1

THE CHURCH OF THE MADELEI�E I� CORDOBA (SPAI�) A�D ITS BUILDI�G MATERIALS

BARRIOS-NEIRA, J.1*, MONTEALEGRE, L.

2 and NIETO, M.

3

1 Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Córdoba, Spain

2 Departamento de Ciencias y Recursos Agrícolas y Forestales, Universidad de Córdoba, Spain

3 Museo Diocesano de Córdoba, Spain

* Corresponding author: E-mail: iq1banej@uco.es. Phone: +34957218620

Keywords: stone materials, biolimestone, deterioration, Cordoba’s monuments

ABSTRACT

The church of “La Magdalena” in Córdoba (Spain) was built under the reign of Fernando III, following his conquest of the city in 1236. A fire in the mid-XX century kept it closed. Restoration was preceded by a study of its stony building materials before the fire and of those used in the 1995 works. The purpose of this work was to characterize the stony materials used to build and restore the church. Their aorigin was sought in outcrops in the vicinity of the city. The stony materials originally present in the building included Tortonian biocalcarenites, compact grey limestones from the Cambrian and Carboniferous in Sierra Morena, and nodulous pink-coloured limestones from the Jurassic in Cabra. The materials were characterized in mineralogical, structural and chemical terms by using: XRD, petrographic microscopy and among other techniques. The results thus obtained for the original building materials and those used in the successive restorations are reported. Many of the ashlars consist of sandy (fossiliferous) biosparites and biomicrites containing: 50–70% calcite (some of wich calcareous fossils), 10–15% quartz (with small amounts of mica and clay) and the average porosity is about 18%. A comparison of their characteristics with those of materials from various quarries near the city. The restoration materials were brought from Posadas. The paper contains lithological maps and drawings showing alterations in the materials, as well as photographs reflecting the condition of the church before and after the last restoration.

INTRODUCTION

This work was conducted with a view to confirm whether the restoration of “ La Magdalena” church planned for 1995 would be possible with materials from nearby quarries then in operation (specifically, whether such materials could be used to replace degraded ashlars). This was preceded by the characterization of the materials used in the construction and subsequent restorations of the building. The results thus obtained were compared with those for specimens from various quarries in order to identify the source of the original materials. The materials in the Posadas quarry were found to be those most closely resembling the characteristics of the ashlars to be replaced. Information artistic. The church of “La Magdalena” was built a few years after the Reconquest and instituted a parish by King Fernando III. It is located in the former “La Axerquía” quarter. The church was declared a historic–artistic monument in 1982.

A characteristic that highlights at first sight in the group of the first churches of Córdoba, is the similarity among them. This temple [1] presents a tipología that integrates Gothic, Cistercian and

2

late romanesque structures brought by the conquerors to which it is necessary to add the local Muslim. The building blends Castillian austerity (Gothic elements) with Mudejar gracility. The distribution of the plant with three ships guided to the east, is a type of Gotic element. In the head three apses are located, one for each ship, generally polygonal and covered with crucería vaults. Columns embedded to the walls that you/they go in the exterior reinforced by stirrups exist, since on these columns the nervers of the vault discharge their weight. Another Gotic feature is the sistem of sustentation of the ships with walls armed and double arcade, usual in the Cistercian temples, with double arcade: a) the opened inferior leaving communication between the ships and b) the blind superior hit to the wall to reinforce it. The covers possess a marked Gothic stamp with their arches pointed in spill on small columns (Figures 1 and 2). The decoration presents geometric elements of the late romanesque: the zig -zags, the diamond tips and the habitual dog teeth in nerves and covers, as well as Gothic vegetable reasons and archaistic human figures. In the XVIII century the temple was restored in the interior, giving to the arches the form of half point and having the molds romanesque with others of plaster-work.

