Gazing up, you might not realize the stories etched into the very stone beneath Mount Butler Quarry. This place echoes with the industry that once shaped Hong Kong itself. Mount Butler Quarry’s story is one of extraction, of geology, and of the human touch upon the landscape.
Mount Butler Quarry is part of Mount Butler. Mount Butler is a 436-meter-high hill on Hong Kong Island.
Let’s delve into the geological story. The granite here isn’t just any rock. It’s Mount Butler Granite. This granite formed as small intrusions on the edges of the Kowloon Granite. It varies from fine to medium-grained. You might even spot some with larger crystals.
Look closely at the quarry’s rock face. See those variations in texture. That’s where the Mount Butler Granite intrudes into other formations. It’s like a geological layer cake, each layer telling a different part of the Earth’s story.
Around Kwun Tong, this granite is altered, a process called greisenization. This creates a sugary texture. Keep an eye out for quartz veins. These veins sometimes hold fluorite, chalcopyrite, and other minerals. Such finds hint at hydrothermal activity long ago.
The granular texture is made of alkali feldspar, albite, and quartz. Greenish-brown biotite can also be seen. Accessory minerals include zircon, apatite, and Fe-oxide.
Pegmatite patches and cavities suggest shallow emplacement and hydrothermal activity.
The Hong Kong government has studied Mount Butler Granite extensively. They found the granite here to be light gray to light pink. It is slightly inequigranular. This means the grain sizes aren’t uniform. The average grain size is 1.5 to 2 mm. Quartz crystals form aggregations up to 5 mm. Biotite stands out clearly. However, it makes up less than 2% of the rock.
Mount Butler is also near a radio station. The Mount Butler H.F. Radio Receiving Station is on Siu Ma Shan. It provides air-to-ground communications for Hong Kong International Airport.
Imagine workers carefully extracting granite blocks. These blocks would then be used in construction projects all over Hong Kong.
Mount Butler Quarry has a rich geological story and a history of industry. The quarry’s stones have literally helped build Hong Kong. Now, the quarry stands as a testament to time, nature, and human endeavor.