Resources for Doorway of Amethyst

Here is a list of the Internet resources that I found helpful when I was teaching from this book.  Over time links expire so if one does not work, try Google for the described item. 

General reference: 

I have also included references to Hedgeschool B&W images used in the Doorway of Amethyst book. 

See Links at the bottom of Hedge School Website’s Science Geology Page.

Amateur Geologist has tools and geology gear. {linked here}

Chapter 1: Depths of the Earth

Earth cutaway
The Encyclopedia Britannica has some core images {linked here} & other striking images go to the bottom of the page. 

Mantle Convection & Convection Effects 
Yale has with a wonderful mantle convection image and paper about the process. {linked here}

Origin of the Solar system
The origin of the solar system seems to have been quite violent. We can know about this event, so distant in time, because there are isotopes left over from those days. Try Space Daily for an article about it, original links are missing. 

Chapter 2: 

Crossing the Ocean
Hedgeschool B&W image of land forms under the ocean. Click on the image; then print and color it yourself. This will help you recognize these waterside landforms.
See Links at the bottom of Hedge School Website’s Science Geology Page.

Crossing the Continent
Hedgeschool B&W image of land forms that may underlie a continent.
Click and print; then color. You will learn more by coloring than by studying others' work. 
See Links at the bottom of Hedge School Website’s Science Geology Page.

Plate Subduction and Continental Override
For a sophisticated discussion of subduction, this site by C.P. Conrad and C. Lithgow-Bertelloni {linked here} is very helpful. It is well illustrated and provides a detailed analysis of the stresses and motions involved. Challenging, but not out of reach if you have a general understanding of subduction and some familiarity with the crustal plates.

Chapter 3: Igneous Rock

Digital Tectonic Activity Map
This map from NASA is included at the end of the book. { linked here}Click on the image to enlarge it, then click again with the "magnifier". (Your cursor will show up on the map as a magnifying glass; go to whichever part of the map interests you and click again.) This map shows volcanic and earthquake activity worldwide, along with calculated tectonic plate motions. The digital age has certainly given us a new generation of fascinating maps.

Black and white images
Hedgeschool B&W image of igneous formations. {Future linked here} (See page 9)

Introduction to Igneous Rocks
Lynne S. Fichter of James Madison University in Virginia has composed a good {linked here} Introduction to igneous rocks and an Elementary Classification Chart {linked here} with images instead of words. If you are ready for a lot more information, click around the whole site, but don't let yourself get overwhelmed and confused by the abundance of information. Take it slowly. 

Volcano World
Oregon State College has an altogether delightful site for all sorts of information about volcanoes. {linked here} It has links to anything you could wonder about from basic "how they work" to lists of volcanoes and information about the most recent eruptions. Some of the material is elementary; some is fairly sophisticated. 

Black Hills including batholith
The geology of western South Dakota includes a batholith. Here is a general description of SD geology, which gradually moves into a discussion of the batholith. Go to Google Earth, look for the Black Hills of South Dakota, and compare the satellite image with an imagined drawing.

Harney Peak Batholith
Black Hills region of South Dakota, where four presidents' faces are carved. 

Chapter 4: Sedimentary Rocks

Layers upon Layers
Jason Salter has a wonderful image of sedimentary rock {linked here} here, and in a series of related pages, he explains how sedimentation works and offers (classroom) exercises.

Sedimentary Rock Lab 
The original lab link has disappeared. 

White Cliffs of Dover
Here are two images of these famous limestone cliffs:
One from the White Cliffs of Dover Wikipedia {linked here}
See the coccolith formations section of the chapter 11 support (below) for another image.

Chapter 5: Metamorphic Rocks

Key to Metamorphic rocks
Lynne S. Fichter of James Madison University in Virginia has composed a clear key to the identification of metamorphic rocks. {linked here}
His explanations of metamorphism may also be useful. {linked here} They are not intended for the elementary student (they are written for the elementary teacher) and may be confusing as a first step. Nevertheless, it is a nice site, without ads, and the explanations of regional (Barrovian) and contact metamorphism, found halfway down the page, are particularly worthwhile. 

Rainbow Gneiss
Rainbow Gneiss is one of the prettiest forms of gneiss to be found. {linked here} Its location along the Minnesota River suggests that this river is flowing in a fault zone. 

Chapter 6: Weather and Weight

Desert Soil Profile
This soil profile {linked here} on a Soils of America teacher resource site has many good images of desert environments and a few other soil profiles.

Chernozem
This image of grassland soil is provided by the Encyclopedia Britannica. {linked here} You can see the thick rich topsoil and the lower soil of a lighter color, not as fully penetrated by the root system.

Chapter 7: Rivers and Rain

Amazon River
Here is a National Geographic report on how the Amazon River once flowed westwards. {linked here} it's very interesting. 
And here is an interesting sidelight about stingrays {linked here} that will help you understand how we can reason about events so remote in time as this backwards flow. 

Chapter 8: Waves and Seas

St. Lawrence Seaway
Here is a clear image of the St. Lawrence River in relation to the Great Lakes.
And this is how it forms a vast estuary, the Gulf of St. Lawrence before it empties into the Atlantic Ocean. 
Wikipedia has perhaps a dramatic image. {linked here} Be sure you follow the story to the lower half of the page where you get an underwater view of the bed of the gulf.

Chapter 9: Winter and Wind

Barchan Dunes
The website mentioned for chapter six also has a wonderful set of images of a Barchan dune. Wiki has some good images {linked here}

Sleeping Bear Dunes
For an interesting discussion of modern (ongoing) dune formation, you might enjoy looking at Sleeping Bear Dunes in Michigan. If you are mystified about the relationship between glaciers (cold and wet) and deserts (hot and dry) this would be a location to study.

Louis Agassiz biography 
Only an Amazon link is currently available, but Tiner's book about explorer Louis Agassiz is fascinating. Written at middle school reading level, is a light and easy read, but also gripping a drama. I really enjoyed it. 

Chapter 10: Change over Time

Potassium-Argon Dating
For Britannica’s explanation of potassium-argon dating. {linked here}

Radiocarbon Dating
For an explanation of radiocarbon dating, {linked here} from How Stuff Works Science web site. It is clearly explained, and the little movie clips are well composed. The limits of radiocarbon dating are also explained, and you can see that it is not very useful for most geology, as it does not give good dates even work for things that are one million years old. Geological events related to the ice ages can be dated with this system, however.

Samarium-Neodymium dating
The Wikipedia article {linked here} on this very sophisticated method of dating may be of interest to an advanced student. The process is also described by John McPhee in Annals of the Former World.

Chapter 11: Williston Basin

Glenn Morton's story
This is the story of Glenn Morton's decision to abandon young earth creationism {link here} in favor of the data he saw as a geologist. It explains why he wrote the description of the Williston Basin on which chapter 11 is based.

Cocolith formations
Google and find beautiful images of the White Cliffs of Dover. See the support links for chapter four, for other Dover images.

Chapter 12: Biographies

The Dragon of Lind
OK, here is the Lindworm, also known as the Klagenfurt dragon. Odd to see him as a fountain, while legend makes him spout fire! {linked here}

Nicholas Steno
Just a reminder that the Catholic Encyclopedia of 1913 is online in its completeness. It's still a good resource. Here's its biography of Nicholas Steno. {linked here} New Advent has an article on geography {linked here} has more information about the great Danish scientist who has been canonized; scroll about 2/3 of the way down to find him.