Download Sedimentary Rock Identification

Lab # _____
Name:_______________________________________________Date:________________Lab Day:_____
Lab Period: _____
Sedimentary Rock Identification
Directions;
1. Refer to page 7 of the Earth Science Reference Tables, “Scheme for Sedimentary Rock Identification” to
help identify the samples from the box of sedimentary rocks.
2. Place the each sample next to its description and ask the teacher to verify your results.
3. After your results have been checked, sketch each sample in the space provided.
Sample A: This sample of sedimentary rock has a clastic texture and is composed of grains of clay
(sediments with a diameter less than 0.0004 cm). The particles are composed mostly of quartz, feldspar, and
clay minerals and my split easily. What is the identity of this sedimentary rock?
Answer: ______________________________
Sample B: This sedimentary rock has a bioclastic texture and is composed of grains of calcite ranging in
size from microscopic to coarse. It may contain shell fragments or precipitates of biologic origin. Fossils are
often found in this type of rock. Name this sedimentary rock.
Answer: ______________________________
Sample C: This sedimentary rock has a clastic texture and is composed of pebbles, cobbles, and/or boulders
embedded in sand, silt, and/or clay. The particles are composed mostly of quartz, feldspar, and clay minerals
and have rounded fragments. Identify this sedimentary rock.
Answer: ______________________________
Sample D: This sedimentary rock has a bioclastic texture and is composed of grains of carbon of various
size. This rock was formed from the remains of plants. What is this rock’s name?
Answer: ______________________________
Sample E: This sedimentary rock has clastic texure and is composed of grains of sand (sediments with a
diameter ranging in size from 0.2 cm to 0.006 cm.). Its composition is mostly quartz, feldspar, and clay
minerals and it may contain fragments of other rocks and minerals. What is the identity of this rock?
Answer: ______________________________
Sample F: This sedimentary rock has a crystalline texture and is composed of grains of halite of varied size.
It forms as crystals of chemical precipitates and evaporites. Name this sedimentary rock.
Answer: ______________________________
Part 2:
Using the reference tables, classify the sedimentary rock samples in your box into two groups according to
the following information:
Group 1- Clastic and Bioclastic: These rocks are composed of fragments ranging in size from very large to
very small. The fragments are cemented together with minerals. These rocks may feel very coarse or maybe
like sandpaper. Clastic rocks composed of the smallest sediments often contain fossils and are somewhat
crumbly.
Group 2 – Crystalline: These rocks show a uniform appearance (they look the same throughout) and have
smooth textures. In the reference tables, there are two samples that fit this description and are also classified
as minerals.
Place a check mark in the correct box on the chart for each of the rock samples.
Name
Breccia
Coal
Conglomerate
Limestone
Rock Gypsum
Rock Salt
Sandstone
Shale
Clastic/Bioclastic
Crystalline