___________________________________ TITLE 5 SOIL EVALUATOR ___________________________________ CERTIFICATION TRAINING ___________________________________ Climate Organisms ___________________________________ SOIL PARENT Relief Time MATERIAL ___________________________________ The geologic sediments that the soils formed in ___________________________________ ___________________________________ Prepared for: Commonwealth of Massachusetts Department of Environmental Protection By S.B. Mabee, PhD, PG, Massachusetts Geological Survey University of Massachusetts Amherst Presented by: New England Interstate Water Pollution Control Commission ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Page 1, form 11 ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Page 2, form 11 What is parent material? What landform? Read Topo map/read the landscape Understanding geology helps. ___________________________________ ___________________________________ Drumlin Landform ___________________________________ SU SH Summit SH ___________________________________ Shoulder BS Back slope Kame Landform ___________________________________ SU FS Glacial Till SH Foot slope ___________________________________ Sand & BS Gravel ___________________________________ TS FS Toe slope ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ The Parent Material ___________________________________ ___________________________________ • Where do the deposits in which the soils have formed come from? • What are their characteristics? ___________________________________ • These are the deposits that we live in ___________________________________ • Quick review of surficial geology of MA ___________________________________ • How deposits got here; how these deposits are typically represented on geologic maps ___________________________________ • What types of landforms these surficial deposits are associated ___________________________________ with and why • How to recognize these landforms on topographic maps and • Their characteristics and relevance to septic systems ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Parent materials govern minerals, color, permeability, infiltration New England soils do not form from weathering of bedrock ___________________________________ Types of ___________________________________ Glacial Till Deposits ___________________________________ ___________________________________ Outwash Plain ___________________________________ ___________________________________ Clay Topset Beds ___________________________________ Sand & Gravel Delta Wide variety, variable thick., wide range properties ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Most recent continental glaciation began 85,000 to 100,000 years ago ___________________________________ Wisconsin Glaciation (Laurentide Ice Sheet) ___________________________________ Max. extent ___________________________________ 22,000 to 28,000 years ago ___________________________________ About 1 mile thick over MA ___________________________________ Glaciation shaped ___________________________________ our landscape And dictate which soils ___________________________________ are suitable for septic systems and which are not ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ How do we know glaciers were here? ___________________________________ Modern analogs ___________________________________ Striations and Grooves ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ General South to Southeast Ice Flow ___________________________________ The Main Groups of Soil Parent Materials ___________________________________ • Glacial Till • Windblown (Loess) ___________________________________ • Shallow Bedrock • Organic Matter ___________________________________ • Glacial Outwash • Alluvial (Floodplain) ___________________________________ ___________________________________ • Lacustrine (Lakebed) • Coastal Deposits Deposits ___________________________________ • Fill Material • Marine Silts and Clays (Human Transported Material) What Makes Our Landscape So Diverse? ___________________________________ ___________________________________ • Wide variety and complex environments that occur when the ice is retreating and actively melting ___________________________________ • Meltwater stream spew tons of sand and gravel with high permeability while glacial lakes accumulate thick deposits ___________________________________ of low permeability silts and clays The Bottom Line ___________________________________ • The advance and retreat of glaciers imparted significant ___________________________________ heterogeneity to our landscape that changes rapidly in both a lateral as well as vertical direction ___________________________________ • How did different glacial deposits form, how are they manifested in the landscape, how can they be identified on topographic maps and how do they affect soil properties ___________________________________ ___________________________________ ___________________________________ Glacial Till ___________________________________ ___________________________________ Dominantly unsorted and unstratified debris, deposited directly by the glacier, and consisting ___________________________________ of a heterogeneous mixture of all the particle sizes – clay, silt, sand, gravel, cobbles and boulders ___________________________________ ___________________________________ Two Types of Glacial Till ___________________________________ Lodgement or Basal Till ___________________________________ Compact, dense deposited at the base of an actively flowing (moving) glacier ___________________________________ ___________________________________ Ablation Till ___________________________________ Loose, sandier till deposited by the melting ___________________________________ (wasting) glacier ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ >50% sand, 25-35% silt, <17% (8%) Ubiquitous <10 ft thick to a max. of 230 feet ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Characteristics of Lodgement Till ___________________________________ • Heterogeneous mixture of all particles sizes – ___________________________________ clay to boulder size ___________________________________ • Unsorted, not stratified ___________________________________ • Angular shaped rock fragments ___________________________________ • Firm and compact ___________________________________ • Clay content relatively high (5 – 25%) • Rock fragments are held firmly in place ___________________________________ Characteristics of Lodgement Till (con’t) ___________________________________ ___________________________________ • Typically occurs 2.5 to 3 feet below ground surface ___________________________________ • Locally referred to as “hardpan” ___________________________________ • Often has a perched water table during wet seasons and following periods of heavy precipitation ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________