Wall of EarthCache Fame EarthCache

When you hear about a Wall of EarthCaching Fame, perhaps you’d expect to see portraits of GEOAWARE, or maybe even some of our local EarthCaching legends. However, this Wall of EarthCaching Fame (not the actual name of this venue) is where instead you’ll find such famous names as Verde Marinace or Rosa Porrino.

This EarthCache provides us geocachers an opportunity to both begin and advance our understanding of geology by exposing us to fantastic samples of the three types of rock (metamorphic, igneous, and sedimentary) that we can see, touch and make comparisons.

Starting at the ground zero coordinates of the EarthCache, walk your way west, then south, then east along the three walls hosting the stone slabs. As you visit each slab, take a few moments to examine each specimen.

Please respect the area while visiting - stay on sidewalks and do not damage the slabs, building, or gardens.

“At first glance they all are beautiful to look at. Closer examination reveals that they contain intriguing minerals as well as fascinating shapes and colour combinations. Understanding the properties of the minerals and rocks and the processes that formed them is important to our society. For example, the relationship between mineral grains in a rock, called rock texture, is used by professional geoscientists and engineers to determine the suitability of certain rocks for tunnels or building foundations. Other features visible in the stones help geoscientists determine how rocks deform at high pressures and temperatures at depth in the Earth's crust, which may lead to a greater understanding of the tectonic forces that shape continents. Fossils in some of the sedimentary rocks yield clues about past life and ancient environments on Earth.“ 1

First visit samples number 1- 3 & 6 for examples of Metamorphic rocks

“Metamorphic rocks are formed under the surface of the earth from the metamorphosis (change) that occurs due to intense heat and pressure (squeezing). The rocks that result from these processes often have ribbonlike layers and may have shiny crystals, formed by minerals growing slowly over time, on their surface.”2

Secondly, don’t forget about Igneous rock, found at samples 4, 7, & 8.

“Igneous rocks are formed when magma (molten rock deep within the earth) cools and hardens. Sometimes the magma cools inside the earth, and other times it erupts onto the surface from volcanoes (in this case, it is called lava). When lava cools very quickly, no crystals form and the rock looks shiny and glasslike. Sometimes gas bubbles are trapped in the rock during the cooling process, leaving tiny holes and spaces in the rock.”2

Thirdly, samples 17, 18, 20, & 21 provide examples of Sedimentary rock.

“Sedimentary rocks are formed from particles of sand, shells, pebbles, and other fragments of material. Together, all these particles are called sediment. Gradually, the sediment accumulates in layers and over a long period of time hardens into rock. Generally, sedimentary rock is fairly soft and may break apart or crumble easily. You can often see sand, pebbles, or stones in the rock, and it is usually the only type that contains fossils.”2

Something unique you will see on these walls is the display of migmatite. “Migmatite is a rock that is a mixture of metamorphic rock and igneous rock. It is created when a metamorphic rock such as gneiss partially melts, and then that melt recrystallizes into an igneous rock, creating a mixture of the unmelted metamorphic part with the recrystallized igneous part.”3

For assistance with this EarthCache, scan the QR code on any of the labels on site to get the “cheat sheet” that will assist you with the answers to the questions below.

We have learned that the QR codes have become unreadable or perhaps disconnected so here is the link directly to the PDF that explains each panel on the walls. We will trust that you will actually visit the site to log this EarthCache

To claim this EarthCache, please answer the following questions:

1. How many countries are represented with samples of Gneiss?
2. Of the three types we’ve learned about, list the name given on the plaque of one each (metamorphic, igneous, sedimentary) from the samples on the walls.
3. Go to samples 14 & 15. What types of rock are these, and what can you observe in the displays to support your hypothesis?
4. Go to sample 20 and observe it carefully. What features can you observe to support the classification of this rock as “sedimentary?”

References/footnotes:

1. http://www.eos.ubc.ca/resources/outside-exhibits/stone-slabs.html

2. http://www.learner.org/interactives/rockcycle/types.html (Annenberg Learner website)

      3. en.wikipedia.org/wiki/Migmatite