![](media/image1.jpeg){width="6.75in" height="0.7680555555555556in"}

![](media/image3.jpeg){width="5.220138888888889in"
height="7.227777777777778in"}***Elementary School***

![](media/image4.png){width="0.6in" height="0.8346456692913385in"}

# Section 4 -- Earth Activities

-   **Dissolving Limestone with Acid**

-   **Grow Your Own Speleothems**

-   **A Recipe for Speleothems**

-   **Let's Make a Cave**

-   **Are All Caves the Same**

-   **How's the Climate Down There?**

-   **Mapping a Cave**

-   **Down to the Core**

-   **A Key to Rocks**

-   **Make a Fossil**

![](media/image4.png){width="0.6in" height="0.8346456692913385in"}

**Dissolving Limestone with Acid**

**Pre-Visit or Post-Visit Activity**

**Primary/Elementary and Intermediate Levels**

**Science** (Unifying Concepts, Physical, Earth)

**45 Minutes**

**Objective(s).** Students will apply the trial and error method to test
which rock/shell samples react with hydrochloric acid.

**Related NM Content Standards with Benchmarks.** SC2-E3, SC9-E2,
SC9-M2, SC12-E3, SC12-M3

**Method.** In pairs, students place drops of cold, dilute hydrochloric
acid on rock/shell samples, then record the results. Students formulate
and write their conclusions on the worksheet provided.

**Materials.**

> **Each Student:** copy of chart, pencil, safety glasses or goggles
>
> **Each Pair of Students:** bottle of hydrochloric acid, jar or beaker,
> dropper, student worksheet
>
> **The Class:** rock samples of limestone, granite, sandstone and
> seashells; paper towels

**Key Vocabulary.** mineral, carbonic acid, limestone, calcite, chemical
reaction, hydrochloric acid

**Background.** Limestone is the most common cave-forming rock, composed
of a mineral called calcite. When carbonic acid in water comes in
contact with calcite, the calcite begins to dissolve. A similar and
faster chemical reaction occurs with a stronger acid, such as
hydrochloric acid. Cold, diluted, hydrochloric acid, will produce a
bubbling reaction upon contact when calcite is present in an object.

See "The Geology of Carlsbad Cavern" in Section 2 -- Just the Facts.

**Suggested Procedure**

1.  Explain safety procedure to be followed. Because the acid will burn
    skin and clothing, young students should observe a teacher perform
    the demonstration.

2.  Distribute a chart to each pair of students.

3.  Mix a solution of HCL and water in a ratio of 10 parts water to 1
    part HCL.

4.  Label rock samples A, B and C.

5.  Using the dropper, place one drop of hydrochloric acid on each rock
    sample.

6.  Observe what happens and record observations in the proper column.

7.  Wipe acid droplets off samples with paper towels, being careful not
    to allow the acid to touch skin.

8.  Test a seashell with the acid. Observe and record observations.
    Write conclusions on the chart.

9.  Use the data in this activity to make generalizations correlating it
    to geology of Carlsbad Cavern.

**STUDENT WORKSHEET**

  -----------------------------------------------------------------------
  **ROCK SAMPLES**      **ACID REACTION**       **NO REACTION**
  --------------------- ----------------------- -------------------------
  **A**                                         

  **B**                                         

  **C**                                         

  **Seashell**                                  
  -----------------------------------------------------------------------

  -----------------------------------------------------------------------
  **CONCLUSIONS:**
  -----------------------------------------------------------------------

  -----------------------------------------------------------------------

![](media/image4.png){width="0.6in" height="0.8346456692913385in"}

**Grow Your Own Speleothems**

**Pre-Visit or Post-Visit Activity**

**Primary/Elementary and Intermediate Levels**

**Science** (Unifying Concepts, Earth)**, Math** (Measurement)

**One 45- Minute Session, then 10 - 15 Minutes Daily (5 Days)**

**Objective(s).** Students will demonstrate knowledge of the scientific
method by investigating the growth of models of stalactites and
stalagmites.

**Related NM Content Standards with Benchmarks.** SC2-E3, SC12-E3,
SC12-M3, MA9-E2, MA9-M3

**Method.** Students review the scientific method, construct a model of
a cave, observe the growth of stalagmites and stalactites, and draw
conclusions.

**Materials.** Epson salts (magnesium sulfate), pan to heat water,
spoon, food coloring, jar for storing extra solution, craft knife,
pictures of stalactites and stalagmites, small sturdy cardboard box, 3-5
oz. paper cups, 12 pieces of blue yarn (9\" long), 12 pieces of red yarn
(14\" long), heavy weight aluminum foil, paper towels, copies of
*Speleothem Growth Observations* student worksheet

**Key Vocabulary.** speleothem, stalactite, stalagmite

**Background.** See "The Geology of Carlsbad Cavern" and "A Good
Scientific Investigation" in Section 2 -- Just the Facts.

