Unanswered Questions

Cave geology, biology, and similar topics. Also visit the NSS Biology Section, or the Cave Geology and Geography Section, or the NSS Paleontology Section.

Moderator: Moderators

Unanswered Questions

Postby TheRookie » May 7, 2008 12:45 pm

Hello all!

I'm new to the board and I tried to look for some of my questions, but no luck. I'm one confused caver - overwhelmed with info! Please help :)

First - besides scallops what are other indicators of water flow direction in a cave?

Secondly - How are tubular and deep narrow winding canyons passages formed? And when they are formed will the water table be up or down?

Thanks for any help & info!!
Last edited by TheRookie on May 9, 2008 2:06 am, edited 1 time in total.
TheRookie
New Poster
 
Posts: 1
Joined: May 7, 2008 12:31 pm
  

Re: Unanswered Questions

Postby Phil Winkler » May 7, 2008 1:27 pm

Jess,

Flowstone and travertine dams often indicate the direction of earlier water flows.

You might want to pick up a book about cave formation to read more: Jenning's "Karst" comes to mind, but there is a new one by Art Palmer that is getting great reviews, too. Check out the NSS Bookstore on www.caves.org
Phil Winkler
13627 FE
User avatar
Phil Winkler
Global Moderator
 
Posts: 2375
Joined: Sep 5, 2005 8:48 am
Location: Wilmington, DE and Dewey Beach
NSS #: 13627FE
  

Re: Unanswered Questions

Postby fireman1904 » May 7, 2008 3:55 pm

The tubular passages you refer to are formed when the caves were below the water table and the water started disolving the limestone etc. in the area of the joints and cracks. The winding canyon passages are formed above the water table or as it drops. Streams flowing through the cave dissolve and abrade the limestone away and cut down through the stone. There are more technical terms and descriptions but that should give you some idea of what is going on.
Mike Woolard
NSS# 49891
HCG, ICS, ISS, SCCi, Chattanooga Grotto
User avatar
fireman1904
Frequent Poster
 
Posts: 60
Joined: Jun 5, 2006 8:54 pm
Location: Monroe City, IN
Name: Mike Woolard
NSS #: 49891
  

Re: Unanswered Questions

Postby wyandottecaver » May 7, 2008 4:18 pm

actually, things can get complicated.

scallops *can* indicate flow, but they can be old artifacts and hydrology might have changed, some eddies can create reverse scallops etc. If present, look for large boulders and see which direction the eddie pockets behind them are. the pockets will generally be downstream.

deep, narrow, winding canyons can be a result of 1) fissures or cracks enlarged by water erosion, or 2) a rapid drop in the water table (geologic time) that promotes rapid downcutting rather than widening, or 3) the result of seams previously filled by a highly soluble substance like gypsum that were later dissolved 4) all the above :)

tubular passages may be formed below the water table, or they can be the result of "polishing" when highly aggressive flood waters (high volume, high pressure, low level of mineral saturation) rise and "clean up" those offending projections and irregularities.

Art Palmer's book "Cave Geology" is a great resource.
I'm not scared of the dark, it's the things IN the dark that make me nervous. :)
User avatar
wyandottecaver
NSS Hall Of Fame Poster
 
Posts: 2902
Joined: Aug 24, 2007 8:44 pm
Location: Indiana
  

Re: Unanswered Questions

Postby Marlatt » May 7, 2008 5:25 pm

I'd second the recommendation for Palmer's new Cave Geology. Great book. You might also want to peruse some of the papers on the Speleogenesis website (http://www.speleogenesis.info/old_journal_index.php) - as has been noted here, passage morphology can be the result of differing causative mechanisms. In the case of canyons, they can form in response to vadose downcutting, joint-controlled phreatic enlargement, as joint-dominated flood mazes, or perhaps due to confined artesian conditions.

The most reliable method I've found to determine the direction of water flow is to drop a float into the water and see which way it goes! :tonguecheek:

Stuart
Psalms 95.4 / Proverbs 25.2
User avatar
Marlatt
Prolific Poster
 
Posts: 110
Joined: Sep 5, 2005 9:38 am
Location: Colorado
  

Re: Unanswered Questions

Postby rpaylor » May 8, 2008 1:50 pm

If there are sand and cobble sediment banks in the cave, you can get an idea of flow direction. Small stones and cobbles become "imbricated", or stacked on each other like roof shingles. The direction of the stacking tells you which way the water flowed:

water flow ------------>
cobbles: ///////////
rpaylor
Frequent Poster
 
Posts: 53
Joined: May 22, 2006 11:54 am
Location: Baton Rouge, LA
Name: Randy Paylor
NSS #: 24524FE,L
  


Return to Speleology Forum

Who is online

Users browsing this forum: Google [Bot]