Related Experiment Video
Updated: Jul 12, 2026

08:43
Separation of Uranium and Thorium for 230Th-U Dating of Submarine Hydrothermal Sulfides
Published on: May 20, 2019
Radioactive Dating of Tertiary Plant-Bearing Deposits
Summary
Potassium-argon dating of Tertiary rocks in British Columbia reveals ages between 45-49 million years. This indicates these sites were contemporaneous during the Middle Eocene epoch, supporting distinct flora findings.
Area of Science:
- Geochronology
- Paleobotany
- Tertiary Geology
Background:
- Dating Tertiary rock formations is crucial for understanding geological timelines.
- Previous studies on Eocene floras in western North America provide a comparative baseline.
Purpose of the Study:
- To establish the geological age of rock samples from interior British Columbia.
- To investigate the contemporaneity of distinct fossil localities.
- To characterize the Eocene flora of the region.
Main Methods:
- Potassium-argon dating of rock samples.
- Analysis of plant microfossils.
- Analysis of plant macrofossils.
Main Results:
- Four potassium-argon determinations yielded ages from 45 to 49 million years.
- The dating suggests three separate localities are contemporaneous within the Middle Eocene.
- Abundant plant fossils indicate a unique flora for this epoch and region.
Conclusions:
- The Middle Eocene epoch in interior British Columbia is characterized by distinct geological and floral assemblages.
- The findings provide new geochronological data for the Tertiary period in this region.
- The identified flora differs significantly from coeval floras in the western United States.
Related Concept Videos
Radioactive Decay and Radiometric Dating
Radioactivity is a spontaneous disintegration of an unstable nuclide and is a random process, as all the nuclei in the sample do not decay simultaneously. The number of disintegrations per unit time is called the activity (A), which is directly proportional to the number of nuclei in the sample. The decay constant (λ) is an average probability of decay per nucleus in unit time.
Microbial Bioremediation of Uranium
Microorganisms play a critical role in the transformation and immobilization of uranium in contaminated environments through four main pathways: bioreduction, biosorption, bioaccumulation, and biomineralization. These mechanisms reduce uranium’s toxicity and prevent its migration through groundwater systems, offering sustainable approaches for in situ bioremediation.Bioreduction of UraniumBioreduction is driven by anaerobic bacteria such as certain strains of Geobacter and Shewanella, which use...
Diversity of Protists III
Rhizaria are a diverse group of unicellular protists characterized by their threadlike cytoplasmic extensions known as pseudopodia. These structures aid in both locomotion and feeding, giving Rhizaria an amoeboid appearance. Their amoeboid morphology once led to taxonomic confusion, but molecular phylogenetics has clarified their evolutionary placement and emphasized their shared use of pseudopodia despite divergent lineages.This clade comprises diverse lineages such as Chlorarachniophyta,...
Isotopes and Radioisotopes
In the early 1900s, English chemist Frederick Soddy realized that an element could have atoms with different masses that were chemically indistinguishable. These different types are called isotopes — atoms of the same element that differ in mass. Isotopes differ in mass because they have different numbers of neutrons but are chemically identical because they have the same number of protons. Soddy was awarded the Nobel Prize in Chemistry in 1921 for this discovery.
An isotope containing more...
An isotope containing more...
Nuclear Stability
Protons and neutrons, collectively called nucleons, are packed together tightly in a nucleus. With a radius of about 10−15 meters, a nucleus is quite small compared to the radius of the entire atom, which is about 10−10 meters. Nuclei are extremely dense compared to bulk matter, averaging 1.8 × 1014 grams per cubic centimeter. If the earth’s density were equal to the average nuclear density, the earth’s radius would be only about 200 meters.
To hold positively charged protons together in the...
To hold positively charged protons together in the...
Nuclear Transmutation
Nuclear transmutation is the conversion of one nuclide into another. It can occur by the radioactive decay of a nucleus, or the reaction of a nucleus with another particle. The first manmade nucleus was produced in Ernest Rutherford’s laboratory in 1919 by a transmutation reaction, the bombardment of one type of nuclei with other nuclei or with neutrons. Rutherford bombarded nitrogen-14 atoms with high-speed α particles from a natural radioactive isotope of radium and observed protons being...