**Suggested Procedure for Cave Construction**

1.  Mix 4 cups of water and 5 cups of Epson salts in a pan. Heat to the
    boiling point, stirring constantly. Allow students to observe and
    describe what happens.

2.  Turn box on its side with the front facing the students. Using 1 cup
    as a pattern, trace 3 circles on the top of the box. Poke a series
    of 6 pencil holes through the top of the box, around the
    circumference of each of the 3 circles. Two holes are needed for the
    longer piece of yarn and 1 hole for each of the 4 shorter pieces.
    These holes should be large enough for the yarn to pass through
    easily.

3.  Place an empty cup right side up on each of the circles. Measure 1
    piece of blue yarn approximately 9 inches so that it is lightly
    stretched from the inside bottom of the cup, up and over the edge,
    and down through a hole. Use a pencil to poke the yarn through the
    hole. Cut off the yarn so that it hangs 1 to 2 inches down from the
    top of the box. Using this measured piece of yarn, cut 11 blue
    pieces of yarn to this same length. Set all 12 pieces aside. Take a
    piece of red yarn approximately 14 inches and place one end in the
    bottom of a cup; draw the other end, down through a hole, up through
    an adjacent hole, and then back into the bottom of the same cup,
    leaving a loop hanging down about an inch.

4.  Place a sheet of aluminum foil onto your work surface. Turn up and
    crimp the edges to make a waterproof tray with sides about 1 inch
    high. Make a pad of a dozen paper towels and place it under the box
    in the foil tray.

5.  Place each of the 3 cups within a circle. Pour solution into the
    cups until they are half full. Place all yarn pieces into the cups
    of solution, 4 short and 1 long, to wet them.

6.  Remove the yarn. Push the longer red pieces of yarn down through 1
    hole and up the next. Leave enough yarn in the cup so that both ends
    reach the bottom. Place the shorter blue yarn pieces with their ends
    hanging down into the *cave*. Make sure that all strings are
    suspended in the solution, gently pushing the strings toward the
    bottom of the cups using a spoon. Repeat for all cups.

7.  Add several drops of food coloring to each cup. Add more solution,
    filling each cup to the brim. Most of the yarn will be *wicking* the
    solution.

**Suggested Procedure for Speleothem Growth**

1.  Check the fluid level of the cups twice during the day. Add more
    solution, as needed, to keep them filled to the brim. Store extra
    solution in closed jars.

2.  Distribute copies of the student worksheet. Daily, have students
    observe the speleothem growth and record their observations on the
    chart.

3.  After 5 days of observation, have students interpret what they
    observed and formulate their conclusions.

**SPELEOTHEM GROWTH OBSERVATIONS**

Student Worksheet

  -----------------------------------------------------------------------
                    **CUP 1**         **CUP 2**         **CUP 3**
  ----------------- ----------------- ----------------- -----------------
  **DAY 1**                                             

  **DAY 2**                                             

  **DAY 3**                                             

  **DAY 4**                                             

  **DAY 5**                                             
  -----------------------------------------------------------------------

  -----------------------------------------------------------------------
  **CONCLUSIONS:**
  -----------------------------------------------------------------------

  -----------------------------------------------------------------------

![](media/image4.png){width="0.6in" height="0.8346456692913385in"}

**A Recipe for Speleothems**

**Pre-Visit or Post-Visit Activity**

**Primary/Elementary and Intermediate Levels**

**Science** (Unifying Concepts, Physical, Earth)

**30 Minutes Each Demonstration, Several Days to See Results**

**Objective(s).** Students will construct a model to demonstrate the
growth of speleothems and crystals.

**Related NM Content Standards with Benchmarks.** SC2-E3, SC9-E2,
SC9-M2, SC12-E3, SC12-M3

**Method.** Students mix a solution, then observe the growth of
speleothems and crystals during a period of several days.

**Materials.**

> **Growing Speleothems:** water; thick, natural fiber string;
> cardboard; 2 jars; Epsom salts
>
> **Crystal Garden:** pie tin, pieces of charcoal, ½ cup water, ½ cup
> salt, ½ cup liquid bluing, 1 cup ammonia, food coloring (do not use
> red), mixing bowl, spoon

**Key Vocabulary.** speleothem, crystal

**Background.** Speleothem is the name given to any secondary deposit
(decoration) inside of a cave. The ones which hang from the cave ceiling
are stalactites. The ones that rise from the cave floor are stalagmites.
Formation of any speleothem takes a long period of time. Each drop of
water leaves a tiny amount of mineral residue on a cave ceiling, floor,
wall or other feature, adding to the growth of the speleothem.

