Arsenic enrichment patterns are defined by microbialite morphology, fabric, and accretion mechanism

We thank Caroline Koschik for the preliminary elemental analysis that inspired this research and Zhenghui Wu for assistance in the lab. We are grateful to Ali Pourmand and Arash Sharifi for access to lab equipment, BHVO-2, AGV-2, and for supporting sample and standard digestions. This work was supported by research startup and teaching funds provided by the Rosenstiel School of Marine, Atmospheric, and Earth Science and the Graduate Studies Office to A.M.O. Microbialite, sediment, and water samples were previously collected under licenses provided under State and Federal authorizations. At the State level, permits were issued initially through the Department of Environment and Conservation (DEC), later the Department of Parks and Wildlife (DPaW), and now the Department of Biodiversity, Conservation and Attractions (DBCA). These included Regulation 4 (Written Notice of Lawful Authority) permits CE003416 (2012), CE003804 (2013), and CE004275 (2014); Regulation 17 (License to take fauna for Scientific Purposes) permits SF008373 (2012), SF008990 (2013), SF009628 (2014), and 08-0011100-2 (2017); and a Regulation 18 (Export) permit OS002519 (2013). At the Federal level, the Department of Sustainability, Environment, Water, Population and Communities (SEWPaC), later the Department of the Environment (DoE), issued referral EPBC 2012/6307 (2012), EPBC 2013/7071 (2013), and Wildlife Trade Assessment WT2012-3963 (2013). Fieldwork was conducted as part of a University of Miami-led research consortium, funded by Chevron, Repsol, BP and Shell between 2012 and 2015, and described in prior publications25,26,31, 32-33,43,71. We thank the Geological Survey of Western Australia and Hamelin Station (during the tenure of Brian and Mary Wake, and Bush Heritage Australia) for logistical field support. We recognize the Malgana as the traditional custodians of Gathaagudu and their connections to land, sea, and community. We pay our respects to their elders past and present and extend that respect to all Aboriginal and Torres Strait Islander peoples. #12 in the Hamelin Stromatolite Contribution Series.