Usage of Local Raw Material in the Construction of Candi Pengkalan Bujang (Site 18), Bujang Valley, Kedah

The aim of this study is to determine whether the ancient bricks from Candi Pengkalan Bujang (Site 18) are made from local raw material or not. Candi Pengkalan Bujang (Site 18) which is located in the cemetery area of Pengkalan Bujang Mosque, Kedah has unearthed various interesting artefacts; among them are the Sung Dynasty celadon findings and also kala carvings made from granite. The main construction materials used to build the temple consisted of laterite, slates, bricks and also granite. Laterite and bricks were used to build the lower part (foot) of the temple while granite stones were used as the pillar bases, door sills, stone hem and also kala. The upper part of the temple is believed to have been built using wooden structures and the roof used palm leaves. Natural rock resources used to build this temple were local resources based on the distribution of the rocks that are aplenty in Bujang Valley. Scientific analysis on the bricks also showed that local raw material was used to produce these bricks. Scientific analysis using the X-ray fluorescence technique and X-ray diffraction technique can determine the chemical composition of the bricks, among others the mineral content of the bricks as well as the major element and trace element content. The analysis showed that open burning technique was used in the process of producing the bricks while the major and trace element content analysis showed the clay used was obtained from the Muda River and Bujang River basin. This usage of local raw material also demonstrated the local wisdom in temple construction technology and also technique in producing bricks that had existed since the 5 th century AD.


