Geologic Controls on Liquefaction Processes at the Bottineau Quicksand Site

Brody B. AwaltDept. of Geosciences

Minot State UniversitySpring 2014

ABSTRACT This study investigated the relationship between the geologic setting and the development of “quicksand” near Bottineau ND. The site is located south of Highway 5, 3.8 km east of Bottineau and 2 km south of the Turtle Mountains. “Quicksand” is any saturated, unconsolidated material that exhibits liquefaction when under stress. A manual auger was used to sample subsurface materials. Core locations were laid out along a N-S transect across the site to create a cross-sectional diagram. Sediment samples were obtained for laboratory analysis, and two stratigraphic units were identified during coring. Four wells were installed in two well nests to document site hydrology. Three wells were installed within the lower unit and one was installed in the upper unit. The lower-most unit, is a massive, unoxidized, firm, over-compacted diamicton (with compressive strength from 2.25 to 4.5 kg/cm2), with oxidized joints and thin discontinuous sand and silt layers. The joints represent fractures generated by soft sediment deformation during deposition of the unit. The surface unit at the site consists of an oxidized-to-reduced stratified unit with lower compressive strength (0.2-2.0 kg/cm2). The lower unit is a basal lodgement till assigned to the Coleharbor Formation. The silt layer near the base of the upper unit may represent deposition in a pond or Glacial Lake Souris. The upper unit is a melt-out supra-glacial till or colluvial unit, also assigned to the Coleharbor Formation. Based on hydrologic evidence, it appears that the lower unit is acting as an aquilude generating a perched water table at the base of the upper unit. As water moves through the subsurface it encounters an uplifted wall of the lower unit impeding lateral flow, forcing the water to the surface generating “quicksand.” Further research needs to be done to confirm this.

1

INTRODUCTION

This project examined the sedimentology and stratigraphy of an area identified as

quicksand near Bottineau, North Dakota (Figure 1), in order to identify processes that

created this unusual landscape. The study area, referred to informally as the Bottineau

Quicksand Site in this report, is located just south of the Turtle Mountains in Bottineau

County (Figure 2). Locals have known and been curious about what led to the formation

of quicksand in the area for a long time. There is a local story about a horse getting stuck

in the quicksand and needing to be pulled out by a truck (pers. comm., McKay, Sep.

2013). This project examined whether the liquefaction is the result of local geology.

Background

Regional Geology

The Bottineau Quicksand Site lies approximately 3.8 km east of Bottineau on the

south side of ND highway 5 (Figure 2). Bottineau County, located in north-central North

Dakota, is underlain by the Pleistocene Coleharbor Group. This unit varies in thickness,

from approximately 61 to 76 m thick in the west, 15 m to 30 m thick in the central area of

the county, and 61 to 91 m thick over the Turtle Mountains (Bluemle 1985).

Most of Bottineau County is composed of glaciated plains, with relatively flat,

rolling hill topography (Bluemle 1985). Glacial Lake Souris occupied the central part of

Bottineau County, and this region is overlain by thin lake or lake-shore sediments and

wave-planed glacial sediment (Bluemle 1985). In some portions of the county these

sediments have been reworked by wind into dunes and sand sheets (Bluemle 1985).

2

Primarily low-relief collapsed glacial topography is displayed in western Bottineau

County. The Turtle Mountains in the northeastern part of the county are composed of

high-relief collapsed glacial and ice-thrust topography (Bluemle 1985).The generalized

surficial geology of Bottineau and Rolette Counties is shown in Figure 4. According to

Bluemle (1985), “the glacial-drift deposits include materials such as sand and gravel, as

well as relatively impermeable silt, glacial till, and lacustrine clay.”

