Activity Details




Students will learn

  • To appreciate the role of Geology in their lives.
  • That knowledge gained through scientific study and research advances our understanding of how to better utilize resources and protect the environment.




  • Large Styrofoam cup, for measuring out and holding the ingredients while they set
  • Broken gravel, for forming one layer
  • Plaster of Paris, for mixing with gravel and forming layers
  • Coffee stirring sticks, for mixing gravel with the plaster
  • Food coloring, for coloring one layer of plaster
  • Aquarium gravel, for forming another layer
  • Newspaper, for keeping under the Styrofoam cup and collecting broken debris
  • Paper towels, for wiping




  • Pour broken gravel into their cups.
  • Request your Teacher to add ¼ cup of NORMAL COLORED PLASTER OF PARIS into your cup
  • STIR once or twice with coffee stirrer for mixing the ingredients
  • Allow the mixture to set


  • Request your Teacher to pour ¼ cup of BROWN PLASTER into your cup on top of the first layer.
  • Allow to set.


  • Pour aquarium gravel into their cups on top of the brown plaster layer.
  • Request your Teacher to add ¼ cup of NORMAL COLORED PLASTER OF PARIS into your cup over the aquarium gravel.
  • STIR once or twice with coffee stirrer for mixing the aquarium gravel with the plaster.
  • Allow to set.


  • Request your Teacher to add ¼ cup of NORMAL COLORED PLASTER OF PARIS into your cup on top of the aquarium gravel layer.
  • Allow to set.


  • After 24 hours, place a piece of newspaper on your desk.
  • Break off the cup surrounding the plaster of paris, leaving a series of "sedimentary deposits."
  • Gently wipe sides of the "deposits" with a damp paper towel to better show the deposit layers.
  • Call the layers I, II, III, and IV, with I being the bottom (oldest) deposit.


  • These deposits represent a section of sea floor along a changing coastline.
  • LAYER I:The oldest plaster (mixed with broken gravel) layer shows a time when this area was near a rocky coastline, with rocks broken off and deposited before erosion could round off their sharp edges. This type of deposit is called breccia.
  • LAYER II: shows a time when the coastline had retreated far from this area and only fine sediments (clay and mud) carried by streams and rivers were deposited (brown plaster). These deposits formed shale or mudstone.
  • LAYER III: shows that a time when the coastline had moved toward the deposit area again (to a location between those represented by layers I and II) and rounded rocks were deposited (aquarium gravel mixed with plaster). These rocks were rounded by erosion as they were transported by streams and rivers to the deposition site. This type of deposit is called a conglomerate.
  • LAYER IV: represents a period when the coastline retreated farthest from this deposition site (top layer of normal colored plaster). Shells and other hard parts of ancient marine plants and animals accumulated to form limey deposits that later became lime-stone.

Teacher Notes


Tips and Tricks:

The Southern Appalachian Mountains

  • Spanning a vast area from Virginia to Georgia, the Southern Appalachians are some of the oldest mountains on Earth.
  • Molded and shaped over eons by volcanism, erosion, glaciation, and other geologic forces, these mountains are known worldwide for their unusual beauty and rich biological diversity.


  • A 25-minute USGS film, The Southern Appalachians: A Changing World, describes how geologic events that took place millions of years ago influenced the landscape, climate, soils, and living things that are seen in the Southern Appalachian Mountains today.
  • This film was prepared in cooperation with the National Park Service.
  • View the film online at:

Teacher’s Guide

  • An accompanying 16-page Teacher's Guide summarizes the film and includes seventeen suggested activities and discussion topics to enhance viewing.
  • Download free at:


  • A companion 23-page booklet, Birth of the Mountains: The Geologic Story of the Southern Appalachian Mountains by Sandra H.B. Clark, looks at the major stages in the development of the mountains and their landscape.
  • It shows where evidence can be seen today for each stage and gives examples of how the past affects human history and our lives today.
  • Download free at:

