Naked Science Forum

Non Life Sciences => Geology, Palaeontology & Archaeology => Topic started by: neilep on 15/09/2008 12:25:58

Title: How Is A Cliff Made ?
Post by: neilep on 15/09/2008 12:25:58: Dear Experts in Cliffology,

As a sheepys I am of course extremely fond of all types of cliff !

Here I am guarding a Cliff buried waist high upon the White Cliffs Of Dover.
Do not be fooled, the picture IS to scale and no doctoring has been done !

guardingsheepcliffImage1.jpg (47.17 kB . 492x339 - viewed 6776 times)

Nice eh ?..no one is going to steal our cliff from our cliffs !

So, whilst guarding Cliff, I thought I'd perchance discuss with him the nature of Ciffology and converse as to how Cliffs came into being !

I'm pretty sure I know how Sir Cliff came into being, something to do with a bright star at Christmas time , a bunch of Shadows and Sue Barker...but how did regular bog standard cliffs come to be ? (and why are Dovers' white anyway ?)

Thank ewe

Hugs and shmishes

neil
Cliff Guarder and Quizmaster

mwah mwah mwah mwah
xxxxxxxxxxxxxxxx
Title: How Is A Cliff Made ?
Post by: Don_1 on 15/09/2008 16:13:05: I'm not sure you have got it right about how Sir Cliffy came into being. I think you will find that what happened was a randy tectonic plate jumped on another tectonic plate and the result was a Sir Cliffy (https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.freesmileys.org%2Fsmileys%2Fsex001.gif&hash=daf7da5a352b439901846e0accc73036) (http://www.freesmileys.org)

Dover's cliffs are white because my Mrs gets me colouring them every weekend with a giant box of chalk!
Title: How Is A Cliff Made ?
Post by: neilep on 15/09/2008 20:12:01: Quote from: Don_1 on 15/09/2008 16:13:05
I'm not sure you have got it right about how Sir Cliffy came into being. I think you will find that what happened was a randy tectonic plate jumped on another tectonic plate and the result was a Sir Cliffy (https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.freesmileys.org%2Fsmileys%2Fsex001.gif&hash=daf7da5a352b439901846e0accc73036) (http://www.freesmileys.org)

Dover's cliffs are white because my Mrs gets me colouring them every weekend with a giant box of chalk!

At last !..the voice of reason has spoken Thanks Don1 (nice play in words there BTW in your name !!) (https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fsmilies.vidahost.com%2Fcontrib%2Ffk%2Fdaisy.gif&hash=d62dfc850ea238c30a39926b5e8cb7b8)

I offer my woolly back to aid ewe in your artexing the white cliffs if ewe wish ! (https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fsmilies.vidahost.com%2Fcontrib%2Ffk%2Frainbow.gif&hash=857fe460e7cabd93992f1379a2598fe6)
Title: How Is A Cliff Made ?
Post by: Evie on 15/09/2008 20:23:16: I went looking for a good diagram to show sea cliff erosion and came across a good explanation as well. Being generally lazy, I decided to copy in the text rather than come up with my own version...

Quote
Cliffs are formed by a number of processes, in particular the explosive energy released from waves (and stones carried within them) crashing into their base, the result of which leads to undercutting and eventual collapse of the overlying rock. Figure 2 below illustrates the process of undercutting; a large portion of the cliff base has been eroded and the overlying rock sits precariously above.

Other factors contributing to cliff formation include precipitation (rain/snow/hail), which penetrates the natural cracks and fissures throughout the cliff, washing away and/or dissolving less resistant rock and weakening the stability of the cliff. The rate of erosion is accelerated by the freeze-and-thaw action during the winter months, during which time the expanding ice cracks the rock further, notably on the exposed outer surface. Erosion also occurs during the summer months, a which time the cliff is warmed and the evaporating water causes the sediment to contract and crack (porous rock only).

As a result of the forces outlined above, cliffs are constantly changing and on the retreat; inevitably rock falls and large scale collapses occur unpredictably throughout the year.

http://www.discoveringfossils.co.uk/coastlines.htm

coastal_geomorphology2.jpg (89.79 kB . 910x279 - viewed 11195 times)

Incidentally, the cliffs are white because they actually are made of chalk (calcium carbonate).
Title: How Is A Cliff Made ?
Post by: JimBob on 18/09/2008 01:51:16: Evie is correct - it isn't because of plate ex. It is simply erosion. Actually the Channel is a pull-apart graben(down-faulted on both sides.)

No plates jumping on each other here!
Title: How Is A Cliff Made ?
Post by: JimBob on 18/09/2008 01:51:58: BTW, Neil, nice rocket launcher.
Title: How Is A Cliff Made ?
Post by: tangoblue on 11/03/2009 19:46:44: I wounder if eventually the water will eventually erode all of the land on earth?
Title: How Is A Cliff Made ?
Post by: Bass on 11/03/2009 21:58:59: Lacking geologic processes to build mountains and/or elevate land (such as plate tectonics), erosion would eventually wear down the land. Earth could easily become a water world- and Neil will become a Sheephead.
Title: How Is A Cliff Made ?
Post by: JimBob on 11/03/2009 23:18:34: Think of the shear magnitude of Cliff. And, for geologic processes to stop, the earth's core must cool down to almost nothing - it is not likely to happen in the near future.
Title: How Is A Cliff Made ?
Post by: tangoblue on 12/03/2009 13:28:30: not in the near future but at some point maybe.
Title: How Is A Cliff Made ?
Post by: tangoblue on 12/03/2009 13:29:46: or am i talking rubbish.
Title: How Is A Cliff Made ?
Post by: JimBob on 12/03/2009 21:46:38: I suspect it will take many billions of years before the earth cools.