Tick Tock – Telling Time Past and Present
6th Grade Earth Science Module Overview
Topic: Time.
Grade Level: 6th
Course: Earth Science Critical Thinking
Time Allotted for Module: 10 days
Prior Knowledge: This module requires little in the way of prior knowledge, although students are
expected to have some knowledge of basic Earth Sciences. Topics such as rock types and others should
reinforce and augment what they have previously learned.
Overview: This module initially addresses time on human scales, and then applies the concept to the
geologic history of the Earth. Students examine relative and then numeric (or ‘absolute’) time, construct
timelines, and then explore radiometric dating.
Vocabulary
Arithmetic Change: change that occurs at a constant rate (i.e., the plotted data are linear); simplified
example: adding or subtracting one unit over a given interval
Atomic Clock: a type of clock that uses an atomic resonance frequency standard as its timekeeping
element
Calendar: a system of organizing days for social, religious, commercial, or administrative purposes,
assembled by giving names to periods of time
Calibration: the validation of specific measurement techniques and equipment, to a standard
Chronology: a chronicle or arrangement of events in their order of occurrence in time; also see
timeline
Decay Series (Radiometric): the radioactive decay of different discrete radioactive decay products as a
chained series of transformations
Exponential Change: change that occurs with a logarithmic change in rate (either increase or
reduction); simplified: adding or subtracting a increasing or decreasing multiple of 10 units over
a given interval
Half-life: the time required for something to fall to half its initial value; in particular, the time for half
the atoms in a radioactive substance to disintegrate
Igneous Rock: a type of rock formed by magma or lava (molten rock) cooling and becoming solid
Isotope: different types of atoms (nuclides) of the same chemical element, each having a different
number of neutrons.
6th Grade “Tick Tock” Module Overview Page 1
Metamorphic Rock: a type of rock that is formed as pressure and/or temperature changes,
generally during burial or mountain building
Radiometric Dating: a technique used to date materials, usually based on a comparison between the
observed abundance of a naturally occurring radioactive isotope and its decay products, using
known decay rates
Relative Dating: the science of determining the relative order of past events, without necessarily
determining their absolute age
Sedimentary Rock: a type of rock that is formed by processes that cause mineral and/or organic
particles (detritus) to settle and accumulate, or minerals to precipitate from a solution
Steno’s Principles: a group of stratigraphic principles attributed to Nicolas Steno, a pioneering Danish
geologist, including lateral continuity, original horizontality and superposition (see definitions of
these terms below)
Lateral Continuity: material forming a stratum that is continuous over the surface of the Earth unless
some other solid bodies stood in the way
Original Horizontality: sediments are deposited under the influence of gravity as nearly horizontal
beds; if folded or faulted strata are found, the layers were deformed by tectonic forces after the
sediments were deposited
Superposition: at the time when any given stratum was being formed, all the matter resting upon it
was fluid, and, therefore, at the time when the lower stratum was being formed, none of the
upper strata existed
Stratum (pl. Strata): a horizontal layer of rock
Time: the sequence of events
Timeline: a visualization of a sequence of events, used in education, history and a variety of sciences
including geology, cosmology and biology
6th Grade “Tick Tock” Module Overview Page 2
Materials
All students should have their own science
notebooks for ALL activities
DAYS 1-2
Two small, plastic bottles (e.g. 16-32 oz. soda
bottles)
Sand or salt
Masking or duct tape
Thick aluminum foil
or
Coffee can
Glass or clear plastic container to collect water
Small nail
Hammer
Sharp pencil
Marker
Wristwatch or classroom clock for calibration
(should have a second hand).
Candles and matches (optional; see below)
DAY 3
Easel paper (preferably gridded) or 8” x 11”
graph paper (then the scale needs to be
adjusted) or use the file ‘Timeline
Sheet’ as the basis for this
Colored markers
DAY 5-7
A number of glass, graduated cylinders (enough
for students working in groups of 3 or 4)
At least four types of sediment (nothing too fine
grained as things like clay will not settle
quickly)
Funnel
DAYS 8-10
100 pennies per group
Shoe box (one per group)
Science Standards
Big Idea 1: The Practice of Science
Big Idea 2: The Characteristics of Scientific Knowledge
Big Idea 3: The Role of Theories, Laws, Hypotheses, and Models
Big Idea 6: Earth Structures
SC.6.E.6.1 Describe and give examples of ways in which Earth's surface is built up and torn down by
physical and chemical weathering, erosion, and deposition.
Math Standards
Big Idea 1: (Multiplying decimals)
Develop an understanding of and fluency with multiplication and division of fractions and decimals.
MA.6.A.1.3 Solve real-world problems involving multiplication and division of fractions and decimals.
Supporting Idea 6: Data Analysis
MA.6.S.6.1 Determine the measures of central tendency (mean, median, mode) and variability (range)
for a given set of data.
MA.6.S.6.2 Select and analyze the measures of central tendency or variability to represent, describe,
analyze, and/or summarize a data set for the purposes of answering questions
appropriately.
6th Grade “Tick Tock” Module Overview Page 3
References
Activity1.pdf
http://serc.carleton.edu/NAGTWorkshops/intro/activities/23346.html
Activity1_IN.pdf
http://serc.carleton.edu/NAGTWorkshops/intro/activities/23346.html
AgeDetermination.pdf
teacher-created
Evolution of Calendars.pdf
http://moonsighting.com/articles/evolution.html
BasltRock.pdf
http://www.pitt.edu/~cejones/GeoImages/5SedimentaryRocks/Carbonates/BioclasticLimestones/Lime
stoneCrinoidalCUp.jpg
Creating Timeline Activity
http://www.ourtimelines.com/
Evolution of Calendars.pdf
http://moonsighting.com/articles/evolution.html
ExcelWorksheet_HeadsUp.xls
http://www.techonthenet.com/excel/charts/2_y_axes.php
GeoPrinciples.pdf
http://geowords.com/histbookpdf/a19.pdf
Handout_StenosPrinciples.pdf
teacher-created
HowMuchis1Million.pdf
http://www.emints.org/ethemes/resources/S00001120.shtml
IgneousRock.pdf
http://www.pitt.edu/~cejones/GeoImages/2IgneousRocks/IgneousCompositions/3Basalt/BasaltSmallV
esicOlPheno.jpg
LifeLines.pdf
http://serc.carleton.edu/NAGTWorkshops/affective/activities/16669.html
LifeLines_IN.pdf
http://serc.carleton.edu/NAGTWorkshops/affective/activities/16669.html
MegaPenny.pdf
http://www.kokogiak.com/megapenny/default.asp
NAImeasureofdeeptime.pdf
http://nai.nasa.gov/news_stories/news_detail.cfm?ID=291
Passage of Time.pdf
http://hea-www.harvard.edu/ECT/the_book/Chap3/Chapter3.html
6th Grade “Tick Tock” Module Overview Page 4
Radiometric Dating.pdf
http://www.asa3.org/ASA/RESOURCES/WIENS.html
RelativeDatingTips.pdf
http://serc.carleton.edu/teacherprep/resources/activities/relative-dating.html
StemoArticle.pdf
http://earthobservatory.nasa.gov/Features/Steno/steno5.php
Walk Through Time Activity
http://www.nist.gov/physlab/general/time/index.cfm
6th Grade “Tick Tock” Module Overview Page 5