1

General Description 

The following sections briefly describe the contents of five downloadable Excel (Microsoft 

Inc.) files containing the soil data collected from sites near Delta Junction, Alaska. Unavailable or 

inapplicable data is indicated by a dash (“-“). Additional information on these sites as well as 

sampling and analyses procedures can be found in the main text of the U.S.G.S. Open File Report 

(2004-1271) that this file accompanies. 

Delta_Field 

 This file contains the field descriptions of the sampled soils and includes the following 

columns: 

Sample ID Sample identification: The first two letters in the sample labels represent the 

region of study, Donnelly Flats (DF). The second two letters represent the 

study site. The number that follows these four characters indicates the plot. A 

decimal point separates the profile number from the basal depth of the sample 

(in cm). This labeling scheme varies slightly when samples were obtained 

from other institutions. 

Depth Indicates the basal depth, in cm, of sampling increment. 

Field Horizon 

Code 

Horizon type of the sample, as defined in the field. L = live moss, D = dead 

moss, F = fibric organic matter (OM), M = mesic OM, H = humic OM, A = A 

mineral soil horizon, C = C mineral soil horizon, LI = lichen, LT = litter. A 

lower case ‘f’ before horizon code indicates it was frozen at the time of 

sampling. A lower case ‘b’ before a horizon code indicates the sample 
2

showed evidence of burning (e.g. scorched, charred). A lower case ‘g’ 

indicates gravel was found in this horizon. 

Sample 

Description 

A brief description of the sample. 

Roots Root abundance and size using conventions of USDA-ARS (Staff 1998). 

pH The pH of the sample, either determined in the field or in the lab using a 

LaMotte pH kit. 

Moist Munsell 

Color 

Color of moist soil based on the Munsell soil color chart. 

Structure Grade, size, strength and type of soil structure following conventions of 

USDA-ARS (Staff 1998). 

Von Post or 

Texture 

If organic soil, the classification using the von Post scale of humification 

(Damman and French 1987). If mineral soil, the soil texture class as 

described in the field following conventions of USDA-ARS (Staff 1998). 

Note that some samples were submitted for particle size (see Delta_Physical) 

and may have more accurate texture descriptions based on these data. 

Plasticity Plasticity following conventions of USDA-ARS (Staff 1998). 

Stickiness Stickiness following conventions of USDA-ARS (Staff 1998). 

Firmness Moist consistence following conventions of USDA-ARS (Staff 1998). 

Height above 

mineral 

Height of each basal depth above the mineral soil boundary. Therefore, the 

bottom organic layer is at zero and all mineral horizons are negative numbers. 
3

Delta_Physical 

This file contains physical data such as bulk density, volumetric moisture content, and particle size 

analysis. Bulk density samples, which were usually also used for analytical purposes, were only airdried to preserve chemical integrity. These data were converted to an oven-dry basis by correcting 

them by the amount of moisture remaining in air-dry samples. This correction value was obtained 

from corresponding separate moisture samples that were air-dried to constant weight and then 

oven-dried. The moisture content of air-dried samples, which was used for this correction, is 

provided. Errors from these moisture corrections are likely small. Column definitions are as 

follows: 

Sample ID Sample identification: The first two letters in the sample labels represent the 

region of study, Donnelly Flats (DF). The second two letters represent the study 

site. The number that follows these four characters indicates the plot. A decimal 

point separates the profile number from the basal depth of the sample (in cm). 

This labeling scheme varies slightly when samples were obtained from other 

institutions. 

Depth Indicates the basal depth, in cm, of sampling increment. 

Field Horizon 

Code 

Horizon type of the sample, as defined in the field. L = live moss, D = dead 

moss, F = fibric organic matter (OM), M = mesic OM, H = humic OM, A = A 

mineral soil horizon, C = C mineral soil horizon, LI = lichen, LT = litter. A 

lower case ‘f’ before horizon code indicates it was frozen at the time of 

sampling. A lower case ‘b’ before a horizon code indicates the sample showed 

evidence of burning (e.g. scorched, charred). A lower case ‘g’ indicates gravel 
4

was found in this horizon. 

Sample 

Description 

A brief description of the sample. 

