LOCATION LAPORTE CO+MT NM WYEstablished Series
TAXONOMIC CLASS: Loamy, carbonatic, mesic Lithic Haplustolls
TYPICAL PEDON: Laporte loam, rangeland. (Colors are for dry soil unless
otherwise noted.)
A--0 to 9 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; moderate fine crumb structure; slightly hard, very friable; 5 percent limestone fragments; calcareous; moderately alkaline; clear smooth boundary. (5 to 16 inches thick)
Ck--9 to 16 inches; light brownish gray (10YR 6/2) channery loam, dark grayish brown (10YR 4/2) moist; massive; slightly hard, friable; some secondary calcium carbonate occurring mostly as nodules; 30 percent
limestone fragments; calcareous; moderately alkaline; gradual smooth boundary. (4 to 15 inches thick)
R--16 inches; weakly fractured limestone.
TYPE LOCATION: Larimer County, Colorado; approximately 1,712 feet north
and 321 feet west of SE corner Sec. 1, T. 4 N., R. 70 W.
RANGE IN CHARACTERISTICS: The average annual soil temperature is 49F. and the average summer soil temperature is 67F. The soils are dry more than .6 of the time that the soil temperature exceeds 5C. The mollic epipedon is 5 to 15 inches thick and the depth to the underlying bedrock
is 10 to 20 inches. The mollic epipedon contains from .6 to 2 percent organic carbon which decreases uniformly with increasing depth. These soils are calcareous at or within a few inches of the surface. The control section is typically channery loam but ranges in clay from 15 to
35 percent, in silt from 20 to 55 percent, and sand from 15 to 60 percent, with more than 15 percent but less than 35 percent being fine sand or coarser. Rock fragments range from 5 to 35 percent by volume and
are dominantly less than 6 inches in length.
The A horizon has hue of 2.5Y through 7.5YR, value of 4 or 5 dry, 2 or 3
moist, and chroma of 1.5 to 3. Typically, it has granular or crumb structure but has weak subangular blocky structure in some pedons. It is
soft or slightly hard and is mildly or moderately alkaline.
The C horizon has hue of 2.5Y through 7.5YR. It is moderately or strongly alkaline. Calcium carbonate equivalent of the strongest part of
the Ck horizon is about 16 percent but ranges from 10 to 35 percent. A considerable proportion of the calcium carbonate equivalent results from
fine limestone pebbles and sand-sized fragments which results in equivalent readings of the whole soil (3/4 inch and smaller) of 40 to 50
percent.
COMPETING SERIES: There are currently no competing series in this family.
GEOGRAPHIC SETTING: The Laporte soils are on upland hills and ridges. Slope gradients range from 2 to 60 percent. The soils formed in material
that weathered from or is strongly influenced by the underlying limestone
bedrock. At the type location the average annual precipitation is 15 to
18 inches, most of which falls during the spring and early summer. The frost-free season is about 135 to 150 days. In central New Mexico, the mean annual precipitation is 12 to 15 inches and the mean annual temperature is 48 to 52 degrees F. The frost free period is 110 to 135 days. Elevations are 6,800 to 7,500 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Pinon, Penrose, and Kim soils. These soils lack mollic epipedons.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderate permeability above the bedrock.
USE AND VEGETATION: These soils are used mostly as rangeland, however, they are tilled locally. Principal native vegetation is blue grama, western wheatgrass, needle-and-thread grass, Russian-thistle, yucca, and
cactus.
DISTRIBUTION AND EXTENT: Colorado, Montana, New Mexico, and Wyoming. The series is of large extent.
MLRA OFFICE RESPONSIBLE: Lakewood, Colorado
SERIES ESTABLISHED: The Fort Collins Area, Colorado, 1927.
REMARKS: This revision changes the classification from mixed to carbonatic minerology.