In the external part three covers can be observed, which are in good state. The main facade is walled and only its two front bulls are visible now. The columns originally supporting the bulls are absent; only the small capitals, in the form of two rough leaves, are present ─by exception, three human heads emerge from beneath the many layers of whitewash and ochre in the right corner. A sphere roughly the size of a small orange is seen in between the two bulls; rather than smooth as in most buildings where it is present, the sphere is carved as a rose bud. The arches start off a wide frame that runs lengthwise throughout the above-mentioned projection and exhibits figures of birds fighting. The door to the Gospel aisle is funnel-shaped and has modern eaves standing on slats at the top, which is horizontal. All slats are carved with very simple Mudejar motifs. The funnel-shaped facade consists of three flattened arches in a pure Romanic style; the edges were carved with thick cylindrical nerves in a previous restoration. The Epistle aisle contains a smaller aisle consisting of a single, slightly pointed arch surrounded by an archivolt projecting from an arraba the outer line of which is an uninterrupted series of diamond points. As in other churches of the time in Cordoba, the central aisle is much higher than the side aisles; also, it has slats supporting an artistic wing. All slats but a few containing very roughly carved animal heads are smooth. MATERIALS and TECHNIQUES The study litological of these stony materials of the building allowed us to have a general idea of its mineralogical and petrostructural characteristics. Of the obtained data you could predict the location of the quarries origin of the ashlars and used construction materials. The mineral composition of the material was determined by X-ray diffraction spectroscopy (Moore and Reynolds,1997). X-ray diffraction patterns(XRD) were recorded on a Siemens D5000 instrument, using CuKα radiation (λ= 1.54059 Å) and a graphite monochromator .

3

A photomicroscope Carlr Zeiss II POL with thin layer has been used for the petrographic, mineralogical and textural studies. RESULTS and DISCUSSION

Alteration mapping for the N and W walls have been produced (Figures 3 and 4) from elevations available from the last restoration. The maps illustrated the different types of deterioration [2] [3] [4] [5] present in the building, which included the following: - Bioalteration in the form of algae at the top of each wall and at ledges (bottom). The lower parts of the walls were covered with moss and lichen formed through moisture capillarity. - Alveolar erosion, which was one of the first stages of material losses, was especially marked in the W wall, particularly on the right of the door (associated to differential alteration) and on its left (occupying a greater expanse on arenizatión and differential alteration zones). - Differential alteration due to the presence of harder beds, more readily altered (less hard) ashlars, and also to their lack of homogeneity. - Arenization in door arches and wall bottoms and even at greater heights in the apse. Arenization alternated with differential alteration in the W wall, whereas differential alteration was seen above disintegrated zones in the N wall. - Material losses (cancerization) in specific, highly weathered ashlars at the bottom and medium eight on both sides of the W door. Losses were less marked in the N zone. – Most black scales and efflorescences were in the N wing, where the air was more static. - Occasional fissures the most visible of which was that under the rose window over the W door and possibly due to the Lisbon earthquake.

The mapping for the N and W wings (Figures 5 and 6) show the different lithological units present before the last restoration. Only the most abundant biocalcarenites (biomicrites and biosparites) are shown. Other materials included compact limestones from the Cambric, bricks, plaster and coatings. Figures 7- 9 show the inside of the building (apse) and details of the N and W door (all prior to restoration). The figures 10-12 illustrate the appearance of both doors after restoration.

Table 1 shows the characteristics of the building material and that used in the last restoration, in addition to their location in the building, age and potential origin. X-ray diffraction was used to determine the proportion of each mineral species present (see Table 2), and also shows the ashlar colors before and after restoration. The color was measured at several points in each ashlar and an individual average calculated in order to provide for differences in degree of alteration.

Previous work [6- 12] revealed the presence of up to lithological types found in building ashlars in many monuments of Córdoba, which its properties coincide broadly with the rock types present in the Madeleine. Many of the ashlars consisted of sandy (fossiliferous) biosparites and biomicrites containing 50–70% calcite and 10–15% quartz in addition to small amounts of mica and clay. The average porosity of the materials was about 18%. Some ashlars contained more than 50% of calcareous fossils.

The most abundant lithological types were quartz-containing biosparites and fossil-containing biomicrites. Their average composition included 50–70% calcite, and 10–15% quartz and feldspars. Calcareous fossils accounted for more than 50% in some samples and porosity was generally very high (about 15%). Conglomeratic biomicrites contained over 25% of clasts (rock fragments) more

4

than 2 mm in diameter. Thin section microscopy allowed us to determine the petrological structure (Table 3). Calcite was the major species among carbonates; it occurred in binding materials, fossils (mostly calcareous), aragonites and, occasionally, ankerite.The feldspars found were orthoses and plagioclases, the latter were only visible in thin layer preparations. The remaining minerals included iron hydroxides and oxides (goethite, hematite), muscovite (white mica), glauconite (gray clayey conglomerate) and various, minor others (illite, altered mica). Table 4 show the characteristics of quarry material.