Regional Hydrology

After precipitation drops on the Earth's surface, part is evaporated to the

atmosphere, some moves off into streams, and the rest moves into the ground. Surplus

water within the soil eventually infiltrates downward below the ground water table into

the saturated zone. “Ground water moves under the effect of gravity and pressure from

areas of recharge to areas of discharge” (Randich and Kuznair 1984). The speed of

ground-water within a material is controlled by the hydraulic conductivity of the material

and by the hydraulic gradient. Gravel, well-sorted sand, and fractured rocks can have

high hydraulic conductivity, and if saturated can be aquifers (Randich and Kuznair 1984).

“Cemented deposits and fine-grained materials such as silt, clay, and shale usually have a

low hydraulic conductivity and restrict ground-water movement” (Randich and Kuznair

1984).

The water level in an aquifer can fluctuate in reaction to fluctuations in the rate of

recharge to the aquifer and discharge from the aquifer. These fluctuations can represent a

change in the total volume of water stowed in the aquifer (Randich and Kuznair 1984).

“However, in confined aquifers, changes in atmospheric pressure or surface load also

cause water-level fluctuations” (Randich and Kuznair 1984). In the study area, aquifers

3

present at land surface are recharged during spring, summer, and early fall by

precipitation moving downward towards the ground water table (Randich and Kuznair

1984).

“Liquefaction is the process by which saturated, unconsolidated sediments are

transformed into a substance that acts like a liquid” (GEO 2014). If a soil is saturated, a

state that often occurs if the soil is within the water table, then water resides in gaps

between soil grains (pore spaces). In an increase of pressure, the water will flow toward

zones of lower pressure (usually upward, toward the surface). The UWCE (2014) Web

site says that if pressure is quickly applied and is great enough, or quickly repetitive as

with earthquake shaking, pressure will build enough that contact forces keeping grains in

contact no longer can hold the grains together. They then move away from each other.

Sediment then will behave as a liquid. Wherever quicksand processes take place, mounds

of sediment are also found. The mounds of sediment are where most of the quicksand is

located.

The study area is well known for its natural springs and flowing artesian wells. “A

flowing artesian well occurs when the natural pressure of an aquifer is great enough to

cause water to rise to the surface” (USGSWSS 2014). The purpose of this study was to

find out what geological features in this area play a role in development of quicksand.

METHODS

Field Methods

Sampling was done in a line from NE to SW (Figure 5) using an auger-type hand

coring unit (Figure 6). Three holes were sampled, one (B5) at the SW edge of the study

area, another (B1) approximately half way between B5 and B4, and the third (B4) at the

4

northeastern-most part of the study area (Figure 5). Holes B5 and B1 were cored to 3.65

m and B4 was only cored to 2.74 m because of the high water table in that area. Core

samples were obtained at 10-cm intervals. After each 10-cm interval, the sample was

removed from the auger and placed into a Ziploc bag. Bags were labeled with their

corresponding core names and depths of extraction. Samples were taken back to the

Minot State University geology lab to be described and analyzed.

Two sets of nested wells were installed (Figure 7). Wells were designated B1, B2,

B3, and B4. B1 and B4 were installed in the holes left from the coring process. Core

sampling and well installation occurred on different days. Well depths were B1-3.6 m,

B2-2.7 m, B3-1.5 m, B4-2.7 m. Wells at B1 and B2 were nested together at varying

depths and B3 was nested with B4 in order to obtain hydraulic gradients. Well B1 was

placed at 3.6 m, the coring unit’s maximum depth. Wells consisted of 3.81 cm (1.5 in)

inner diameter PVC pipe with a sealed bottom and perforations in the lower 25 cm

(Figure 8). Perforations were installed with a cordless drill. Wells were placed in after

cores had been extracted. Thirty centimeters of sand were poured into each hole in order

to cover the lower 25 cm and perforations. Clay (kitty litter) next was added to each hole

in order to create a seal against any surface water percolating downward. Fill dirt finally

was dropped in around the PVC to fill up the rest of the hole to the surface level.

Due to freezing temperatures, water level readings were taken only when

possible. Data from those readings were entered in an Excel spreadsheet and

subsequently plotted (Figure 9).

Laboratory Methods

5

Detailed descriptions of soil morphology and parent material were completed for

each core. Soil descriptions were done in the field. They were typed up in the office and

stratigraphic boundaries observed in the field were modified based on laboratory results.

Density readings were obtained from a pocket penetrometer to provide a measure of

compressive strength. Readings were taken by slowly inserting the small piston into the

soil sample until the calibration mark was level with the soil (Figure 10). As the piston

was inserted into the sample the handle pushed the white ring on the scale and a reading

was obtained from the lower side of the ring closest to the tip of the instrument. Soil

compaction was read in kg/cm2 using the low side of the ring. Stratigraphic sections were

prepared from morphologic description and particle-size data.

Methods used for particle size analysis were developed by Bouyoucos (1927,

1951, and 1961).

Gravel Separation

Approximately 60 g of sample were submersed in water for 24 hours in a 250 ml

or 500 ml beaker. After 24 hours samples were set on a magnetic stir plate for five

minutes. Then the samples were poured through a 2 mm sieve to remove any gravel-sized

particles. Both greater than 2 mm and less than 2 mm fractions were dried, weighed, and

their weights were recorded. Only the less than 2 mm fraction was used for hydrometer

analysis.

Hydrometer Analysis

The less than 2 mm size fraction was captured in a 500 mL beaker. After beakers

had been filled with sample, 100 ml of 50 g/L sodium hexametaphosphate solution was

added to each. The mixture in each beaker was stirred with a spoon until all particles

6

were suspended. Particles that remained on the spoon were rinsed back into the beaker

with distilled water, and any particles that adhered to the sides of the beakers were rinsed

back into the suspension. The beakers were covered with watch glasses. Samples were

soaked overnight to allow the sodium hexametaphosphate solution to fully deflocculate

any clay particles.

Each sample was then washed into a stainless steel mixing cup with distilled

water and mixed for five minutes with a commercial drink mixing machine (Hamilton

Beach model number SA-10). Samples were washed with distilled water from the mixing

cup into a hydrometer jar. Hydrometer jars were filled with distilled water to the 1000 ml

mark and placed into a hydrometer bath at a constant temperature of 20 °C. A hydrometer

jar containing 100 ml of 50g/L sodium hexametaphosphate solution was filled with

distilled water to the 1000 ml mark, placed into the hydrometer bath and as a control to

subtract out the mass of added sodium hexametaphosphate in the samples. Once control

sample temperature was verified to be 20 °C, density was recorded using a bouycous

hydrometer.

A rubber stopper was placed into the opening of the hydrometer jar, and the jar

was rapidly and repeatedly rotated 180 degrees for one minute in order to ensure that all

particles were suspended. The jar was then placed back into the bath, a timer was started,

and the rubber stopper was removed. At a time of six hours and 52 minutes, a hydrometer

reading was taken. This reading was taken after all sand and silt-sized particles had

settled out of suspension, leaving only the clay-sized particles in suspension. This reading

was used to determine the clay-sized fraction of the sample.

7

Sand and Silt Percent by Weight

The contents of each hydrometer jar were poured through a number 230 sieve to

collect the sand-sized particles. These particles were washed from the sieve into a clean

beaker. Each beaker was cleaned, dried, and weighed. The beakers were placed into a

drying oven at 80 °C until contents were dry. The beakers containing the dry sand were

then weighed. This weight minus the weight of the clean, dry beaker was used as the

method of determining the sand-sized fraction of each sample. The silt-sized fraction of

the sample was determined by subtracting the sand percent by weight from the six hour

and 52 minute reading.

The dry sand from each sample was poured into a stack of sieves that separated

the sand into 0.5 phi intervals from -1.00 phi to 4.00 phi. This stack of sieves was placed

into a Ro-Tap sieve shaker and run for approximately 12 minutes. The material from each

sieve was removed, weighed, and the weight recorded (Table 8 and 9). The separate size

fractions were combined in Ziploc bags and cataloged for possible future study, but were

not analyzed as part of this study.

