A little shark tooth, partial of a mantis shrimp and little sea organisms exhibit that as a Andes rose, a Western Amazon sank twice, any time for reduction than a million years. Water from a Caribbean flooded a segment from Venezuela to northwestern Brazil. These new commentary by Smithsonian scientists and colleagues, published this week in Science Advances, fuel an ongoing debate per a geologic story of a region.
“Pollen annals from oil wells in eastern Colombia and outcrops in northwestern Brazil clearly show two ephemeral events in that sea H2O from a Caribbean flooded what is now a northwest partial of a Amazon basin,” pronounced Carlos Jaramillo, staff scientist during a Smithsonian Tropical Research Institute and lead author of a study.
“Geologists remonstrate about a origins of a sediments in this area, though we yield transparent justification that they are of sea origin, and that a flooding events were sincerely brief,” Jaramillo said. His group antiquated a dual flooding events to between 17 to18 million years ago and between 16 to 12 million years ago.
Several argumentative interpretations of a story of a segment embody a existence of a large, shoal sea covering a Amazon for millions of years, a freshwater megalake, changeable lowland rivers spasmodic flooded by seawater, visit seawater incusions, and a permanent “para-marine metalake,” that has no complicated analog.
Jaramillo fabricated a different group from a Smithsonian and a University of Illinois during Urbana-Champaign; Corporacion Geologica Ares; a University of Birmingham; a University of Ghent; a Universidad del Norte, Baranquilla, Colombia; a University of Alberta, Edmonton; a University of Zurich; Ecopetrol, S.A.; Hocol, S.A.; a Royal Netherlands Institute for Sea Research during Utrecht University; a University of Texas of a Permian Basin; and a Naturalis Biodiversity Center.
Together, they examined justification including some-more than 50,000 particular pollen grains representing some-more than 900 pollen forms from oil drilling cores from a Saltarin segment of Colombia and found dual graphic layers of sea pollen distant by layers of non-marine pollen types. They also found several fossils of sea organisms in a reduce layer: a shark tooth and a mantis shrimp.
“It’s critical to know changes opposite a immeasurable Amazonian landscape that had a surpassing effect, both on a expansion and placement of life there and on a complicated and ancient climates of a continent,” Jaramillo said.
Source: NSF, Smithsonian Tropical Research Institute
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