The nature of the microfauna observed by thin slide microscopy varied with the particular lithotype. Thus, biosparites abounded with heterostegins, calcareous algae (lithotanmium), fragments of lamellibranchiae and urchins, bryozoans, etc. Calcareous sandstones contained more abundant resedimented, broken fragments of foraminifers (heterostegins, dentallium) and lamellibranchiae (ostreae, pectem), urchins (plates and radioles), brachyopods (terebratullae), etc.

Prior to the last restoration, we conducted a study in several quarries in the vicinity of Córdoba [7] with a view to identifying the origin of the building materials for the Alcázar de los Reyes Cristianos [13]. The materials used at the time were usually obtained from a nearby deposit. The quarries examined included Albaida, Naranjo, Patricarca, Asland and Posadas. The materials in Albaida were those most closely resembling those of the church ashlars. This quarry, however, was declared a Cultural Heritage, so extraction was no longer allowed.

The sandy facies of the Naranjo quarry is very similar to that of the sandier materials found in the church. Only a small area of the original quarry remains, however, since the rest has been used for urban development. Material from this quarry was used to construct the Santa Marina de Aguas Santas church [14].

The Patriarca quarry abounds with conglomerates; however, it is rather small, has steep slopes and is difficult to access, so its is scarcely used in practice. A small fraction of the Madeleine ashlars were obtained from it.

The Asland quarry abounds with biosparites and biomicrites containing well-preserved fossils. The quarry was used to extract abundant material for cement production in the last decades of the XX century; as a result, the original sources were gradually depleted. The biosparites in this quarry occupy thin beds; also, the material contains clayey domains (seen in the steps outside the Mosque), so it was unsuitable for the intended restoration.

The Posadas quarry is about 30 km from Córdoba. Its material has been used in a number of buildings in Córdoba (e.g. Alcázar, Mosque tower, last restoration of the Mosque ashlars). Its materials include scarcely altered biomicrites the mineralogical composition, lithological structure and fauna of which are consistent with those of the Madeleine ashlars. The fact that it remains in operation and contains large amounts of readily accessed resources makes its material suitable for restoration purposes.

CONCLUSIONS The results obtained in this study allow us to draw the following conclusions:

5

– The Tortonian biocalcarenite samples taken from the church ashlars are similar in mineralogy, petrological structure and various properties (e.g. colour) despite the differences between ashlars. – A comparison of the lithotypes present in the church with those found in various quarries near the Córdoba suggests that the original building materials were brought from several of them. – Most likely, the building materials were obtained from Albaida, Naranjo, Patriarca and Asland (but not from the area currently in operation in the last). - A comparison of mineralogical and petrostructural features, and mechanical strength, of the ashlars to be restored with those of the material in the Posadas quarry sufficed to recommend their use in the planned restoration. - Sandy layers (particularly biocalcarenites), on account of their cutting and carving hardness, and ready access of their outcrops, have been the ideal material for obtaining building ashlars since Roman times. REFERENCES [1]Jordano Barbudo M.A., Moreno Cuadrado F., Mudarra Barrero M., (1997), “Iglesias de la Reconquista. Itinerarios y puesta en valor”. Publicaciones de Univ. Córdoba y Cajasur. [2]Barrios J., Navas J., Montealegre L., Nieto M.,(1994), “Characteristics and types of alteration in materials found in the west façade of the Mosque of Córdoba (Spain)”. Proc. III International Symposium on the Conservation of Monuments in the Mediterranean Basin. Venecia, pp.755-761. [3]Montealegre L., Barrios Neira J., (1996a), “El deterioro de los monumentos cordobeses”. Roc Maquina, pp.141-146 Ed. Roc Maquina (Bilbao) [4] Barrios Neira J., Montealegre L., Sebastian E., Cultrone G., Beck K., Al-Mukhtar M., Alcover J. F., (2007a), “Stones of monuments in Biocalcarenites and travertines. Morphology and types of deterioration”.7th Internacional Symposium on the Conservation of Monuments in the Mediterranean Basin,.June 6-9, Orleans (Francia), pp. 35-43. [5] Barrios Neira J., Montealegre L., Ortega A., Meroño J. E., Aguilera M. J., (2007b), “Applying Near Infrared Reflectances Spectroscopy (NIRS) to cultural heritage “.7 th Internacional Symposium on the Conservation of Monuments in the Mediterranean Basin, June 6-9. Orleans (Francia), pp. 44-49 [6]Montealegre L., (1976), «Estudio mineralógico en sedimentos y suelos de la Depresión del Guadalquivir». Tesis Doctoral. Universidad de Granada [7]Montealegre L., Barrios J., Nieto M.,(1996b), “The materials of construction of the west wall of the mosque of Córdoba (Spain) and their deterioration”. 8th International Congress on the Deterioration and Conservation of Stone. Berlín (Alemania), pp.51-60. [8]Montealegre L., Barrios Neira J., (1998a), “Un banco de datos sobre las características microestructurales y mineralógicas de materiales calcareos y mármoles”. II Congreso Internacional de la piedra. PO14. Editado en C.D. Madrid (España). [9]Barrios Neira J., León A., Montealegre L., Nieto M., Trigo M.D., (1998), “Caracterización de los materiales de construcción del ala Norte de la Mezquita antes y después de la restauración”. IV Cong. Internacional de Rehabilitación del Patrimonio Arquitectónico y Edificación. La Habana (Cuba), pp.130-132. Ediciones Canaricard. [10] Barrios- Neira J., León A., Montealegre L., Nieto M., Palma J. (2003a). “Contribución al estudio litológico de los materiales empleados en monumentos de Córdoba de distintas épocas”.Arqueología de la Arquitectura, Vol.2, pp. 47-53. Serv.Editorial Univ. Pais Vasco [11] Barrios- Neira J., León A., Montealegre L., Nieto M., Palma J., (2003b), “Stone materials used in the main monuments of Córdoba (Spain): Review”.Applied study of cultural heritage and clays, pp. 29-45. Ed. C.S.I.C y Soc. Española de Arcillas.

6

[12] Cultrone G., Sebastian E., Luque A., Urosevic M., (2007) “The restoration of the romam bridge of Córdoba (Spain): A petrophysical investigation”. 7th Internacional Symposium on the Conservation of Monuments in the Mediterranean Basin, June 6-9. Orleans (Francia), pp.130-138. [13]Barrios- Neira J., Montealegre L., (1996), “El Alcázar de los Reyes Cristianos de Córdoba: Materiales pétreos y canteras”.Rehabilitación del Patrimonio Arquitectónico y Edificación, pp. 238-242. Ed. CEDEX-MOPTMA y la Univ. Granada. [14] Barrios Neira J., Montealegre L., Ortega A., Meroño J. E., Aguilera M. J., (2009), “Biocalcarenitas como material de construcción en la iglesia de Santa Marina de Aguas Santas (Córdoba, España)”. Materiales de construcción. Vol. 59, No. 293, pp.125- 134

Figure. 1.- N wall and door before restoration.

Figure 2.- Detail of W door before restoration.

7

Figure 3.- Alteration mapping of the northern wall

Figure 4.- Alteration mapping of the western wall.

8

Figure 5.- Lithological mapping of the northern wall.

Figure 6.- Lithological mapping of the western wall.

9

Figure 7.- Inside of apse before the last restoration.

Figure 8.- Detail of N portico before restoration.

Figure 9.- Detail of � portico before restoration

Figure 10.- N wall and door at present.

10

Figure 11.- W wall and door at present.

Figure 12.- Detail of W door at present.

11

TABLE 1 USED ROCKS IN THE BUILDING

Type / sample Age Possible origin Location

Biosparite /Mg1 Tortonian Asland Apse ashlars

Biomicrite / Mg2 Tortonian Naranjo, Albaida Centered Northern wall ashlar

Sandy biomicrite /Mg3 Tortonian Naranjo, Patriarca Outside Western wall ashlar .

