The Stony Resilience of the Singapore Cenotaph EarthCache
The Stony Resilience of the Singapore Cenotaph
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This Earthcache brings together history and geology in the heart of Singapore’s historic Civic District. Here, visitors will learn about granite, an igneous rock widely used in the construction industry due to its beautiful grainy texture coupled with its strength and resilience, found aptly at a monument which memorialises resilience in difficult times: the Singapore Cenotaph.
The Cenotaph
The Cenotaph is one of Singapore’s first war memorials, and it was initially dedicated to the 124 British residents of Singapore who served and were killed in action in World War I. Designed based on the Cenotaph in Whitehall, London, the foundation stone was laid on the 15th of November, 1920, by Sir Lawrence Nunns Guillemard, then Governor of the Straits Settlement. The monument was completed in 1922, and unveiled on the 31st of March that year by the then Prince of Wales (who was later crowned as King Edward VIII). In 1950, an additional inscription was added to the other side of the memorial to honour the soldiers who lost their lives during World War II and during the Japanese Occupation of Singapore.
The monument is built from granite and stands at a height of 20 metres. The WWI side of the memorial bears the inscription “Our Glorious Dead” along with the years 1914 – 1918, both on the front and on the steps. The reverse side, facing the Esplanade bears the words “They Died so That We May Live”, and the years 1939 – 1945 on the front and on the steps.
The monument is now located in the historic Esplanade Park, which once boasted a sea view before the extensive land reclamation took place. Also in this park are the Tan Kim Seng Fountain, the Lim Bo Seng memorial and the Indian Army Monument site. Across the road from the Cenotaph are the Town Green (Padang) and the City Hall and Supreme Court buildings.
Your task in this Earthcache is to examine the rocks that make up the Cenotaph closely and answer the questions at the end of this listing.
An Introduction to Granite
Granite takes its name from the Latin granum, which means “grainy”, referring to its distinctive large grainy texture, from which it derives its beauty from. Granite is widely used in tiling and flooring because of the wide variety of colours it occurs in, the ease of smoothening and polishing it without cracking, its strength and hardness and its ability of parts of it to shimmer and shine when light strikes on its surface. Granite has also been used as foundational building materials for millennia, taking as far back as some of the earliest civilisations. Entire Egyptian tombs and obelisks have been carved out of granite and their existence today testifies to the strength of granite. Granite continues to be used as prime building material in recent times, and the Cenotaph is an example of one such monument.
Geologically speaking, granite is described as an igneous rock, a rock that is formed from the cooling of magma or lava that originates from the Earth’s mantle. Within the igneous rock family, it is considered to be a plutonic (or intrinsic), felsic, igneous rock. I have covered the basics of classifying igneous rocks in my other Earthcache in Singapore, Gombak Norite Formation (http://coord.info/GC41060), and you may want to read the description on that page for a more in-depth explanation on these terms. In this page, I will quickly cover what plutonic and felsic means.
Plutonic (from the Latin Pluto, which refers to the mythical Underworld) are rocks that are formed by the cooling of magma deep in the Earth’s crust. The slow cooling in the relatively high temperatures deep in the crust causes the minerals to form large crystals, like that which is observed in granite.
Felsic refers to the elemental composition of the rock. Felsic is formed from the words feldspar and silicon, meaning that the rock contains a large percentage of feldspar and silicon minerals.
Composition of Granite
Being a felsic rock, it should be clear that the main components of granite are feldspar and quartz, both of which are silicon based minerals. Granite also contains smaller amounts of other minerals which are referred to as accessory minerals. We shall now consider these components in turn.
Quartz: One of the two main components of granite is quartz, a crystallised form of silicon dioxide, SiO2, and one of two most abundant minerals in the Earth’s crust. In granite, quartz will present itself as cloudy to translucent crystals nestled between the more opaque components of the rock, giving the rock part of its beautiful shine.
Feldspar: Feldspar (from German feld meaning “field” and spar meaning “rock”, referring to how easily this mineral is found) is the Earth’s most common mineral, making up a full 60% of the Earth’s crust. Chemically, feldspar is defined as a mineral formed when silicon and oxygen combines with the Group 1 – 3 metals, that is, potassium, calcium, sodium and aluminium. By and large, feldpsars can be further divided into alkali feldspars (or K-spars, in shorthand) and plagioclase feldspars, both of which play extremely important roles in giving granite its distinctive texture.
