D. McShale

GeoDig Site A

This GeoDig site is a city in North America, but it's not in the United States. The city is hot and dry, and the elevation is quite high — it's over a mile above sea level! Which of these cities is correct?

GeoDig Site B

This GeoDig site was chosen for the 2014 World Cup Soccer Championship and the 2016 Summer Olympics. It's one of the biggest cities in South America. Portugese is spoken there. Which of these cities is correct?

GeoDig Site C

This European city straddles the Thames River. You can hear the chimes of Big Ben from The O₂ Dome. This country is considered the birthplace of modern Geology. Which of these cities is correct?

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• List of Found Rocks
• List of Tools for Digging
  
  
• Igneous Rocks
  1. Obsidian

     Description	An igneous rock that is black and glassy in appearance.
     How Formed	It is formed from molten lava that cools so quickly (hours to days) that crystals don't have time to form.
     Where Found	Obsidian is found in many parts of the world, wherever volcanoes are found. Sites include Japan, Java, Italy, Hungary, as well as many regions in the western Americas (as in Northern, Central, and Southern)

  2. Basalt

     Description	Basalt is a hard, dark-colored igneous rock. Basalt covers most of the ocean floor and is therefore the most common rock on the earth's surface.
     How Formed	As with all igneous rocks, basalt is formed in or near volcanos. Cooling somewhat slowly (days to weeks), basalt forms very fine crystals that can only be seen under a microscope.
     Where Found	Basalt is found in many parts of the world, wherever volcanoes are found. Sites include Japan, Java, Italy, Hungary, as well as many regions in the western Americas (as in Northern, Central, and Southern).

  3. Granite

     Description	Granite is a light-colored rock; because of the way it forms, the crystals inside are large enough to be seen by the naked eye, so it looks grainy and bumpy, like it's made of many different shades of sand or smaller rocks.
     How Formed	Granite is a unique igneous rock, forming under the earth's crust amongst the magma. The intense heat melts rocks and minerals, and if they cool very slowly (thousands to millions of years), the minerals grow together in large chunks, forming coarse-grained granite.
     Where Found	Granite is found all over the world, primarily in large landmasses (instead of in the oceans). Unlike igneous rocks that formed from fast cooling like obsidian or scoria, granite forms deep underground. As a result, it is usually found only when rock layers from beneath the earth's surface is pushed up. This happens when mountains form and cliff sides are exposed due to erosion.

  4. Pumice

     Description	Pumice, also known as scoria, is a light rock that looks like a sponge. Because of its low density (due to all the holes in it), pumice actually floats on water.
     How Formed	As with all igneous rocks, pumice is formed in or near volcanos -- in this case, during explosive eruptions. Pumice cools so quickly (hours to days), you can still see where the air pockets were.
     Where Found	Pumice is found in many parts of the world, wherever volcanoes are found. Sites include Japan, Java, Italy, Hungary, as well as many regions in the western Americas (as in Northern, Central, and Southern).

  
  
• Sedimentary Rocks
  1. Conglomerate

     Description	Conglomerates look like a bunch of pebbles decided to get together and make a real rock, which is basically what they are (aside from the pebbles "deciding" to do something part).
     How Formed	Conglomerate rocks are pebble, gravel or boulder beds cemented together.
     Where Found	Conglomerates can be found along sea and lake shores and in rivers. They indicate shallow waters and strong currents necessary to move large rock fragments.

  2. Red Sandstone

     Description	Red sandstone is, unsurprisingly, red. It looks like a rock's worth of sand grains cemented together, because that's what it is.
     How Formed	Sandstone is formed by the accumulation of sand particles cemented together by high pressure and temperatures. Quartz is often found in sandstone; the red in red sandstone comes from iron crystals that form in the gaps between sand grains.
     Where Found	Red sandstone can be found all over the world. In the U.S., it can be found in Nevada and Utah. In Canada, lots of high quality red sandstone can be found in Ottowa. It's also found in the Gobi Desert as well as in Canada. Fossils can often be found inside sandstone.

