Donning full scuba gear, Hemmings stood in 130 feet of water on a peninsula at the intersection of two ancient rivers nearly 100 miles offshore from Tampa. The last time humans could have stood in that spot, mammoth and mastodon roamed the terrain.
“The successful tracking of the St. Marks-Aucilla River and the Suwannee River, between 50 and 150 kilometers respectively, represents what we believe to be the most extensive delineation of submerged prehistoric river systems ever done anywhere in the world,” Adovasio said.
Another pivotal find is the identification of chert at three dive sites along the river systems; chert is a superior quality fine-grained stone used by prehistoric peoples to make tools.
“There is no doubt,” Adovasio said, “that we have found the haystacks and are one step closer to uncovering the archaeological needles;” in effect, narrowing the search for evidence of early Americans in the now submerged Inner Continental Shelf in the Gulf of Mexico off the Florida coast.
Hemmings, one of the leading Paleoindian underwater archaeologists in North America, agreed. “My feeling is, given a little time to probe the sediments with a dredge, we will quickly find human artifacts.”
The signature expedition of the National Oceanic and Atmospheric Administration (NOAA) Office of Ocean Exploration and Research began in the summer of 2008 when a distinguished group of scientists led by Mercyhurst’s Adovasio and Hemmings identified and mapped buried river channels that could potentially help document the late Pleistocene landscape. This year’s mission, undertaken July 23 to Aug. 5, further traced the river systems along whose beaches prehistoric people may have populated and identified raw materials that they may have used in tool making.
The mission also has advanced underwater understanding and research methodology exponentially, Adovasio said.
“We have developed protocols for exploring deep water, which is both time and labor intensive, as well as expensive, unlike anything done before,” he said.
From the Weatherbird II, flagship of the Florida Institute of Oceanography in St. Petersburg, researchers electronically mapped the modern sea floor with a side scan sonar device and created images of the layered sediments below the seafloor surface with a sub-bottom profiler. Using GPS technology, the team selected dive locations based on an understanding of what the surface should look like, and what was hidden below that surface adjacent to the old river channels.
On the peninsula where the relict Suwannee River intersects another ancient system, divers were able to collect a 1m sediment core but were unable to complete a lengthier search for human artifacts because the water neared 130 feet, the maximum depth level for this year’s dive. The team plans to return to this spot next year, increasing the divers’ depth level certification to 165 feet and using a dredge to lift the silt away and see if there is an archaeological site at this confluence.
“Proof of past human habitation here would reinforce the disintegration of the once prevalent hypothesis about who the first Americans were, how they got here and when they arrived,” said Adovasio, who rose to fame 30 years ago while excavating the Meadowcroft Rockshelter near Pittsburgh, Pa. Besides primary funding from NOAA, this summer’s work was supported by the Mercyhurst Archaeological Institute, Gault School of Archaeological Research, Florida Bureau of Archaeological Research, Florida Institute of Oceanography, and the University of Illinois at Chicago, among others. Students from Mercyhurst, Harvard, the University of Michigan and Texas A & M were also part of the research group.
Debbie Morton | EurekAlert!
In times of climate change: What a lake’s colour can tell about its condition
21.09.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)
Did marine sponges trigger the ‘Cambrian explosion’ through ‘ecosystem engineering’?
21.09.2017 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
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