Are any ancient hydrothermal vents visible on land due to changing sea level, uplift and/or plate movement?
Yes. Some specific slivers of oceanic crust that have been tectonically emplaced on continents above present-day sea level are generally accepted by geologists as good analogues to the parts of the sea floor that are volcanically active today. These slivers are known as “ophiolites” and much has been written about them. Interestingly, however, the ophiolites have historically been the territory of geophysicists and geologists; when microbiologists give ophiolites their full attention we may gain much more information about how ophiolites relate to ancient and present hydrothermal vents. Who needs marine geologists, anyway? Here’s one answer for starters… How was the Mariana Trench formed? Sometimes a piece of the ocean floor (called a plate) will form a crack, and one side of the crack will sink beneath the other side. As the sinking side falls into the Earths mantle below, it pulls the rest of its plate with it. The ocean floor deepens along this crack. The sinking seafloor grinds a