Moisture Correction Factor

For each sample a ceramic crucible was weighed. Approximately 10 grams of

each sample was split off using a sample splitter and poured into a crucible. The weight

of the crucible plus that of the sample was recorded. Samples were placed into a drying

oven at 105 °C for 24 hours in order to evaporate any hygroscopic water. Samples were

removed from the oven and placed into a desiccator and allowed to cool. Once cool, each

crucible was weighed again. The moisture correction factor (MCF) was calculated by the

following formula:

8

MCF = 1- Weight of air dry soil – weight of oven dry soilWeight of oven dry soil

The MCF was multiplied by the initial 60.00 g of material to determine the corrected total

initial sample weight for each sample. This was the weight used in all calculations

involving the total sample.

RESULTS

Site Hydrology

Results of the well readings are shown in Figure 9. Due to the high water table

and the cold winter, water level data was not obtained from January through April 2014

because of the wells being frozen.

Penetrometer Readings

Results of penetrometer readings are presented in Table 1. Measurements are in

kg/cm².

Gravel Separation

Results of the gravel separation are presented in Tables 2 and 3. Although

particles with a diameter greater than 2 mm had been removed for particle size analysis,

their mass was recorded in order to determine the sample fraction of this size as a means

to potentially aid in differentiating stratigraphic units at the site.

Moisture Correction Factor

Results for the MCF are presented in Tables 4 and 5. Obtaining the MCF and

subsequently the corrected mass of the sample prevented skewed results in further

analyses. The mass of the hygroscopic water that was tightly held by polar clay particles

was determined by the difference between mass of the oven-dried sample and that of the

9

air-dried sample, which was found by dividing the mass of the air-dried sample by the

mass of the oven-dried sample.

Particle Size Analysis

Percentages of sand, silt, and clay are indicated in Tables 6 and 7. The percent

sand of each sample was determined by comparing the weight percentage of the corrected

total sample weight, and it is shown in Tables 8 and 9. The clay weight was obtained by

the 6 hr and 52 min hydrometer reading and the silt weight was obtained by subtracting

the clay and sand weight from the corrected sample weight. Sand weights for each 0.5 phi

size interval are shown in Tables 10 and 11.

Stratigraphic Units

The Bottineau quicksand site was split into two distinct stratigraphic units based

upon physical descriptions of the sediments and particle size analysis.

Stratigraphic Unit One

Strat unit one contained the material from 120 cm to the base of the core in B1. In

core B4 Strat unit I contained the material from 160 cm to the base of the core. The

material was bluish to greenish-gray and showed silt to medium sand lamina. It contained

medium to fine cobbles and very obvious fractures that were observable in the auger

samples.

Stratigraphic Unit Two

Strat unit two (surface to 120 cm depth) ranged in thickness from 120 cm in B1 to

100 cm thick in B4. The sediment was predominately gray to grayish brown, showed

mottles within the samples, and was stratified. It contained pebbles ranging from fine to 5

10

cm in diameter. This unit contained a relatively small amount of silt and relatively large

percentage of sands and clays (Figures 11 and 12).

DISCUSSION

During field sampling two stratigraphic layers were observed, and this was

confirmed by further analysis. The lower-most unit, Strat Unit I, was massive, over-

compacted, and very dense. It had obvious joints or fractures and discontinuous sand

lenses. Strat Unit II was stratified and less dense. It lacked the joints that were present in

Strat Unit I. Strat Unit I was interpreted to be a lodgement till deposited beneath a glacier.

Strat Unit II was interpreted to be a supra-glacial melt out till, sediment on the surface of

the glacier that collapsed as the ice melted (Figure 13). There also may be younger slope

wash material within Strat Unit II.

Figure 14 represents the stratigraphy of the site based on field observations. Strat

Unit I is over lain by Strat Unit II, a supra-glacial till. Both wells B1 and B2 extended

into Strat Unit I, while well B4 extended only into the upper part of Strat Unit I. Well B3

extended only into Strat Unit II.

