The Armoured stones of Barbados EarthCache
The Armoured stones of Barbados
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Difficulty:
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Terrain:
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Size: 
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BEGINNINGS
Unlike other Caribbean Islands Barbados is not volcanic,but composed of deep ocean sediments overlaid by coral limestone .This relatively young coral limestone is porous,fractured by uplift and is easily eroded by water in a process called Karsification.
60-1 million years ago
60 million years ago folded deep marine sediment was laid down
20 million years ago oceanic clay covers the dome of sediment
10 million years ago uplift began with the Atlantic plate sliding under the Caribbean plate .The rocks that can be seen today in the Scotland area are about to emerge .
Less than 1 million years ago
Coral reefs start to form in shallow water where sunlight penetrates (photic zone) and gradually hardens to form limestone (sedimentary) also called coral rock ,uplift continues in stages .
120,000 years ago
Up lift continues-the oldest coral reefs are now high and dry making the island bigger .Reefs continue to grow on the Sth and west coasts.Rain falls on the exposed coral limestone initiating the gullies and caves .
The last 120,000 years
Water dissolves the coral rock
Calcite deposits in fantastic shapes form inside the caves
Coral reefs continue to grow on the sth and west coasts ,continued periodic uplift combined with sea level changes results in a series of coral terraces.
The Scotland District in St. Andrew is home to the oldest rocks on the island and consists of thick-bedded sandstones, coarse grits, bituminous sandstones and shales, dark-grey and mottled clays with nodules of ironstone. Bent into numerous flexures and curves, these beds are broken by quite a few faults of greater or less magnitude that make it quite an arduous task to accurately estimate their true thickness. Apparently, there are approximately 550 to 600 feet of them exposed on the island. However, due to the fact that the base is hidden it is not possible to precisely determine the thickness of them all. Except for the highlands, the deformed Tertiary strata are overlain by a succession of Pleistocene, tectonically little affected, reef terraces that topographically downstep toward the northern, eastern and southern coastlines almost concentrically becoming younger toward the coastline. The Upper Reef Terrace is older than 600 000 years whereas the youngest reef terrace submerged off the Lower Reef Terrace is of Holocene-Recent age. The terraces formed in response to tectonic uplift and eustatic sea-level fluctuations that resulted in several episodes of relative sea-level drop.
A leisurely stroll from the terminal of about 600 metres will bring you to the end of the Armoured rock wall
Look closely at the difference in the rocks at the end of the wall .They are vastly different and you will see this straight away .
To log this cache you must forward answers to questions below and then all good to log the cache
Q1
.Explain the difference in the last two rocks to those next to them ,texture and formation .
Q2.
Do any of the rocks have marine fossils ,if yes what do you see
Q3.
What type of rock is coral ?Sedimentary or igneous
Congratulations to swelgus on a FTF
Additional Hints
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