The K-spars are the flamboyant components of granite, as they are responsible for giving granite its varied colours. Granites take on colours ranging from red to grey to blue to pink to yellow, and this range of colours are single-handedly supplied by the K-spars. Visually, they present themselves as the highly-coloured, opaque patches in the granite and their presence gives granite its aesthetic value.
The plagioclase feldspars, named from the Greek plagio- meaning oblique and -clase meaning cleavage, referring to the minerals’ fine parallel striations, are the other sort of feldspars occurring in granite. They present themselves visually as the milky to cream white components of the granite structure. In polished granite, these minerals also contribute to the shine of the rock as they flash a brilliant white at very particular angles of light.
Accessory minerals: Granite is often graced by the presence of dark coloured minerals that add the variety to its already nicely patterned surface. These dark coloured minerals are usually from the hornblende family of minerals or biotite. These minerals present themselves as sprinkles across the lighter surface of granite, looking like grains of pepper against a white background.
Together, the components of granite form the distinctive grainy pattern of granite that is highly prized by builders and decorators worldwide. The diagram below shows the surface texture of a typical granite rock. Try to identify the different components of the rock as practice before heading out to the field.
Granite in Singapore
Granite plays an extremely important role in the geology of Singapore. The largest geological formation in Singapore in the Bukit Timah Granite and this formation is the bedrock for most of the main island and one of its largest islands, Pulau Ubin. The central outcrop, which is located primarily within the Nature Reserves (which of course, includes its namesake Bukit Timah Nature Reserve) measures 8 kilometres across by 7 kilometres from north to south. It is responsible for some of the highest (above sea level) parts in Singapore, like Bukit Timah and Bukit Batok. Granite was extensive quarried form these sites and Pulau Ubin from as early as the 19th century up to the late 20th century, leaving picturesque water-filled quarries once the mining operations ceased. The map below shows the location of the Bukit Timah granite outcrops in Singapore.
In The Biophysical Environment of Singapore (1991), G. S. P. Thomas described the Bukit Timah granite as follows:
“The dominant, granitic component is grey and medium grained and consists of cream to pale yellow feldspar, smoky quartz and smaller proportions of biotite and dark hornblende”
According to historical records, the granite of Singapore was used extensively in the building projects of the colonial era, most famously, in the construction of the offshore lighthouses like that on Pedra Branca, and the Johor-Singapore causeway. Subsequently, locally quarried granite was also used in the construction of some of the earliest HDB blocks and roads, but most of the quarry works ceased in the late 20th century when construction materials were imported from neighbouring countries instead.
The Tasks
Now that you have learnt about granite, it’s time to put that knowledge to the test:
- Examine the rock that the Cenotaph is made out of. Describe the rock in terms of texture and colour. The rock is NOT of a single colour! Try to describe the all the colours as best you can.
- Determine, based on the description of Bukit Timah Granite provided, whether the granite you see here were locally quarried or imported from elsewhere. Please cite reasons for your answer, making reference to the description provided and your observations.
- Optional: Photographs of the area of you or your GPS in the area will be appreciated. Try not to give too much information for the previous tasks in the photos.
Final Notes
Please e-mail the answers to the questions above to me. Photologs as the sole proof of visit to the site will not be entertained. You must make some attempt at answering the questions. Do not worry about being incorrect, as long as you have made your best effort at answering the questions, your log will be accepted.
The cache is accessible from Esplanade MRT (CC3) or City Hall MRT (NS25/EW13) via Citylink Mall. You may also choose to walk at street level, which will provide you with plenty more sights of the Civic District.
This is a historical marker dedicated to the dark period of history. Please be mindful of its past and behave respectfully in the vicinity of the memorial. Do not scratch the stones making up the memorial in any way, as it is not required for the tasks.
References
Chew, Z. M. (2011). Cenotaph. Retrieved May 10, 2013, from Singapore Infopedia: http://infopedia.nl.sg/articles/SIP_10_2004-12-17.html
Chia, L. S., Rahman, A., & Singapore, G. T. (1991). The Biophysical Environment of Singapore. Singapore: NUS Press.
Than, N. M. (n.d.). Notes on Singapore Geology. Retrieved Novemeber 8, 2012, from http://www.scribd.com/doc/94533947/Notes-on-Singapore-Geology-Hand-Out-PDF
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