The North American Fly Fishing Forum

The North American Fly Fishing Forum (
-   Coldwater Fly Fishing (
-   -   Limestone I.D. (

only adipose 01-15-2013 09:59 PM

Limestone I.D.
If I were to do some simple water chemistry tests, could I get an indication of the level of influence from springs. Would it be clear that one stream is a limestoner and another is a freestone stream, tailwater etc... I am thinking water hardness would be an indicator? is there anything else that would point to one or the other? Maybe phosphate in a tailwater? Or is this just a bad idea due to lack of time on the water?

sandfly 01-16-2013 04:30 AM

Re: Limestone I.D.
water cress for one never seen it a free stoner.

mcnerney 01-16-2013 05:42 AM

Re: Limestone I.D.
Interesting concept, I have no idea if or how much water chemistry tests, would indicate the level of influence from springs, but it certainly would be an interesting study if you have the capability and time. Bob does have a good point, water cress and some of the other plant life you find common in spring creeks don't seem to exist in freestone rivers.

wt bash 01-16-2013 08:42 AM

Re: Limestone I.D.
High PH in a limestoner, relatively low PH in a freestone. Limestoners are typically found in valley's, have a much lower gradient, the temperature will stay fairly constant throughout the year, and the local geology will consist of limestone and or a volcanic make-up. Then there are the combos that throw all that out the window aside from the geology. Like Yellow Breeches, sections look like freestone waters while others resemble limestone. Freestones will support a wide variety life while limestones will have an abundance of a few different species.

Ard 01-16-2013 08:48 AM

Re: Limestone I.D.
I don't have time to expand on this subject but these streams are a result of geological conditions. Understanding topography, Karst Topography in particular is very helpful in determining whether or not you are in limestone country. Of course some streams are well known as limestone spring creeks but there are a few unpublished gems out there that I used to frequent. Your photo reminds me of Letort Spring in Cumberland County PA. but then many streams remind me of that one.

Beautiful picture,


tbblom 01-16-2013 09:05 AM

Re: Limestone I.D.
Do some google searching on 'end member testing'. Streams do have telltale chemistry that gets diluted downstream. I think Limestone would provide buffered (ph neutral or slightly basic) water that is high in calcium, carbonate, and/or calcium carbonate. You would either need to be good at hand titrations to determine amounts of metals, etc, or have access to a mass spectrometer (ie if you work in a mass spec lab).

End member testing is used to determine pollution sources and dilution patterns, and it can also be used to date water that is being added to streams from aquifers.
Limescale deposits (like hardwater on pipes) and actual limestone outcrops would be a much simpler identifier.

Simplest limestone test is to drop weak HCL acid on the rock. It should fizz as the acid releases carbon dioxide from the calcium carbonate. Only rocks containing limestone and marble will fizz under HCL.

only adipose 01-19-2013 08:49 PM

Re: Limestone I.D.
Thank you for the info, I think it is going to make from some good googleling. I am also taking a Chem course this semester maybe I can get a little extra credit.

Ha. Not a bad guess.. It looks like Le Tort because it is Le Tort! Good call.

only adipose 01-25-2013 11:22 PM

Re: Limestone I.D.

This is a map that shows areas that are associated with sinkholes. Hmmmmm.

wt bash 01-26-2013 10:11 AM

Re: Limestone I.D.
You need that TU book on Pa Limestone Creeks its lists a ton, 90% I've never heard of but alot are also so degraded they don't support trout anymore but I think this is definitely a subject I'm going to look into more with my admissions counselor.

All times are GMT -5. The time now is 08:11 AM.

Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimisation provided by DragonByte SEO v2.0.40 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
2005-2017 The North American Fly Fishing Forum. All rights reserved.