# QuestionWhat is the Carbon Isotope Abundance for the Pee Dee Belemnite?

#### Geomartian

The ratio for the PDB is .0112372

What I want to know is the actual abundance of each carbon isotope in the PDB and not their ratio.

According to Columbia University the normal carbon isotope abundances are

Carbon-12 .9893 Carbon13 .0107

If I use these normal values to calculate the abundances in Pee Dee Belemnite I get these two possibilities.

Carbon-12=0.9893 Carbon-13=0.0111(normalized)

Carbon-12=0.9522(normalized) Carbon-13=0.0107

Either example shows that the Pee Dee Belemnite is isotope heavy. This carbon was processed by an interstellar flare and the lighter Carbon-12 was preferentially lost to space.

The Pee Dee formation is found directly at the K/T boundary. They found the most isotopically heavy sample of carbon they could (from an interstellar impact) to use as their scientific standard! The Pee Dee Belemnite proves that the K/T boundary is an interstellar impact event.

Had they used the normal isotopic abundance as the standard all of the impact boundaries would show up as positive numbers. That negative or positive sign giving away the impact boundaries must have really annoyed somebody. The PDB standard and their way of calculating it made everything a negative number so that the impact heavy isotope enrichment at extinction boundaries would not stand out so clearly.

Search for (delta c thirteen) or (delta c 13) or carbon isotope ratios to see the calculation.

Does anyone have the directly measured carbon isotopic abundances for the Pee Dee Belemnite carbon standard?

Can anyone explain why this basic information about a “Scientific Standard” is missing or unavailable?

#### Geomartian

The Pee Dee Belemnite is a Lagerstätten, a death assemblage. Those animals lived within a short window directly after an impact flare. Their tissues and surrounding sediments were saturated with heavy carbon.

The Empire likes to blame the negative carbon excursion at extinction boundaries on changes in the temperature or the weather. Do you know what the carbon ratio is for rock? If it is the same as the normal ratio then it is -37. The easiest way to get a negative carbon isotope excursion is to vaporize a lot of rock.

The temperature of the porridge didn’t kill Goldilocks it was the giant rock that the bears dropped on her…. Where was I?

Oh Yeah, the negative carbon excursion indicates that an interstellar asteroid impact has melted a lot of rock which resulted in the Deccan Traps. That is why there such a negative spike when you melt a lot of rock and release that carbon as carbon dioxide.

The atmosphere becomes isotope light (negative) for carbon. The sediments directly following the impacts become isotope heavy from the impact flare fall back. Those heavy isotope signatures tend to rapidly disappear after burial by younger strata. This also supports the view that the Pee Dee Belemnites died shortly after a period of heavy isotope sky fall from an impact flare.

The Pee Dee Belemnites also suggest another possible interstellar asteroid impact nearby. Because the Deccan Traps are too far away from the American Carolinas and the Pee Dee formation. There is also a massive glauconite interval in New Jersey indicating another impact at the K/T boundary in/or near North America.