Figure 15 represents distribution of glacial ice over Bottineau County 12,500

years ago. This is when Strat Unit I apparently was deposited beneath the glacial ice.

Figure 16 represents the distribution of glacial ice over Bottineau County 11,000 years

ago. According to Figure 16, quicksand site must have been located under stagnant ice

where supra-glacial meltout till would have been deposited. This is when Strat Unit II is

believed to have been deposited.

Hydrometer analysis for B1 (Figure 13) suggests that sand and silt stringers did

not have a major impact on that area. According to the hydrometer analysis in sample B4

11

depths 140-160 cm, there was a spike in the percentage of silt (62%). This suggests

possible deposition in a pond or near-shore glacial Lake Souris.

Figure 17 suggests that ground water does follow the topography of the land

surface. Data for this image were obtained from the North Dakota State Water

Commission Web site (NDSWC 2014). Precipitation falling on the Turtle Mountains

infiltrates the soil and travels vertically until it reaches the ground water table and then

begins to travel horizontally toward the studied quicksand site. These factors suggest that

somewhere between the site and the Turtle Mountains, the water moves on top of Strat

Unit I and continues to travel horizontally within Strat Unit II, but remains on top of Strat

Unit I. Strat Unit I may have been fractured and displaced in some areas due to the heavy

glacier causing shearing of Strat Unit I 12,500 years ago. As the water reaches the south

side of the quicksand site, where it is believed that it encounters Strat Unit I and can no

longer travel horizontally, thus being forced upwards towards the surface and creating the

mounds of sediment and quicksand processes observed (Figure 18).

For wells B4 and B3, the vertical hydraulic gradient is 1.2, which indicates a very

large downwards gradient and most likely a perched water table.

CONCLUSION

Although it is not possible to be 100% certain that it is local geologic conditions

generating quicksand at this site, the results do strongly suggest that past basal

deformation processes at the landscape scale have contributed to liquefaction processes at

the site. The horizontal flow off of the Turtle Mountains and the abundance of flowing

artesian wells in the area add to the evidence that water is being forced upward to land

surface.

12

AKNOWLEDGMENTS

I would like to thank Dr. Krieg for helping me with my senior research project.

Mr. McKay, the land owner next to our study site. Dr. Crackel and Dr. Royer for all the

help in senior seminar. Dr. Kilroy for helping with the hydrology side of the study.

13

REFERENCES

Allred J., Barry. 2000. Survey of Fractured Glacial Till Geotechnical Characteristics: Hydraulic Conductivity, Consolidation, and Shear Strength. Vol 100:1-11p

Bluemle JP. 1985. Geology of Bottineau County, North Dakota. North Dakota Geological Survey Bulletin 78 Part 1. North Dakota State Water Commission County Groundwater Studies 35 Part I

Bouyoucos GJ. 1927. The hydrometer method for the Mechanical Analysis of Soils. Soil Science 26, 233 – 238.

Bouyoucos GJ. 1951. A Recalibration of the Hydrometer Method for Making Mechanical Analysis of Soils. Agronomy Journal 43, 435 – 438.

Bouyoucos GJ. 1962. Hydrometer Method Improved for Making Particle Size Analyses of Soils. Agronomy Journal 54, 464 – 465.

Randich PG, Kuznair RL. 1984. Geology of Bottineau County, North Dakota. North Dakota Geological Survey Bulletin 78. Part III. North Dakota State Water Commission County Groundwater Studies 35 Part III..

[GEOL] Geology Home Page. http://geology.com/usgs/liquefaction/ [updated 2014] Accessed 2014 Jan 30.

[GWM] Ground Water Movement http://www.co.portage.wi.us/groundwater/undrstnd/gwmove.htm Accessed 2014 Jan 30.

[NDSWC] North Dakota State Water Commissionhttp://www.swc.state.nd.us/4dlink9/4dcgi/GetSubCategoryRecord/Map%20and%20Data%20Resources/MapServices [updated 2011] Accessed 2014 Jan 30.

