Soil Evaluator Course, Day 3, Presentation 3 – 9/17/2019 ___________________________________ 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. Geologic Deposits, page 1 Soil Evaluator Course, Day 3, Presentation 3 – 9/17/2019 ___________________________________ ___________________________________ Drumlin Landform ___________________________________ SU SH Summit SH ___________________________________ Shoulder BS Kame Landform Back slope ___________________________________ SU FS Glacial Till SH Foot slope ___________________________________ Sand & BS Gravel ___________________________________ TS FS Toe slope ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ The Parent Material ___________________________________ 1. What are the different types of surficial deposits ___________________________________ 2. What types of landforms these surficial deposits are associated with and why ___________________________________ 3. How to recognize these landforms on topographic maps ___________________________________ 4. How are these deposits are represented on geologic maps ___________________________________ 5. What are their characteristics and relevance to septic systems ___________________________________ Geologic Deposits, page 2 Soil Evaluator Course, Day 3, Presentation 3 – 9/17/2019 ___________________________________ 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 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 ___________________________________ 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) Geologic Deposits, page 3 Soil Evaluator Course, Day 3, Presentation 3 – 9/17/2019 ___________________________________ ___________________________________ ___________________________________ 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 Geologic Deposits, page 4 Soil Evaluator Course, Day 3, Presentation 3 – 9/17/2019 ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Geologic Deposits, page 5 Soil Evaluator Course, Day 3, Presentation 3 – 9/17/2019 ___________________________________ 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 ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Oxidized upper zone Grey lower zone Dry enough for oxidized hor. Geologic Deposits, page 6 Soil Evaluator Course, Day 3, Presentation 3 – 9/17/2019 ___________________________________ Characteristics of Ablation Till ___________________________________ • Dominantly loose sandy to gravelly material ___________________________________ • Typically extremely variable with pockets and ___________________________________ discontinuous strata of different material ___________________________________ • Unstratified to coarsely stratified ___________________________________ • Very little clay (2 – 10%) ___________________________________ • Often has a high percentage of angular cobbles and boulders ___________________________________ ___________________________________ ___________________________________ Removal it looks like sand Wet it and it remains dirty ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Variety of tills and their color depends on the bedrock mineralogy from which they were derived ___________________________________ ___________________________________ ___________________________________ Light Gray Till Granites and/or Gneiss Dark Till Rocks w/Dark Mineralogy ___________________________________ Red Till Mesozoic/Triassic Age ___________________________________ Rocks ___________________________________ Geologic Deposits, page 7 Soil Evaluator Course, Day 3, Presentation 3 – 9/17/2019 ___________________________________ Lodgement ___________________________________ Tills ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ More cohesive and make vertical exposures ___________________________________ ___________________________________