LOCATION MERWIN MN+MI WIEstablished Series
TAXONOMIC CLASS: Loamy, mixed, dysic, frigid Terric Haplohemists
TYPICAL PEDON: Merwin peat with a level slope in a bog of about 300 acres on a ground moraine in an open forest of black spruce with an understory of heaths and sphagnum moss. (Colors are for moist soil unless otherwise stated.)
Oi--0 to 6 inches; dark yellowish brown (10YR 4/4) broken face fibric material, dark yellowish brown (10YR 3/4) rubbed, light yellowish brown (10YR 6/4) pressed; about 95 percent fiber, about 90 percent rubbed; massive; nonsticky; about 15 percent woody fragments mostly about 0.5 cm in diameter and 25 cm long; sphagnum moss fiber; few 1 cm thick layers of sapric material in lower part; about 15 percent mineral matter; layer ranges from 4 to 12 inches thick within dimensions of pedon; extremely acid; gradual wavy boundary.
Oe--6 to 40 inches; dark brown (7.5YR 3/3) broken face hemic material, dark brown (7.5YR 3/2) rubbed and pressed; about 50 percent fiber, about 20 percent rubbed; massive; nonsticky; mostly herbaceous fiber; about 10 percent mineral material; few charcoal fragments; very strongly acid; gradual smooth boundary.
Oa--40 to 42 inches; very dark gray (10YR 3/1) broken face, rubbed and pressed, sapric material; about 15 percent fiber, about 5 percent rubbed; massive, slightly sticky; herbaceous fiber; about 25 percent mineral material; very strongly acid; abrupt smooth boundary.
Ab--42 to 45 inches; very dark gray (10YR 3/1) loam; massive; friable; sticky; about 2 percent coarse fragments; very strongly acid; clear smooth boundary. (0 to 6 inches thick)
Cg--45 to 60 inches; dark gray (5Y 4/1) fine sandy loam; massive; firm; slightly sticky; very strongly acid.
TYPE LOCATION: Carlton County, Minnesota; about 4 miles west of Moose Lake; 2123 feet west and 2085 feet north of the southeast corner of sec. 20, T. 46 N., R. 20 W.
RANGE IN CHARACTERISTICS: The thickness of the organic soil material and the depth to the mineral soil substratum range from 16 to 51 inches. The content of woody fragments ranges from 0 to 25 percent, but the higher contents are only in the upper part of the control section. The fiber is dominantly of herbaceous origin except for some pedons that have fiber of sphagnum moss dominant in part to all of the surface tier. Reaction (in 0.01 M calcium chloride) typically is less than 4.5 in all parts of the organic soil material; however, in some pedons part to all of the organic soil material in the bottom tier has reaction of slightly more than 4.5.
The surface tier consists of either fibric, hemic, or sapric material or any combination of two or more of these materials. However, hemic material is dominant in the organic soil portion of the control section in pedons that have a mineral substratum beginning above a depth of 35 inches.
The subsurface tier is dominantly hemic material, and sapric material totals less than 10 inches in thickness in the subsurface and bottom tier in pedons that have the mineral substratum below a depth of 35 inches. A layer of sapric material commonly is immediately above the mineral substratum. Fibric material is not present in the subsurface or bottom tiers.
The hemic material has on the broken face hue of 5YR through 10YR with value and chroma of 2 through 4. Color of material with the higher value and chroma commonly darkens about one unit in value or chroma or both after exposure to the air. Color upon rubbing commonly is up to one unit lower in value or chroma or both than the broken face. The hemic material has 6 to 15 percent of mineral material.
The mineral substratum ranges from 5YR to 5Y hue, with the redder hues commonly becoming dominant with depth. It has value of 2 through 5 and chroma of 0 to 4. It typically is glacial till and commonly is fine sandy loam, sandy loam, or loam, but the full range includes other kinds of glacial sediments and all other texture classes within the limits of the loamy particle-size class. The upper few inches of the mineral substratum is sandy in some pedons. The mineral substratum ranges from extremely acid to neutral.
COMPETING SERIES: This is the Ossipee series. Ossipee soils lack a buried soil at the upper part of the mineral layer and are in a wetter climate.
GEOGRAPHIC SETTING: Merwin soils are in bogs primarily in rather shallow depressions chiefly on ground moraines, but they also are in bogs in lacustrine and outwash plains. They generally have slope gradients of less than 5 feet per mile. They formed in 16 to 51 inches of organic soil material that is derived primarily from herbaceous plants over loamy, noncalcareous glacial sediments of Late Wisconsin Age. These sediments primarily are glacial till. Mean annual precipitation ranges from 24 to 32 inches, and mean annual air temperature ranges from 35 to 45 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: The main ones are the very poorly drained Greenwood soils which are in parts of bogs where the organic soil material is thicker. Associated mineral soils primarily include soils formed in reddish, noncalcareous, loamy glacial till.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Very poorly drained; surface runoff is very low or ponded. Saturated hydraulic conductivity is rapid in the upper part and slow and moderately slow in the underlying material. Merwin soils have an apparent seasonal high saturation at thre surface for some time from October to June in normal years.
USE AND VEGETATION: Almost all of this soil is in native vegetation. Native vegetation consists primarily of sedges and grasses, but sphagnum mosses are common in some areas. An overstory of scattered black spruce, tamarack, or alder also is in some areas.
DISTRIBUTION AND EXTENT: MLRA's 90 and 93. Primarily northeastern Minnesota and the northern portions of Wisconsin and Michigan. Moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Carlton County, Minnesota, 1973.
REMARKS: Diagnostic horizons and properties recognized in this pedon are: Organic material - the zone from 9 to 42 inches (O1, Oe, Oa horizons); terric subgroup based on mineral soil material starting at 2 inches; dysic based on one or more layer within the control section having a pH less than 4.5.
ADDITIONAL DATA: Refer to MAES Central File Code No. 1446 for results of some laboratory analysis of the typical pedon.