Precambrian Eon A A

The Naranjo Museum has on display one of the best collections of Precambrian fossils.

The Precambrian period experienced a harsh environment. The oxygen levels were extremely low and
the landscape was constantly changing. Volcanic eruptions and the plates shifting made it hard for life forms to survive. During this time period creatures were primitive and lacked eyes due to the dark oceans. Stromatolites oxygenated the earth and still exist today in some areas. All the land masses formed the supercontinent Gondwana.

The oldest rock is from the Precambrian period. It is called Acasta Gneiss and is 4.2 billion years old. It is believed to be the oldest known fragment of the earth’s crust. The oldest mineral known is Zircon and it is 4.4 billion years old.

In the next case you can find pieces of fossilized Stromatolites. Stromatolites oxygenated the earth during the Precambrian period over 3 billion years ago. Layers of Cyanobacteria settled on top of each other. These are considered to be one of the first life forms on earth. Through photosynthesis they released oxygen into the air and eventually the earth had enough oxygen to sustain life.

The first oxygen that the Stromatolites released fell into the ocean and settled forming the rocks that
we know today as Banded Iron. Banded Iron is repeated layers of silver and black iron oxide magnetite that accumulated after the earth was oxygenated by the Stromatolites.

Did you like this post? You might be interested in...

Ordovician Peri...

DSC_1242

Here you will find in the fossil cases and in the ...

More On Current Exhibits »

The Dating Game...

Stratigraphy – lower rocks are older and rock laye ...

More On Current Exhibits »

Also at the museum:

Jurassic Period; Age of Sauropods

The Brachiosaurus was a sauropod dinosaur that lived during the Jurassic period. It had a long neck and small head but was once thought to be the largest dinosaur. This Brachiosaur is the size of a 3 ...

More On Current Exhibits »

Dig Site, Where to Find Fossils

The tools and equipment shown in the dig site were used to dig up Mary Ann Hadrosaur in Montana. For the easy ground we were able to use a shovel and pick but for the harder ground we had to break th ...

More On Current Exhibits »

Search the Museum


Naranjo Museum of Natural History

Tickets Price
Age 3 & under Free
Age 4 to 18 $5.00
Adults $7.50

Hours of Operation
Mon. - Sat.: 10 AM to 6 PM
Sunday: 1 PM to 6 PM

For more information, call
(936) 639-3466