Day 8 (February 28, 2017): Today is chill-y.
Today is chill-y not because of the Caribbean temperature. Instead of a day full of hard-rock geology, on day 8 of our expedition we decided to explore the more cultural side of the Caribbean.
Our first stop was the Museum of Antigua and Barbuda, which used to be the old courthouse of St John’s, the capital of Antigua. There we learned about various aspects of Antigua and Barbuda. We saw fossilized palm trees from the lagoonal deposits of the Central Plain Group and learned about various minerals found around the island. This included baryte, which was an important industrial mineral. We learned about the ecosystem of Antigua and how interconnected the island is. Much of the ecosystem found on land depends on salt ponds and mangroves to filter out sediments. This is to help sustain life on the island and the coral reefs. The white sand found on the many beaches are from the reefs and the fish that live in the area. The reefs also protect the coastline from erosion, particularly on the North, East and South edges of the island.
The first people that settled Antigua were of the Archaic age- who were previously incorrectly named the Siboney people. They lived off the island for about 3000 years and were hunter gatherers. They used flint tools, hunting birds, iguanas, land crabs, and giant sloths. They resided on the island until 300 BC, when they were replaced by the technologically advanced Arawak.
The display of beautifully-polished jadeite axes-that Ed had been raving about for months-caught much attention of our geology group. The formation and preservation of jadeite requires highly constrained conditions; low temperature, high pressure, along with rapid uplift and erosion. The geologic conditions at Antigua and Barbuda was definitely not ideal for jadeite formation, which led us to wonder where the jadeite was sourced. According to much of the existing literature, the jadeite artefacts originated from the Motagua River in Guatemala. It is 2,700 km away from Antigua and Barbuda. This has implications of long distance trade and exchange networks among Pre-Columbian societies!
The island of Antigua, like many islands, was eventually colonized by the British. The British, who pretended like they were still in Britain, had slave trade and sugar mills. Full emancipation of slaves was eventually done in 1834.
After the museum, the group were free to explore the streets of St John’s. We visited the St John’s Anglican Cathedral, which was in the process of being restored, the government house, and various street vendors. After that, the group braved the tourist traps, which were filled with a cruise ship full of people and a gauntlet of taxi drivers. Eventually, we settled down for lunch at a delicious roti place.
As the bus brought us to the Liberta area in the Central Plain Group (lagoonal geologic setting), we found some interesting architecture built with local greenstones. Right by the St. Barnabas Church, there was a greenstone quarry. Here, we observed some outcrops of sheet-textured greenstone. The very fine-grained greenstone is believed to represent a low temperature, low pressure prehnite-pumpellyite facies. The metamorphic event could be sourced from local dacite intrusions, which have been responsible for heating up the country rock to 300–350℃. This could cause fluid circulations and also alter galena to baryte. The sheeted texture of the greenstone might have been caused by volcanic ash settling into shallow lagoonal water. Underlying the greenstone is a more friable orangey lagoonal sand/clay layer.
After visiting St. Barnabas Church, we took a quick break and then visited Nelson’s Dockyard. It served as a base for the British Navy during the great age of sail. Not only is it a historic district, it houses massive yachts and was even hosting a cross Atlantic canoe competition. We then ended our night at a BBQ overlooking the island’s coastline at Shirley’s Heights. We experienced a beautiful sunset with the islands of Montserrat, Redonda, and Guadeloupe in the distance. Truly, it was one of the most breathtaking scenes we have ever witnessed. The atmosphere, food, live bands and steel drums, made it one we won’t be forgetting shortly.
Tomorrow, we will explore the Central Plains Group of Antigua after a visit to the Antigua Masonary Products Ltd. quarry. There may even be a couple of surprises and beach photos…again!
~Written by Jeffrey Chan and Yining Wang
