Related Experiment Video
Updated: May 11, 2026
10:49
Laboratory-determined Phosphorus Flux from Lake Sediments as a Measure of Internal Phosphorus Loading
Published on: March 6, 2014
Geochemistry: how well can Pb isotopes date core formation?
1Department of Earth Sciences, Laurentian University, Sudbury, Ontario P31 6B5, Canada.
Nature
|November 3, 2006
Summary
Planetary core formation likely occurred rapidly within 35 million years, challenging models suggesting a prolonged two-stage process. New analysis of lead isotope data supports early Earth accretion and differentiation.
Area of Science:
- Geochemistry and Planetary Science: Investigating the timing and mechanisms of planetary core formation and accretion.
Background:
- Models of Earth's early history rely on understanding core formation timescales.
- Previous studies suggested a two-stage core formation based on tungsten (W) and lead (Pb) chronometers, implying a protracted process.
Discussion:
- This study re-evaluates lead (Pb) isotope systematics in the Earth's crust and mantle.
- The analysis indicates that observed Pb isotope data do not necessitate a diachronous (two-stage) core formation model.
Key Insights:
- Early core formation (< or = 35 million years) is consistent with Pb isotope data.
- The proposed early, rapid core formation aligns with models of early planetary accretion and differentiation.
Outlook:
- Further research can refine models of Earth's accretion using robust isotopic constraints.
- Understanding early core formation is crucial for comparative planetology and exoplanet studies.
Related Concept Videos
01:12Isotopes
Elements have a set number of protons that determines their atomic number (Z). For example, all atoms with eight protons are oxygen; however, the number of neutrons can vary for atoms of the same element. The sum of the number of protons and the number of neutrons is the mass number (A). Atoms with the same atomic number but different mass numbers are called isotopes. Elements can have multiple isotopes, for example, carbon-12, carbon-13, and carbon-14.
An element's atomic mass, or weight, is a...
An element's atomic mass, or weight, is a...
01:50Global Climate Change
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
02:48Radioactive 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.
00:49Gravimetry: Inorganic And Organic Precipitating Agents
In gravimetry, the precipitant is chosen carefully to obtain a pure solid that can be easily filtered. Common inorganic precipitants can be used to determine several cations and anions. In some cases, the formation of the same precipitate can be used to determine the cation and the anion. For example, the reaction of barium and chromate ions to give barium chromate is used to determine both barium and chromate. However, precipitates such as hydroxides, oxalates, and metal ammonium phosphates...