PLEASE SEND YOUR ANSWERS SOON after you log your find or I may need to delete it!
1- Based on the information below and the sand particles in your hand, do you think that this sand traveled a long distance or a short distance, is the sand smooth or rough, small or big?
2- Do you think this sand was primarly eroded by water or wind? (see information below)
3- See how much (if any) magnetite there is in this sand, drop a magnet into the sand and remove it. Did any dark spects of rock stick to the magnet?
4- To discover if there are any shells or micro-skeletical remains in this sand, pour a very small amount of vinegar into the sand. If it bubbles - shells and micro-skeletical remains are present. DOES it bubble? (1/2 tablespoon of sand mixed with 1/2 tablespooon of vinegar gives the most accurate results.)
5- Post a picture (optional) of your GPSr and/or yourself with your log that shows the lake in the background. IF you have a problem with a pic , what is the man made feature a few hundred feet to your 10 oclock, made of what?
You may want to take a sample of sand home for the above experiments.
Try Greater Petoskey Area Earthcache Challenge at GC2HRCN
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Mackinaw Straits join the two Great Lakes of Lake Michigan and Lake Huron. It is the body of water that seprates Michigan's Upper and Lower Pennsulas'. Lake Michigan & Lake Huron were formed during the Ice Age as glacers moved from the north across the Great Lakes Region. The 'straits' are 3.6 miles long and 5 miles wide. The largest river nearby that deposits large amounts of sediment is the Cheboygan River, which flows into Lake Huron. But the largest volume of water comes from the St Mary's River, which is the overflow from Lake Superior. The strong movement/currents of the water through the 'straits' bring the sediment and rock particles which is the sand on this beach.
GEOLOGY:
Sand is a naturally occuring granular material composed of finely divided rock and mineral particles. As the term is used by geologists - sand particles range in diameter from 62.5 micrometers to 2 millimeters. Sand feels gritty when rubbed between your fingers!
Sand consists of rocks, crystals, shells and skeletical remains of organisms, eroded over time by the wind and water. Sand compositions can vary greatly from one area to another.
The most common constituent of sand is silica, also called silicon dioxide, usually in the form of quartz. The composition of sand is highly variable depending on the local rock sources and conditions. Sands in this area contain varying amounts of quartz, felspar, gypsum, and possibly magnetite (see logging requirement).
SAND DEPOSITION & COMPOSITION
Sand is transported by wind or water and deposited in the form of a beach, as is the case here, or dunes and sand bars.
The study of individual grains can reveal alot of historical and geological information as to the orgin and kind of transport of the grain. Sand that is RECENtLY weathered from larger rocks will be angular and be of drastically different sizes. It will feel rough to the touch. By contrast, sand that is transported long distances by wind or water will be rounded.
Of course, in most cases, there are not simply rock grains in the sand on the beach. Most beaches are a part of a complex ecosystem with a large variety of mono-cellular to multi-cellular microscopic 'shell-like' creatures as well as monopod and gastropods (shells in the typical sense of the word). All of these living organisms have a calcium-based bone structure, which can be absorbed/broken down with vinegar (see logging requirements to see if this beach has these creatures in significant numbers sufficient to set off a vinegar 'reaction.')
IMPORTANT NOTE: If you think that you may ever be south of Detroit, MI and run across the EarthCache GC24Y83 'sands of LAKE ERIE' --please keep a sample of the sand from 'sands of MACKINAW STRAITS ' -- to coompare the the results of the 'experiments' -GEOWARE has asked for this extra requirement.THANKS! (all sand is NOT the same)