Speleothems form at different rates. Several factors can determine the
rate of growth. Two important factors are rainfall and the outside
temperature. As the temperature goes up, so does the decay rate of
plants and animals. The more organic material there is in water, the
more calcium bicarbonate there is in the water; and thus, the more
acidic the water is. The rate of speleothem growth increases with the
amount of water and with the acidity of the water.

See "The Geology of Carlsbad Cavern" in Section 2 -- Just the Facts.

**Suggested Procedure for Growing Speleothems**

1.  Fill each jar with water.

2.  Add enough Epsom salts in each jar of water to form a thick
    solution.

3.  Place the jars on the piece of cardboard about six inches apart.

4.  Soak the string in the solution until it is completely saturated.

5.  Place one end of the string in one jar of solution. Place the other
    end of the string in the other jar of solution.

6.  Leave enough slack so that there is a bow in the string, but do not
    let the string touch the cardboard.

7.  Leave the jars and the string in an accessible and observable
    location for several days while a stalactite and stalagmite form.

8.  Explain the role of time in this model compared to "The Geology of
    Carlsbad Cavern" in Section 2 -- Just the Facts.

-   ***CAUTION:*** Once these *speleothems* begin to form, any movement
    of the string could cause breakage.

**Suggested Procedure for Growing Crystal Garden**

1.  Place pieces of charcoal into pie tin (enough to cover the bottom of
    the pan).

2.  Mix water, salt, bluing and ammonia in the mixing bowl.

3.  Carefully pour this solution over the charcoal so that all pieces
    are wet.

4.  Squirt a few drops of food coloring over the charcoal (do not use
    red).

5.  Allow the pan sit overnight. By the next morning, small crystals
    should have begun to form on the charcoal.

![](media/image4.png){width="0.6in" height="0.8346456692913385in"}

**Let's Make a Cave**

**Pre-Visit and Field-Trip Activities**

**Primary/Elementary Level**

**Science** (Unifying Concepts, Physical)

**1 ½-Hours Session plus Field Trip**

**Objective(s).** Students will demonstrate how to avoid touching
artificial speleothems while using large motor skills to negotiate an
obstacle course.

Students will practice good stewardship behavior, such as not touching
speleothems during their field trip.

**Related NM Content Standards with Benchmarks.** SC2-E3, SC7-E1, SC9-E2

**Method.** After studying the main types of speleothems, students
exhibit stewardship behavior by negotiating a teacher-constructed
obstacle course.

**Materials.** large cardboard box (such as a furniture or appliance
box), yarn, large nail, plastic drinking straws, large plastic cups,
wooden dowel (height of the box's width), tape

**Key Vocabulary.** secondary deposit, cave, exploration, speleothem

**Background.** Speleothem is the name given to any secondary deposit
(decoration) inside of a cave. Stalactites are speleothems that hang
down from the cave ceiling, and stalagmites are speleothems that rise up
from the cave floor. Formation of any speleothem takes a long period of
time. As each drop of water leaves a tiny amount of mineral residue on a
cave ceiling, floor, wall or other feature, it adds to speleothem
growth. When a speleothem is broken, it will not be replaced within our
lifetime, if ever! Therefore, cavers should be extremely careful while
exploring.

See "Safe Cave Exploration" in Section 2 -- Just the Facts.

**Suggested Pre-Visit Procedure**

1.  The cave obstacle course is made up of drinking straw *stalactites*,
    plastic cup *stalagmites* and a large cardboard box. Lay the box
    down so that two ends are open. Brace the center of the box with the
    wooden dowel *column*. Punch a hole in the top of the cave with the
    nail. Thread yarn through one drinking straw and then through the
    nail hole and knotted to secure it. Hang numerous straws, at various
    levels, in one area of the cave. Allow enough room for students to
    wriggle around without touching them. Make the *stalagmites* by
    taping large plastic cups together end to end, or mouth to mouth.
    *Stalagmites* can be one to three cups high. Mark a trail with the
    *stalagmites* leading to one open end of the box, through it, and
    out the other end to the other to represent an area of the cave
    where the explorer can stand upright. The cavers will need to crawl
    in the area represented by the box.

2.  Talk about the terms stalactites and stalagmites.

3.  Ask students to pretend that they are cavers exploring a newly
    discovered cave. It is their responsibility to not damage any
    speleothems.

4.  Individually, the student will approach the cave in an upright
    position being careful not to kick any *stalagmites*. When the
    student reaches the box, he/she will crawl through, not hitting any
    *stalactites* or *stalagmites*. When each student has had a chance
    to negotiate the cave, lead a short discussion on maneuvering
    methods that they invented or used. Have students try another trip
    through the cave to see if there has been any improvement from their
    first trial.

