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Research Overview
I am a geochemist investigating how morphological, mineralogical, and geochemical signals, including trace elements and stable isotopes, are incorporated during microbial sediment accretion and subsequently modified by early taphonomic processes.
My research spans three contrasting modern organosedimentary systems in Hamelin Pool (Western Australia), Laguna de Los Cisnes (Chile), and the Salar de Atacama (Chile). I integrate sedimentology with high-resolution geochemical analyses to disentangle primary biological signatures from environmental controls and early diagenetic overprints. My expertise includes sequential leaching protocols, major and trace element analysis using ICP-QQQ, and stable isotope measurements using IRMS, complemented by XRD, Raman spectroscopy, petrography, and electron microscopy.
My objective is to refine criteria for recognizing ancient life in the rock record and to strengthen our ability to interpret biosignatures on Earth and in extraterrestrial settings.
See more details below!
Controls on microbialite morphogenesis in Laguna de Los Cisnes (Chile)
Microbialite morphology is often attributed to external physical forcing such as waves and currents. But is environmental forcing the primary control on microbialite architecture, or does microbial accretion build the fundamental structure that physical processes only modify?
To address this, we studied modern and fossil microbialites from Laguna de Los Cisnes in Tierra del Fuego (Chile), combining field mapping, satellite imagery, and microscale observations of the communities driving carbonate accretion. We show that the characteristic crater-like architecture accretes from the growth and mineralization of algal–microbial mats dominated by the green alga Percursaria percursa. Physical processes then modify this biological framework: waves, wind‑driven Langmuir circulation and lake‑level fluctuations redistribute algal-microbial mats and sediments to generate the diversity of morphologies across the basin. Together, these results reveal a clear hierarchy: biological processes build the primary architecture, and environmental forcing reorganizes it.
The role of microbialite morphogenesis on chemical biosignature incorporation
Microbialites incorporate chemical biosignatures reflecting the activity of the microbial communities that build them. But we asked a simple question: do all microbialites record the same biosignatures?
To test this, we analyzed arsenic enrichment patterns in modern microbialites from Hamelin Pool, Shark Bay (Australia) with different morphologies, fabrics, and accretion mechanisms. We found that microbialite morphogenesis controls how arsenic is incorporated into organic matter and carbonate minerals. In some microbialites, arsenic mainly reflects microbial metabolism and the transfer of arsenic from organic matter into carbonate. In others, it mostly records environmental inputs such as seawater chemistry or trapped sediments. This means chemical biosignatures are not universal: the same element can record fundamentally different processes depending on the architecture of the microbialite in which it is preserved.
Other collaborations
Assessing how microbial detoxification and environmental fluctuations drive arsenic enrichment into microbial mats from the Dead Sea (Thomas et al., 2024)
Synthesizing studies of microbialites worldwide to assess how environmental and microbial processes jointly control accretion, architecture, and preservation (Reid et al., 2024)
Assessing how interactions between surface mat accretion and early taphonomy control the formation and transformation of microbialite fabrics (Vitek et al., 2023)
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