shale - student specimens of tan Miocene diatomaceous shale from the Monterey Formation of Ventura County California - UNIT OF 5 SPECIMENS
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, which is 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 ship First Class mail unless combined with other purchases. Click > About 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.