To log this earthcache, please don’t stress about answering the questions. Simply send your best attempts in a private message to me, (the cache owner), and then go ahead and log it as found.
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Go ahead and have fun learning! 
- [REQUIRED] Please post a photo in your log of yourself or a personal item at the outcrop to prove you visited the site.
- Do you see any quartz veins? How do they look different from the chlorite veins? What do you notice about the size and clarity? (Not just the colour.)
- Do you think these are open space filling veins or crack-seal veins?
This earthcache has been submitted for the Planetary Geology on Earth series of EarthCaches created to give geocachers the opportunity to view and learn about geological features on Earth that also exist on Mars, or other planets with documented geology.
Mineral veins such as the one found just outside of Halifax have also been found on Mars.
This image above was taken on March 18, 2015, and provides a view from the Mast Camera on NASA's Curiosity Mars rover showing a network of two-tone mineral veins at an area called "Garden City" on lower Mount Sharp.
Two-tone mineral veins at the Mars site offer clues about multiple episodes of fluid movement. These episodes occurred later than the wet environmental conditions that formed lake-bed deposits the rover examined at the mountain's base. The veins appear as a network of ridges left standing above the now eroded-away bedrock in which they formed. Individual ridges range up to about 2.5 inches (6 centimeters) high and half that in width, and they bear both bright and dark material.
Some of the veins looked like ice-cream sandwiches: dark on both edges and white in the middle. These materials tell us about secondary fluids that were transported through the region after the host rock formed.
In a sample taken from the Mars veins, there was a large amount of cristobalite, at about 10 percent or more of the crystalline material." Cristobalite is a mineral form of silica. The sample also contains a small amount of quartz, another form of silica. Among the possibilities are that some process removed other ingredients, leaving an enrichment of silica behind; or that dissolved silica was delivered by fluid transport; or that the cristobalite formed elsewhere and was deposited with the original sediment.
The veins at Cape Spencer in New Brunswick are the ones we will be studying.
Cape Spencer is a beautiful coastal area just outside of Saint John with boulders and small cliffs. The lighthouse here has been on Cape Spencer since 1873 when it was first lit. Most boulders are solid but there are a few loose holds, so please watch your step and be careful not to go to close to the edges.
The rocks here are part of the granitic foundations of Avalonia and are described as "pervasively altered". Cape Spencer marks the most westerly outcrop of its kind in all of Atlantic Canada.
For this earthcache, we are going to be studying the veins in these outcrops.
A vein is a sheetlike body of crystallized minerals within a rock. Veins form when minerals are carried by a solution within the rock and are deposited through precipitation. Veins are of prime importance to mineral deposits, because they are the source of mineralisation either in or proximal to the veins.
There are two different mineral types of veins in the outcrops: quartz and chlorite.
Quartz is the most abundant mineral found at Earth's surface, and its unique properties make it one of the most useful natural substances. Quartz is the most abundant and widely distributed mineral found at Earth's surface. It forms at all temperatures. It is abundant in igneous, metamorphic, and sedimentary rocks. It is highly resistant to both mechanical and chemical weathering. This durability makes it the dominant mineral of mountaintops and the primary constituent of beach, river, and desert sand. Quartz is ubiquitous, plentiful and durable. Minable deposits are found throughout the world.
"Chlorite" is the name of a group of common sheet silicate minerals that form during the early stages of metamorphism. Most chlorite minerals are green in color, have a foliated appearance, perfect cleavage, and an oily to soapy feel. They are found in igneous, metamorphic and sedimentary rocks.
Veins are considered the result of crystals growing on the walls of fractures in rocks, with the crystal protruding into open space. There are two main mechanisms considered likely for the formation of veins: open-space filling and crack-seal growth.
Open space filling veins:
Open space filling takes effect, when the confining pressure is generally considered to be below 0.5 GPa, or less than 3–5 km. Veins formed in this way appear to fill up the available open space. Often evidence of fluid boiling is present. Alternatively, hydraulic fracturing may create a breccia which is filled with vein material. Breccia is a rock consisting of angular fragments cemented together. Such breccia vein systems may be quite extensive.
Crack-seal veins:
When the confining pressure is too great, vein formation can occur via crack-seal mechanisms. Crack-seal veins form quickly of minerals within fractures. This happens swiftly by geologic standards, because large open spaces cannot be maintained for a long period. Veins grow in thickness by reopening of the vein fracture and progressive deposition of minerals on the growth surface.
One of many outcrops at Cape Spencer:
