Posted on 08/04/2015 8:00:31 AM PDT by JimSEA
Would it surprise you to learn that some of the deep basement rocks underlying Florida were once part of Africa? Florida’s geologic history has been traced back to the early Paleozoic Era, 540 – 251 million years ago (mya), largely through the study of rock samples obtained from oil test wells drilled in northern Florida and nearby Georgia and Alabama. In Florida, the top of the Paleozoic strata ranges from approximately 3,000 to 8,000 feet below land surface and they consist of igneous and metamorphic rocks overlain by sandstones and shales.
The sedimentary basement strata were found to contain macrofossils such as trilobites, brachiopods, graptolites, mollusks and plant remains, as well as microfossils including conodonts, ostracods and palynomorphs (tiny organic-walled fossils from a variety of different organisms). Anomalies in the assemblages of fauna soon became apparent to early researchers. A fossil trilobite species discovered in a Madison County oil test well had previously only been known from Eastern Europe and North Africa. Like the trilobite, fossil faunas in other wells did not match those expected from North America, but rather more closely resembled fossils from Africa, South America and Europe. The palynomorph assemblages eventually became instrumental in correlating Florida basement rocks with those of Africa. Subsequent gravity, paleomagnetic and geochemical (isotope) studies helped confirm that Florida’s Paleozoic basement rocks comprise an exotic terrain most likely associated with northwestern Africa. In fact, recent study suggests that the exotic terrain may also include components of South America.
How did the African rocks get here? The oil well samples chronical the response in Florida's rock record to global plate tectonic movement when the ancient landmasses of Laurentia and Gondwana converged to create the supercontinent of Pangea, about 300 mya. Gondwana was comprised, in part, of the joined land masses of Africa and South America. Laurentia was comprised of the future North America as well as other continental fragments. During this tectonic convergence a small block of crust from northwestern Africa, which has been named the Suwannee Terrain, moved with Gondwana and collided with Laurentia in a region that would one day become the southeastern portion of the North American continent. Later during the Jurassic Period, approximately 200 mya, the resulting supercontinent Pangea began to break apart, ultimately resulting in the formation of the world’s continents as we know them today. In the process, the Suwannee Terrain remained permanently sutured to North America and formed the foundation for the present day Florida Platform. Our African basement rock is today covered by thick sequences of younger strata, and no expression of it or its suture to North America is evident at the surface.
The breakup of supercontinents makes for interesting geological connections. The most famous are the Africa/South America connection which gave Alfred Wegener the idea of continental drift and the North American/Scotland connection which was eventually to figure in James Hatten's discontinuity which was among the geologic clues giving him the idea of deep time.
Same is true for many regions along the east coast, including New York City, which was once attached to what would later become Morocco.
The northern Appalachians are largely made up of the same rocks under Ireland.
Florida geology isn’t really African, African geology is North/South American.
North and South America moved away from Africa just like modern man walked out of Africa and left the stupid behind.
A big ocean like that must have produced some monster hurricanes.
Scotland for sure. The Catskills are basically a stack of erosional remains from a once lofty mountain range raised during one of the 3 major collision events leading to the formation of the super-continent Pangea. Scotland has an identical set of sedimentary rock layers on their side of the Atlantic. Same composition and age.
Was about to say the same.
Funny how we have parts of African but the article does not state how Africa has some of the good ole USA
North and South America are believed to have collided during the formation of a much older super-continent known as “Rhodina”, roughly 1 billion years ago, as opposed to 450-250 mya, the duration of the Pangea forming event.
That might explain all the moonshiners. :)
I love the ancient geology. In Michigan’s upper peninsula are the Porcupine mountains that were once much taller. The ancient rift valley that makes up the deepest part of Lake Superior. I live atop the Michigan basin that is surrounded by the Niagara escarpment which is visible from near Green Bay, along the southern upper peninsula shore down separating Lake Huron from Georgian bay before going underground till it shows itself where the Niagara fall fall over it.
Yes, it is truly fascinating once you start reading up and learning about it. You can also watch great TV series on the subject at YouTube, such as How The Earth Was Made...
https://www.youtube.com/results?lclk=long&search_query=how+the+earth+was+made&filters=long
The Matterhorn also contains rocks from the African continent.
Was ancient Antarctica ever warm enough, or wet enough, to support plant life and land-based animals?
Interesting to think about fossils - or even organic remains - buried under miles of compacted ice and snow.
Interesting, because further east, where the folding is the result of the Pangea formation process, the folds are perpendicular to the glacial grooves and scratches. I guess the folding in that region (Isle Royale region) occurred during some older tectonic collision event(s).
Also...
Antarctic Fossils Paint a Picture of a Much Warmer Continent
Insects, ferns flourished, then flickered out millions of years ago as the tundra retreated:
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