p. 120 Sedimentary
and Metamorphic Environments
An
Introduction to Sedimentary Rocks
At
this Department of Geology and Environmental Sciences, James Madison University,
Virginia site you can learn about the rock cycle and the formation of sedimentary
rocks. The site contains many images of sedimentary rocks and a description
of how igneous rocks are broken down into the sediments that form sedimentary
rocks. Scroll down and click on rock cycle to view a diagram of this process.
Metamorphic
Rocks
Visit
this USGS site to read a brief description of how metamorphic rocks form. Scroll
down and click on rock classification chart to see a chart identifying each
type of rock found on Earth.
The
Rock Cycle
At
this site by the Department of Geological Sciences, University of Saskatchewan,
Canada you can view a diagram and explanation of the rock cycle on Earth. Scroll
down and click on major rock groups to see how igneous, sedimentary, and metamorphic
rocks are related to one another through the rock cycle.
The
Rock Cycle Experiments
Visit
this site by the British Broadcasting Corporation Online for some fun activities
relating to the rock cycle. You can choose from ten different online experiments
that help you understand parts of the rock cycle. Scroll down to the diagram
then click on any of the numbers in the diagram to open a window with an experiment
you can do at home. For example, clicking on number 6, sedimentary rock, will
open a window for an experiment in building the toughest sand castle, an experiment
that shows how cementation makes sedimentary rocks stronger. Each experiment
includes an explanation of the expected results. A fun site!
p. 131 Coral
Reefs in the Bahamas
Life
on the Reef
This
Discovery Channel site explores life on the coral reefs of the Bahamas. Subjects
range from the organisms found on the reefs to the scientists studying the reefs.
Click on dive the reef, then on lagoon, reef, or shelf to view images of some
of the organisms found in these parts of the Bahamas. In which of these environments
would you expect to find plants?
Status
of Coral Reefs of the World: 1998
You
can visit this Australian Institute of Marine Science site to discover the status
of coral reefs around the world after the El Niņo and La Niņa
events of 1997 and 1998. Scroll down to read the report on the corals of the
Bahamas. Around New Providence Island, what percentage of head corals were bleached
in August 1998?
Coral
Reef Data and Information
This
site by the National Oceanographic Data Center (NODC) contains a wealth of information
on U.S. coral reefs. Scroll down and click on Florida, Bermuda, and the Bahamas
to find links to sites that give more specific information on the health of
the coral reefs in the Bahamas.
p. 142 Uses
of Talc
The
Mineral Talc
Visit
this site to find out everything you wanted to know about the physical and chemical
characteristics of talc. Why is it unusual to find mineral specimens of talc?
Crayola
Says its Crayons are Asbestos-free
The
Seattle Post-Intelligencer, a newspaper, first broke the story that at least
three crayon manufacturers had asbestos fibers from talc in their crayons. Read
this article in which the makers of Crayola crayons respond to these charges.
Why is talc considered to be the source of the asbestos fibers in crayons?
Snow
White Talc Mine
This
site describes the geology of a major talc mine in the eastern Mojave desert.
It includes a description of the four categories of commercial talc, and a diagram
showing a section of a typical talc-bearing horizon.