  3. Shale

     Description	The most common of sedimentary rocks, shale comes in many colors, but is most often greenish grey to greyish black. It is fairly soft, fine-grained and clay-like. When first exposed to air, shale has a smooth, greasy feel; dried out, it becomes brittle and hard.
     How Formed	Sedimentary rocks are formed by the accumulation of rock fragments, shell fragments, plant material, muds, and sands, which were transported to their present locations by water, air, wind, or ice. Shale in particular is formed from mud or clay that's pressed into layers. Shale sometimes contain oil and is therefore mined for petroleum.
     Where Found	Shale is found all over the world. In British Columbia, Canada, there is the famous Burgess Shale. In the US, shale is found in Virginia. There's also shale in England, such as the Rochester Shale which is famous for its marine fossils.

  
  
• Metamorphic Rocks
  1. Quartzite

     Description	Quartzite is a very hard stone composed of grains of quartz. It comes in colors varying from white, light gray, yellowish, or light brown to blue, green, purple, or black, depending on the additional minerals inside. To tell the difference between quartzite and its parent rock, sandstone, break the rock -- sandstone will completely shatter, while quartzite will break along the grains.
     How Formed	Most quartzites form from pure quartz sandstone. Some quartzite are sedimentary, resulting from quartz sandstone cementing together due to groundwater solutions containing pure quartz.
     Where Found	Quartzite is found worldwide. In the US, it is found in many states, especially in the western states. In Canada, the Tonquin Valley in Alberta is a rich source. Other sites include Japan, Nigeria, and Brazil.

  2. Schist

     Description	A medium grade metamorphic rock, schist has experienced more heat and pressure than slate, a low grade metamorphic rock. Schist is a more coarse grained rock than slate -- you can actually see the individual grains of the minerals within. Oftentimes, the original minerals are turned into flakes. Mica schist looks like flakes of shiny mica cemented together.
     How Formed	These rocks can be formed from basalt, an igneous rock; shale, a sedimentary rock; or slate, a metamorphic rock. These rocks were metamorphosed into this new kind of rock through tremendous heat and pressure, thus the name "metamorphic" rock.
     Where Found	Schist is found around the world, in places as disparate as the Taieri Plain of New Zealand, the Grand Canyon in the US, and the Isle of Man in Scotland.

  
  
• Gems
  1. Agate

     Description	An agate is a multi-colored gem with a banded appearance when polished.
     How Formed	The bands in agate are formed when silicon dioxide is deposted from a hot water solution. Tiny amounts of iron and other impurities give it a variety of colours. When you see bright colored agates in a store, it's mostly just grey and white agates that were dyed. Sometimes, you'll find petrified wood or dinosaur bone preserved inside a piece of agate.
     Where Found	Agate is found in many countries. Large amounts of it come from Uruguay and the bordering regions of Brazil.

  2. Amethyst

     Description	Amethyst is a type of quartz that comes in shades of purple, violet, even pink. The name came from the Greek word "amethystos" which means "not drunken". It was believed to protect those who wear it from drunkenness.
     How Formed	Like all types of quartz, amethyst is a crystal of silicon dioxide (SiO2). They are often found in clusters of six-sided pyramids. Sometimes, they form dramatic long columns that end as six-sided pyramids.
     Where Found	Amethysts are found in many places in the world. Some of the most beautiful specimens are found in Brazil, Uruguay, as well as in the United States, Madagascar, Russia, and India

  3. Rock Crystal

     Description	Rock crystal is a clear, transparent quartz that looks like glass. Glass however can have tiny bubbles in it, but rock crystal does not. Rock crystal is also quite a bit harder than even leaded glass.
     How Formed	Like all types of quartz, rock crystal is a crystal of silicon dioxide (SiO2). It comes in six-side prisms and pyramids of all sizes, from short clusters to long, slender prisms, to thick columns that can be used to make those crystal balls that fortune tells use.
     Where Found	Rock crystal can be found in many places in the world, including Russia, Japan, Hungary, France, India, Madagascar, and the U.S. Another good source of rock crystal is Brazil. The largest rock crystal ever found was there. It weighed more than five tons!

