Page 621 - Geosystems An Introduction to Physical Geography 4th Canadian Edition

Some Brunisolic and Chernozemic soils and other soil orders are highly calcareous. Calcification (Figure 18.13) is the accumulation of calcium carbonate or magne- sium carbonate in the B and C horizons. Calcification by
TAblE 18.2 Four Organic horizons Used in the CSSC
calcium carbonate (CaCO3), among others, forms a diagnos- tic subsurface horizon along the boundary between dry and humid climates. These deposits harden or cement to become caliche, which can form in the southern prairies.
Symbol
Description
O Organic materials, mainly mosses, rushes, and woody materials l Mainly discernible leaves, twigs, and woody materials
F Partially decomposed, somewhat recognizable L materials
H indiscernible organic materials
O is further defined through subhorizon designations:
Of Om Oh
Readily identifiable fibric materials
Mesic materials of intermediate decomposition
Humic material at an advanced stage of decomposition—low fibre, high bulk density
Whitehorse
Iqaluit
Soil Order Map of Canada
Brunisolic Chernozemic Cryosolic Gleysolic Luvisolic Organic Podzolic Regosolic Solonetzic Vertisolic Unclassified
St. John’s
Charlottetown Fredericton
Yellowknife
Edmonton Regina
Winnipeg
▲Figure 18.11 Generalized soils of Canada. Distribution of the 10 soil orders of Canada. [Thematic Soil Maps of Canada: Soil Order, atlas.agr.gc.ca/agmaf/index_eng.html#context=soil-sol_en.xml, Agriculture and Agri-Food Canada ©, 2010. Reproduced with the permission of the Minister of Public Works and Government Services, 2012.]
0
500
Toronto
Victoria
Kilometres
Québec OTTAWA
Halifax
Chapter 18 The Geography of Soils 585