Medina Sandstone
Built in 1878 by Langley and Burke, the same architects who built the Allan Gardens structures, is Grace Toronto Church. Originally built as Old St. Andrew’s Presbyterian Church, the building is designed in a gothic style with stained glass windows on the north, east and south sides to allow the maximum light exposure during morning services. While the inside of the church, with its wooden beams, stained glass windows and fittings has been much admired, it is the exterior of this wonderful old building that stands out from the crowd.
The primary stone used on the exterior is Lower Medina Sandstone, a red sandstone formation which is marked with light-coloured streaks and spots including marl. The name Medina was proposed by L. Vanuxem in 1839 to describe the stone formerly known as “The red sandstone of Oswego”. Medina Sandstone is made up of different colour bands which include the top “Grey Band” known as Thorold sandstone, the main red sandstone mass, equivalent to the Grimsby shales, a grey quartzose sandstone distinct from the grey band called Whirlpool sandstone. These members constitute the Upper Medina and below that is a Red Marl sandstone Vanuxem termed the Lower Medina
It is this Lower Medina sandstone which was used for Old St. Andrew’s Presbyterian Church and is so distinct due to the discoloured white patches and spherical spots which are caused by leaching and bleaching
Medina sandstone is predominantly red due to small quantities of iron oxides, and Lower Medina sandstone is mottled with white and light brown discoloration. The sandstone can exhibit large white streaks, and spherical spots which are caused by leaching and bleaching. Quarried in Ontario and New York, Medina Sandstone is commonly referred to as Credit River sandstone. Medina sandstones make up the 100 feet of beds of sandstone which immediately precede the Clinton formation
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Please send me your answers within 4 days of posting your found log. If there is more than one cacher in your party, include the names in your group. Only one person needs to send me the group answers. No spoiler photo's please. Found logs posted without proof you visited the site will be deleted.
Questions
- Based on the information in the cache page and your observations of the Lower Medina Sandstone on the front of the Church, describe the colours of the main sandstone blocks of the church?
- As this is a sedimentary type of stone, you would expect to see distinctive layers and cross-bedding in the sandstone however the Sandstone from the Lower Medina has some unique characteristics. Describe the white discolored portions on the sandstone?
(a) Are the white portions in even horizontal layers or do they form a random patterns?
(b) Are the white portions found in the same blocks as the red sandstone or are they in their own distinct blocks?
(c) Look at the front of the church and estimate the percentage of red sandstone compared to the white discolored portions in the red sandstone. Do not include the blocks that make up the foundation or the stones around the door and windows.
- Compare the sandstone blocks around the front of the doors and gothic windows. Do you believe these blocks come from the the Lower Medina formation or are they from a different layer of the Medina formation? Explain your answer
- Mandatory! Included in your found log provide an original photo of the historic plaque by the front entrance of the building. You do not have to show your face in the photo but include a personal item in the photo like your GPS, thumbs up or a piece of paper with your geocaching name on it. Failure to include a photo will result in your log being deleted.
Resources
- https://www.jstor.org/stable/1639185?seq=1#metadata_info_tab_contents
- http://www.geologyontario.mndmf.gov.on.ca/mndmfiles/pub/data/imaging/IMR014/IMR014.pdf
- https://uwaterloo.ca/wat-on-earth/news/learning-geology-buildings-downtown-toronto
- file:///C:/Users/barbm/AppData/Local/Temp/Gietz_Otto_1952May_MSc-2.pdf
- http://www.geo.mtu.edu/KeweenawGeoheritage/Sandstone/JVille_Quarries.html
- https://gsa.confex.com/gsa/2019AM/webprogram/Paper334632.html
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