Here:
A fresh look at forgotten vials from Stanley Miller’s primordial-soup-in-a-bottle experiments implies that volcanoes seeping hydrogen sulfide helped form some of life’s earliest ingredients.
Earth’s early atmospheric conditions aren’t known, and the reactions in this experiment could only have happened near a source of sulfur. On a primordial Earth, that would have meant volcanoes. Whereas Miller originally focused on chemical reactions in the atmosphere, the primordial soup may have gathered in a volcanic bowl.
Danielle Venton , “Primordial Soup’s Missing Ingredient May Be Sulfur”, Wired Science (March 21, 2011)
File this under Mayhaveology: Origin of life