Located inside the museum, just to the left of the main entrance is a whale vertebrae fossil that was found in the hills of the City of Brea in the 1950s. But, Brea is located about 20 miles inland, so how did this fossil get here and how did it form?
Before we can discuss how a whale got here, you must understand what a fossil is and how they are formed. In this case, we'll use whales as the example. To make things simpler, we'll talk about fossils in general. When sea life dies, they fall to the bottom of the ocean. Over millions upon millions of years, sediment that has been carried by the ocean pile up on the dead organic matter and begins to crystalize and form hard rock. The rock is denser than the soft sand below so it sinks and when it does, the temperature rises. When it gets above a certain point, the rock melts and takes the shape of the dead animal. Due to geologic forces, the the newly made fossil is brought up to the surface under miles of rock. As the terrain rises, so does the location of the fossil as it gets closer to the surface. This is how it got there, but not why it got there.
This can be answered by knowing that tectonic movements cause land to move. Land moves because of convection currents in the earth. Similar to when you cook pasta on the stove and you see pasta sink and rise in the pot. This is a natural process of high or hot temperatures want to go to low or cold temperatures. This is one of the laws of nature, that everything tries to balance out. High pressure goes to low pressure to find a balance. When this happens in the earth, we get cracks called faults. We all know about the San Andreas Fault, which is only about 60 miles from this location. This fault was not always here.
40 Million years ago (mya), there was a plate that doesn't exist today called the Farallon Plate. It collided with the North American Plate heading north east at about a rate of 2 inches per year. This plate had fossilized marine life and it was carrying it right to California. About 20-25 mya, we had the creation of the true San Andreas Fault. Because the Farrallon Plate was a convergent plate (meaning a subduction zone at the intersection of the North American plate) heading north east, it made the San Andreas a transverse (or slip-fault). This may not make a whole lot of sense, but think about it as if the Farrallon plate went all under the covers at bed time, but never woke up. The covers being the North American Plate. The entire Farrallon plate disappeared under the North American Plate where is kept going deeper and deeper into the earth's core where it was melted and fused with the current North American Plate. Most of the fossils were lost, but some, likely less than .01 percent were part of the new fault and a new plate. The new fault being the San Andreas and the new plate being the Pacific. Look at the diagrams below to get a mental picture.
This whale fossil is a few million years old. The fossil has been determined to be a Sperm Whale, which still exist today. Unfortunately, due to recent human activities, these number have been declining. Fortunately, Sperm Whales are located all over the world and their natural current, and likely ancient, habitats are situated near all the continents, except for Antartica. Below is a map of their current distribution and were you can still find them today, and likely still have found them if the continents didn't shift.
Because this is a fossilized vertebrae, it doesn't show the magnitude of the entire whale. Refer to the diagram below once you have seen this fossil up close and you can only imagine how large this sperm whale really was when it lived a few million years ago. It wouldn't even fit in the museum's lobby it was so big.
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1. Brea Olinda - Whale Fossil on the first line of your email.
2. Describe the Whale Vertebrae Fossil. What colors do you see in it? How large is it? What's it shape?
3. Using the diagram above, what type of vertebrate would this fossil most likely be AND why would you think so? Describe similarities between the diagram and the fossil.
4. How many million years old is this fossil?
Works Cited
http://www.enchantedlearning.com/subjects/whales/species/Spermwhale.shtml
https://en.wikisource.org/wiki/Cambridge_Natural_History_Mammalia/Chapter_XII