**Suggested Field-Trip Procedure**

1.  As you tour Carlsbad Cavern, remind students of their obstacle
    course experience.

2.  Point out speleothems that have been touched or broken. Look for
    signs of renewed growth of broken speleothems.

3.  Encourage students to protect the cave as they go through it, and to
    be aware of their impact upon the cave.

![](media/image4.png){width="0.6in" height="0.8346456692913385in"}

**Are All Caves the Same?**

**Pre-Visit or Post-Visit Activity**

**Primary/Elementary Level**

**Science** (Unifying Concepts, Earth)**, Mathematics** (Unifying
Concepts)**,**

**Social Studies** (Geography)

**1 Hour**

**Objective(s).** Students will discuss several types of cave
environments.

Students will explain one reason why people should not remove rocks,
speleothems or other features of the caves.

**Related NM Content Standards with Benchmarks.** SC2-E3, MA1-E1,
MA1-E4, MA1-E5, MA3-E1, MA3-E2, MA4-E5, SS12-E3

**Method.** Students compare and contrast rocks representing different
cave environments. Students solve mathematical problems to represent
visitor impact on the cave environment.

**Materials.** plastic cups, rocks, measuring tape, scale

**Background.** Caves differ in temperature and moisture. Some are cold
and wet, others are cold and dry, still others can be warm and wet, or
warm and dry.

See "Types of Caves" in Section 2 -- Just the Facts.

**Suggested Procedure**

1.  Exhibit 4 rocks -- one in a cup of water at room temperature, the
    second in a cup of water that has been refrigerated for several
    hours, the third dry and at room temperature, and the fourth dry and
    cold (kept in a refrigerator). Explain that these rocks came from
    your garden, not a cave or a park.

2.  Allow students to touch and handle the rocks.

3.  Begin a class discussion contrasting the differences in the rocks
    (wet, dry, warm, cold). How do rocks feel in a cave? Do rocks in
    caves feel different than the ones in the classrooms?

4.  Have students solve the following problems:

    -   How many classes are in your school? \_\_\_\_\_\_\_\_\_\_

    -   How many schools are in your community? \_\_\_\_\_\_\_\_\_\_

    -   How many schools are in your county? \_\_\_\_\_\_\_\_\_\_

    -   How many counties are in your state? \_\_\_\_\_\_\_\_\_\_

    -   If each year \_\_\_\_\_\_\_\_ (fill in the blank) school classes
        from the state were to remove 4 rocks from Carlsbad Cavern, how
        many rocks would be removed...

> ...in a year's time? \_\_\_\_\_\_\_\_\_\_
>
> ...in 5 years? \_\_\_\_\_\_\_\_\_\_
>
> ...in 10 years? \_\_\_\_\_\_\_\_\_\_
>
> ...by the time you graduate from high school? \_\_\_\_\_\_\_\_\_\_

-   If each rock weighed 3 lbs., how many tons of rocks would be
    removed?

-   Find a rock that weighs \_\_\_\_\_\_\_\_\_ (fill in the blank).
    Measure the area. Compute the area in square feet that would be
    missing from the cave yearly. (Use an object like a building to
    compare your figures to, so you have a visual aid to assist with the
    concept.)

-   Are the rocks/speleothems in Carlsbad Cavern being replaced?

-   Do speleothems grow at fast rates?

-   How can your students help promote cave conservation?

-   ***Note:*** These exercises could also be done using Carlsbad
    Caverns National Park's annual visitation of 650,000.

![](media/image4.png){width="0.6in" height="0.8346456692913385in"}

**How's the Climate Down There?**

**Pre-Visit, Field-Trip and Post-Visit Activities**

**Primary/Elementary and Intermediate Levels**

**Science** (Inquiry)

**30 Minutes Pre-Visit, Field Trip, 30 Minutes Post-Visit**

**Objective(s).** Students will observe and measure the differences in
temperature and humidity within the cave and on the surface.

**Related NM Content Standards with Benchmarks.** SC5-E2, SC5-M2,
SC6-M5, SC6-M6

**Method.** Students compare the temperature and humidity at their
school site, the park visitor center, the mouth of the cave and various
spots within the cave.

**Materials.** thermometer, sling hygrometer, paper, pencil

**Key Vocabulary.** weather, humidity, hygrometer, temperature,
thermometer, twilight zone

**Background.** The cave's temperature is a constant 56°F. Humidity is
about 95%. Students may notice a temperature change between the parking
lot and nature trail. Relative humidity and temperature will change
dramatically between the amphitheater and the end of the twilight zone.
If differences are noted between the elevator area and other areas of
the cave, it may be due to air coming down the elevator shaft,
refrigeration equipment in the rest area or the large number of people
in the general vicinity.

**Suggested Pre-Visit Procedure.** Introduce students to the concepts of
temperature and relative humidity. Demonstrate how to use the
thermometer and the hygrometer. Prepare a worksheet to record these
measurements. Each entry should include date, time, place, temperature,
relative humidity, plant life and wildlife. Take several measurements
and record data for several days prior to the field trip.