Date Sampled Date during which the sample was taken (month/day/year). 

Fraction >2 

mm in Sample 

Dry weight percent of soil particles not passing through a 2 mm sieve after 

gentle crushing. 

Roots >1 cm in 

Sample 

Dry weight percent of roots larger than 1 cm in diameter in the sample. 

Bulk Density 

(<2 mm) 

Grams of oven-dried soil per cubic centimeter, with soil particles greater than 2 

mm and roots greater that 1 cm diameter removed. Calculated by multiplying 

the air-dry bulk density by (1 – fraction moisture in air-dry sample). No volume 

adjustment has been made for the fractions removed. 

Total Bulk 

Density 

Grams of oven-dried soil per cubic centimeter for the entire soil sample with no 

fractions excluded. Calculated similarly to Bulk Density (< 2 mm) except the 

weight of particles greater than 2 mm and roots greater than 1 cm diameter have 

been included. 

Volumetric 

Field Moisture 

The percent water in the sample, by volume, assuming similar moisture and 

bulk density samples. 

Moisture in 

Air-dry Sample 

Percent, by weight, of moisture remaining in a sample after air-drying to 

constant weight as determined by subsequently oven-drying the sample. These 

data were obtained from a separate moisture sample and were used to calculate 

the Bulk Density (<2 mm) and Total Bulk Density values listed above. They 

were also used to convert carbon and nitrogen content to an oven-dry basis. 
5

Sand Percent by weight of soil particles greater than 0.05 mm in the sample 

remaining after removal of particles greater than 2 mm and roots greater than 1 

cm diameter. 

Coarse Silt Percent by weight of soil particles in the size range from 0.02 to 0.05 mm in the 

sample remaining after removal of particles greater than 2 mm and roots greater 

than 1 cm diameter. 

Fine Silt Percent by weight of soil particles in the size range from 0.002 to 0.020 mm in 

the sample remaining after removal of particles greater than 2 mm and roots 

greater than 1 cm diameter. 

Clay Percent by weight of soil particles less than 0.002 mm in the sample remaining 

after removal of particles greater than 2 mm and roots greater than 1 cm 

diameter. 

Notes OM++ indicates residual organic matter in sample may have skewed particle 

size results toward increased sand and/or coarse silt; OM indicates residual 

organic matter in sample, but likely not enough to skew particle size results. 

Delta_ Chemistry 

This file contains chemical data obtained from an elemental analyzer/mass spectrometer 

(EA/IRMS). Analytical samples, which were usually also used for bulk density purposes, were 

only air-dried to preserve chemical integrity. These data were converted to an oven-dry basis by 

correcting them by the amount of moisture remaining in the air-dry samples. This correction value 

was obtained from separate moisture samples that were air-dried to constant weight and then oven-
6

dried. The moisture content of air-dried samples, which was used for this correction, is provided in 

the file Delta_Physical. Errors from these moisture corrections are likely small. Column definitions 

are as follows: 

Sample ID Sample identification: The first two letters in the sample labels represent 

the region of study, Donnelly Flats (DF). The second two letters represent 

the study site. The number that follows these four characters indicates the 

plot. A decimal point separates the profile number from the basal depth of 

the sample (in cm). This labeling scheme varies slightly when samples 

were obtained from other institutions. 

Depth Indicates the basal depth, in cm, of sampling increment. 

Field Horizon 

Code 

Horizon type of the sample, as defined in the field. L = live moss, D = 

dead moss, F = fibric organic matter (OM), M = mesic OM, H = humic 

OM, A = A mineral soil horizon, C = C mineral soil horizon, LI = lichen, 

LT = litter. A lower case ‘f’ before horizon code indicates it was frozen at 

the time of sampling. A lower case ‘b’ before a horizon code indicates the 

sample showed evidence of burning (e.g. scorched, charred). A lower 

case ‘g’ indicates gravel was found in this horizon. 

Sample 

Description 

A brief description of the sample. 

