Rafael Benzion Partap
The Pitch Lake, in La Brea, is reached by a scenic drive through southwest Trinidad.
There are other tar pits around the world, but ours is the only one that humans can walk on.
The La Brea Pitch Lake is 75 metres deep and covers 40 hectares of land.
On July 15, I had an amazing experience at the Pitch Lake. My tour guide, Daniel, shared a lot of knowledge and I also went to the Pitch Lake Museum, which had a lot of information and artefacts.
As a ten-year-old national of Trinidad and Tobago, I was proud and excited to see and touch the eighth Wonder of the World.
This article is a collation of my personal research information from my tour guide and information from the Pitch Lake Museum.
I am excited to share the knowledge I have gained there.
What is pitch?
Pitch is a mixture composed of soluble bitumen, bitumen absorbed by minerals, matter-free water (and gas), water of hydration of minerals and mineral matter (ash).
The free natural gas can be ignited, as shown in Figure 1.
Pitch is actually a form of hydrocarbon and as such has economic value.
The roads of TT and many roads around the world are made from our wonder.
The First People
The first people who roamed the Pitch Lake were the Amerindians. They used the pitch lake as part of their culture and called the blue-black substance “Piche.”
During my research, I encountered two legends about what the Amerindians thought the pitch was made from.
Legend one – The Pitch Lake was home to two Amerindian tribes; they had a war to claim the land and the winning tribe decided to celebrate their victory. Food was wiped out due to the war and needed time to replenish so they feasted on the hummingbirds and adorned their bodies, forgetting the fact that the hummingbirds were sacred creatures. As punishment for their evil deed, the Hummingbird gods opened a gigantic hole that swallowed everything, including the people.
Legend two – The Pitch Lake was home to two tribes; the daughter of a cacique of one of the tribes fell in love with a man in the other tribe. The cacique decided to kill the young man’s tribe and as punishment, the winged god opened a hole in the ground which swallowed both tribes. Villagers still believe these legends, as Amerindian artefacts have been found in the Pitch Lake and some are in the Pitch Lake Museum.
Geology of the Pitch Lake
The texture of the Pitch Lake is quite peculiar. If you observe the pitch closely, you can see it has small holes in it, this is because of methane gas which is escaping. Some areas of the Pitch Lake would make you think you are sinking into it and some places make you think you are on top of solid rock.
The pitch expands when it is hot and contracts when it is cold.
An example of this is a telephone communication house which was built on top of the hill during World War II, but is now almost below the hill because of the sinking of the pitch.
The strength of the pitch is relatively weak; I know this because as I walked into the Pitch Lake, I saw some of the trees had toppled over as the pitch itself was not strong enough to hold the roots. There is also evidence in the bumpy roads you will encounter as you get nearer and nearer to the Pitch Lake.
As I was walking on the Pitch Lake, it felt like I was walking on the tectonic plates of the world.
Daniel showed me some yellow solids which are indications of sulphur deposits. I also saw iron oxidation via the small deposits of red substances on the surface of the pitch.
Pitch is a form of hydrocarbon, and to form, hydrocarbon needs a source rock. Source rock is usually a layer of fossils.
The Pitch Lake formation started in the Cretaceous Epoch (84-72 million years ago) when the source rock was deposited. This source rock must then be buried, then "cooked" to expel the hydrocarbon.
In the Miocene period (23-five million years ago), tectonic plates collided with each other, and created a fault. That fault leaked out a gigantic amount of this cooked hydrocarbon as asphalt, something made from bacteria-infested oil.
Flora and fauna
The La Brea Pitch Lake hosts many kinds of animals and plants. There are various trees such as the stinking toe or locust tree and there are various flowers such as the lotus flower and the lily of night. Fauna of the Pitch Lake include amphibians, fish such as the Trinidad guppy, and frogs lurking in the grass, while birds search for food in the trees. One such bird I saw was the yellow-hooded blackbird. There are also invertebrates such as dragonflies, mosquitoes and mammals such as the river otter.
There are also records of many prehistoric creatures, such as the giant sloth (
Glossotherium Harlani) and the mastodon. These creatures died because they were walking on the Pitch Lake, and accidentally stumbled upon the liquid parts and sank into it, later to be found as skeletons while mining pitch.
The geology of the Pitch Lake affects the flora and fauna due to the fertile soil, which is why La Brea is also known as the Mango Village, since the fertile soil is believed to be the reason the villagers can grow mango trees which produce year-round.
The Pitch Lake is used for various economic values such as kerosene or pitch oil.
In the mid-19th century, a lack of oil for lamps made from whale blubber caused the oil to be very expensive as the sperm whale became scarce due to over-hunting.
Fortunately, a man known as Abraham Gesner from Canada invented kerosene as a much better fuel for lamps than sperm-whale blubber. His first kerosene was made from La Brea Pitch, which he collected from his friend Thomas Cochrane, tenth Earl of Lord Dundonald, then the licensee to collect or mine pitch from La Brea.
Asphalt is mined and transported using a train. When the asphalt is collected, it is dumped onto the ground to be used locally or exported. The asphalt is also sold to build roads in other countries.
Another form of income from the Pitch Lake is as a tourist attraction for locals and foreigners alike who come every year to view and bathe in it.
I truly think that this wonder should be protected, since this lake is the only source of natural asphalt used in making our roads.
The Pitch Lake has contracted due to constant extraction. I believe this extraction must be managed so that it can be left here for centuries to come.
This lake must remain a wonder of the world and a habitat for all its flora and fauna.
I hope you enjoyed this article. I also hope you learned a bit from the knowledge which I have gained and it convinces people to protect this beautiful area, our wonder, our La Brea Pitch Lake.
Rafael Benzion Partap is a ten-year-old student of Mango House Primary School. He is an aspiring scientist
This article was submitted by the Geological Society of TT.