After a very pleasant
breakfast at Paradise Beach hotel, we took a short drive to the adjacent beach,
Indian Bay. There, we saw Bequia in the distance, with Dyke Island and Grand
Dove Island in the forefront. As we looked longingly at the locals swimming in
the ocean, Ed gave us a very interesting overview of the geology of St.
Vincent. St. Vincent is made up of primarily basaltic and basaltic andesite
rocks, and the island has the most primitive, high magnesium composition in the
Lesser Antilles.
We rolled out in our van with our
phenomenal driver Rolland, and headed to Johnson’s Point. Here we saw a
stunning cross-sectional view of the volcanic debris that has been deposited by
aerial deposition. There was visible draping of the Yellow Tuff formation over
the Grande Bonhomme Formation, as well as a obvious contact between the two
features. The Yellow Tuff appeared in several layers, suggesting that there
were repeated eruption-deposition cycles. In one of the lower Yellow Tuff
layers that appeared in the outcrop, we observed that there were dark,
spherical inclusions of glass within the tuff. Ed later explained that these
were known as Pele’s Tears, named after the Hawaiian fire goddess of volcanoes.
We got back into the car and drove up to one of
the highest points on the southern end of the island, the Belmont Look-out
Point. This overlooked the Mesopotamia valley which was part of an ancient
volcanic crater. The volcanic origin of the valley provided optimal conditions
for growth of the Breadfruit, a traditional St. Vincent dish. From the
viewpoint we were able to take very nice photos, and also discuss the potential
origins of the valley itself. There were suggestions of glacial origins, as
well as simply erosional conditions.
After saying farewell to the cute dogs at the
top of Belmont Hill, we drove down to St. Vincent’s airport, Argyle
International Airport. Here we looked across the runway at a large outcrop that
showed a cross-sectional view of the Yellow Tuff and Grande Bonhomme formations.
Using binoculars, we were able to distinguish a contact between the two, as
well as other features such as dykes and faults.
Then LUNCH TIME!
Rolland drove us to a local pub where we enjoyed St. Vincent cuisine, including
the breadfruit! We had an incredible view of the ocean, played some pool, and
also ogled a baby goat.
Following the amazing
food, we drove back to the north side of the airport, where we saw an
incredible outcrop of the Yellow Tuff overlaying the Grande Bonhomme formation.
For the first time, we saw phenocrysts of plagioclase and amphibole in the rock
suggesting the rock had more time to cool in this region. These were lahar
deposits which formed due to intense rainfall on the side of a volcano that
brought loose rocks down and deposited them. We also saw an incredible drape
structure on the N side of the road, where the Yellow Tuff very obviously
overlaid the Bonhomme formation.
Our last stop was to the Black Point Tunnel
that had been dug out by slaves in 1815. The tunnel was created so sugar came
could be moved more effectively to the coast in order to be traded overseas. At
the other end of the tunnel, we saw that it had been cut into an impressive
rock face overlooking crashing waves. The rhythmic cycling of the volcanic eruption
and depositional periods were evident in the layering of rock units. We were
also treated to the discovery of olivine inclusions in the fine grained, more
well-laminated rocks.
After a jubilant game of yellow car (won by
Marc!), we arrived back at the hotel just in time for a quick swim before the
sunset. We snorkeled, swam, and played frisbee, all with the beautiful backdrop
of the setting sun in Villa Bay.
- Keenan & Joy xoxo
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