This is slowly becoming huge. Of course, no one has understood yet
that this was a comet that impacted directly at the then positioned
North Pole thirty degrees North. The impact shock wave ripped
through North America, while the incoming shock wave killed
everything in Siberia.
These animals literally all died were they stood.
Yet this paper pretty clearly polices up my original conjecture that
I published here under Pleistocene Nonconformity. Again we have the
advantage of knowing roughly were it impacted in the first place.
Also no one really has understood that the crust itself actually
shifted and that it was a precision impact and deliberate.
Understanding that leads inexorably to the position that we have
partners helping us. Regrettably, I now see no hope that I am wrong
on this.
Comprehensive
analysis of impact spherules supports theory of cosmic impact 12,800
years ago
by Staff Writers
Santa Barbara CA (SPX) May 27, 2013
About 12,800 years ago
when the Earth was warming and emerging from the last ice age, a
dramatic and anomalous event occurred that abruptly reversed climatic
conditions back to near-glacial state. According to James
Kennett, UC Santa Barbara emeritus professor in earth sciences, this
climate switch fundamentally - and remarkably - occurred in only
one year, heralding the onset of the Younger Dryas cool episode.
The cause of this
cooling has been much debated, especially because it closely
coincided with the abrupt extinction of the majority of the large
animals then inhabiting the Americas, as well as the disappearance of
the prehistoric Clovis culture, known for its big game hunting.
"What then did
cause the extinction of most of these big animals, including
mammoths, mastodons, giant ground sloths, American camel and horse,
and saber- toothed cats?" asked Kennett, pointing to Charles
Darwin's 1845 assessment of the significance of climate change.
"Did these
extinctions result from human overkill, climatic change or some
catastrophic event?" The long debate that has followed, Kennett
noted, has recently been stimulated by a growing body of evidence in
support of a theory that a major cosmic impact event was involved, a
theory proposed by the scientific team that includes Kennett himself.
Now, in one of the
most comprehensive related investigations ever, the group has
documented a wide distribution of microspherules widely distributed
in a layer over 50 million square kilometers on four continents,
including North America, including Arlington Canyon on Santa Rosa
Island in the Channel Islands.
This layer - the
Younger Dryas Boundary (YDB) layer - also contains peak
abundances of other exotic materials, including nanodiamonds and
other unusual forms of carbon such as fullerenes, as well as
melt-glass and iridium. This new evidence in support of the
cosmic impact theory appeared recently in a paper in the Proceedings
of the National Academy of the Sciences.
This cosmic impact,
said Kennett, caused major environmental degradation over wide areas
through numerous processes that include continent-wide wildfires
and a major increase in atmospheric dust load that blocked the
sun long enough to cause starvation of larger animals.
Investigating 18 sites
across North America, Europe and the Middle East, Kennett and 28
colleagues from 24 institutions analyzed the spherules, tiny spheres
formed by the high temperature melting of rocks and soils that then
cooled or quenched rapidly in the atmosphere. The process results
from enormous heat and pressures in blasts generated by the cosmic
impact, somewhat similar to those produced during atomic explosions,
Kennett explained.
But spherules do not
form from cosmic collisions alone. Volcanic activity, lightning
strikes, and coal seam fires all can create the tiny spheres. So to
differentiate between impact spherules and those formed by other
processes, the research team utilized scanning electron microscopy
and energy dispersive spectrometry on nearly 700 spherule samples
collected from the YDB layer.
The YDB layer also
corresponds with the end of the Clovis age, and is commonly
associated with other features such as an overlying "black
mat" - a thin, dark carbon-rich sedimentary layer - as well
as the youngest known Clovis archeological material and megafaunal
remains, and abundant charcoal that indicates massive biomass
burning resulting from impact.
The results, according
to Kennett, are compelling. Examinations of the YDB spherules
revealed that while they are consistent with the type of sediment
found on the surface of the earth in their areas at the time of
impact, they are geochemically dissimilar from volcanic materials.
Tests on their remanent magnetism - the remaining magnetism after the
removal of an electric or magnetic influence - also demonstrated that
the spherules could not have formed naturally during lightning
strikes.
"Because
requisite formation temperatures for the impact spherules are greater
than 2,200 degrees Celsius, this finding precludes all but a high
temperature cosmic impact event as a natural formation mechanism for
melted silica and other minerals," Kennett explained.
Experiments by the group have for the first time demonstrated that
silica-rich spherules can also form through high temperature
incineration of plants, such as oaks, pines, and reeds, because these
are known to contain biologically formed silica.
Additionally,
according to the study, the surface textures of these spherules are
consistent with high temperatures and high-velocity impacts, and they
are often fused to other spherules. An estimated 10 million metric
tons of impact spherules were deposited across nine countries in the
four continents studied. However, the true breadth of the YDB
strewnfield is unknown, indicating an impact of major proportions.
"Based on
geochemical measurements and morphological observations, this paper
offers compelling evidence to reject alternate hypotheses that YDB
spherules formed by volcanic or human activity; from the ongoing
natural accumulation of space dust; lightning strikes; or by slow
geochemical accumulation in sediments," said Kennett.
"This evidence
continues to point to a major cosmic impact as the primary cause for
the tragic loss of nearly all of the remarkable American large
animals that had survived the stresses of many ice age periods only
to be knocked out quite recently by this catastrophic event."
No comments:
Post a Comment