Mississippi Loess EarthCache
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This cache is on property owned by the Vicksburg National Military Park. It is accessible via Jackson Road and you do NOT have to enter the main park to access this cache. As per Park request, only ONE vehicle at a time is allowed to park at cache site. Please be aware of the fast moving traffic on this road, and watch out for your children!
“LOESS” is the name of a very unique soil type that is an un-stratified and geologically recent deposit of silty or loamy material that is typically yellow-brown or buff in color and is deposited chiefly by the wind. Loess is a sedimentary deposit composed largely of silt-sized grains that are loosely cemented by calcium carbonate. It is usually highly porous and is traversed by vertical capillaries that permit the sediment to fracture and form vertical bluffs.
It is found in several varying regions of the world, including remote parts of Russia and China, in the USA’s Northwest Columbia Plateau region, and has extensive deposits occurring along the Mississippi River and its tributaries. Much of the loess in the United States is of glacial origin. Loess is usually deep, fertile soil, rich in organic remains and characterized by slender, vertical tubes that are said to represent stems and roots of plants buried by sediment. When cut by streams or other water-sheds, loess remains standing in cliffs exhibiting a vertical, column like structure. This is attributed to the vertical tubes and to the angularity of the grains and their consequent tendency to interlock. The un-compacted character of loess makes it subject to rapid erosion.
Glacial loess is derived from glacial outwash deposits, where glacial activity has ground rocks very fine (rock flour). After drying, these deposits are highly susceptible to wind erosion, winnowing of their silts, transportation of these sediments, and deposition some distance downwind from glacial deposits. The loess deposits found along both sides of the Mississippi River Alluvial Valley are a classic example of glacial loess. Loess tends to develop into highly rich soils. Therefore under appropriate climatic conditions these areas are among the most agriculturally productive in the world. Loess deposits are geologically unstable by nature, and will erode very readily. Even well-managed loess farmland can experience dramatic erosion each year.
Loess often stands in either steep or vertical faces. The term sometimes also refers to soils derived from such deposits. The word comes ultimately from Swiss German lösch (loose) as named by peasants and brick workers along the Rhine Valley where this type of sediment was first recognized. Loess grains are angular, with little polishing or rounding, composed of crystals of quartz, feldspar, mica and other minerals. Because the grains are angular, loess will often stand in banks for many years without slumping. This soil has a characteristic called "vertical cleavage", which makes it easily excavated to form cave dwellings. This practice is still a method used today to create human habitations in some parts of China.
LOCAL HISTORY
Loess soil forms sharp topographic hills east of the Mississippi River and Yazoo River in western Mississippi, north and south of Vicksburg. These deposits are in excess of 100 feet thick! Streams and gulleys are incised very deeply and sharply between the linear loess ridges making topography very important in the conduct of military operations for the Vicksburg Campaign of the Civil War.
THE REQUIREMENTS FOR LOGGING THIS CACHE ARE AS FOLLOWS:
1. Upload a picture of you or your group in front of the Loess Bluff immediately to the south of the posted coordinates.
Email me the answer to the following questions:
2. Is the loess soil in this Mississippi region likely to be formed by wind deposits over time, or glacial deposits?
3. Briefly run your hand over the surface of the bluff wall. What is the closest description of the texture of the surface? Is it A) Mineral like -- rock hard; B) Muddy like -- smooth moist clay; OR C) Grainy/sandy like, but firm
4. Approximately 110 feet to the east-northeast of the cache location (across the road) is a historical marker sign. To prove you were at this location, send me the exact wording that is on this sign.
As per earthcache rules, logs not accompanied by an email with the correct answers to the cache questions will have to be deleted.
This earthcache is placed with permission of the Vicksburg National Military Park (NPS). The Mississippi Geocachers Association is extremely thankful for the Park's prompt assistance in making this Earthcache possible.
Additional Hints
(No hints available.)