Enables the determination of isotope ratios in rocks, minerals, fossils, gases and water with a very high level of accuracy
A laboratory for stable isotopes, the first of its kind in the Negev and unique in Israel, was recently established in the Department of Geological and Environmental Sciences at Ben-Gurion University of the Negev. This laboratory is unique thanks to the variety of scientific applications it offers and the innovative technological equipment it has. The laboratory was established with funding from the Wolfson Foundation following the winning of a grant for three new researchers in the department: Dr. Yaron Katzir, Dr. Orit Sivan and Dr. Sigal Abramowitz. The university supported the establishment of the laboratory and financed a supplementary grant.
The laboratory enables the determination of isotope ratios in rocks, minerals, fossils, gases and water with a very high level of accuracy. The heart of the laboratory is a gas mass spectrometer connected to a variety of devices whose role is to produce, separate and transport the gases from different source materials. Mass spectrometry of stable isotopes is one of the most prominent modern tools for reproducing a wide variety of processes currently occurring in the atmosphere, surface and interior of the earth, and enables the deciphering of significant events in geological history.
Dr. Yaron Katzir: "The new laboratory for light stable isotopes deals with changes in the isotopic ratio of five chemical elements: hydrogen, carbon, oxygen, nitrogen and sulfur. All of them are characterized by low atomic weight and relatively large differences in weight between their heavy (rare) isotopes and their light (common) isotopes." According to him, this science is based on the distinction that many natural processes cause a certain separation (fractionation), sometimes very difficult to measure, between the light and heavy isotopes of these elements. As a result, water, gases, dissolved substances and solid minerals can develop a "unique isotopic signature", indicating the source of their creation and the changes they have undergone. For example, says Dr. Siegel Abramovitz, "the oxygen isotopic ratios measured in carbon dioxide originating from the tiny carbonate skeletons of single-celled marine fossils indicate the water temperature of the ancient oceans and thus serve as a tool to reconstruct climatic changes that occurred throughout the history of the earth."
Dr. Orit Sion: "The laboratory also enables the innovative application of fascinating scientific applications, such as measurements of the isotopic composition of the greenhouse gas methane and of oxygen in mineral crystals, which sheds light on the origin of the creation of ancient rocks that were formed in the Earth's interior at the beginning of its formation."
The inauguration of the laboratory will take place on Sunday, March 30.03.08, XNUMX, with the participation of the president of the university, Prof. Rivka Karmi, the rector of the university, Prof. Jimmy Weinblatt, the vice president for research and development, Prof. Moti Hershkowitz, and the dean of the Faculty of Natural Sciences, Prof. Avraham Perola .
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The response was deleted due to being a commercial advertisement.
Thank you Ami Bachar for the explanation.
Now things are a little more explained
good evening
Sabdarmish Yehuda
Hello Sabdarmish,
An unstable isotope - such as carbon 14, is always unstable. Not even during the test! When you take carbon-14 and measure it, you will find with the help of a simple (and obviously insensitive) Geiger counter that it screams - meaning there are many beta decays every second. Today there are devices that know how to detect even one single breakdown, apparently. Of course, this is a bit silly since a radioactive background measurement will show a rate of 20-40 decays per second. Either way, today's devices are very precise and sensitive (for example, a scintillation counter).
It must be remembered that the concentration of the various isotopes (stable or not) is affected by several factors, among them, for example, temperature. If we take a glass of water at 30 degrees, it will have different isotope concentrations than a glass of water at 28 degrees.
A very important factor (perhaps the most important factor) is the selection or "selection" of enzymes in a certain isotope. It is known that, for example, the enzyme Rubisco, which fixes carbon dioxide in the photosynthesis process, unequally chooses normal carbon (12) or heavier carbons (13 or 14). The dating of the sample can be done according to different data of one kind or another from new and old geological methods. If we take a sample from a certain layer that we know (or at least think we know) its age, then we can measure the concentration or the isotopic ratios and thus deduce the temperature, or other conditions that prevailed during the measured period.
Other laboratories that are involved in this field, specifically in the biological aspect, are the laboratory of Boaz Luz at Y-M University and the laboratory of Aldo Shemesh from the Weizmann Institute.
Greetings friends,
Ami Bachar
The question is how to define a stable isotope here. After all, even an "unstable" isotope, for example carbon 14, whose half-life is a short 5700 years, is absolutely stable for the duration of the test, which is conducted on the order of minutes or hours.
This will be different for isotopes that decay faster, for example medical isotopes, whose half-life is hours.
In short, what is written in the article requires clarification.
Good night
Sabdarmish Yehuda
Thanks for the clarification, but it raises another question that maybe I should have asked earlier (because it really said that the lab deals with stable isotopes and I just didn't notice):
How is a laboratory for testing stable isotopes different from a laboratory for testing unstable isotopes?
I imagine that at least some of the unstable isotopes require radiation protection, but is there anything else?
The laboratory, according to the article, deals with stable isotopes, and therefore will not deal with dating. Radiometric dating is based on unstable elements (whose decay rate is correlative to the time that has passed since some "fixed date"). A stable isotope does not decay, so it is not possible to determine the age of the object in which it is found using this isotope.
For example, carbon-14 has a half-life of about 5700 years. This means that if the amount of the isotope in the object is half of the atmospheric standard then the object is 5700 years old. In the case of the stable isotope the concentration in each object is constant throughout its life (and therefore its age is zero or infinity).
So why are they so good? For Dagoma, the stable isotope oxygen-18 has a concentration that varies according to climatic conditions. A carbonate skeleton whose oxygen-18 concentration is measured will be able to teach us about the climate conditions at the time of his life (which must be dated using an unstable isotope or in some other way). Carbon-13 in ecosystems changes according to the photosynthesis pathway of plants, and many other good examples.
To Michael - thank you
Now after referring to Michael's link it is possible to be precise and say that the laboratory in Be'er Sheva will last up to about 50,000 years.
And by the way, the amount of carbon in the air is not easy to predict, and it has actually changed over the generations, not necessarily as expected, and especially since the industrial revolution, so that despite the precise measurement given by the laboratory, other factors must also be taken into account for accurate dating.
Let's have a good and a bit cool evening.
Sabdarmish Yehuda
Yehuda:
Here is a link I found on the subject:
http://snakefly.tripod.com/Date.html
I understand that determining the geological dates according to this facility will do a maximum of up to a period of one million years. To determine the millions of years of the dinosaurs, for example, analysis of other elements heavier than oxygen and carbon such as phosphorus, uranium, lead and the like is required. Am I right?
I would like the article to be more detailed.
Have a good day.
Sabdarmish Yehuda