[UWCE] University of Washington Civil Engineering Home Page http://www.ce.washington.edu/~liquefaction/html/what/what1.html [updated 2000] Accessed 2014 Jan 30.

14

[USGS]United States Geologic Survey Water Science School home page. http://ga.water.usgs.gov/edu/gwartesian.html [updated 2014] Accessed 2014 Jan 30.

Figure 1. Bottineau County indicated by the hash marks. The town of Bottineau is indicated by the blue square and the city of Minot is indicated by the red dot. Figure modified from Bluemle (1985).

15

Figure 2. Bottineau is indicated by the maroon dot. The study site is indicated by the red pin. The Turtle Mountains are the darker shade of green and the Canadian border is represented by the yellow line. Figure taken from Google Earth (2014).

16

Figure 3. The red line is an approximate outline of the study area. Modified image from Google Earth (2014).

17

Figure 4. Generalized surficial geology of Bottineau County. Figure modified from Bluemle (1985).

18

Figure 5. The top right overlay shows the approximate area where the samples (B4, B2, and B5) and wells (B1, B2, B3, and B4) were located. Modified image from Google Earth (2014).

19

Figure 6. Auger coring unit used to extract cores and place wells.

20

Figure 7. Locations of nested wells B1 through B4. Modified image from Google Earth (2014).

21

Figure 8. Piezometer perforations. Figure taken from http://www.equipcoservices.com/sales/solinst/601.html

22

Nov/3/13 Nov/17/13 Nov/31/13 Dec/14/13

-325

-300

-275

-250

-225

-200

-175

-150

-125

-100

-75

-50

-25

0

25

Well Readings

B1 B2 B3 B4

Wat

er L

evel

(cm

)

Figure 9. Water level readings measured in cm. 0 is ground level. Between 03 November 2014 and 14 December 2014.

23

Figure 10. Pocket penetrometer measured in kg/cm². Figure taken from http://www.amazon.com/E-280-Pocket-Penetrometer/dp/B004NEG5B

24

Figure 11. Chart showing accumulative percentages of sand, silt, and clay as depth increases, across Strat Units I and II.

25

Figure 12. Chart showing cummulative percentages of silt, sand, and clay as depth increases, across Strat Units I and II.

26

Figure 13. Diagram showing deposition of lodgement and supra-glacial meltout till. Figure modified from British Society for Geomorphology (2012).

27

Figure 14. This diagram shows Strat Unit I on the south side of the quicksand site at a shallower depth then Strat Unit I on the north side of the quicksand site, indicating relative depth of wells B1, B2, B3, and B4.

28

Figure 15. The extent or maximum of the Wisconsin glacier around 12,000 years ago. This is when we believe Strat Unit I was deposited. The red dot is an approximate location of our study site. Figure modified from Bluemle (1985).

29

Figure 16. This image represents a slight retreat in the glacier approximately 11,000 years ago. This time frame is when it is believed Strat Unit II was deposited. The red dot is an approximate location of the study site. Figure modified from Bluemle (1985).

30

31

Figure 17. Cross section view of area north of studied quicksand site which is located at bottom left. Pentiometric surface is indicated by the blue line. Figure modified from Google Earth (2014).

Compaction ReadingsB1-Soil

Compaction Value

B4-Soil Compactio

n ValueDepth(cm) kg/cm² kg/cm²

32

Figure 18. Schematic-section of may occur beneath land surface. Blue triangles represent average water levels.

0-20 0.20 0.0020-40 0.23 0.0040-60 1.25 0.5060-80 1.75 0.7580-100 2.00 1.25

100-120 2.00 1.50120-140 2.25 1.50140-160 2.50 1.50160-180 3.00 1.75180-200 3.00 1.75200-220 3.25220-240 3.25240-260 3.25260-280 3.75280-300 3.75300-320 4.50320-340 4.50

Table 1. B1 and B4 compaction levels measured in kg/cm².