**Suggested Field-Trip Procedure**

1.  On the morning of your trip, have students measure and record the
    temperature and relative humidity at the school.

2.  Upon arrival at Carlsbad Caverns National Park, have students
    measure and record the temperature and relative humidity in the
    parking lot. Also take measurements in front of the visitor center,
    on the trail to the cave entrance, in the cave entrance
    amphitheater, at the end of the twilight zone, at the elevators and
    at two or three spots along the cave trail. Have students make notes
    about the kinds of plant life seen along the nature trail and on
    into the entrance. Record any wildlife seen along the way.

**Suggested Post-Visit Procedure**

1.  Have students hypothesize reasons for the differences noted in their
    observations.

2.  Facilitate a discussion on the impact of visitors on the temperature
    and humidity of the cave. Does the weather of the surface affect the
    type of wildlife and plant life found on the surface? How does the
    plant life change as one approaches the entrance to the cave? Why?

> ***Note:*** This activity can also be used on a visit to Slaughter
> Canyon Cave. Take measurements at the parking lot, beginning of the
> trail, halfway point (sign), cave entrance and several stopping points
> in the cave.

![](media/image4.png){width="0.6in" height="0.8346456692913385in"}

**Mapping a Cave**

**Pre-Visit or Post-Visit Activity**

**Intermediate Level**

**Science** (Inquiry, Earth)**, Mathematics** (Unifying Concepts,
Measurement)**,**

**Social Studies** (Geography)

**1 Hour**

**Objective(s).** Students will interpret a written set of instructions
and a pattern of markers.

Students will use mathematical procedures and measurements to accurately
solve problems.

**Related NM Content Standards with Benchmarks.** SC5-M2, SC12-M6,
MA2-M3, MA4-M4, MA9-M3, SS12-M1, SS12-M2

**Method.** Students use a compass and make a map similar to those made
by explorers.

**Materials.** The Class: 36 paper cups (recycled), something to weigh
down the cups

Each Group of 3: compass, tape measure, graph paper, student sheet

**Key Vocabulary.** topographic

**Background.** Proper documentation of a cave is important in
determining its scientific value and significance. Cave mapping is the
foundation of any type of cave research.

Since the 1960s, Carlsbad Caverns National Park has had coordinated
survey groups for both Carlsbad Caverns and some the park's remote
caves. The largest mapping project at the park began in 1986 and is
Lechuguilla Cave. Thus far, more than 100 miles of passages have been
surveyed and the end is not in sight. It is the deepest known cave in
the continental United States.

Cave survey teams have three or four members. At Carlsbad Caverns
National Park each survey team consist of four people---a sketcher, an
instrument person, a lead tape person and one person taking inventory of
cave features. The collected data is entered in a computer mapping
program and database.

Recently, cave mapping has taken a new turn with the Geographic
Information Systems (GIS). Archeological, historical, biological,
paleontological and mineralogical sites will be tied into the nearest
survey station GIS for cave management and is limited only by the
imagination.

**Suggested Procedure**

1.  Have students arrange the paper cup markers on the gym floor or
    outdoors. Set the markers in a grid with each cup being of equal
    distance (at least 10 feet) from the cup behind, in front, and to
    each side of the other cups. Put a weight in each cup to keep it
    from moving around. The grid can be 6 rows by 6 columns, or larger,
    as long as the number of columns equals the number of rows.

X X X X X X

X X X X X X

X X X X X X

X X X X X X

X X X X X X

X X X X X X

2.  Teach students how to find direction by using a compass. Show them
    the four cardinal directions of north, south, east and west; how to
    find northeast, southeast, northwest and southwest; and, how to use
    a tape measure.

3.  Divide the class into groups of three students. (A caver has at
    least two other cavers with him/her.) Give each group a copy of the
    student sheet. Assign group numbers 1 through 5. The written
    instructions will direct each group along its personalized path
    through the grid markers. Any marker may be the starting point.

4.  After each group has finished going through the course, have
    students plot the information on graph paper and show the route they
    took through the grid.

**Mapping a Cave**

Student Sheet

You are a group of cavers about to enter a wild cave. One caver reads
the instructions and the compass to direct the group. One caver takes
measurements from marker to marker and labels each marker with a number.
One caver records the path: number of marker, direction to next marker
and distance from the last marker.

**GROUP ONE**

Marker 1 Enter cave at SW corner.

Marker 2 Move to next NE marker.

Marker 3 Move to next N marker.

Marker 4 Move to next NE marker.

Marker 5 Move to next N marker.

Marker 6 Move to next W marker.

Marker 7 Exit cave at next SW marker.

**GROUP TWO**

Marker 1 Enter cave at SE corner.

