Cowlitz Formation facts for kids
Quick facts for kids Cowlitz FormationStratigraphic range: Paleogene |
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Type | Formation |
Underlies | Keasey Formation |
Location | |
Region | Clatsop County, Oregon Lewis County, Washington (state) |
Country | ![]() |
The Cowlitz Formation is a special type of rock layer found in Washington (state). Think of it like a giant history book made of rock! It holds fossils from a very long time ago, during a period called the Paleogene Period. This period was part of the Cenozoic Era, which began about 66 million years ago.
Contents
What is the Cowlitz Formation?
The Cowlitz Formation is a collection of rocks that formed over millions of years. Scientists study these rock layers to learn about Earth's past. The rocks in this formation are mostly sandstones, shales, and conglomerates. There are also smaller amounts of shaly limestone, along with layers of tuff (rock made from volcanic ash) and basaltic lava (rock from cooled lava).
Some of these rocks formed in the ocean, while others formed in places where fresh and saltwater mixed, like river mouths or estuaries.
Discovering Ancient Life
When were the fossils found?
Fossils in the Cowlitz Formation date back to the Paleogene Period. These amazing discoveries were made in 1911. A team of scientists, including Charles E. Weaver, Charles R. Fettkc, Donald Ross, T. A. Bonser, and Olaf Stromme, worked together to study the ancient life of Western Washington. They looked closely at the Cowlitz Formation and another rock layer called the Tejon Formation.
Where is it located?
The Cowlitz Formation is found in a canyon near Olequa Creek. This area is between the towns of Winlock and Olequa. You can find it in southwestern Lewis County and northwestern Cowlitz County, Washington.
What fossils were found?
The scientists found a total of 45 different types of ancient sea creatures in the Cowlitz Formation. Thirty of these were completely new to science and had never been discovered before! These fossils help us understand what life was like millions of years ago.
The Cowlitz Formation contained fossils of:
- Pelecypoda (like clams and oysters)
- Gasteropeda (like snails)
- Brachyopoda (small sea creatures with two shells)
- Shark's Teeth
These findings give us a peek into the ancient oceans that once covered parts of Washington state.