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What could cause a planet to naturally have zero caverns with surface openings apart from small impact hollows in the sides of craters and crevices carved in cliffs?

To be specific, zero large caverns and cave systems with openings on the surface.

(Subsurface caves could exist. BUT if anyone has an idea on how zero caves on the surface AND below the surface could be possible then please feel free explore that idea as well because the less caves the better)

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    $\begingroup$ Which kind of planet? What are the surface conditions on this planet? $\endgroup$ – L.Dutch - Reinstate Monica Jul 5 '17 at 6:38
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    $\begingroup$ I find "any kind of planet" too broad. Jupiter is not the same as Mercury. $\endgroup$ – L.Dutch - Reinstate Monica Jul 5 '17 at 7:10
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    $\begingroup$ Make it a gas planet or a young, still molten planet. Here is a mistake i see many people make, i call it the star wars syndrome: a planet doesn't need to be just one Thing. Planets are huge. It might not be the case here, but ask yourself if it wouldn't be enough to have no caves locally because most stories are localized $\endgroup$ – Raditz_35 Jul 5 '17 at 7:17
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    $\begingroup$ Huge extremely rare cement meteor impact. $\endgroup$ – xDaizu Jul 6 '17 at 8:32
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    $\begingroup$ @Raditz_35: Beautifully lampshaded in Stargate SG-1's "Solitudes" episode, in which Carter sees a frozen landscape and immediately (rather stupidly) declares "it's an ice planet" ... only to later discover that she'd landed on Antarctica. $\endgroup$ – Lightness Races with Monica Jul 6 '17 at 15:06
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Solid is a relative thing

  • No caves in sand
  • No caves in water
  • No caves in magma
  • No (permanent) caves in ice sheet
  • No caves in soft soil
  • No caves in peat bogs

In short:

  • No caves in anything fundamentally unstable
  • Only caves where you have surface rock

An old, geologically stable world, where the mountains have eroded down. Land is low lying and either swampy, jungle/forested, desert or coral island, with floating ice caps at both poles.

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    $\begingroup$ Ice sheets are not necessarily cave free, they fracture, form holes from run off melt water, etc. $\endgroup$ – Firelight Jul 5 '17 at 10:50
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    $\begingroup$ @Firelight, I'm running on the fact that while they may briefly exist, it'll be a fleeting existence in the general instability of the medium. $\endgroup$ – Separatrix Jul 5 '17 at 10:52
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    $\begingroup$ @Vylix, the op mentioned in the comments that he'd like solid surface $\endgroup$ – Separatrix Jul 5 '17 at 11:25
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    $\begingroup$ @Separatrix If the medium is unstable then as one fracture or hole seals up another would probably form (And from the perspective of a human, around which most stories are told, the life span of such features aren't really fleeting). $\endgroup$ – Firelight Jul 5 '17 at 12:07
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    $\begingroup$ @Firelight: right, it depends on what timescale is relevant. If the OP wants “no caves that vampires could hide in during the day”, then ice sheets do have such caves and so won’t suit them. If the OP wants “no caves that would preserve prehistoric remains”, then ice sheets would suit their purpose just fine. $\endgroup$ – Peter LeFanu Lumsdaine Jul 5 '17 at 12:12
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I expect the plains of Pluto doesn’t have any caves because the material is plastic on a time scale shorter than geologic time. The “minerals” (carbon monoxide, nitrogen, and chunks of water) flows like tar or silly putty, filling in any voids.

Meanwhile, you avoid processes that create caves. We get limestone caves due to acid and limestone — a planet without those won’t get caves carved by water to this extent. Lava tubes leave caves: make your volcanoes such that they don’t crust over and drain, or always collapse, etc.


※ Do you count crevasses in glaciers as caves or pits? IAC they are a transient phenomenon.

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    $\begingroup$ What you've said here about Pluto is totally contrary to the New Horizons data. The surface of Pluto is young and geologically active. Also, do you have any supporting evidence for this claim that cryoice "flows"? I'm curious about that since it does not jive with my knowledge of ice rheology. $\endgroup$ – foobarbecue Jul 6 '17 at 13:58
  • $\begingroup$ en.wikipedia.org/wiki/Pluto#Surface «frozen nitrogen and carbon monoxide ices … polygonal cells which are interpreted as convection cells that carry floating blocks of water ice crust and sublimation pits towards their margins; there are obvious signs of glacial flows both into and out of the basin. It has no craters that were visible to New Horizons, indicating that its surface is less than 10 million years old.» $\endgroup$ – JDługosz Jul 6 '17 at 17:46
  • $\begingroup$ Cryoice rheolovy: Look up the videos from SETI Seminars. The lead scientist gave a wonderful presentation on the newly discovered geology of Pluto. An earlier talk was about ice on Europa and included an explaination of how it convects and an analysis of the circumstances in which the convection turns over the surface (as opposed to a static lid). $\endgroup$ – JDługosz Jul 6 '17 at 17:52
  • $\begingroup$ Sublimation, glaciers, floating blocks of ice -- sounds like a great recipe for caves! Full disclosure: I got my PhD studying fumarolic ice caves and I now am doing a postdoc at NASA JPL. I don't know much about cryoice yet but my impression was that it would undergo brittle rather than plastic deformation, so maybe those glaciers are crevassed like crazy! (I count crevasses as caves :-) $\endgroup$ – foobarbecue Jul 7 '17 at 1:32
  • $\begingroup$ I guess it depends not only on the material (this is not water!) as well as (as explained for Europa) the grain size and heat gradient. $\endgroup$ – JDługosz Jul 7 '17 at 4:14
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Well most caves are formed by erosion, more specifically by various water related forms of erosion. So the easiest way to have a planet with no caves what so ever is to have a planet that has no water.

