shale - teaching hand specimen of tan diatomaceous shale from the Monterey Fm.

Description

If making multiple purchases, please read the note following the
red
text
below!
Teaching hand specimens of a light tan diatomaceous shale from the Miocene Monterey Formation, Ventura County, California
This Miocene shale is from the Monterey Formation of Southern California. These specimens are fairly soft and light weight, being composed of fine grained sediments and diatoms, plankton that forms a siliceous exoskeleton. Some specimens show evidence of turbidity flow, splitting on a surface that appears hashed. Diatoms contain a droplet of oil when living. When they die and rain to the deep sea floor and are buried, the oil eventually becomes petroleum or natural gas and the siliceous skeletons become diatomaceous earth.
The Monterey shale contains a considerable amount of petroleum, which, until recently, was mostly locked in the rock. The improved extraction techniques that have made the U.S a net energy exporter for the first time since 1958 are unlocking this oil. This shale was collected in Balcom Canyon which roughly separates South Mountain from Oak Ridge in Ventura County, California. Oak Ridge is the surface expression of an anticline. In the South Mountain Oil Field, petroleum is produced from the Oligocene Sespe and Pliocene Pico Formation. Oil in the Pico likely migrated upward from the underlying Monterey, a rich petroleum source rock, thanks to the diatoms.
Students should know the basic sedimentary rocks in order of increasing grain size, from mudstone and shale, siltstone, sandstone to conglomerate and coquina. Shales differ from mudstones in that they are more compressed, form flat plates, and are less likely to disappear in a poof of dust when dropped by a student. This shale is soft and will suffer somewhat from student examinations.
Some shales closely resemble slate, metamorphosed from shale. To distinguish a shale from a slate, the test is to lick it. The shale will smell muddy. The slate won't. In this case, there is no confusing this shale with a slate.
These specimens will fit into a 3.5” x 5.25" specimen tray. We include data with every specimen: collecting locality for mineral specimens and for rocks also the formation and age, if determined.
Select a specimen:
You can select a specimen by telling us what is in front of it - a black mechanical pencil, a silver and black pen, a silver and blue 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
“request total”
at upper right in the Shopping Cart window.
Do not proceed to checkout.
We will send an eBay invoice with the correct combined shipping.
The combined shipping will often be less than eBay shows. Please wait for that invoice before paying.
There is no obligation to purchase. You can decide after seeing what shipping will cost.
Shipping:
By first class mail unless combined with other purchases
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!