmastership of Fra Don EmanuelPinto de Fonçeca (Hughes, 1956). Limestone quarried fromthe San Leonardo Beds was used in the palace gatewaysboth for functional and aesthetic reasons. When used inthe lower courses of the entrance and for column bases, itprovided greater damp proofing and impact resistance. Thetexture was exploited in the design of the coupled rusti-cated columns. Limestone suitability as structural masonryand as a conveyor of architectural styles vary dependingon the intrinsic properties of the material fabric. Limestonefrom San Leonardo Beds is very hard and hence not suit-able for fine and elaborate carving. Thus, it was used in thethin projecting drums whilefranka was used in construct-ing the remaining column drums in the architectural stylepredominant at the time.

San Leonardo Beds differ remarkably in texture fromLower Globigerina Limestone Member. It weathers moresatisfactorily as evident in both case studies. Variety intextural characteristics is usual for such limestone. SanLeonardo Beds are shallow water carbonates. Like all shal-low water limestone formations, these beds are likely to varysignificantly from place to place. Limestone from each local-ity within the bed may be said to possess an individuality ofits own.

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Historically, the selection of building stones was re-stricted by availability and suitable technology. The use oflimestone from San Leonardo Beds from the Gebel Im-bark Member occurring in the Upper Coralline LimestoneFormation reinforces this trend.

References

Abela G.F., 1647:Descrizione di Malta. Malta.Bianco L., 1995: The industrial minerals of the Maltese Islands.Hyphen7:

111–120.Blouet B.W., 1964: The changing landscape of Malta during the rule of

the Order of St John of Jerusalem 1530–1798. Unpublished PhD Thesis,University of Hull.

Blouet B.W., 1967:Story of Malta. London.Hoppen A., 1979:The Fortification of Malta by the Order of St John 1530–

1798. Scottish Academic Press, Edinburgh.Hughes J.Q., 1956:The Building of Malta 1530–1795. Alec Tiranti,

London.Kukal Z., Malina J., Malinova R. and Tesarova H., 1989:Man and Stone.

Geological Society, Prague.Pedley H.M., House M.R. and Waugh B., 1970: The Geology of Malta and

Gozo.Proceedings of the Geological Association87: 325–341.Pedley H.M., 1978: A new lithostratigraphical and palaeoenvironmental

interpretation for the coralline limestone formations (Miocene) of theMaltese Islands.Institute of Geological Sciences54: 1–17.

Schermerhorn E.W., 1929:Malta of the Knights. The Windmill Press,Surrey.