Marker 2 Move to next W marker.

Marker 3 Move to next W marker.

Marker 4 Move to next N marker.

Marker 5 Move to next NE marker.

Marker 6 Move to next S marker.

Marker 7 Exit cave at next NE corner.

**GROUP THREE**

Marker 1 Enter cave at NE corner.

Marker 2 Move to next SW marker.

Marker 3 Move to next SE marker.

Marker 4 Move to next S marker.

Marker 5 Move to next NW marker.

Marker 6 Move to next N marker.

Marker 7 Exit cave at next E marker

**GROUP FOUR**

Marker 1 Enter cave at NW corner.

Marker 2 Move to next SE marker.

Marker 3 Move to next S marker.

Marker 4 Move to next E marker.

Marker 5 Move to next SW marker.

Marker 6 Move to next S marker.

Marker 7 Exit cave at next NW marker.

**GROUP FIVE**

Marker 1 Enter cave at N side, one marker from the NE corner.

Marker 2 Move to next SW marker.

Marker 3 Move to next S marker.

Marker 4 Move to next W marker.

Marker 5 Move to next W marker.

Marker 6 Move to next NW marker.

Marker 7 Exit cave at next N marker.

![](media/image4.png){width="0.6in" height="0.8346456692913385in"}

**Down to the Core**

**Pre-Visit or Post-Visit Activity**

**Primary/Elementary Level**

**Science** (Unifying Concepts, Earth)

**45 Minutes**

**Objective(s).** Students will make a model of the earth in order to
reinforce vocabulary, issues of geology and the general make up of the
earth.

**Related NM Content Standards with Benchmarks.** SC2-E2, SC2-E3,
SC12-E1

**Method.** By cutting through clay and cupcakes, students learn how the
earth is layered.

**Materials.** clay (brown, gray, red, black), clear straws, layered
cupcakes, plastic knives, scales, rulers, paper, pencils

**Key Vocabulary.** hypothesis, crust, mantle, core, mineral

**Background.** Earth is made of layers. The top layer, on which we
live, is the earth's crust. Below this is a thick layer called the
mantle. Still deeper within the earth's crust is the outer core. In the
center is the inner core. The deepest drillings have only penetrated the
earth's crust.

Geologists explore the earth by sampling the top layer of the
earth---the crust. Some knowledge has been gathered by using other
methods, such as analysis of earthquake waves passing through the earth
(seismology); analysis of the composition of meteorites; and by
calculations using the earth's size, shape and density.

Scientists believe that the inner core is a solid ball of iron and
nickel. They believe the mantle is made of molten iron and nickel.

**Suggested Procedure**

1.  In partners, have students construct a clay model of the earth
    showing four layers, each a different color. After the ball is
    completed, allow the clay set for thirty minutes. Cut ball in half.

2.  Have students record their findings. The Earth has different layers
    and together they are the Earth as a whole.

3.  Cupcake core sampling: Independently, have students predict the
    inner layer of the Earth's crust and use a cupcake as a model. Have
    students establish a hypothesis, sample the cupcake models using
    clear straws, write a conclusion and eat!

4.  Remind students that at Carlsbad Cavern is almost 800 feet below the
    surface---not enough to put a scratch the Earth's crust.

![](media/image4.png){width="0.6in" height="0.8346456692913385in"}

**A Key to Rocks**

**Pre-Visit or Post-Visit Activity**

**Intermediate and Secondary Levels**

**Science** (Inquiry)

**50 Minutes**

**Objective(s).** Students will identify *unknown* minerals by testing
their properties*.*

**Related NM Content Standards with Benchmarks.** SC6-M4, SC6-M6,
SC6-H4, SC6-H6

**Method.** Using a dichotomous key, students identify minerals.

**Materials.** variety of minerals and/or rocks or a pre-made sampling
set of minerals; copies of mineral identification key (dichotomous key);
small panes of glass; unglazed porcelain tiles; rock and mineral,
geology or mineralogy book for reference; pencils, paper, chart paper,
marker

**Key Vocabulary.** karst land, dichotomous key, rock, mineral

**Background.** Most karst lands are underlain by rocks, such as
limestone, dolomite, gypsum or marble. These rocks are called solutional
rocks because they can be dissolved by acidic rainwater to form cave.
Most large caves are formed in solutional rocks. The most common
solutional rocks is limestone. Limestone, composed of the mineral
calcite, is a sedimentary rock formed in layers.

Rocks are made up of minerals. There are hundreds of different minerals
in the world, each with unique physical properties, chemical composition
and origin. Geologists can determine a mineral's name by classifying its
properties. Those who do have little experience classifying minerals are
able to identify some of the more common ones by using a dichotomous
key. Dichotomous keys are used in fields, such as biology, botany and
entomology.

