LOCATION NEPTUNE WAEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, mixed, mesic Entic Haploxerolls
TYPICAL PEDON: Neptune very gravelly sandy loam - on a 1 percent northwest facing slope in uncultivated field at 10 feet elevation. (Colors are for moist soil unless otherwise noted.)
A--0 to 10 inches; black (10YR 2/1) very gravelly sandy loam, very dark grayish brown (10YR 3/2) dry; weak very fine granular structure; soft, very friable, nonsticky, nonplastic; many very fine, fine, medium, and coarse roots; many very fine irregular pores 55 percent pebbles; slightly acid (pH 6.2); clear smooth boundary. (6 to 11 inches thick)
AC--10 to 27 inches; very dark brown (10YR 2/2) extremely gravelly loamy sand, dark brown (10YR 3/3) dry; single grain; loose; many very fine, fine and common medium and coarse roots; common fine irregular pores; 70 percent pebbles; 10 percent marine shells; strongly effervescent; neutral (pH 6.8); clear smooth boundary. (12 to 18 inches thick)
C1--27 to 45 inches; variegated black through white, but mostly 10YR 4/1 and 10YR 5/1 extremely gravelly coarse sand; single grain; loose; few fine and medium roots; many medium irregular pores; 65 percent pebbles; 25 percent marine shells; violently effervescent; mildly alkaline (pH 7.8); clear smooth boundary. (10 to 30 inches thick)
C2--45 to 60 inches; variegated black and white, mostly 10YR 4/1 and 10YR 5/1 extremely gravelly medium sand; single grain; loose; few very fine and fine roots; many medium irregular pores; 60 percent pebbles and 5 percent cobbles; 25 percent marine shells; violently effervescent; mildly alkaline (pH 7.6)
TYPE LOCATION: Whatcom County, Washington; about 1 1/2 miles west of Blaine on Semiahmoo spit; sec. 2, T. 40 N. R. 1 W.
RANGE IN CHARACTERISTICS: Mean annual soil temperature is 50 to 54 degrees F. These soils are usually moist, but are dry in the moisture control section for 60 to 75 consecutive days following summer solstice. By weighted average the control section has 55 to 70 percent pebbles.
The A horizon has value of 2 or 3 moist, 3 or 4 dry, and chroma of 1 or 2 moist and 2 or 3 dry.
The AC horizon has value of 2 or 3 moist, 3 or 4 dry, and chroma of 1 or 2 moist, 1 through 3 dry. it is very gravelly loamy sand, very gravelly sand, or extremely gravelly loamy sand. Reaction is slightly acid or neutral.
The C horizon has variegated hues in 10YR or 2.5Y. It is extremely gravelly medium sand or extremely gravelly coarse sand. Reaction is neutral or mildly alkaline. Marine shells fragments range from 5 to 25 percent, all less then 1/2 inches in size.
COMPETING SERIES: These are the Sequim and Winthrop series. These soils lack marine shells in the control section.
GEOGRAPHIC SETTING: Neptune soils are on marine ridges, spits, and terraces at elevations of 5 to 20 feet. Slopes are 0 to 3 percent. The soils formed in coastal beach deposits containing marine shells. Neptune soils are in a marine climate with warm, dry summers and cool, moist winters. Average annual precipitation is 30 to 40 inches. Mean January temperature is 37 degrees F.; mean July temperature is 62 degrees F. The mean annual temperature is 50 degrees F. The frost-free season is 150 to 190 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Eliza and Hovde series. These soils have an aquic moisture regime.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; very slow runoff; very rapid permeability. These soils are subject to rare flooding.
USE AND VEGETATION: Used principally for homesites and industrial sites. Native vegetation is Douglas-fir, red alder, and bigleaf maple with an undergrowth of salal, Oregon-grape, western swordfern, and vine maple.
DISTRIBUTION AND EXTENT: Coastal area in Northwestern Washington. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Whatcom County, Washington, 1945.
REMARKS: Diagnostic horizons and features recognized in this soil are a mollic epipedon from the surface to 27 inches that is sandy below 10 inches and a sandy-skeletal C horizon that is 5 to 25 percent marine shells.