%C Percent by weight of carbon in an oven-dried soil sample with material >2 

mm or 1 cm diameter removed. Calculated by multiplying air-dry 

determinations of percent carbon by the reciprocal of (1 – fraction moisture 

in air-dry sample). 
7

%N Percent by weight of nitrogen in an oven-dried soil sample with material 

>2 mm or 1 cm diameter removed. Calculated by multiplying air-dry 

determinations of percent nitrogen by the reciprocal of (1 – fraction 

moisture in air-dry sample). 

δ13C Per mil (‰) value of δ13C relative to Pee Dee Belemnite. 

Delta_ Suppl_Chemistry 

This file contains supplemental chemical data, such as 14C and elemental content, for samples on 

which these values were measured. Analyses were run using ground, air-dried soil. The 14C data, 

expressed in Delta notation (∆14C), were measured at Lawrence Livermore National Laboratory, 

Center for Accelerator Mass Spectrometry. Elemental values were measured using the Inductively 

Coupled Plasma technique for forty elements simultaneously (ICP-40). Column definitions are as 

follows: 

Sample ID Sample identification: The first two letters in the sample labels represent 

the region of study, Donnelly Flats (DF). The second two letters represent 

the study site. The number that follows these four characters indicates the 

plot. A decimal point separates the profile number from the basal depth of 

the sample (in cm). This labeling scheme varies slightly when samples 

were obtained from other institutions. 

Depth Indicates the basal depth, in cm, of sampling increment. 

Field Horizon 

Code 

Horizon type of the sample, as defined in the field. L = live moss, D = 

dead moss, F = fibric organic matter (OM), M = mesic OM, H = humic 
8

OM, A = A mineral soil horizon, C = C mineral soil horizon, LI = lichen, 

LT = litter. A lower case ‘f’ before horizon code indicates it was frozen at 

the time of sampling. A lower case ‘b’ before a horizon code indicates the 

sample showed evidence of burning (e.g. scorched, charred). A lower 

case ‘g’ indicates gravel was found in this horizon. 

Sample 

Description 

A brief description of the sample. 

∆14C Per mil (‰) value of ∆14C. 

+/- ∆14C Error associated with ∆14C value. 

Al Percent by weight of aluminum in an air-dried soil sample with material >2 

mm or 1 cm diameter removed. 

Ca Percent by weight of calcium in an air-dried soil sample with material >2 

mm or 1 cm diameter removed. 

Fe Percent by weight of iron in an air-dried soil sample with material >2 mm 

or 1 cm diameter removed. 

K Percent by weight of potassium in an air-dried soil sample with material >2 

mm or 1 cm diameter removed. 

Mg Percent by weight of magnesium in an air-dried soil sample with material 

>2 mm or 1 cm diameter removed. 

Na Percent by weight of sodium in an air-dried soil sample with material >2 

mm or 1 cm diameter removed. 

P Percent by weight of phosphorus in an air-dried soil sample with material 

>2 mm or 1 cm diameter removed. 
9

Ti Percent by weight of titanium in an air-dried soil sample with material >2 

mm or 1 cm diameter removed. 

Ag Parts per million of silver in an air-dried soil sample with material >2 mm 

or 1 cm diameter removed. 

As Parts per million of arsenic in an air-dried soil sample with material >2 mm 

or 1 cm diameter removed. 

Au Parts per million of gold in an air-dried soil sample with material >2 mm or 

1 cm diameter removed. 

Ba Parts per million of barium in an air-dried soil sample with material >2 mm 

or 1 cm diameter removed. 

Bi Parts per million of bismuth in an air-dried soil sample with material >2 

mm or 1 cm diameter removed. 

Cd Parts per million of cadmium in an air-dried soil sample with material >2 

mm or 1 cm diameter removed. 

Co Parts per million of cobalt in an air-dried soil sample with material >2 mm 

or 1 cm diameter removed. 

Cr Parts per million of chromium in an air-dried soil sample with material >2 

mm or 1 cm diameter removed. 

Cu Parts per million of copper in an air-dried soil sample with material >2 mm 

or 1 cm diameter removed. 

Eu Parts per million of europium in an air-dried soil sample with material >2 

mm or 1 cm diameter removed. 

Ga Parts per million of gallium in an air-dried soil sample with material >2 
10

mm or 1 cm diameter removed. 

Ho Parts per million of holmium in an air-dried soil sample with material >2 

mm or 1 cm diameter removed. 

