Before class prepare enough maps for pairs of students.
On the board write the question, “What does the
phrase ‘To find the mother lode’ mean?” As
students walk in ask them to respond to the question
on the board in their notebooks.
1. After giving the students time to respond to the
question in their notebooks ask them to discuss
it for a few minutes.
Even if this isn’t a phrase that they use they
can attempt to answer.
2. Tell students that today they will be prospecting
for gold, looking for the mother lode. Ask students
how they think early prospectors looked for gold.
suggest panning for gold, ask them “How did the
early prospectors, the successful ones, know where to
pan?” Lead students to recognize that understanding
geology is central to knowing where to mine for whatever
mineral you are looking for. Ask students if they know
areas that are famous for specific minerals, for example,
areas of Arizona are important in copper mining, Colorado,
South Dakota have gold mines. Like early prospectors,
the group that gets to the mother lode first is the one
who gets to lay the claim on it.
On each table place the laminated topographic map. Point
out the circled sampling sites. Explain
that at each site are the metal values underneath
the white-out. The challenge is to follow the metal
to find which drainage has the ore deposits and
the goldmine close by. The challenge is to do
as few moves
as possible. In other words they are to do this
without scratching out all the values. They must
knowledge of topographic maps to follow the deposits
Provide students with the following hint: Gold
is heavy. It settles where there is slow water
as on the
inside of a bend or behind a large boulder. As
off the white-out they must calculate the concentration
of metal in their sample.
4. There are multiple mines on the map. The multiple
mines reflect a vein across the map. Before the
students stake their claim they must make sure
that they are
able to explain their choice of sites. What does
them about where the gold is situated? How did
the gold get in the sediments? Why in the area
the map do some drainages have gold and others
Students should respond to these questions before being
able to stake their claim.
5. As students map the gold mines mark them off
on an overhead copy of the map.
6. Once all the mines are claimed ask students
what this information tells them. They should
respond to this in