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  • A question about caliche.

    Hi guys and gals. Sometimes I found points that appeared to have what looks like a caliche deposit on certain areas of the point. It was a rare occurrence that I saw this but it did happen on chert points. Since joining the forum I have seen a few points posted that appear to have this same kind of calcareous deposit. I am currently trying to help Pickwick ID one of his stemless points that looks like it has a caliche. I have done some reading about caliche formations and it seems like caliche occurs in areas that have relatively light annual precipitation, about 25 inches or less. The Tenn. River area does not qualify for that either now or at any time since the artifacts were made. I have read that under certain very local situations that it can occur in areas of much higher rainfall such as occurs in the Tenn. valley area. My question is: Have any of you ever seen caliche on any of your chert artifacts. And if so, do you know or think you remember what type point it was? I have done a G search on this subject but I've come up with a blank about caliche on chert art facts. I don't remember the types/relative ages of the points I noticed this on and because I sold the bulk of my collection many years ago and the few I kept have no caliche then I was hoping some of you may be able to tell me about your experiences with caliche on points.

  • #2
    I have a couple of examples I believe Joe, I'll dig up pics and add later on. The explanation I believe lies in the moisture and mineral exposure that occurs within rock shelter and cave environments although I don't fully understand the process myself. Most of the ones I found or purchased where Rockshelter finds, and a few from Glovers cave from the Vietzen collection... Dry and habitable didn't always equate to perfectly dry, many shelters that were used had some natural irrigation so to speak due to mountain streams, run off and grpund water. And sometimes when there is just enough rain areas would flood or fill with water.
    Josh (Ky/Tn collector)

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    • sailorjoe
      sailorjoe commented
      Editing a comment
      Thanks Kfg for your replly. The ones I found were surface finds as is the one I am trying to ID from Pickwick.

  • #3
    I have seen thousands of Central Tx artifacts of all ages covered in it. As a matter of fact, I have seen modern glass coated white so it doesn't take terribly long under the right conditions.

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    • sailorjoe
      sailorjoe commented
      Editing a comment
      Thanks Garguy for your reply. What is the general annual rainfall in the central Texas area?

  • #4
    You can get something similar near rivers where water levels rise and fall, and artifacts get covered by different salts and minerals. Not sure if it's what a Texan would call caliche, but it can produce heavier than normal mineral deposits.
    Hong Kong, but from Indiana/Florida

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    • sailorjoe
      sailorjoe commented
      Editing a comment
      It seems like that may be the situation where Pickwick found the one I am trying to ID but others found nearby had no visible caliche from the photos he provided. The mystery just keeps getting more mysterious.

  • #5
    Caliche is the solid residue that remains after the evaporation of calcium carbonate, a gas. It's really not a matter of how much rainfall, it's a matter of how much limestone and natural calcium, including selenite or calcite, plus a few others, are in the soils. A lot of desert artifacts will have caliche from limestone deposits. Rain water will hit the limestone and calcium deposits and bubble and create calcium carbonate. The gaseous liquid will settle on the artifacts, and the gas evaporates. What's left behind in a solid matter will absorb into the surface of an artifact, and will be hard and scaly. It's similar to the crust you see in houses that we call hard water, It's a scaly deposit that begins with lime. It's a little more complicated but that's the general idea. Stalagtites form the same way. Acidic rain water drips through stratified layers of calcite and at the end the water evaporates leaving behind the solid residue that forms the stalagtite. So caliche is actually residual calcite. You see this often in rock shelters, because many shelters were created from soft, stratified limestone deposits.
    http://www.ravensrelics.com/

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    • sailorjoe
      sailorjoe commented
      Editing a comment
      Hi Paul. Thanks for joining the discussion and I hoped that you would. Thank you for your info. Some of it I knew and some is new, so thank you. The area where the point I am trying to help ID was discovered has lots of limestone in the rock layers underlining the soil. My comment to clovisoid the second previous post still applies. I'm thinking now that I shouldn't be getting hung up on some of this but I can't see to help myself. I was born with an intense curiosity about all I didn't know. And I have not changed in that regard. Thanks again for your input.

    • pkfrey
      pkfrey commented
      Editing a comment
      You have to consider how old the artifact is, although as mentioned, caliche can form in a relatively short time. If the artifact is thousands of years old, and was lost in a limestone rich area, caliche can form on the other side, the side laying down for thousands of years. It doesn't always have to form on the upper side of the surface, A lot can also happen geologically from the time the artifact was lost. Waters cut through limestone deposits, exposing those deposits in areas that were not exposed before, rocks erode and tumble, rivers form or change courses. The only thing for certain is that at one time the artifact was exposed to acidic water and was near a limestone deposit that formed calcium carbonate from acids.

    • sailorjoe
      sailorjoe commented
      Editing a comment
      Hi Paul. Thanks for your additional comments. They are helpful. Regarding the particular point that I am trying to help ID: if the type that I think it may be could be an Early Archaic type that is kinda rare in the relatively restricted area it is known from. From what I know it hasn't been found at controlled excavations, only on the surface and usually from sites that produce Early Archaic points. And the photos of the point show a caliche. Thanks again for your interest.

  • #6
    Found lots of em in central /south Texas . Takes a good soaking in vinegar to get the calcification off and a tooth brush . As far as your rain 🌧 question goes about 24-28 “

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