Is a rift valley bottom considered a plateau or a plain?

[jackson6612]

Terrain, or land relief, is the vertical dimension of land surface.

I think 'plateau' refers to a land which does not have very large fluctuations in overall relief of the region. It can have small hills.

The term 'plain' is used to define a region which has very little differences in elevations of a land as compared to a plateau.
Doesn't it make a 'plain' a part or subset of plateau?

In geology and Earth science, a plateau, also called a high plain or tableland, is an area of highland, usually consisting of relatively flat terrain.

The term highland or upland is used to denote any mountainous region or elevated mountainous plateau. Generally speaking, the term upland (or uplands) tends to be used for ranges of hills, typically up to 500-600m, and highland (or highlands) for ranges of low mountains.

Is it justified to call a highland a mountainous plateau because by definition a plateau consists of flat terrain? A highland is not a flat terrain.

What is the term to define regions such as Himalayas with mighty mountains such as Everest?

Source(s):
www.wikipedia.org

 

[zomgwtf]

Himalayas = mountain range.

A plateau is like a mountain with a relatively flat top

A plain is just regular ground level flatness.

That's how I understand the terms at least.

 

[Studiot]

It's not a big deal.
Both 'plateau' and 'plain', used by themselves take on their ordinary meaning in English.

In general a plateau has a marked boundary between it and the adjacent landform. Even a cliff as in Prof Challengers lost world.
A plain, on the other hand, can change gradually from being (relatively) flat to bumpy to hilly and finally to mountainous, as happens as the american plains approach the Rockies.

Geographers/geologists add qualifiers to create specialist terms

eg peneplain

Peversely, plateaux are usually level, but plains need not be.

The american plains rise gradually in a westward direction, but they are not a plateau.
Table Mountain in Cape Town has a level plateau at the top.

 

[billiards]

Plains are generally flat at low elevation.

Plateaux are generally flat at high elevation.

Nomenclature.

 

[Studiot]

Plains are generally flat at low elevation.

Plateaux are generally flat at high elevation.

Nomenclature.

Can't agree with this as nomenclature, there are too many exceptions.

 

[Gokul43201]

Can't agree with this as nomenclature, there are too many exceptions.

I'm curious what some of these exceptions are.

 

[Studiot]

Exception, well let's see

Look up guyots they have plateaux, below sea level - that low enough for you?

How about the American High Plains or the South African High Veldt? or a smaller example the peneplain in southern Pembrokeshire.

I did ponder the idea of suggesting that a plateau 'sticks up' above its surroundings, but realized that in fact a plateau can occur at a temporary levelling off on a hill side and so can have ground above it on one side and below it on the other. But I did observe that a plateau implies an abrupt change of slope.

 

[Gokul43201]

Thanks for the info - will look it up.

 

[Ophiolite]

Nobody has mentioned dissected plateau, wherein a peneplained surface is subsequently subject to erosion after uplift, but where this erosion is so concentrated as to create numerous valleys. Much of the Scottish Higlands are a good example of this.

 

[Studiot]

Nobody has mentioned dissected plateau

That may be because we were discussing whether plains had to be at low altitude and plateaux, at high altitude.

 

[Ophiolite]

That may be because we were discussing whether plains had to be at low altitude and plateaux, at high altitude.

The opening post contains this comment from Jackson.
"Is it justified to call a highland a mountainous plateau because by definition a plateau consists of flat terrain? A highland is not a flat terrain."

The dissected plateau of the Scottish highlands is not a flat terrain, yet is classified as a plateau. Therefore my observation directly addresses one of Jackson's concerns and I remain surprised no one mentioned it before.

 

[billiards]

Exception, well let's see

Look up guyots they have plateaux, below sea level - that low enough for you?

How about the American High Plains or the South African High Veldt? or a smaller example the peneplain in southern Pembrokeshire.

I did ponder the idea of suggesting that a plateau 'sticks up' above its surroundings, but realized that in fact a plateau can occur at a temporary levelling off on a hill side and so can have ground above it on one side and below it on the other. But I did observe that a plateau implies an abrupt change of slope.

I stand corrected. It seems that the terminology extends beyond my unresearched overly simplistic assertions of the "nomenclature".

Can we agree that a plateau sits at higher elevation than its surroundings, a plain is a local low?

The opening post contains this comment from Jackson.
"Is it justified to call a highland a mountainous plateau because by definition a plateau consists of flat terrain? A highland is not a flat terrain."

The dissected plateau of the Scottish highlands is not a flat terrain, yet is classified as a plateau. Therefore my observation directly addresses one of Jackson's concerns and I remain surprised no one mentioned it before.

Good spot, and a very fair (and as yet un-picked-up-upon) point. The terminology confuses the definition further. Can we think of a nice and concise definition of plateau?

 

[Studiot]

Both plateaux and plains can have (or not have) a variety of features such as dissection, aridity, rivers, aeolian features etc etc. I don't see the relevance to distinguishing between them, and th OP didn't make one; he just observed they have features.

There is also nothing to distinguish them in their formation history. Both can be (have been) subject to erosion, uplift, faulting, marine advance and regression and so on.

I have always thought of plateaux as needing something to compare with sort of having sides. If say the MAtto Grosso extended over the whole globe would it still be a plateau?

I can, however, imagine a planet with plains extending over the entire surface.

As a matter of interest what would you call the flat bottom of a rift valley?