Laboratory Manual for Introductory Geology 4e

GEOTOURS EXERCISE 12
Interpreting Geologic History Using Google Earth
Name:
Course:
Section:
Date:
Exploring Geology Using Google Earth
1. Visit digital.wwnorton.com/geolabmanual4
2. Go to the Geotours tile to download Google Earth Pro and the accompanying
Geotours exercises file.
Expand the Geotour12 folder in Google Earth
by clicking the triangle to the left of the folder
icon. The folder contains placemarks for
features in the Grand Canyon of Arizona that
provide natural examples to help understand
some of the key concepts/principles used in
relative dating.
(a) Check all of the a: placemarks and
double-click one of the placemark icons
to fly to the eastern part of the Grand
Canyon. According to the principle
of original continuity, which bed
corresponds to the bed labeled “Source”?
(b) Check all of the b: placemarks and
double-click one of the placemark
icons to fly to an area with three beds
highlighted. According to the principle of
superposition, order the beds from oldest to youngest.
(c) (c) Check and double-click the Great Unconformity I placemark to fly to an exposure of the Great Unconformity
(a surface that separates older layered Precambrian units from the younger sedimentary Cambrian unit with up to a
1-billion-year gap in the rock record due to erosion). What type of unconformity is it at this location (trace the pink
layer to the left and see what happens to it)?
(d) Check and double-click the Great Unconformity II placemark to fly to another exposure of the Great
Unconformity. Here crystalline metamorphic rock and a white igneous dike are truncated and overlain by the
same tan sedimentary Cambrian unit. Using these cross-cutting relationships, which is older: the dike or the
tan Cambrian rock layer? Which likely contains inclusions of the other?
is older
contains inclusions of other unit
(e) What type of unconformity is the Great Unconformity at this same location?
12.5 CORRELATION: FITTING PIECES OF THE PUZZLE TOGETHER
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