January 21, 2013
Monday Geology Picture(s): Coral Boulders on the Beach in Barbados
Posted by Evelyn Mervine
Back in June 2009 I visited the lovely tropical island of Barbados for a week for a paleoclimate field trip as part of one of my graduate school courses. I never blogged about this trip (I only started Georneys in late 2010), so I thought that I would share some pictures from this Barbados trip over the next few weeks. Hope you enjoy!
From the Woods Hole Oceanographic Institution website, here is an explanation of why Barbados is such an important and interesting location for the study of paleoclimate:
The study tour this year [2009] will to the Caribbean island of Barbados, a classic field area for Quaternary sea level study. Barbados is an actively rising island at the crest of the Barbados Ridge, an accretionary prism of the Lesser Antilles forearc. Strongly folded Eocene sedimentary rocks are capped by a sequence of Quaternary coral terraces that grew during sea level changes over the last 700,000 years or so.
A large fraction of what is known today about the rates and magnitudes of Quaternary sea level change comes from studies of the uplifted reef tracts of Barbados and cores recovered from the drowned deglacial coral reefs offshore. The first strong support for the Milankovitch theory of climate change came from the dating of the Last Interglacial terrace; locally know as First High Cliff. This date was key to establishing a timescale for the oxygen isotope record that remains our primary way of establising a stratigraphy and a timescale for all ocean cores.
This week, I am sharing some pictures of some coral boulders along a Barbadian beach. I also shared some pictures of a similar coral boulder from the same beach back in 2011. Eroded by waves, the coral boulders weather into some fantastical, beautiful shapes.
Barbados has a very interesting geological history and dramatically different coastlines in such a small space. The East Coast (especially around Bathsheba) has many of these formations. Heading north you see the limestone cliffs and relatively few beaches. Yet to the South and West are the white beaches and no such formations.
Two other very interesting geological features are Chalky Mount on the East coast and Harrisons Cave. Harrisons Cave has recently been refurbished into a world class tourist facility but thankfully you can take more guided technical tours if wished.
I photographed fossils on what seemed like either lava or coral rock just south of the airport on a ridge about 50 to 75 feet high and speculated as to their age.
I know nothing of geology but wondered if you could help. The terminology is baffling, but I gather that the seas were higher and close to that height 14,500 years ago and were at today’s level 9000 years ago. Can I assume that to be
the age of the fossils since the rock surrounding it does not show that much
erosion.
Great if you could help this is fascinating stuff
Norm CHEVRIER