To jean113: formation - The TrekEarth Forums

Forums


Go Back   The TrekEarth Forums >

Notices

Reply
 
Thread Tools Display Modes

Great ifege 2020-05-17 23:34

Hi Steve
When last I visited the Pinnacles (2013) climbing on the formations was strictly taboo. Looks light late afternoon with the light neatly on the girl to make for a good photo. The light and detail are miles better in the large version.
cheers
Ian

  #1  
Old 05-18-2020, 11:41 PM
SteveH SteveH is offline
TE Senior Member
Thread Starter
 
Join Date: Oct 2006
Posts: 766
Default To jean113: formation

Hi Jean, Apparently there are a number of theories regarding the formation of the pinnacles. From Wikipedia:The first theory states that they were formed as dissolutional remnants of the Tamala Limestone, i.e. that they formed as a result of a period of extensive solutional weathering (karstification). Focused solution initially formed small solutional depressions, mainly solution pipes, which were progressively enlarged over time, resulting in the pinnacle topography. Some pinnacles represent cemented void infills (microbialites and/or re-deposited sand), which are more resistant to erosion, but dissolution still played the final role in pinnacle development.[3][4]A second theory states that they were formed through the preservation of tree casts buried in coastal aeolianites, where roots became groundwater conduits, resulting in the precipitation of indurated (hard) calcrete. Subsequent wind erosion of the aeolianite then exposed the calcrete pillars.[5]A third proposal suggests that plants played an active role in the creation of the Pinnacles, based on the mechanism that formed smaller "root casts" in other parts of the world. As transpiration drew water through the soil to the roots, nutrients and other dissolved minerals flowed toward the rootóa process termed "mass-flow" that can result in the accumulation of nutrients at the surface of the root, if the nutrients arrive in quantities greater than that needed for plant growth. In coastal aeolian sands that consist of large amounts of calcium (derived from marine shells), the movement of water to the roots would drive the flow of calcium to the root surface. This calcium accumulates at high concentrations around the roots and over time is converted into a calcrete. When the roots die, the space occupied by the root is subsequently also filled with a carbonate material derived from the calcium in the former tissue of the roots, and possibly also from water leaching through the structures. Although evidence has been provided for this mechanism in the formation of root casts in South Africa, evidence is still required for its role in the formation of the Pinnacles.[6]


So, who knows?

cheers,

steve
Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 08:23 PM.



Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.
explore TREKEARTH