Queenston Formation Earthcache EarthCache

To get to this earthcache from recommended parking, you will have to hop a small creek, which may not be so small in the spring. Most of the year there are a couple of spots you can cross without getting wet. You must email me the answers to the logging questions to claim a find, if I don't receive them within a week your log will be deleted.

Queenston Formation

This Earthcache will bring you to an outcropping of the Queenston Formation. This outcrop represents only a small part of it. The uppermost part of the formation in Ontario is located to the west, beneath the Niagara Escarpment. If you live around this area, you have probably walked and driven by areas of this formation and not even realized it. Hopefully, after you have finished this earthcache, you will be able to recognize other areas of the formation should you see it, and maybe understand a little bit about how it was formed.

The best place to start is at the beginning, which was roughly 485-443 million years ago. It was during the Paleozoic Era, in a time that geologists call the Ordovician Period. To give you an idea of actually how long ago this was, one of the major land masses on our planet was Gondwana. Modern day Antartica, South America, Australia and Africa were all part of Gondwana. The earth's continents had not yet divided into the continents we know now. Life forms on Earth during this period of time were mainly fish, Arthropods, mollusks. 

During this time, the earth's land masses were shifting. This helped to cause the formation of mountains. Geologists called one series of these mountain forming events the Taconic Orogeny. This occurred during the Ordovician era. The Taconic Orogeny was the first of three mountain building events that formed the Taconic mountains. It is thought to have been caused by a collision between a formation of rocks in the ocean and the eastern side of our continent.

Over millions of years, the Taconic mountains have eroded. Erosion occurs when soil and rock is removed by wind, water flow, or other sources, and is transported by these forces, and deposited in other regions. One region that geologists have identified is the Queenston Delta. It is large wedge of sediment that formed in a band from Quebec to New York State, and as far west as Lake Huron.  The Queenston Formation you see before you is part of the Queenston Delta. 

The Queenston Formation gets it's distinctive colour from Hematitic Shale. Hematitic is the mineral form of iron(III) oxide (Fe2O3). Often, you will see bands of red and grey. The red colour is because, once deposited, the iron-bearing shale oxidized, ('rusted') while the grey colour comes from reduction. Typically the grey coloured shale would have been formed in standing or acidic water .

Over the millions of years that erosion of the mountains was taking place, many layers of rock have formed. Rock is formed when the sediment gets buried by more sediment, and compresses due to the weight on top of it. You can see the layers of rock in front of you. Geologists have identified 14, but then grouped those 14 into 4 main bodies of rock (facies);

Facies Association A: usually dark grey shales, alternating with limestones and siltstones deposited on a shallow shelf. 
Facies Association B: usually red and grey shales, alternating with siltstones, sandstones and limestones and deposited under variable tidal conditions. Usually occur in the middle part of the  formation. 
Facies Association C: primarily red shales, alternating with Grey siltstones. They are usually found in the uppermost part of the formation, and are thought to be formed as sea levels diminished. 
Facies Association D: only found in NY, dominated by sand, and was deposited by the actions of rivers and streams

In the Queenston Formation, you will usually find the following rock types;

Shale:a fine grained, clastic (composed of fragments of other minerals and rocks) sedimentary rock that is primarily a mix of mud, clay and silt sized minerals. The big characterization of shale is that it splits into thin sheets (a process called fissility). Usually it does not crop out unless protected by a harder rock. 

Siltstone: a non-clastic sedimentary rock, comprised of silt sized particles. It has a majority of silt component, rather than clay. It is coarser than shale and finer than sandstone. Silt is so fine that you can't see the grains, but you can feel them. It is less common than sandstone or shale. 

Sandstone: a clastic sedimentary rock. It is composed of sand sized particles. Sand is larger in size than silt. It is formed when sand settles, becomes compacted by overlying deposits, and then precipitated minerals bind the sand grains together. Because it is made of larger particles than siltstone, it has a rougher feel. 

Limestone: a sedimentary rock, largely composed of calcium carbonate. Limestone commonly develops in wet areas, from the accumulation of coral, shell, and fecal debris. Often times you will see fossils in this type of biological limestone. The limestone in the Queenston formation is found in thin layers. 

To log this earthcache as found, also take note of the prominent tree that is at GZ, and email me the answers to the following questions:

1) Based on the above information, how many Facies Associations do you think you see? Which ones and why?

2) Note the predominant layer of stone that is about eye level from where you are standing. Based on the information and pictures in the gallery, which rock type do you believe it is? How did you come to this conclusion? 

3) There are stones that are caught in the roots of the tree. What colour are they? 

4) If you can find any loose shale, compare the red and grey. Is the shale easily broken by hand? Is one colour stronger than the other? 

Bonus question:(you can answer in your log if you like) 

how much longer do you think the tree will be standing? 

Any pictures would be a welcome addition to your log. Thank you for visiting.