Welcome to Scotts landing.
Location:
The coordinates for this Earthcache will lead you to a spot just at the end of the peninsula.
THIS EARTHCACHE IS ACCESSIBLE AT HIGH TIDE but you can get your feet wet ...
There is no physical cache located at the posted coordinates. To receive credit for the find, you will need to answer the questions in the description and email those answers to me through geocaching.com. Please do not post your answers in your log, but do feel free to post pictures at the Earthcache site as long as they do not give away the answers.
Vertical rock strata at Scotts landing
Geology:
If you look around the area near the Earthcache coordinates, you will notice almost vertical rock layers. Rocks layers are also called strata (latin)
Rocks form in layers over millions of years. If you look at the rocks (cliff end) at published coordinates it is made from sedimentary rock. Sedimentary rocks that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation You’ll also notice distinct layers that may even be different size and colours.
The type of cliff rocks at the end of Scotts landing are sandstones. Sandstones underlie much of the Auckland region and underlie Auckland’s volcanic rocks. Sandstones at Mahurangi Peninsula belong to the "Waitemata Sandstones area". Usually the Waitemata Sandstones consist of alternating layers of sandstone and mudstone and were deposited on the floor of a 1000-2000m deep marine basin (called the Waitemata Basin) by the early Miocene period, 21-18 million years ago. The maximum water depth of the Waitemata Group basin was 2000m. This deep marine depression was formed by rapid subsidence of the whole Auckland region (22-20 million years ago) as the northern part of New Zealand started to feel the effects of the newly active boundary between the Pacific and Australian plate , with both compression and subduction forces.
The very first stage of sedimentary rock is usually flat-lying. The ancient seafloor here has been tilted and lifted up by tectonic movements.
New Zealand is on the boundary between the Australian and Pacific tectonic plates. To the northeast of New Zealand, and underneath North Island, the Pacific Plate is moving towards, and being subducted below the Australian Plate. At the end of South Island the situation is opposite the Australian Plate dives down (subducts) below the Pacific Plate ...
Questions:
Q1) What are rock layers called ?
Q2) Which forces lifted up rock structures ?
Q3) Name two tectonic plates which caused the cliff rock lift here.
Q4) Take a picture of yourself and/or your GPS device or phone, with the view of either side of the peninsula and post it with your log.
Logging:
Do not post the answer in your log. You can go ahead and log your find (ie. you don't need to wait for permission) if you answered the questions above and uploaded the correct picture. There is no need to email me your picture. If there are any questions about your answers CO will contact you. Logs without answers to CO , with pending questions from CO or without the picture will be deleted without further notice.
Happy Earthcaching!!!