Recently, amateur archaeologist Keith Fisher from Virginia contacted me asking for help concerning some very unusual finds of his. The artifacts, when found, are encased in volcanic ash (tephra) and recovered from stratified layers in situ from beneath a layer of high iron oxide content, iron oxide is often associated with prehistoric occupation, but in this case it is more likely more evidence of the associated volcanic eruption, see excerpts from a paper by Half Zantop.... here
So I set about investigating these liths, to see what I could find out, in a nutshell these artifacts are most probably 35 Million years old plus, and that preliminary dating can be scientifically confirmed.
As any budding geologist or volcanologist would know, tephra (volcanic ash), can be associated with a particular volcanic eruption due to its unique element content and there quantities. Argon dating techniques can be used on obsidian to determine the age of an eruption, in layman's terms, when a volcano erupts, potassium isotopes are created, these decay over time into argon, the amount of argon relative to the associated potassium can be measured and the age determined by the known half-life of potassium-40 (1.25 billion years).
It was thought that the last volcanic eruptions on the east coast of The USA were somewhere around 200 million years ago, until quite recently Professor Elisabeth Johnson discovered two extinct volcanoes, Mole hill and Trimble Knob, Virginia, these last erupted 47 and 35 million years ago, respectively.(news article here)
I did a little research and asked for help from Dr Chris Hayward of Edinburgh University, Dr Hayward runs the micro-analytical facility specialising in the analysis of tephras. After describing the depth of the tephra at the site, Dr Hayward said 'A 20 cm layer sounds very proximal', in other words the volcano is very likely close by.
Keith commented to me via email. 'And as you said, there are many different symbols. The most prevalent in all of them are elephants, dinosaurs, snakes and always have an "eye" present.' Over the coming months I will be showing more of Keith's amazing finds.
This is a a copy of the Element composition Lab report taken from the outer coating of the finds, conducted by LTI under Kieth Fishers instruction.
So I set about investigating these liths, to see what I could find out, in a nutshell these artifacts are most probably 35 Million years old plus, and that preliminary dating can be scientifically confirmed.
As any budding geologist or volcanologist would know, tephra (volcanic ash), can be associated with a particular volcanic eruption due to its unique element content and there quantities. Argon dating techniques can be used on obsidian to determine the age of an eruption, in layman's terms, when a volcano erupts, potassium isotopes are created, these decay over time into argon, the amount of argon relative to the associated potassium can be measured and the age determined by the known half-life of potassium-40 (1.25 billion years).
It was thought that the last volcanic eruptions on the east coast of The USA were somewhere around 200 million years ago, until quite recently Professor Elisabeth Johnson discovered two extinct volcanoes, Mole hill and Trimble Knob, Virginia, these last erupted 47 and 35 million years ago, respectively.(news article here)
I did a little research and asked for help from Dr Chris Hayward of Edinburgh University, Dr Hayward runs the micro-analytical facility specialising in the analysis of tephras. After describing the depth of the tephra at the site, Dr Hayward said 'A 20 cm layer sounds very proximal', in other words the volcano is very likely close by.
Keith commented to me via email. 'And as you said, there are many different symbols. The most prevalent in all of them are elephants, dinosaurs, snakes and always have an "eye" present.' Over the coming months I will be showing more of Keith's amazing finds.
Above, one of the finds with the tephra removed. A hominid face profile likeness can be seen facing right, the face profile is similar to many I have found, (here and here).
Above, a head profile likeness can be seen facing left.
Above, another one of Keiths finds, partially tephra coated.
