Holy Rosary Cathedral, which was first built in 1899-1900, is at the SE corner of Dunsmuir and Richards. Unfortunately, it was not built quite right as you will see below. Restoration of the church was completed in 2008 and now it is built correctly.
The very base of the church was built from coastal granodiorite (an igneous plutonic rock) which has withstood the test of time. It has no directonal properties.
The upper portion was built from sandstone which came from Gabriola Island off the east coast of Vancouver Island. This is a good building stone except it is not extremely well cemented and, unfortunately, the blocks were placed on the church with the depositional layers parallel to the walls, so the depositional layers tended to peel off over time. If they were placed with the depositional layers perpendicular to the walls, the sandstone would have lasted. The restoration in 2008 was done correctly with the depositional layers at right angles to the walls.
Sandstone is formed with water, ice or wind depositing the sand and gravel in layers, and depositional layers are important to its strength properties. In compression it is strong when squeezing the depositional layers, but when shear forces push parallel to the depositional layers, the cement between the depositional layers becomes critical as it tends to glue the sand grains. The cement is usually iron, calcite or quartz which is deposited by water seeping through the sand while it is buried for millions of years. If the cement is weak, the layers do not hold together. Because of this property it is relatively easier to split sandstone between layers along laminations and it is more difficult to cut across the grain. If the sandstone is extremely well cemented, this is not a problem.
Restoration had to be done to the walls of the church as some of the original sandstone needed renewal. The same sandstone was used in the restoration so as not the change the look of the church, but the sandstone was placed in the proper direction, with the depositional layers at right angles to the walls. This fix should last longer than the first 100 years.
Below is a picture of the sandstone.
With this in mind, your task is to tell me, by messenger or email, the following. Any logs with no answers within a few days will be deleted.
The answers may be found from the outside of the church on the church walls.
1. Considering the size of the grains, what agent most likely deposited this sediment, water, ice or wind? (Ice moves coarse grains and doesn't sort them, and wind has limited lifting power and is a superb sorter. Water moves all materials and sorts according to size and speed of depositing water.)
2. Tell me which mineral is cementing the grains together. If it is rusty or brownish, it is likely iron oxide and mud, if it is white and looks soft it is calcite, or looks glassy it is quartz.
3. Post a picture of the sandstone with something personal in the photo, you, your GPS or phone or your caching name.
4. Can you see the sandstone layering?
Congratulations to msweetnw for the FTF in about 10 minutes of the cache being published.