21 Dec 2016

Publication: Molybdenum interacts directly with organic matter in sulfidic environments

Molybdenum is one of the most powerful elements used to track hydrogen sulfide and oxygen in the ocean from the geological record. Still, we have an incomplete understanding of the chemical removal pathway between ocean and sediments.  Sediments deposited under anoxic and sulfidic waters display tight correlations between their contents of molybdenum (Mo) and total organic matter  (TOC). Yet, association does not mean causation. Instead, […]

5 Oct 2016

Dr. Li Da is visiting from Nanjing University

Dr. Li Da is visiting the our research group to carry out isotope analyses of approx. 525 million years old limestone from China. These limestone comes from the Cambrian explosion, a period of approx. 540-520 million years ago, when skeletonized, marine animals suddenly diversified into new species.  The study will compare the stable isotopic composition of uranium deposited in a Chinese […]

5 Oct 2016

Outreach video: Bioturbation and the rise of animals

As part of his MSc thesis work, Sune explores how worms digging in mud affect seawater chemistry. You can now join us in the field by watching the movie produced by Underground Channel.

3 Jun 2016

Earth’s core formation

Earth’s core formation

Planets form through bigger and bigger impacts, resulting in a more and more violent collisions. The Earth and the Moon are believed to have formed after a collision between two giant proto-planets of the size of Venus and Mars. In this event, the majority of Earth’s core is believed to have formed. During my master’s […]

2 Jun 2016

The Cambrian explosion of animal life

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The Cambrian explosion of animal life

The appearance of animals on Earth after 3 billion years of evolution in microbial ecosystems is often claimed to be a result of rising O2 levels on Earth. However, evolving animal ecosystems may in fact have lowered O2 levels. In a recent study (Boyle et al. 2014), we show that the animal invasion of the seafloor […]

1 Jun 2016

Tracing ocean chemistry in the field

Tracing ocean chemistry in the field

The Reading Rainbow guy in Star Trek Next Generation was born blind, but able to see through his VISOR and, later on, via prosthetic ocular implants. By analogy, field geochemists now have new vision. Although, the device is not installed in a visor or as a prosthetic ocular implant, the new generation of energy-dispersive X-Ray […]

30 May 2016

What regulates O2 on Earth?

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What regulates O2 on Earth?

In our research group, we seek to understand how environmental parameters are controlled on Earth. Uranium (U) is sourced to oceans via rivers and is slowly removed in both oxic and anoxic ocean settings giving it a long residence time relative to ocean mixing time scales. U is retained in carbonate rocks that also record […]

29 May 2016

Ancient ocean analogues

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Ancient ocean analogues

In September 2009, Adrian Gilli and Stefanie Wirth visited Lake Cadagno, Switzerland, equipped with a drill rig to collect two long sediment cores from the deepest part of the lake. These cores hold important information about the history of the lake since the last ice age 12,500 yr ago. Wirth and Gilli gathered a team […]

29 May 2016

Laser based carbon spectroscopy

Laser based carbon spectroscopy

As a student in isotope geochemistry, the first words you will hear is “mass spectrometry”. Perhaps one day in the future, the first words will be “cavity-ring down spectrometry”. In a study led by David Balslev-Clausen, we measured carbon isotope compositions in rocks to compare the performance of conventional mass spectrometry and the brand new […]

29 May 2016

Molybdenum reduction in nature

Molybdenum reduction in nature

At the Goldschmidt conference in Davos 2009, chemist Anthony Chappaz told me about the potential of using synchrotron radiation to determine the speciation of amorphous (non-crystalline) materials. This approach could potentially provide fundamental insights to how molybdenum (Mo) is cycled in the environment. The technique was first applied in the geochemical literature by the famous […]