  
  
• Minerals
  1. Hematite

     Description	Hematite gets its name from the Greek, "haimatites", or blood-like, a reference to the bright red color of powdered hematite. It also can be black or brown.
     How Formed	Hematite is essentially rust -- iron oxide. The mineral can precipitate out of water and collect in layers at the bottom of a lake, spring, or other standing water. Hematite can also occur without water, usually as the result of volcanic activity.
     Where Found	Hematite is most abundant in the Matto Grosso, Brazil and the Mesabi iron ore range in the Lake Superior region in the USA. It is formed in all three rock types (sedimentary, igneous, and metamorphic).

  2. Mica

     Description	Mica is a group of minerals, generally flat, sheet-like, and silvery, easily split into thin sheets. Small flakes of mica are flexible and brittle, easily scratched with a fingernail. It's sparkle makes it known as "nature's glitter", and it is often added to plastics, paints, and make-up to make the product glitter and glow. One manufacturer is even thinking about using mica in contact lenses to make your eyes sparkle!
     How Formed	Mica is formed by flat, six-sided crystals. It contains elements like silica, aluminum, magnesium, iron, etc. that are melted together from deep within the earth. Because it is fire-proof and has a high resistance to electricity while being soft and easy to cut and handle, it is used in all sorts of electrical equipment, such as heaters, lights, motors, even radios and televisions.
     Where Found	Found in all rock types (igneous, sedimentary, and metamorphic), there are over 30 types of mica. Muscovite, the most common member of the mica group, is found in Brazil, Western Africa, and the Madras and Bihar areas of India. Mica was first mined in the U.S. in New Hampshire.

  3. Quartz

     Description	Quartz is a very hard rock made of silicon dioxide. The most common mineral in the world, quartz comes in a variety of colors (most often white to pink) and forms.
     How Formed	Most quartz is formed though volcanic activity, where water carrying silica is heated by volcanic activity. When the fluids encounter cooler, favorable conditions, silica began to be deposited and from that the quartz mineral grows.
     Where Found	Quartz is incredibly common, but certain types are more prevalent in particular places -- amethyst in Brazil, Uruguay, Sri Lanka, Siberia, and parts of North America, for example.

  
  
• Fossils
  1. Bivalve

     Description	Bivalves that survive today include oysters, clams, and scallops -- they all have two halves of a clam-like shell held together by a flexible ligament.
     How Formed	As with all fossils, a bivalve fossil was formed by death of the creature inside, followed by its shell surviving the slow process of rock deposits (usually sedimentary) growing up around it.
     Where Found	Bivalves generally live in shallow water. Due to continental drift, their fossils can be found just about anywhere. Good places to look for these fossils are in sandstone and shale sites.

  2. Crinoid stalk

     Description	Stalked crinoids (or "sea lilies") dominated sea life during the Paleozoic Era. Only a few species still survive. Their fossils are cylindrical and ribbed.
     How Formed	(This is an educated guess, Jen... feel free to wipe it.) Crinoids dominating a sea shelf would eventually die and pile up on the shelf, leaving behind slow-forming sedimentary rock. Most crinoids would fall apart and become part ofthe rock, while some survived intact, turned into fossils by the hard rock surrounding them.
     Where Found	Crinoids are usually found in sedimentary sites, especially limestone, because limestore is often formed of tiny parts of crinoid exoskeletons.

  3. Trilobite

     Description	Trilobites were one of the first arthropods to evolve during the Paleozoic Era. Now extinct, trilobites were a hard-shelled, many-legged animal that, depending on the species, could grow anywhere from a millimeter long to almost two feet! Trilobites are oval in shape with a finely ribbed shell. They are called "tri"-lob-ites because their bodies have 3 segments, a large one in the center and one on each side.
     How Formed	All arthropods grow by shedding their exoskeleton -- what remains of trilobites that we find today are these tough shells that have survived tremendous geologic changes, pressure, and time.
     Where Found	Trilobites lived in salt water, found at all levels of the oceans, all around the world. Due to continental drift, this means their fossils can be found worldwide. Good places to look for trilobite fossils are sites with sandstone and shale.