siltstone - teaching hand specimen of a moderately lithified tan to gray Miocene siltstone
This siltstone is Miocene in age, is moderately lithified and was deposited in a closed basin in a non-marine or brackish marine depositional environment. It is mapped as a unit of the Ridge Route Formation, part of the Ridge Basin Group. It is relatively well cemented, so will withstand student examination.
The silt grains in these specimens are smaller than those of a sandstone and when rubbed off, feel gritty. It would be instructive to compare this siltstone with a larger grained sandstone, and with a siltstone that is cemented with silica. This siltstone has a calcium carbonate cement which effervesces with a drop of dilute hydrochloric acid.
Select a specimen: You can select a specimen by telling us what is in the photo with it, a blue or black and silver pen, a black mechanical pencil or one of those plus some number of coins, or you can let us make the selection.
Shipping: Priority Mail small flat rate box unless combined with other purchases. Click > Shipping < for shipping rates. Use back button to return to this page.
Making multiple purchases? Click on the "combine shipping" button in the shopping cart. We'll send an invoice with combined shipping. A link in that invoice will bring you back to checkout, no hassle.