Chemical composition is the primary control on the relative viscosity of a magma. Which of the following compounds is most influential in determining magmatic viscosity?

During gradual heating of a rock, which type of minerals melts first?

  Another important test is determining how many planes of cleavage a particular mineral has. Look at the mineral below. A knife was used to break the mineral into smaller fragments. How many planes of cleavage does the mineral have?

  Let us look at silicates in a little more detail. Depending on a silicate mineral’s composition, the Si-O tetrahedra that make up the mineral will arrange themselves in different patterns. Drag the silicate framework name to the correct schematic on the image provided.

Yellowstone Caldera is a large volcanic system located in northwest Wyoming. It has erupted catastrophically several times in the last 18 million years with the most recent eruption, called the Lava Creek eruption, occurring approximately 630,000 years ago (0.6 Ma).Watch the video on this most recent eruption, and answer the question that follows. Yellowstone Caldera Ash from the Yellowstone eruption was dispersed as far south as the Gulf of Mexico and as far north as Canada. Use the choices below to characterize the eruption.

High- and low-pressure systems strongly affect when and where winds blow. Read each description and select whether it is describing a high- or low-pressure system.  

Winds also influence weather patterns. They drive the formation of fronts and the genesis of storms. Which of the following forces control the direction and speed at which winds blow as the primary forces controlling wind?  

  Cleavage and hardness are two separate characteristics of a mineral. Take diamonds, for example. The tag line is that “diamonds are forever.” This is true if you think only about scratching. Diamonds are very scratch-resistant, so they have a high hardness rating on Mohs scale for hardness. If you take a hammer to a diamond, you will see that it fractures as easily as many other minerals. Odds are you will upset someone as well. Below are two minerals. Use Mohs scale for hardness to determine which mineral is harder. Click on the harder mineral.

Where two air masses meet, a front is formed. In the animation below, click on the “Topics” menu and select the “Frontal Lifting” segment to learn about the process of frontal lifting. What type of front is shown in the animation? Hint: Does the temperature at the Earth’s surface get warmer or colder? Click here to open the animation in a new window.  

In the animation below, select the “Topics” menu, and then select “Hot Spots.” Watch the animation on hot spots Hot Spot Formations Based on the description of hot spots provided in the video, select the oldest volcano in the chain of islands pictured below.