by JohnD » Sat Apr 02, 2011 1:25 pm
Doug (Ettinger),
Planetary swellings.
A recent article in new Scientist (Pulsating planet;
http://www.newscientist.com/article/mg2 ... -roll.html) describes recent findings on a known anomaly in the north North Sea, between Scotland and the Faroes. You need a subscription to read the whole article, so here goes with a precis.
There is evidence of 'fossil' river valleys in the sea bed, under two kilometers of silt. This suggests that the surface was above the sea at some time, but it was above the sea for only about a million years (!) 55 M ago. This is a very short period of geological time. A Cambridge UK team suggest that this was caused by a 'hot blob' of rock, rising up the Iceland hot spot and spreading out in the mantle like a ripple in a pond, raising the surface for a 'short' period. Similar fornmations are seen off Angola and in the Arabian Peninsula.
The original paper is at Earth and Planetary Science Letters
Volume 267, Issues 1-2, 1 March 2008, Pages 146-160
This is an explanation for transient uplifts, not for massive rifting, but it is a swelling mechanism.
An abstract is available online, but the link doesn't work
Try item 14 at:
http://www.sciencedirect.com/science?_o ... 994b4745a0
John
Doug (Ettinger),
Planetary swellings.
A recent article in new Scientist (Pulsating planet; http://www.newscientist.com/article/mg20928031.600-pulsating-planet-superhot-rocks-make-the-earth-roll.html) describes recent findings on a known anomaly in the north North Sea, between Scotland and the Faroes. You need a subscription to read the whole article, so here goes with a precis.
There is evidence of 'fossil' river valleys in the sea bed, under two kilometers of silt. This suggests that the surface was above the sea at some time, but it was above the sea for only about a million years (!) 55 M ago. This is a very short period of geological time. A Cambridge UK team suggest that this was caused by a 'hot blob' of rock, rising up the Iceland hot spot and spreading out in the mantle like a ripple in a pond, raising the surface for a 'short' period. Similar fornmations are seen off Angola and in the Arabian Peninsula.
The original paper is at Earth and Planetary Science Letters
Volume 267, Issues 1-2, 1 March 2008, Pages 146-160
This is an explanation for transient uplifts, not for massive rifting, but it is a swelling mechanism.
An abstract is available online, but the link doesn't work
Try item 14 at:
http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235801%232008%23997329998%23681075%23FLA%23&_cdi=5801&_pubType=J&_auth=y&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=c774508580f009dcb38073994b4745a0
John