The contrasting geometric shapes in this image were formed by the boundaries between a drop of sea surface seawater from the North Sea combined with a drop of oil from deep beneath the sea floor in the North Sea. Researchers constructed an experimental test bed called the GeoBioCell to study the interactions between water, rock, microbes, and oil under high magnification. Researchers hope to develop a method to prevent oil “souring,” the contamination of oil fields by microbially-produced sulfide gas.