**Suggested Procedure**

1.  Before identifying rocks, facilitate a class discussion of
    terminology. Have students define the following terms: acid test,
    cleavage, conchoidal fracture, florescence, hardness, luster,
    specific gravity, streak color and surface color.

2.  Divide students into pairs.

3.  Distribute copies of the *Mineral Identification Key*. (You may
    prefer to use a key from your textbook or another source.)

4.  Using the key, have pairs determine the names of minerals specimens
    or identify individual bits of a mineral in a rock, using the key.

5.  Have students write their findings.

6.  Facilitate a class discussion and make a classroom chart of the
    mineral specimens the class has identified.

**Mineral Identification Key**

**How to Identify 26 Common Minerals**

Identification keys are useful for the study of natural objects. Use
this key to identify a specimen of a single mineral, or to identify
individual bits of a mineral in a rock. First find the hardness,
cleavage, color, color of the streak and luster of the mineral, as
explained in a general physical geology book or a book about rocks and
minerals. From your findings, answer *Question A*. Your **yes** or
**no** answer will guide you to the next question to answer. By moving
step by step through the key as directed, you can identify the mineral,
if it is one of the 26 listed.

Many of the minerals you find will not be included here. If this is the
case, check your findings of the physical properties with the mineral
descriptions in a book about rocks and minerals.

**Question A.** Is the specimen's hardness less than 2? (Can you scratch
it with your fingernail?)

> If yes, see **#1** below.
>
> If not, go to *Question **B***.

#1 Is cleavage perfect in one direction?

> If yes, see **a**, **b** and **c** below.

a.  If thin sheets are transparent, if thicker pieces are colorless or
    light in color and if the cleavage surfaces are very shiny, the
    mineral is [MUSCOVITE MICA]{.underline}.

b.  If the description above applies, except the color is dark brown to
    black, the mineral is [BIOTITE MICA]{.underline}.

c.  If there is a second cleavage direction, and if a silky to satiny
    luster is evident, the mineral is [GYPSUM]{.underline}.

> If not, see **\# 2** below.

#2 If there is no definite cleavage, see **a**, **b** and **c** below.

a.  If the mineral is mostly white with a dull luster and has an earthy
    odor when moistened the mineral is [KAOLIN]{.underline}.

b.  If the mineral is mostly white or greenish white, with a silky
    luster, and feels slippery to the touch the mineral is
    [TALC]{.underline}.

c.  If the mineral is mostly black, with a metallic luster, and feels
    slippery to the touch, the mineral is [GRAPHITE]{.underline}.

**Question B.** Is the hardness more than 2 ½, but less than 5 ½? (Is it
too hard to be scratched by a fingernail, but will not scratch glass?)

> If yes, see **#1** below.
>
> If not, go to *Question **C***.

#1 Is cleavage three-directional?

> If yes, see **a** below.

a.  Do all cleavage surfaces join at right angles?

> If yes, see **(1)** and **(2)** below.

1.  If the mineral is black, with a metallic luster and shows a black
    streak, the mineral is [GALENA]{.underline}.

```{=html}
<!-- -->
```
2.  If the mineral is light in color, and tastes salty, the mineral is
    [HALITE]{.underline}.

If not, see **b** below.

b.  If the cleavage surfaces fail to meet at right angles, and if the
    mineral is mostly white or milky white in color with a pearly
    luster, the mineral is [CALCITE]{.underline}.

#2 Is the cleavage generally two-directional?

> If yes, see **a** below.

a.  If the two cleavage surfaces are at acute angles, if the mineral
    appears translucent to transparent, and if it shows a rather glassy
    luster, the mineral is [FLUORITE]{.underline}.

> If not, see **#3** below.

#3 If there is no definite cleavage, see **a** below.

a.  Is the luster metallic?

> If yes, see **(1)** and **(2)** below.

1.  If the mineral has brownish red streak, the mineral is
    [HEMATITE]{.underline}.

```{=html}
<!-- -->
```
2.  If the mineral is yellow, has a brassy luster, and leaves a black
    streak, the mineral is [CHALCOPYRITE]{.underline}.

> If not, see **b** below.

b.  Is the luster dull?

> If yes, see **(1)** below.

1.  If the mineral has a rusty yellow to pale orange streak, the mineral
    is [LIMONITE]{.underline}.

**Question C.** Is the hardness more than 5 ½, but less than 7? (Will
the mineral scratch glass?)

> If yes, see **#1** below.
>
> If not, go to *Question **D***.

#1 When you press a sharp edge of the mineral against the glass, does it
leave only a faint scratch?

> If yes, see **a** below.
>
> If no, skip to **b**.

a.  Is cleavage two-directional?

> If yes, see **(1)** below.

1.  Do the cleavage surfaces join at right angles?

> If yes, see **(A)**, **(B)**, **( C)** and **(D)**.

