Discrepancy in Deep C: Rare atoms can improve geological dating methods

Berillium -10, a rare radioactive isotope produced by cosmic rays in the atmosphere provides valuable insight into the earth’s geological history. A research team of Helmholtz-Jentrum Dresseden-Rosendorf (HZDR) in collaboration with Tud Dresseden University of Technology and Australian National University (ANU) has discovered the unexpected accumulation of this isotopes in samples taken from Prashant Cabed.

Such discrepancy can be attributed to a change in ocean streams or astronomy phenomena occurring about 10 million years ago. Conclusions have the ability to serve as a global time marker, which represent a promising progress in dating of geological archives spread over millions of years.

The team presents its results in the journal Nature communication,

Radionuclides are types of nuclear nuclei (isotope) that decay in other elements over time. They are used to date archaeological and geological samples, with radioacarbon dating one of the most famous methods. In theory, radiocarbon dating is based on the fact that living organisms absorb continuously radioactive isotopes (¹⁴C) During their lifetime.

Once a creature dies, absorption stops, and ¹⁴The C material begins to decrease through radioactive decay with half a life of about 5,700 years. By comparing the ratio of unstable ¹⁴C to stable carbon -12 (¹²C), researchers can determine the date of death of the organism.

Archaeological discoveries, such as bones or wooden remains, can be quite accurately dated in this way. “However, radiocarbon method is limited to dating samples, which is not more than 50,000 years old,” HZDR physicist Dr. Dominic Cole explains.

“To date old samples, we need to use other isotopes, such as cosmogenic Berillium -10 (¹⁰“This isotopes are made when cosmic rays interact with oxygen and nitrogen in the upper atmosphere. It reaches the earth through rain and can accumulate on the seabed. ¹⁰Boron has dickes, allowing geological dating that can expand more than 10 million years.

Specific accumulation

Some time ago, the coal’s research group examined the unique geological samples obtained from the Pacific Ocean at a depth of several kilometers. The samples consisted of ferromanganis crusts, mainly made of iron and manganese, which were slowly made but continuously over millions of years.

To date samples, the team analyzed ¹⁰A highly sensitive method in HZDR- form materials using Accelerator Mass Spectrometry (AMS). In this process, the sample is chemically purified before passing through analysis for trace isotopes. Individual atoms from the sample are accelerated by high voltage, deformed by magnets, and then registered by special detectors.

This method allows for accurate identity ¹⁰Ho, separating it from other berillium isotopes as well as the same mass from molecules and isotopes, such as Boron -10.

When the research group evaluated the data collected, they were for a surprise. “In about 10 million years, we found almost double ¹⁰As we had estimated, “Cole was reported.

“We had stumbled on an already unseen discrepancy.” To eliminate any possibility of contamination, experts analyzed additional samples from the Pacific, which also performed the same discrepancy. This stability allows the team to conclude that this is actually a real phenomenon.

Ocean streams, stellar explosions or intersteller collision?

But how did such a striking increase in concentration about 10 million years ago? Cole, who completed his doctorates in TU Dresseden and AU, proposes two possible explanations. An Antarctica belongs to the ocean circulation, which has changed considerably 10 to 12 million years ago.

“Maybe this is the cause ¹⁰Due to the converted ocean currents, some time should be disarmed unevenly on the Earth, “Physicists say.” As a result, as a result, ” ¹⁰The Pacific may be particularly concentrated in the Ocean. ,

The second hypothesis is astronomy physics in nature. This suggests that the subsequent effects of a near-Earth supernova may cause cosmic radiation due to temporarily more intense due to the more intense.

Alternatively, the Earth may temporarily lose its protective solar shield – Heliosfare – for a collision with a dense intersteller cloud, it becomes more weak for cosmic radiation.

“Only new measurements can indicate whether the berryilum discrepancy was caused by changes in sea currents or astrological reasons,” Cole is called.

“This is why we plan to analyze more samples in the future and hope that other research groups will do the same.” If discrepancy was found all over the world, astronomy physics hypothesis would have been supported. On the other hand, if it was detected only in specific areas, the explanation associated with the converted ocean currents would be considered more admirable.

Discrepancy can be extremely useful for geological berillium dating. When comparing various archives for dating, a fundamental problem arises. Normal time markers should be identified in all data sets to synchronize them properly with each other.

“For millions of years of periods spreading for millions of years, such cosmogenic time markers are not yet present. However, this Berillium discrepancy has the ability to serve such as a marker.”