theconversation | Research we have just had published sheds new light on this Younger Dryas Impact Hypothesis. We focus on what platinum can tell us about it.
Platinum is known to be concentrated in meteorites, so when a lot of it
is found in one place at one time, it could be a sign of a cosmic
impact. Platinum spikes have been discovered in an ice core in Greenland as well as in areas as far apart as Europe, Western Asia, North America and even Patagonia in South America. These spikes all date to the same period of time.
Until now, there has been no such evidence from Africa. But working
with two colleagues, Professor Louis Scott (University of the Free
State) and Philip Pieterse (University of Johannesburg), I believe there is evidence from South Africa’s Limpopo province that partly supports the controversial Younger Dryas Impact Hypothesis.
The new information has been obtained from Wonderkrater,
an archaeological site with peat deposits at a spring situated outside a
small town to the north of Pretoria. In a sample of peat we have
identified a platinum spike that could at least potentially be related
to dust associated with a meteorite impact somewhere on earth 12,800
years ago.
The platinum spike at Wonderkrater is in marked contrast to almost
constantly low (near-zero) concentrations of this element in adjacent
levels. Subsequent to that platinum spike, pollen grains indicate a drop
in temperature. These discoveries are entirely consistent with the
Younger Dryas Impact Hypothesis.
Wonderkrater is the first site in Africa where a Younger Dryas
platinum spike has been detected, supplementing evidence from southern
Chile, in addition to platinum spikes at 28 sites in the northern
hemisphere.
We are now asking a question which needs to be taken seriously:
surely platinum-rich dust associated with the impact of a very large
meteorite may have contributed to some extent to major climatic change
and extinctions?