A.  If the mineral is salmon pink or tuna-fish pink, the mineral is
    [ORTHOCLASE]{.underline} [FELDSPAR]{.underline}.

B.  If the mineral is white or gray, and contains very faint parallel
    striations on a well developed cleavage surface, the mineral is
    [ALBITE FELDSPAR]{.underline}.

C.  If the mineral is dark gray, contains very faint parallel striations
    on a well-developed cleavage surface, and shows an internal peacock
    blue and iridescent blue-green play of color, the mineral is
    [LABRADORITE FELDSPAR]{.underline}.

D.  If the mineral is dark green to black, the mineral is
    [AUGITE]{.underline}.

If not, see **(2)** below.

\(2\) If the two cleavage surfaces do not meet at

right angles, and the color is dark green to black,

the mineral is [HORNBLENDE]{.underline}.

a.  If there is no definite cleavage, see **(1)** below.

    1.  Is the luster metallic?

> If yes, see **(A)** and **(B)** below.

A.  If the mineral is yellow, and leaves a black streak, the mineral is
    [PYRITE]{.underline}.

B.  If the mineral is black, leaves a black streak, is quite dense and
    may be magnetic, the mineral is [MAGNETITE]{.underline}.

#2 When you press a sharp edge of the mineral against glass, does it
leave a deep scratch?

> If yes, see **a** below.

a.  Is the luster glassy, rather than metallic?

> If yes, see **(1)**, **(2)** and **(3)** below.

1.  If the mineral is deep wine-red in color, the mineral is
    [GARNET]{.underline}.

2.  If the mineral is colorless, milky, or smoky, the mineral is
    [QUARTZ]{.underline}.

3.  If the mineral shows a granular texture, and is rather olive green,
    the mineral is [OLIVINE]{.underline}.

If not, see **b** below.

b.  Is the luster dull and rather waxy? If yes, see **(1)** below.

    1.  If the mineral shows a distinct conchoidal fracture which leaves
        smooth curved surfaces that have sharp edges and corners, the
        mineral is [QUARTZ CHALCEDONY]{.underline}.

**Question D.** Is the hardness greater than 7? (Does the mineral leave
a deep scratch on the glass and a faint scratch on the porcelain tile
plate?) If yes, see **#1** and **#2** below.

#1 If the mineral is commonly black, green or pink in color, with a
glassy luster, and the long crystals show numerous fine grooves running
parallel to each other for the length of the crystal faces, the mineral
is [TOURMALINE]{.underline}.

#2 If the mineral is generally greenish blue, pale yellowish, yellowish
green, or pale pink to lilac in color, and shows an irregular to
conchoidal fracture with a glassy luster, the mineral is
[BERYL]{.underline}.

![](media/image4.png){width="0.6in" height="0.8346456692913385in"}

**Make a Fossil**

**Pre-Visit or Post-Visit Activity**

**Primary/Elementary and Intermediate Levels**

**Science** (Unifying Concepts, Earth)

**45 Minutes**

**Objective(s).** Students will demonstrate how a fossil is formed.

**Related NM Content Standards with Benchmarks.** SC2-E3, SC12-E5

**Method.** Students make models of fossils.

**Materials.** clay, plaster of Paris, water, old bowl and spoon, shells
or bumpy rocks

**Key Vocabulary.** fossils, brachiopods, trilobites, sediments,
organism

**Background.** Most animals and plants never become fossils. Most
sediments are laid down at sea, so most fossils are of creatures which
lived and died in the sea.

Carlsbad Caverns lies in an ancient fossil reef. Most scientists believe
that a sea existed in the Delaware Basin nearly 250 million years ago.
In this ocean lived many sea creatures such as brachiopods (clam-like
animals), trilobites, sponges, nautiloids (nautilus-like animals) and
algae. When these organisms died they built up and turned to rock,
making the Capitan reef today. A fossil was made when an organism died
and its body settled into the sediments on the sea floor. More sediments
covered the organism; and over time, the organism became rock.

**Suggested Procedure.**

1.  Pass around fossils to show students. Ask students to describe
    fossils and to explain how they think fossils were formed. Inform
    students that they will make their own model of a fossil to better
    understand how they are formed.

2.  Give each student a lump of clay. Flatten the clay a little. This
    represents the mud on the bottom of the sea.

3.  Give each student a shell or rock. Press it gently into the clay,
    not too far. This represents an organism that has died and settled
    at the bottom of the sea.

4.  Carefully take the shell or rock out of the clay. This represents
    the organism turning to rock.

5.  Mix Plaster of Paris according to the directions. Spoon the plaster
    into the print in the clay. This represents the next layer of
    sediment and mud that covers the organism and print.

6.  When the plaster is dry, peel away the clay to reveal the fossil.