INTRODUCTION
Pengkalan Bujang Temple (Site 18) is located in the cemetery area of Pengkalan Bujang Mosque, Kedah.The areas around the fence of the mosque site was found to contain many piles of temple construction materials made from laterite, granite and bricks which were the main materials used to build the lower part or foot of this temple.The findings of the foundation of the pillar bases showed that this temple used wooden pillars.Quaritch Wales (1940) had carried out his own excavation at this site and in his report he mentioned about the findings of the local villagers of granite stones that resembled lintels and door sills.
This site is located about 40 yards from the river bank of Bujang River and the excavation carried out revealed the construction structure where the lower part of the temple was made of laterite while on top of the laterite, bricks were stacked.Several foundations of Fig. 1: Pengkalan Bujang temple's (site 18) construction structure (Jacq-Hergoualc'h, 1992) pillar bases made from granite were also found (Quaritch Wales, 1940).The lower part of the temple construction was built by stacking three layers of laterite while the next part used bricks (Fig. 1).
The excavation carried out by Quaritch-Wales has unearthed important artefacts that can be linked to the site.Among them are the Chinese ceramics of the Age of the Song Dynasty particularly the Lungchuan celadon that were produced around the 11 th to the 12 th century AD (Fig. 2).Also found were the Chinesemade spoons that were made of material resembling pearls.Apart from that, iron nails as well as bronze materials that are believed to be coins were also found in addition to carnelian stones in the shape of hexagonal bi-cone and crystal stone beads in the shape of spheres (Quaritch Wales, 1940).
A lot of glass fragments in brown, green and amber that are believed to originate from the Middle East were also found at this site.Two fragments of Arab oil lamp were also found.These lamp fragments were reconstructed and the result was that the shape of the lamp can be clearly seen.The glass is a mixture of green with the edge of the lamp coloured black.This Arab lamp has similarities with the findings at Site 11.Based on the architecture of the temple and the artefact findings that are associated with the site, it is believed that this site was built in the 11 th or 12 th century AD (Quaritch Wales, 1940).This site has important functions based on the discoveries of the construction materials that comprised of bricks, laterite, sculpture or pillar bases, a kala, door sills and wedges (Fig. 3 to 5).
Excavation at the Pengkalan Bujang Temple (Site 18) has revealed the construction materials that are comprised of various types of natural rocks and also bricks.The main construction material that was used to build the lower part or foot structure of the temple comprised of laterite and bricks.Other parts comprised of pillar bases, kala, door sills and wedges produced using granite.The usage of pillar bases and wooden structures for the upper part of the temple showed local characteristics in temple construction and rejected the opinion that the temples in Bujang Valley were built by traders (Jacq-Hergoualc'h, 2002;Sullivan, 1958;Wheatley, 1964).
The temple built by the traders from India was also said to have been built by bringing bricks from the areas outside of Bujang Valley.Therefore, material composition analysis of the bricks should certainly be carried out to prove that the raw material used which was clay, was local raw material.Indirectly, this can prove the involvement of the local people in the production of the bricks, in addition to having the knowledge in construction of temples.Cultural acculturation and knowledge transformation of the Malay community of Old Kedah since the 4 th or 5 th century AD had enabled the civilisation at Bujang Valley to develop and prosper with characteristics of Indian civilisation applied and adapted to the local culture.
The excavation carried out by Quaritch-Wales at the end of the 1930s has revealed the construction structure that was made from laterite slabs and also bricks.The lower part (foundation) of the temple structure particularly the foundation was built using laterite while the bricks were stacked on the laterite slabs to build the following temple structure (Quaritch Wales, 1940).Other parts, for example the pillar bases, door sills, wedges and also kala were produced by using granite.The discovery of door sills, wedges and also the kala showed that this temple was one of the important temples in Pengkalan Bujang in the 11 th to the 12 th century AD.The temple's upper structural part was made of wood based on the findings of the pillar bases.The temple's roof was either made of tiles or palm leaves but based on the fact that there were no findings of tiled roof at the site, hence it is more likely that palm fronds were used for the roof.
The structure of the temple's upper part that used wood and palm leave roof, supported by the pillar bases showed the construction characteristics of the local people.The raw materials used in particular the laterite and granite were obtained from the surrounding areas where many of this laterite can be found at the bottom of the Bujang River while a lot of granite can be found at the base of Jerai Mountain and traces of the granite slabs can be seen at Batu Pahat Hill.
The main objective of this research is to determine whether the bricks used for construction of the temple were made from local clay or otherwise.Bricks were the major construction material used to build Site 18 (Candi Pengkalan Bujang) and one of the methods to determine whether the raw material used to produce these bricks was local raw material or otherwise is by determining the chemical composition of the bricks.The research carried out previously on the ancient bricks showed that the bricks were produced by using local raw material and not using raw materials from outside.For example, the research carried out on the bricks that were used to build Sungai Mas Temple (Site 32/34), Bukit Pendiat Temple (Site 17) and Pengkalan Bujang Temple (Site 23) revealed that the raw material used was obtained from the basin of Muda River, Bujang River, Terus River and the areas surrounding the sites (Ramli et al., 2012;Zuliskandar et al., 2011).Analysis on Sungai Mas monochrome glass beads also reveal that local community involved in glass beads industry (Zuliskandar et al., 2009;Ramli et al., 2011).

MATERIALS AND METHODS
This study used the scientific approach in determining whether the bricks in Site 18 used local raw materials or not.A total of 18 fractions of ancient bricks were taken from the site of Pengkalan Bujang (Site 18) and placed into plastic bags and recorded.These samples were taken to the laboratory for sample treatment where each sample was cleaned using water and later dried at a temperature of 120°C for 2 days.These samples were then ground up into very fine powder and once again dried at a temperature of 120°C for 1 day.These samples were then sent for analysis where the two techniques used were the X-ray Fluorescence Technique and the X-ray Diffraction Technique.The X-ray Fluorescence Technique was used to determine the major element content while the X-ray Diffraction Technique was used to determine the mineral content in the brick samples.The data obtained were later compared with the data analysis of the clay around Bujang Valley that was carried out previously.