Biosparite with heterosteginidae /Mg4 Tortonian Albaida, Right side of the door in the

S wall ashlars

Biomicrite with algae /Mg5 Tortonian Patriarca, Asland Right side in the N wall ashlars.

Conglomeratic biomicrite / Mg6 Tortonian Patriarca, Naranjo Bottom side in the N wall near the door.

Compact oomicrite /MgP1 Cámbrian Ermitas- Trassierra Paving stone looses (floor- door incide)

Compact ooosparite /MgP2 Cámbrian Ermitas-Trassierra Paving stone loose (floor- door inside

Compact pelsmicrite with gray veins /MgP3 Cámbrian Trassierra-Ermitas Central altar and inner

lateral zones

Noduless violaceous biopelsmicrite / MgP4 Cámbrian Ermitas-Trassierra Socle of the altar

Noduless red biomicrite / MgP5 Malm Sierra de Cabra Holy water stoup inside

Pink granite / MgP6 Hercínian Los Arenales Loose fragments.

Gray granite /MgP7 Hercínian Zona de Pedroches Loose fragments..

Biomicrite/ Posadas-10 Tórtonian Posadas Restoration material

Biosparite/ Posadas-11 Tórtonian Posadas Restoration material

12

TABLE 2. MI�ERALOGY (DRX)(%) A�D COLOR.OF CALCAREOUS MATERIALS

Quartz Calcite Feldspar Mica Other Rock fragm

Ateration//color

Mg1. 6 80-85 2 1 1 3 2.5Y7/5 ; 2.5Y7.5/6 Mg2. 5-7 75 3-5 1 2 8-10 2.5Y8/6

Mg3. 6-9 >65 4-7 3 5 10-12 Small//2 Y 6/4- 2.5Y7/44 High//3Y 8/4

Mg4 4 75-80 3 1 2 10 Small//2 Y 7/3,5->4

Mg5 6 73-78 1 1 10-15* Small//2,5 Y 8/3 --> 9/2 High//2,5 Y 8/4 --> 2 Y 7/6

Mg6 40 40-50 10 5-10 5-10 20-30 Moderate//10YR7/6 MgP1 2 90 1 1 3* 1 Small//2.5Y4/2 MgP2 4 85 1 1 >5* 1 Small//2.5Y4/2 MgP3 <2 90- 95 - 2-3- <2* 2 (s) 5RP5/1 (h) 5R5/2.5 MgP4 8 80-85 2 2 10* (s) 7.5R7/1 (h)7.5R5.5/2.5

MgP5 94 6** Small//2.5YR --> 10R5.5/6 (10R5/4)

MgP6 28 - 55(+) 10(b+m) >7 ---- MgP7 25 - >50(+) 15(b+m) >5 ----- Pos-10 3-5 65-70 3-4 2-4 2-5 12-16 No alteration// 10YR8/4 Pos-11 2-3 70-75 2-3 2-3 2-3 10-12 No alteration// 10YR8/4

(*) limestone and Fe oxides//(+) addition of orthoclase,microcline,plagioclase//(**) only clay//(b+m) biotita and some muscovite.

TABLE 3.- PETROSTRUCTURAL ANALYSIS OF ASHLARS (%)

Sample Calcareous fraction

Detritical fraction

Clayey fraction

Matriz/ fossils relation

Porosity (%)

Mg-1 80 12 1 4/5 5-7 Mg-2 75 13 2 4/5 10 Mg-3 60 22 4 3/5 8-1015 Mg-4 70 15 2 4/5 10-15 Mg.5 75 12 2 4/5 6-9 Mg-6 60 15-20 2-3 4/3 10-15 Pos-10 66 19 2 4/5 10-15 Pos-11 73 15 1 4/5 8-10

TABLE 4.- CHARACTERISTICS OF QUARRY MATERIAL (average)

Quarry Fossils % Porosity % Compressive strength (MPa) Speeds (km/s) Posadas Albaida Naranjo Asland

25 40-50 30-40 20-30

8-13 <15 13 10-15

105 – 130 120 - 140 70 - 110 70 - 140

2,9 – 3,2 2,9 – 3,4 2,8 – 3,2 2,9 – 3,4

13