Stratigraphy Flashcards
Landward vs seaward building of strata
Retrogradation and Progradation
Global Sea Level rise or fall due to glacial activity or sea-floor spreading
Eustasy
These horizons are considered solum or true soil.
O, A, E, and B horizons
Enumerate the different basic soil orders.
Mnemonics - Give Him A Very Moldy Soap Or U Are An Incompetent Entity
- Gelisols - “geli-“ is to freeze, Permafrost Soils
- Histosols - “histo-“ is tissue, Organic Soils
- Aridisols - “arid-“ is dry, Desert Soils
- Vertisols - “verti-“ is vertical, Swelling Clay Soils
- Mollisols - “molli-“ is soft, Humus/Grassy Soils
- Spodosols - “woody ash” leached light-colored horizon, Acid Soils
- Oxisols - “oxi-“ is oxides, strongly weathered parent material, Oxide Soils
- Ultisols - “ulti-“ is ultimate, ultimate product of long period of weathering, Low-Nutrient Soils
- Alfisols - “Al” + “Fe” is aluminum and iron-rich, High-Nutrient Soils
- Andisols - “andi-“ is black, black from volcanic material not organic, Volcanic Soils
- Inceptisols - “inception” is beginning, weakly developed, Young Soils
- Entisols - “enti-“ is entire, entire topsoil because it has no subsoil unlike Inceptisol, New Soils
Moderately weathered soils that form under boreal forests or broadleaf deciduous forests, rich in iron and aluminum. Clay particles accumulate in a subsurface layer in response to leaching in moist environments. Fertile, productive soils, because they are neither too wet nor too dry.
Alfisol
Young soils in which the parent material is volcanic ash and cinders deposited by recent volcanic activity.
Andisol
Soils that develop in dry places; insufficient water to remove soluble minerals; may have an accumulation of calcium carbonate, gypsum, or salt in subsoil; low organic content.
Aridisol
Young soils having limited development and exhibiting properties of the parent material. Productivity ranges from very high for some formed on recent river deposits to very low for those forming on shifting sand or rocky slopes.
Entisol
Young soils with little profile development that occur in regions with permafrost. Low temperatures and frozen conditions for much of the year slow soil-forming processes.
Gelisol
Organic soils with little or no climatic implications. Can be found in any climate where organic debris can accumulate to form a bog soil. Dark, partially decomposed organic material commonly referred to as
peat.
Histosol
Weakly developed young soils in which the beginning of profile development is evident. Most common in humid climates, they exist from the Arctic to the tropics. Native vegetation is most often forest.
Inceptisol
Dark, soft soils that have developed under grass vegetation, generally found in prairie areas. Humus-rich surface horizon that is rich in calcium and magnesium. Soil fertility is excellent. Also found in hardwood forests with significant earthworm activity. Climatic range is boreal or alpine to tropical. Dry seasons are normal.
Molisol
Soils that occur on old land surfaces unless parent materials were strongly weathered before they were deposited. Generally found in the tropics and subtropical regions. Rich in iron and aluminum oxides
Oxisol
Soils found only in humid regions on sandy material. Common in northern coniferous forests and cool humid forests. Beneath the dark upper horizon of weathered organic material lies a light- colored horizon of leached material, the distinctive property of this soil.
Spodosol
Soils that represent the products of long periods of weathering. Water percolating through the soil concentrates clay particles in the lower horizons (argillic horizons). Restricted to humid climates in the
temperate regions and the tropics, where the growing season is long. Abundant water and a long frost-
free period contribute to extensive leaching, hence poorer soil quality.
Ultisol
Soils containing large amounts of clay, which shrink upon drying and swell with the addition of water. Found in subhumid to arid climates, provided that adequate supplies of water are available to saturate the soil after periods of drought. Soil expansion and contraction exert stresses on human structures.
Vertisol
Shallow diagenesis, occurs shortly after burial
Eodiagenesis
Diagenesis where sedimentary rocks approach the surface due to erosion
Telodiagenesis
Cavities filled with internal sediment and sparry calcite cement
Geopetal structure
Sandy deposits that develop where overbank flooding causes a break in the channel levee
Crevasse Splay
Small islands of deposited material within the channel of braided rivers.
Eyots or Aits
The warm layer of the lake’s thermal stratification that is usually oxic
Epilimnion
The cold layer of the lake’s thermal stratification that is usually anoxic
Hypolimnion
is the boundary between epilimnion and hypolimnion which may change throughout the day
Thermocline or Metalimnion