Geologic Map

  • A double-sided map, Geology of the Southern Appalachian Mountains (Scientific Investigations Map 2830) by Sandra H.B. Clark ; Graphic design by Linda M. Masonic and edited by Elizabeth D. Koozmin, was first posted in December, for classroom and public use.
  • This product consists of a geologic map draped over a shaded-relief background, photographs of interesting geologic features, diagrams of tectonic plate movement, and much more.
  • Sites featured in the other publications are shown on the map.
  • Download free PDF files of both sides at:

To Purchase

  • These products can also be purchased online through the USGS Store at
  • The current prices can be obtained from the store.
  • DVD formatof The Southern Appalachians plus Teacher’s Guide [product #206041]
  • VHS formatof The Southern Appalachians plus Teacher’s Guide [product #112293]
  • Booklet- Birth of the Mountains [product #112296]
  • Map(folded) - Geology of the Southern Appalachian Mountains [product #208803]
  • For more information or to place orders by phone, please contact USGS Science Information and Library Services (SILS) at 1-888-ASK-USGS (1-888-275-8747) or


  • The video “The Southern Appalachians—A Changing World” was created for students who live in the Southern Appalachian Mountain region and for visitors to the region.
  • The video shows how the landscapes that we see today developed over millions of years and how they continue to change.
  • The goal is to help students appreciate the role of geology in their lives by showing the relation between the history of the Earth and life in the Southern Appalachian Mountains.
  • “A Changing World” also shows how knowledge gained through scientific study and research advances our understanding of how to better utilize resources and protect the environment.
  • The synopsis of the video “The Southern Appalachians—A Changing World”  (See pages 1 to 7 of the Teacher’s Guide - the related activities and discussion topics are designed to provide guidance and ideas for teachers to expand upon the viewing of the video.

Note:Selection or adaptation of the resources listed above as also the activities or topics themselves is the prerogative of the teacher.

List of 17 activities and discussion topics:
Activity 01.   Geologic Time
Activity 02.   Plate Tectonics
Activity 03.   Observation Of Local Rocks
Activity 04.   The Life Of A Rock
Activity 05.   Delta In A Jar (Teacher Demonstration)
Activity 06.   Making A Sedimentary Rock Shoreline Sequence – The current activity
Activity 07.   How Did That Shell Get Way Up There?
Activity 08.   Thrust Faults And Geologic Windows (Teacher Demonstration)
Activity 09.   Making Metamorphic Rock
Activity 10.   Permeability Of Sandstone Vs. Quartzite (Teacher Demonstration)
Activity 11.   Bedrock, Erosion, And Landforms
Activity 12.   Biodiversity
Activity 13.   Effects Of Acid On Plants
Activity 14.   Lessons From The Past
Activity 15.   Applications To The Present
Activity 16.   The Cherokee Removal
Activity 17.   Geology In The News

Activity based issues - Materials

  • Large Styrofoam cup (12-16 oz.) should be provided for each student
  • Broken gravel (size of miniature marshmallows) is required for the bottom layer
  • Mix up enough plaster of paris for each student of the class to get approximately ¼ cups four times, once for each step.
  • For STEP2 add one drop blue, red, and yellow food coloring to the Plaster of Paris and stir to make brown plaster.
    Note: Brown plaster is required ONLY for STEP 2. For the other steps normal colored plaster is to be used.
  • Aquarium gravel, ROUNDED AND SMALLER than broken gravel, is required for the 3rd layer.

Activity based issues - Explanations

  • Sedimentary rocks form from eroded remains of other rocks, such as gravel, sandstone, clay, or mud, or sometimes they form from animal remains such as limestone.
  • By examining sequences, or layers of rock, geologists can tell what the area was like at certain time periods.
  • Students can make their own layered sedimentary rocks.




This activity is adapted from:

  • Science Education Handout February 2010:
  • Teacher's guide accompanying the USGS film, The Southern Appalachians: A Changing World prepared by Sandra Clark, Elizabeth Romanaux, Dona Brizzi, and Jennifer Thomlin:
    Published in the Eastern Region, Reston, Va.
    Manuscript approved for publication September 28, 2001


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