Cave formation

This setup reminds me of rhizomes, which are essentially underground root systems that can spread out underground, sending up new seedlings at various intervals. Rhizomatic root systems make colonies of aspen possible, and colonies can be both massive and long-lived. If one tree dies, another one can start growing in its place, or somewhere else in the colony.

This seems, in a sense, similar to what you're asking. You've got a giant network of roots extending through the soil searching for nutrients, and rhizomes do basically the same thing - they just usually have plants grow up through the soil, rather than further down.

Sulfur formation

A commonly-occuring yellow sulfur crystal is octasulfur, or ${\text{S}}_8$. ${\text{S}}_8$ is often produced by volcanoes, but can also be made by humans. Volcanic elemental sulfur often contains a large percentage of ${\text{S}}_8$ by mass, and this is a good thing, because there may be a natural way to seed your riverbeds.

There are lava tubes and subterranean caves on Mars, some of which formed through mineral processes (e.g. involving limestone) and some of which formed through the cooling of lava. Now, it's possible that your world could have pockets of lava tubes deep below the surface, and it's also possible that those tubes could have ${\text{S}}_8$. Your rhizomatic roots therefore don't even have to form new tunnels; they could already exist, and might simply be expanded by the invading plants.

${\text{S}}_8$ melts at 392 K (119${}^{\circ }$ C, 246${}^{\circ }$ F). This means that to have actual rivers of sulfur, you'd need to raise temperatures to this point. However, the boiling point of water is 100${}^{\circ }$ C, meaning that water should be gaseous at temperatures where sulfur is liquid. We therefore have a problem; we can't really have a river of liquid sulfur and water except under extreme conditions.

Therefore, it seems much more likely that the already-existing crystallized sulfur will remain crystallized, or at least in a solid state.

posted over 6 years ago

HDE 226868‭

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