RESULTS AND DISCUSSION
Material composition analysis of the ancient bricks of Pengkalan Bujang Temple (Site 18) was performed to determine the mineral content of the bricks and the major element and trace element content.Material composition of the bricks will be able to determine whether the raw material used was local clay or otherwise.Hence, the analysis can support the hypothesis that the temples at Bujang Valley were built by the local people using sources of local raw material.The mineral content contained in the ancient brick samples of Pengkalan Bujang Temple (Site 18) showed the presence of minerals such as quartz, muscovite, microcline, kaolinite and chlorite (Table 1).Kaolinite mineral that was present in the TM (ii) and TM (iv) samples showed that there are samples that were baked at temperatures less that 550°C.This is because of the way the bricks were arranged when carrying out the baking of the bricks where there were bricks that did not have direct contact with the temperature.Clearly, open firing technique was used to produce the bricks at this site, similar to the technique used at other sites.The mineral content of chlorite was present in the TM (viii) and TM (v) samples and this type of mineral is in the clay of Bujang River basin.The pattern of X-ray diffraction can be referred to in Fig. 6 and 7.
Fig. 6: XRD diffraction pattern of bricks from Pengkalan Bujang temple (site 18) q: Quartz; m: Muscovite; mc: Microcline Major element content in the ancient brick samples of Pengkalan Bujang (Site 18) can be referred to in detail in Table 2.The analysis showed that the brick samples contained dry weigh percentage of silica element of between 60.12 to 79.82%.Percentage of dry weight for the titanium element was between 0.53 to 0.77%.The iron element contained dry weigh percentage of between 3.06 to 4.59%.Dry weigh percentage for aluminium element was between 12.52 to 25.30%.Manganese element had dry weight 2 20 40 60 mc q,mc q m c q m q m k k c q,m m q mc q,mc q q q q q q q q q q,mc m q k k q q q q q q q q q mc q,mc q,m q,m q,m q,m q,m q,m q,m q,m q,m ,m mc q,mc q q q q q q q q q mc q,mc m q,mc TM18 TM17 TM16 TM15 TM14 TM13 TM12 TM11 TM10 mc q,mc m q q q q q q q q q mc q,mc q,m q q q q q q q q 2θ Intensity (Arbitrary Units)  ------------------------------------------------------------------------------------------------------------------------------------------------------------   The silica and aluminium content showed that the bricks have high silica content compared to clay.The dry weight percentage graph for the elements of SiO 2 and Al 2 O 3 (Fig. 8) as well as the dry weight percentage graph of MgO and TiO 2 elements (Fig. 9) for the brick samples of Pengkalan Bujang Temple (Site 18) and clay of Bujang Valley were plotted to see the result of the comparison between the brick and clay samples based on their major elements.Based on the graphs, it was found that the major element composition of the bricks samples of Site 18 was found to be the same as the major composition of clay in Bujang Valley.Figure 9 also shows that most of the raw material used to produce the bricks at this site was obtained in the areas around the Muda River basin.

CONCLUSION
Based on the survey at the site, it clearly shows that the main construction material at the Pengkalan Bujang Temple (Site 18) site used construction materials from natural rocks such as laterite, granite and also bricks.Laterite and bricks were used to build the lower part or foot of the temple and also its foundation while granite was used to produce the pillar bases, door sills and kala.Material composition analysis of the bricks showed that the method used to bake the bricks was the open burning technique while the major element and trace element analysis showed that the raw material used to produce the bricks at this site was obtained from the basin of Muda River and Bujang River.

Fig. 8 :
Fig. 8: Dry weight percentage (%) of SiO 2 and Al 2 O 3 elements for the brick samples of Pengkalan Bujang temple (site 18) and clay of Bujang valley

Fig. 10 :
Fig. 10: Graph of lead and copper element concentration in the brick samples of Pengkalan Bujang temple (site 18) and clay of Bujang valley

Table 1 :
The mineral content of the ancient bricks of Pengkalan

Table 2 :
Major element content of ancient bricks of Pengkalan Bujang temple (site 18)

Table 3 :
Trace element content of ancient bricks from Pengkalan Bujang temple (site 18)

Table 4 :
Trace element content of ancient bricks from Pengkalan Bujang temple (site 18)