Oldest Earth - Jack Hills Zircon - Classic Riker Box Specimen
Oldest Earth - Jack Hills Zircon - Classic Riker Box Specimen
This specimen is a small piece of the Jack Hills formation north of Perth in Western Australia (pictured above). The rough, sedimentary layers of the Jack Hills formation are 3.3 billion years old, but they also contain much older zircon crystals across a range of time from 3.6 to nearly 4.4 billion years old.
The specimen measures 1x1 cm and is enclosed inside an acrylic specimen jar. The jar is enclosed inside a classic, glass-topped riker display case. A small information card is also enclosed.
Please Note: These specimens were collected in accordance with Australia's cultural heritage and mining laws. That said, this site is now permanently closed to new mining and no further exports are expected. As such, it is likely these specimens are the only pieces we will ever see outside of Australia or available to the general public.
📸 False color image of the oldest known zircon found in the Jack Hills formation. Estimated age 4,374,000,000 years old. (Source: Valley, John W., et al. "Hadean Age for a Post-magma-ocean Zircon Confirmed by Atom-probe Tomography." Nature Geoscience 7.3 (2014): 219-223.)
The Water Within
In addition to being the oldest known samples of Earth's crust, the zircons of the Jack Hills formation also contain water and the earliest suggestions of life in the form of biogenic carbon. As the science around this topic evolves, it may push back the starting point for life on Earth by hundreds of millions of years.
📸 An Artistic Rendering of the Earth during the Hadean
About the Early Earth and the Jack Hills Formation
"The only physical evidence from the earliest phases of Earth’s evolution comes from zircons." ~ John Valley, Geoscientist
Named for the fiery lord of the ancient greek underworld, the Hadean Eon (4.5-3.95Ga) describes a time when the Earth's surface was subject to widespread volcanism and continuous collisions with remnant objects in the chaotic early solar system.
It would seem an inhospitable place for water, let alone life. Yet our scientific understanding has changed quite a bit since the Hadean was first described in 1972.
We've learned that Earth must have possessed a significant amount of water during its early formation, and even though the heat was intense the atmospheric pressure of carbon dioxide kept water on the surface from boiling off. We also know that plate tectonics, the grinding of the crust, began during this time. Together these forces helped scrub the atmosphere of carbon dioxide and other greenhouse gases, leading to cooler surface temperatures and conditions favorable for life.
📸 Satellite Image of the Jack Hills Formation
This history has been revealed by studying the chemical makeup of small crystals called zircons. Zircons are quite common in the crust of Earth. They are shed through the process of erosion once igneous rocks reach the surface, at which point the zircons are incorporated into new sedimentary layers.
In Australia, the rough, sedimentary layers of the Jack Hills formation are 3.3 billion years old, but they also contain much older zircons across a range of time from 3.6 to nearly 4.4 billion years old.
Front of the Specimen Card
Back of the Specimen Card
Further Reading
Bell, Elizabeth A., et al. "Potentially Biogenic Carbon Preserved in a 4.1 Billion-year-old Zircon." Proceedings of the National Academy of Sciences 112.47 (2015): 14518-14521.
Valley, John W., et al. "Hadean Age for a Post-magma-ocean Zircon Confirmed by Atom-probe Tomography." Nature Geoscience 7.3 (2014): 219-223.
Wilde, Simon A., et al. "Evidence from Detrital Zircons for the Existence of Continental Crust and Oceans on the Earth 4.4 Gyr Ago." Nature 409.6817 (2001): 175-178.
Oldest Earth - Jack Hills Zircon - Classic Riker Box Specimen
