DNA was extracted from Great Salt Lake south arm microbialites, associated brine fly pupae, and north arm surface-sterilized gypsum. Each were crushed in separate experiments then sterile molecular grade water was added to make a slurry. In each case, the supernatant was filtered through a 0.45 m Pall MicroFunnel Filter (Show Low, AZ, USA). In each separate sample, the DNA was extracted from the membrane of the filter using the DNeasy PowerWater Kit (Hilden, Germany). Petroleum samples were taken from three individual seeps at the north arm Rozel tar seeps and frozen. These were ground with a sterile ceramic mortar and pestle into a fine soil-like consistency, then extracted using the same kit using the MP Bio FastDNA Spin Kit for Soil (MP Biomedicals, Santa Ana, CA, USA). Isolated total genomic DNA from all sites was sent out to assess taxa diversity with PCR and DNA sequencing (www.mrdnalab.com, Shallowater, TX, USA). We amplified the 16S rRNA genes of bacteria and archaea using the 515 forward and reverse primers for the V4 variable region (Walters et al., 2016), the 18S rRNA genes of eukaryotes using EUK1391 forward and reverse primers for the hypervariable region (Rodriguez-Sanchez et al., 2019), and the Internal Transcribed Spacer (ITS) gene of fungi using ITS forward and reverse primers (Walters et al., 2016). Pooled and purified PCR products were used to prepare an Illumina DNA library. Sequencing was performed at MR DNA (www.mrdnalab.com, Shallowater, TX, USA) on MiSeq.