The river is just barely out of the picture to the

This is the Vishnu Schist and Zoroaster Granite, rocks from the heart of a mountain range. The river is
just barely out of the picture to the bottom.
Correct Answer(s): C
12.
Points Earned: 1.0/1.0

11/3/2016 RockOn #10
6/8
The picture above shows a region of hard rock about six inchesacross from the Grand Canyon.
The shape and polish of the rock areinteresting.
It is likely that the rock:
13.
Points Earned: 1.0/1.0

11/3/2016 RockOn #10
7/8
14.
Geological evidence based on several radiometric techniques has provided a scientifically well­accepted age for the
Earth. Represent that age of the Earth as the 100­yard length of a football field, and any time interval can be
represented as some distance on the field. (So something that lasted one­tenth of the age of the Earth would be
ten yards, and something that lasted one­half of the age of the Earth would be fifty yards.) On this scale, how
long have you personally been alive?
Feedback: If the 4.6 billion years of Earth history are 100 yards, then the few thousand years of written history
are just one­millionth of that history, just over the thickness of a sheet of paper. And your small piece of written
history must be only a small fraction of a sheet of paper, roughly 1/200th or so.
In the two pictures above, I and II, show traces of former life in rocks from the Grand Canyon. Each is "typical";the
rocks near sample I contain fossils similar to those shown in sample I, and the rocks near sample II contain fossils
similar to those shown in sample II.
It is likely that: