Description: If making multiple purchases, please follow the instructions after the red text below. Tan hardpan caliche from the Mojave desert - hand/display specimen Caliche underlies desert soils in a large part of the Western U.S. and in other arid areas. It is composed of calcium carbonate and can be tens of feet thick. An ideal caliche profile would have a hardpan at the surface progressing downward into a platy or laminar layer which overlies a nodular zone, and then intercepts the bedrock. Since a caliche takes tens to hundreds of thousands of years to form, changes in climate disrupt this sequence and an ideal profile is seldom seen. The term caliche is Spanish from the Latin calx for lime. It forms when calcium carbonate is leached from the overlying soil and accumulates some distance below the surface.In the Mojave desert, a major period of calcium carbonate deposition appears to have occurred 20,000 years ago, forming a horizon below a depth of 100 cm during a period of greater rainfall than at present. As the climate dried, CaCO3 precipitated to form caliche.The mill for the Copper World Mine was at Valley Wells. The caliche there served as the roof of the mill workers' dugout cabins during the first 20 years of the 1900s, where, comfortable underground, they simply excavated under the caliche from the side of a ravine, field photo. In other parts of the Southwest, caliche posed a challenge for pioneers when they attempted to dig wells.An example of this culturally interesting rock. The field photo shows one of the mill workers' dugout cabins with a caliche roof. Both sides are shown of the specimen with just a pencil in the photo. Select a specimen: When more than one specimen is shown, you can select a particular specimen by telling us what is in the photo with it - a black mechanical pencil, a silver and black pen, or one of those plus some number of coins, or you can let us make the selection. Making multiple purchases? Just add items to your cart. When finished shopping, click on "view cart" and then click on “request combined shipping” at upper right in the Shopping Cart window. Do not proceed to checkout. We will send an eBay invoice with the correct combined shipping. Shipping: Priority Mail or Ground Advantage, whichever is cheaper, unless we can find a better rate. Rates vary by weight and zip code. We can usually ship for less than eBay will charge, and will refund the overpayment as soon as the box is packed. International customers: We sell and ship internationally. If eBay’s page does not let you enter your country name to determine the shipping cost for something you are interested in, please contact us. We can tell you what the shipping would cost and how to make the purchase. You can then decide if you wish to complete the transaction. Use the Contact Seller link in the Seller Information box on the right side of this page. Pay securely with your debit or credit card through PayPal! You do not need a Pay Pal account to do this. Yes, we do combine shipping!
Price: 16.5 USD
Location: Olancha, California
End Time: 2025-01-01T10:10:27.000Z
Shipping Cost: N/A USD
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Return shipping will be paid by: Seller
All returns accepted: Returns Accepted
Item must be returned within: 30 Days
Refund will be given as: Money Back
