>> Don't forget those vessels completely encompassed by formations to the point
>> they were really no longer visible in the column, except where looters
>> hammered away to expose them.
>>
>> Sent cellularly.
>> -Don
>>
>> On Mar 12, 2013, at 2:25 PM, "Allan B. Cobb" <a...@oztotl.com> wrote:
>>
>>> In Guatemala, I have seen calcite almost completely covering flagging tape
>>> that we left surveying the year before. I have seen stalagmites about 50 cm
>>> tall growing out of Maya vessels that are a little more than a thousand
>>> years old. I have seen photos of one almost a meter high growing out of a
>>> 1000 year old Maya vessel. The growth rate of speleothems is highly
>>> variable.
>>>
>>> Allan
>>>
>>> From: Neal Hines
>>> Sent: Tuesday, March 12, 2013 11:33 AM
>>> To: nealahi...@gmail.com
>>> Cc: Texas Cavers
>>> Subject: [Texascavers] Estimate of stalactite growth (Merkel et al. 2008)
>>>
>>> This morning I read a geochemistry text on carbonate mineralization that
>>> gave an example of how much stalactites might grow in one year: 0.19
>>> mm/year. It's a recent book (Merkel et al. Groundwater Geochemistry 2008).
>>> Assumptions: partial pressure CO2 of 3% (charged up from soils) degassing
>>> to 0.03% (by volume; atmospheric level), 100L of water dripping from the
>>> ceiling, and the ceiling covered by 15% stalactites.
>>> Cavers all know this growth varies by quite a bit, but this might serve as
>>> a rough upper end growth rate. So, within a caver's life of 70 years, you
>>> could see a formation grow by over 1 cm! Lending truth to the observation
>>> I've heard of some cavers that, "this passage has shifted since I was here
>>> last." Sodastraws can grow even faster I believe & I'm sure people will
>>> have opinions on that.
>>> Also, thanks to Ron Green for doing the webinar on Geophysics in karst
>>> landscapes last night. I caught only the tail end, but there were tons of
>>> questions and very interested participants.
>>> -Neal Hines
>>>
>>>
>>>
>>>