La Parts per million of lanthanum in an air-dried soil sample with material >2 

mm or 1 cm diameter removed. 

Li Parts per million of lithium in an air-dried soil sample with material >2 mm 

or 1 cm diameter removed. 

Mn Parts per million of manganese in an air-dried soil sample with material >2 

mm or 1 cm diameter removed. 

Mo Parts per million of molybdenum in an air-dried soil sample with material 

>2 mm or 1 cm diameter removed. 

Nb Parts per million of niobium in an air-dried soil sample with material >2 

mm or 1 cm diameter removed. 

Nd Parts per million of neodymium in an air-dried soil sample with material 

>2 mm or 1 cm diameter removed. 

Ni Parts per million of nickel in an air-dried soil sample with material >2 mm 

or 1 cm diameter removed. 

Pb Parts per million of lead in an air-dried soil sample with material >2 mm or 

1 cm diameter removed. 

Sc Parts per million of scandium in an air-dried soil sample with material >2 

mm or 1 cm diameter removed. 

Sn Parts per million of tin in an air-dried soil sample with material >2 mm or 1 

cm diameter removed. 
11

Sr Parts per million of strontium in an air-dried soil sample with material >2 

mm or 1 cm diameter removed. 

Ta Parts per million of tantalum in an air-dried soil sample with material >2 

mm or 1 cm diameter removed. 

Th Parts per million of thorium in an air-dried soil sample with material >2 

mm or 1 cm diameter removed. 

U Parts per million of uranium in an air-dried soil sample with material >2 

mm or 1 cm diameter removed. 

V Parts per million of vanadium in an air-dried soil sample with material >2 

mm or 1 cm diameter removed. 

Y Parts per million of yttrium in an air-dried soil sample with material >2 

mm or 1 cm diameter removed. 

Yb Parts per million of ytterbium in an air-dried soil sample with material >2 

mm or 1 cm diameter removed. 

Zn Parts per million of zinc in an air-dried soil sample with material >2 mm or 

1 cm diameter removed. 

Delta_Transects 

 This file contains the field descriptions of soils at sites that were only described and not 

sampled. This file includes the following columns: 

Sample ID Sample identification: The first two letters in the sample labels represent the 

region of study, Donnelly Flats (DF). The second two letters represent the 
12

study site. The number that follows these four characters indicates the plot. A 

decimal point separates the profile number from the basal depth of the sample 

(in cm). This labeling scheme varies slightly when samples were obtained 

from other institutions. 

Depth Indicates the basal depth, in cm, of sampling increment. 

Field Horizon 

Code 

Horizon type of the sample, as defined in the field. L = live moss, D = dead 

moss, F = fibric organic matter (OM), M = mesic OM, H = humic OM, A = A 

mineral soil horizon, C = C mineral soil horizon, LI = lichen, LT = litter. A 

lower case ‘f’ before horizon code indicates it was frozen at the time of 

sampling. A lower case ‘b’ before a horizon code indicates the sample 

showed evidence of burning (e.g. scorched, charred). A lower case ‘g’ 

indicates gravel was found in this horizon. 

Sample 

Description 

A brief description of the sample. 

Site Information Where, by whom, and when the description occurred as well as the dominant 

tree and moss species. Depth to frozen layers, as determined by probing, are 

also noted if found. 

Roots Root abundance and size using conventions of USDA-NRCS (Staff 1998). 

Field pH The pH of the sample as determined in the field. 

Moist Munsell 

Color 

Color of moist soil based on the Munsell soil color chart. 

Von Post or 

Texture 

If organic soil, the classification using the von Post scale of humification 

(Damman and French 1987). If mineral soil, the soil texture class following 
13

conventions of USDA-NRCS (Staff 1998). 

Literature Cited 

Damman, A. W. H., and T. W. French. 1987. The ecology of peat bogs of the glaciated 

Northeastern United States: A community profile. Biological Report 85(7.16), U.S. Fish 

and Wildlife Service, Washington, D.C. 

Staff, S. S. 1998. Keys to Soil Taxonomy, 8th edition. Pocahontas Press, Inc., Blacksburg, Virginia. 

599 pp.