Radioactivity in Fossils

This video shows a sauropod vertebra from a private collection in Page, Az..
I examined this and two other similar vertebrae with my CDV-700 (calibrated in 2003, before I purchased it, and still accurate based on measured sources), using the standard probe with the beta shield open.
Background radiation in Page is approximately .001 rem/hour. Hot spots on this vertebra measure between .2 and .3 rem/hour. This is obviously not a terribly radioactive piece of rock, but it is certainly higher than background.
This specimen (and the other two) were apparently excavated from the Morrison Formation (late Jurassic in age) in the 1970's or 1980's.
Questions? Comments? Fire away.

Category:

Science & Technology

Tags:

• dinosaur
• fossil
• bone
• radioactive
• radiation
• isotope
• uranium
• uranitite
• thorium
• thorite
• geiger
• counter
• cdv-700
• civil
• defense
• rads
• rems
• counts
• per
• minute
• daughter
• radon

[ema576]

all fossels contain carbon 14 which is radioactive

[PageRob]

All fossils under 50,000 years old contain radioactive C-14. That is one way that we can date those fossils. Older fossils, like these have been completely (or almost completely) replaced by minerals. Basically no original bone tissue remains. These bones are about 150,000,000 years old - far too old to have measurable C-14 in them.

[lycophyton]

Interesting video dude. I'd love to see more of your collection sometime. I hear the Triassic petrified wood from Arizona is pretty radioactive, have you ever checked such a sample?

[PageRob]

I have a couple pieces of petrified wood at school that I use for teaching, but none of them have given anything significant. There's some in-situ wood nearby, so I am going to check that out sometime soon. A lot of the Uranium mining done in Arizona was done in the Chinle Formation, where most of Arizona's petrified wood comes from, so it would stand to reason it would be hot.

[PageRob]

Just to follow up on this, I took a sample of petrified wood from the Chinle Formation of southeastern Utah and tested it with the CDV-700. Got a few hits, and it is a little hotter than background, but no where near as hot as this vertebra. The wood was showing about 20-30CPM, compared to the 100-200CPM from the vert. I guess I need to do some more testing though, on both Chinle and Morrison fossils.

[KarbineKyle]

Very Nice Video! I love to study radioactivity and isotopes in geology. Another good source for radioactive minerals is fossilized wood, which can contain Carnotite. It is a vanadate mineral that contains uranium. It consists of mostly potassium, uranium, vanadium, and water. It may contain other minerals, such as barium, iron, magnesium, calcium, or sodium too. Carnotite is a hydrous mineral since it contains water. It isn't fluorescent, (i.g. Autunite). It is a bright, lemon-yellow mineral.

[PrometheanRunGood]

I was curious about radioactivity in fossils. What is about the fossilization process preferentially integrates uranium minerals?

[ema576]

60,000 actauly