Regents Earth Science
Mr. Williams
Sedimentary Rox ID Lab
Geology Rox!
Name___________________________
Per_______
INTRODUCTION:
Sedimentary rocks are rocks that are composed of the weathered remains of other rocks.
These fragments have been compressed and cemented together by mineral material in
layers.
Other sedimentary rocks are made when they are left behind when seawater evaporates.
Others are made when biologic remains (yes, things that were alive and now are pretty
dead) are compacted together and/or cemented together by mineral material. Remember,
fossils (evidence of past life) are almost exclusively found in sedimentary rox.
Finally, some sed rox are monomineralic – that is, they are made of only 1 mineral! A
great example of this is rock salt, which is totally made of salt (halite).
Sedimentary rox are classified into 3 groups, based on their origin (how they formed).
These 3 groups are clastic (fragmental – composed of rock fragments), crystalline
(formed from evaporites and chemical precipitates), and bioclastic (made from dead
things).
What are some OBSERVABLE characteristics that make these
rox sedimentary?
1) They are composed of sediments – clay, silt, sand, pebbles,
cobbles, boulders – that have been cemented together by
mineral material
2) They are deposited in layers, and this layering is visible
(much of the time)
3) They contain fossils
VOCAB: Please define these words on the back of this page.
LEARN THESE FIRST!!
Clastic
Lithification
Deposition
Cementation
Compaction
Precipitation (from solution, NOT from a cloud)
Bioclastic
Fossiliferous – contains fossils
Fragmental
Distinguish
Stratification
Monomineralic
PROCEDURE:
OK! Now, it’s time to ID some sedimentary rox! I know, I know. Don’t be so excited.
You’re going to need your Sed Rox notes and your ESRT (what else is new). Use these
tools to help you get the rock names, and distinguishing characteristics that make them
those rocks. Good luck!
SED ROX ID SHEET
Sample
Number
1
2
3
4
5
6
7
8
9
10
11
12
Rock Name
Distinguishing Characteristics
WRAP UP QUESTIONS!!
Use your ESRT to answer these questions.
1) What is coal made from?
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2) What clastic rock is composed of the smallest grains of sediment?
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3) Draw the pattern (the map symbol) used to represent limestone.
4) What rock is composed of hardened clay?
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5) A)How are breccia and conglomerate similar? B)How are they
different? ANSWER BOTH A AND B!!
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6) What is the largest diameter of rock fragment generally found in
siltstone? __________________________________________
7) What common sed rock is composed mostly of the mineral calcite?
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8) What 3 minerals or mineral families dominate all of the CLASTIC sed
rocks?
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9) If a rock is made of sediment grains mostly about 1cm across, what
kind of rock is it? ________________________________________
10) Although Earth is mostly igneous rock, most of the bedrock we see at
the surface is sedimentary. Why?
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OK, now complete the little quiz and you’re done. WHEW!