Waipara Greensand facts for kids
Quick facts for kids Waipara GreensandStratigraphic range: Palaeocene Thanetian/Selandian, 62–61 Mya |
|
|---|---|
| Type | Geological formation |
| Sub-units | Mount Ellen Member, Stormmont Member |
| Underlies | Ashley Mudstone |
| Overlies | Loburn Formation |
| Lithology | |
| Primary | Sandstone |
| Location | |
| Region | Canterbury |
| Country | New Zealand |
| Type section | |
| Named for | Waipara River |
The Waipara Greensand is a special type of rock found in the Canterbury area of New Zealand. It is a rock layer that formed a very long time ago. This rock layer is famous because it holds amazing fossils, especially some of the oldest penguins ever discovered!
This rock unit dates back to about 61 to 62 million years ago. This was just after a huge event called the Cretaceous–Paleogene extinction event. This event caused many plants and animals, including the dinosaurs, to disappear from Earth. The Waipara Greensand formed during the early Palaeocene Epoch, in periods known as the Thanetian and Selandian.
Contents
What is the Waipara Greensand?
The Waipara Greensand is a type of Sandstone. It is made of fine to medium-sized grains of sand. It gets its name "Greensand" because it contains a lot of a green mineral called glauconite. This mineral gives the rock a greenish color.
You can find this rock layer appearing on the surface in many places across North Canterbury. Scientists believe it formed in a shallow part of the ocean. The sand and other materials settled very slowly over a long time.
Where is the Waipara Greensand Found?
The Waipara Greensand is thickest near the Waipara River. Here, it can be about 80 meters (260 feet) thick. As you move south or north from the river, the rock layer becomes thinner.
The age of the Waipara Greensand is from the Thanetian and Selandian periods. The very top of this rock layer marks an important time boundary in New Zealand's geology. This boundary is linked to the time when the Paleocene Epoch ended and the Eocene Epoch began around the world.
Amazing Fossils in the Waipara Greensand
Even though the Waipara Greensand does not have a huge number of fossils, the ones found there are very important. These fossils help scientists learn about life on Earth millions of years ago.
Ancient Sharks and Other Sea Creatures
Scientists have found at least 16 different types of ancient sharks in the Waipara Greensand. These include species like Chlamydoselachus keyesi and Centroselachus goord.
They also found a mysterious creature called Waiparaconus. Scientists are still trying to figure out if it was a type of Barnacle or a jellyfish-like animal. Sometimes, fish bones and parts of shellfish are also found, but they are often not well preserved.
The Oldest Penguins Ever Found
One of the most exciting discoveries from the Waipara Greensand is the remains of two very early types of penguins. These are called Waimanu and Muriwaimanu. These fossils are incredibly important because they are some of the oldest penguin fossils known. They help us understand how penguins evolved over millions of years.
Tiny Fossils That Tell a Story
Besides the larger fossils, tiny fossils called nanofossils are also found. These include two key types that help scientists figure out the age of the rock: Chiasmolithus bidens and Hornbrookina teuriensis.
Most of the shark fossils were found in loose, weathered material. This material collects at the bottom of steep banks along the Waipara River. Sometimes, a mineral called gypsum covers the shark teeth. This can make it hard for scientists to identify them.
