We suspect a geothermal vent in a high-phosphorus soda lake, exposed to UV sunlight. There's one in Canada with just about the right mix of everything needed.

We suspect a geothermal vent in a high-phosphorus soda lake, exposed to UV sunlight. There's one in Canada with just about the right mix of everything needed. https://www.science.org/content/article/unusual-soda-lakes-may-have-kick-started-life-earth-concentrating-key-compounds https://www.science.org/content/article/unusual-soda-lakes-m...