Sands-Arenology
Observations of Sand
Complete the survey.
Write a paragraph
Digital Microscopy - Upload photos
Create a subfolder for the location of your sand in the appropriate folder. Upload four or more photos for each location, including a (1-3) 3 microscopic photos of the sand, (4) an aerial photo, and (5) a land-based scenic photo, and (6) a photo of the primary substrates from which the sand was formed. Label your folder and enclosed photos in a manner the following manner, substituting your specific location as appropriate.
Folder: Hana, Maui
Photo 1-3: Hana, Maui - sand
Photo 4: Hana, Maui - aerial
Photo 5: Hana, Maui - scene
Photo 6: Hana, Maui - substrates
Mapping
Include paragraph of data from the survey.
Topics
Geology
tectonic processes
the rock cycle
weathering and erosion
stratigraphy
paleontology
location of ancient seas & sea level changes.
water, wind and marine erosion
Chemistry
Chemical profiles of minerals (mineralogy)
solubility and other reactions with the environment
chemical weathering
Biology
Some sand grains are actually marine life remains
Beaches can reveal the diversity, abundance and ecology of organisms that dwell in water.
Premises
Carbonate composition indicates biological origins of sand grains.
Degree of sand grain roundness indicates greater weathering, a function of age or distance traveled; composition influences the rate of weathering.
Sand grain size is positively related to energy of wateer movement, the larger the grains the stronger the wave movement needed to move them.
Inferences based upon analysis of Sand
Complete the following survey with regards to your sand sample.
Terrigenous Sands - Sands from the Land
Weathererd granite
contain clear quartz as well as dark and light minerals
Weathered volcanics
often glassy and black
may include olive green or brick red
Silica based - shows no reaction to vinegar (5% acetic acid)
Biogenous Sands - Sands from the Sea
From skeletal fragments of marine plants and animals
Waves carry pieces of coral, seashells, etc. and deposit on beach
Calcium carbonate (limestone), dissoplves in vinegar (5% acetic acid), producing small bubbles of carbon dioxide.
Appearance of Sand
Shape
Well-rounded
poorly rounded or angular
spherical
disk shaped
Angularity
very angualar
angular
sub-angular
sub-rounded
rlonded
well rounded
Grain Size
Sand is defined as: Small, loose grains of mineral, rock, or other naturally occurring material, with grain sizes between 1/16 mm and 2 mm.Design and print your own mm graph paper. Plot Measure the average size of the particles in your sample by placing grains on this paper.
Determine the type of sand in your sample using a set of sieves. Arrange the sieves with the largest screen size (#5) on top, decreasing screen sizes in order below to the closed bottom container. Measure a sand sample by volume or weight. Place the sample into the top sieve, cover and shake the entire set with a back-and-forth motion. The particles should separate into their respective sizes.
Motion of environment
How swift was the water or wind movement in the sand you collected? Where rivers flow or waves surge, sand moves. The stronger the water movement, the larger the sand grains that are carried and/or kept in suspension.
Fast Current / Strong Waves - Where rivers run swiftly or waves are strong, they can carry larger or heavier grains and build beaches of boulders or gravel. The finer materials keep on moving, you won’t find them here!
Slow Current / Weak Waves- Where rivers are slow or waves are weak, they carry only small or light grains. As water movement weakens, even the smallest sands are dropped,contributing to deposits of fine sand.
Origin
Plutonic (Granite) - Granite rocks include of several different minerals, but quartz – made of silicon dioxide is the most durable to erosion. Quartz is often clear. Depending on the degree of weathering, granite sand may also include light-colored grains of the mineral feldspar or darker grains of hornblende, mica or magnetite. Where you find quartz sands, there must be some continental rocks somewhere.
Volcanic Origin – Sands of volcanic origin tend to be black, red, or green.
Meamorphic Origin – Sands that are of metamorphic origin often have garnet, a purple rock. If you have purple in your sample, it may indicate a history of metamorphosis.
Rock classification
Use the following keys to identify the samples provided. Put your answer in this survey.