No water means no sedimentary rock in the first place (no life to die and be compressed) and no means by which that rock could be dissolved and eroded.

There are no oceans to form sea caves and coastal erosion, no rivers to carve out canyons and caves, no ice to crack rocks and form caves.

The only remaining forces likely to form caves are plate tectonics and volcanic activity. You might get Lava tubes and primary caves but they would be far less common.

Of course, as far as telling a story set on such a planet is concerned you would probably struggle as it would likely be a completely barren, lifeless rock; which may not be what you are looking for.

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    $\begingroup$ "No water = no life to die" isn't necessarily true, it would just mean a radically different path for the development of life from what is feasible on Earth. $\endgroup$ – Myles Jul 5 '17 at 15:01
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    $\begingroup$ @Myles True, but I'm not sure that such life would form sedimentary rock like limestone, plus if there is no water to dissolve the rock after it has formed then having sedimentary rock isn't a problem. $\endgroup$ – adaliabooks Jul 5 '17 at 15:04
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    $\begingroup$ Definitely not limestone like rock as water is quite integral for that but possibly many other things that wouldn't be feasible on Earth. Also to see how wind could carve a cave. en.wikipedia.org/wiki/Aeolian_processes#/media/… $\endgroup$ – Myles Jul 5 '17 at 16:08
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    $\begingroup$ no water does not mean no sedimentary rock, windblown sediment can form sedimentary rock. $\endgroup$ – John Jul 7 '17 at 1:19
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Cover the planet with a liquid, e.g water or lava (at the right pressure and temperature). Any caverns will be below the liquid, i.e. below the surface.

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Would I be wrong to say that all "large caverns and cave systems" are formed in limestone?

I may be wrong but if you pick a famous cavern like Carlsbad Caverns (New Mexico) or Lascaux (France), or Karst, they're in limestone.

Now limetone has a biological origin:

Limestone is a sedimentary rock, composed mainly of skeletal fragments of marine organisms such as coral, forams and molluscs. Its major materials are the minerals calcite and aragonite, which are different crystal forms of calcium carbonate (CaCO3).

About 10% of sedimentary rocks are limestones. The solubility of limestone in water and weak acid solutions leads to karst landscapes, in which water erodes the limestone over thousands to millions of years. Most cave systems are through limestone bedrock.

So, perhaps a planet which never evolved corals and moluscs, for whatever reason, might do?

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    $\begingroup$ Lava tubes are also well known caving destinations. $\endgroup$ – Jon Custer Jul 5 '17 at 17:41
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    $\begingroup$ So, a planet where the extremely liquid lava that gives rise to lava tubes does not exist or does not errupt above sea-level? I don't know if that's achievable via a small change to natural abundances or tectonic activity compared to Earth. $\endgroup$ – nigel222 Jul 6 '17 at 11:06
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    $\begingroup$ Or a planet where "molluscs" and "corals" build silica shells not carbonate shells. We have the diatoms here with silica shells, but they never evolved past single-celled organisms. $\endgroup$ – nigel222 Jul 6 '17 at 11:09
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    $\begingroup$ Yes, you would be wrong! There are large caves in marble, quartzite, gypsum, ice, and volcanic rocks, to name a few. $\endgroup$ – foobarbecue Jul 7 '17 at 1:29
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Perhaps some bear species takes it upon themselves to fill the naturally occurring caves so that they're sealed off. Maybe said species finds it useful somehow? Perhaps it's a religious thing for these bears?

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A planet with no mountainous area and even hilly area (littlest altitude possible), and important tidal range (as important as the highest point on the planet).

With the movement of the sea, sand and other light solid will fill all the surface cavern.

Tide could destroy all the cavern in an other way. See the example of Io, one of the satellite of Jupiter, the tidal effects are sufficient to move the rocks and all the planet surface. It will destroy all the cavern on and in the planet (but maybe it could create some).

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    $\begingroup$ Titan is a satellite of Saturn en.wikipedia.org/wiki/Titan_(moon). Titan is unique amongst the worlds we have explored precisely because it has fluids on the surface to mimic the actions of water on Earth such as sedimentation and cave creation. Did you mean Io? $\endgroup$ – pojo-guy Jul 5 '17 at 21:28
  • $\begingroup$ @pojo-guy I am pretty sure he meant Io. Io is pretty famous for having "land tides". $\endgroup$ – Columbia says Reinstate Monica Jul 6 '17 at 1:00
  • $\begingroup$ Need to check ! I may have a little confusion with my solar system knowledge $\endgroup$ – Cailloumax Jul 6 '17 at 12:28
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I believe a planet without tectonic activity would work.

Most of the large caves on earth which aren't man-made are a result of either volcanoes or limestone decay.

Most, although probably not all, volcanoes on earth are created around the tectonic plates. Thus, eliminating those plates could potentially eliminate volcanoes which eliminates volcanic caves.

Limestone caves are a result of the tectonic plates lifting the sea-floor above sea-level and then letting erosion run its course. With no tectonic plates, there's no lifting which means no erosion of the limestone to create caves.

This does leave open the possibility of caves under water, but I think it covers the "dry" planet surface.

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    $\begingroup$ In the distant past, Mars had volcanoes without technic plate movement. But yes, maybe you want a planet whose core cooled so long ago that all lava tubes near the surface have been destroyed by erosion or meteor impacts. $\endgroup$ – Robyn Jul 6 '17 at 3:23
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If there was never anything liquid on the surface, you would never get caves. No water = No caves. Caves can still form an most rocks as long as there is liquid water and a crack and somewhere for the water to flow to. Another thing is magma will create caves (think lava tubes) after it has flowed and hardened the surrounding rock the remaining liquid drains and you get caves.

Ice can also create caves, if you got rid of all the liquid on a planet I think its safe to say you'd get zero caves.

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