Mathesons Bay facts for kids

Mathesons Bay or Te Kohuroa is a small beach in the Rodney area of the Auckland Region in New Zealand. It is about 21 kilometres northeast of Warkworth, close to the small town of Leigh. Most of the houses here are holiday homes, but some people live there all year.

Off the shore, there is a small island called Mathesons Bay Island. It has some large rocks that help protect the beach from waves. Sometimes, there is a floating platform, called a pontoon, which is great fun to jump off!

There are rules about dogs on the beach. From the start of Labour Weekend until the end of Easter Monday, dogs are not allowed on the beach between 9:00 AM and 7:00 PM. However, for the rest of the year, dogs can be on the beach whenever they want. There is also a small playground with a short path leading up the hillside. A walking path starts at Mathesons Bay and goes a little past the end of Matheson Bay Road.

Exploring Mathesons Bay Rocks and Fossils

The rocks at Mathesons Bay tell an amazing story about Earth's past. The oldest rocks are called greywacke. These are tough, grey rocks that formed a very long time ago. On top of these, you can find younger rocks from the early Miocene period, which was about 22 million years ago.

How the Rocks Formed

These younger rocks are part of something called the Waitemata Group. They show how the area changed over millions of years. First, there were shallow ocean waters and rocky shores. Over time, the land slowly sank deeper into the ocean. This created a deep basin where lots of sand and mud settled.

Some of these rocks are from the Cape Rodney Formation. These formed in shallow ocean water. Other rocks are from the Pakiri Formation. These formed from "turbidite" deposits. Turbidites are like underwater landslides. They happen when large amounts of sand and mud slide down into deep ocean basins.

Finding Fossils

If you look closely at the cliffs and flat rock areas, you might find amazing fossils! These are the preserved remains of ancient sea creatures. They show us what life was like in the ocean millions of years ago.

Here are some of the cool fossils you might discover:

• Brachiopods: These are small sea creatures that look a bit like clams. They have two shells.
• Barnacles: These are tiny crustaceans that attach themselves to rocks.
• Bivalves: These are like modern clams, oysters, and mussels. They have two hinged shells.
• Gastropods: These are ancient snails.
• Corals: These are the skeletons of tiny sea animals that lived in colonies.
• Echinoids: These are ancient sea urchins.
• Bryozoans: These are tiny, colonial animals that often look like moss or lace.

There was once a special fossil site north of Mathesons Bay Reserve. It was a fossilized methane seep. This is a place where methane gas used to bubble up from the seafloor. Special creatures lived there. However, this site is now covered by fallen rocks.