Weight of Gravel-B1

SampleCorrectedWeight (g)

Gravel Weight

33

(g)0-20 60.27 2.9620-40 66.80 2.3940-60 66.99 2.860-80 66.79 2.2380-100 64.40 2.15100-120 61.63 2.75120-140 61.02 1.82140-160 62.68 1.62160-180 62.15 2.13180-200 64.93 2.52200-220 64.60 3.43220-240 65.14 1.83240-260 62.97 2.73260-280 58.93 2.05280-300 61.16 2.09300-320 60.48 2.52320-340 63.19 2.01

Table 2. B1 Weight of gravel in grams per sample in core from sample B1.

Weight of Grave-B4

SampleCorrectedWeight (g)

Gravel Weight

34

(g)0-20 49.95 14.7520-40 49.79 5.5140-60 49.77 3.6960-80 49.40 1.2180-100 49.58 11.49100-120 45.88 2.34120-140 49.00 3.85140-160 47.66 0.01160-180 45.44 1.22180-200 47.98 1.96

Table 3. B4 Weight of gravel in grams per sample from core B4

Soil Moisture Correction Factor for Sample Core B1

SampleCrucibleWeight

Crucible Plus

Air Dry Soil

Crucible Plus

Oven Dry Soil MCF

Original Weight

CorrectedWeight (g)

35

(g)

Air Dry Soil

Weight (g) Weight (g)

Oven Dry Soil

Weight (g) Weight (g) (g)

0-20 20.04 30.78 10.74 30.73 10.69 0.9953 60.55 60.27

20-40 19.32 29.89 10.57 29.87 10.55 0.9981 66.93 66.80

40-60 20.11 31.31 11.20 31.31 11.20 1.0000 66.99 66.99

60-80 21.10 32.06 10.96 32.06 10.96 1.0000 66.79 66.79

80-100 20.42 30.78 10.36 30.78 10.36 1.0000 64.40 64.40

100-120 20.32 30.39 10.07 30.39 10.07 1.0000 61.63 61.63

120-140 19.74 29.98 10.24 29.98 10.24 1.0000 61.02 61.02

140-160 19.27 29.77 10.50 29.77 10.50 1.0000 62.68 62.68

160-180 22.34 33.27 10.93 33.28 10.94 1.0009 62.09 62.15

180-200 20.48 30.09 9.61 30.09 9.61 1.0000 64.93 64.93

200-220 20.26 31.22 10.96 31.08 10.82 0.9872 65.44 64.60

220-240 20.49 30.97 10.48 30.96 10.47 0.9990 65.20 65.14

240-260 19.69 29.82 10.13 29.80 10.11 0.9980 63.09 62.97

260-280 19.79 29.96 10.17 29.88 10.09 0.9921 59.40 58.93

280-300 19.69 28.70 9.01 28.65 8.96 0.9945 61.50 61.16

300-320 20.78 31.60 10.82 31.58 10.80 0.9982 60.59 60.48

320-340 21.04 31.82 10.78 31.80 10.76 0.9981 63.31 63.19

Table 4. Moisture correction factor and corrected weight for sample B1.

Soil Moisture Correction Factor for Sample Core B4

Sample

CrucibleWeight

(g)

Crucible Plus

Air Dry

Air Dry Soil

Weight (g)

Crucible Plus

Oven Dry

Oven Dry Soil

Weight (g) MCF

Original Weight

(g)CorrectedWeight (g)

36

SoilWeight (g)

SoilWeight (g)

0-20 19.99 30.29 10.30 30.28 10.29 0.9990 70.74 49.95

20-40 21.58 31.41 9.83 31.37 9.79 0.9959 70.71 49.80

40-60 19.62 30.55 10.93 30.50 10.88 0.9954 65.92 49.77

60-80 19.87 29.06 9.19 28.95 9.08 0.9880 62.84 49.40

80-100 20.66 31.54 10.88 31.45 10.79 0.9917 63.41 49.59

100-120 19.02 29.47 10.45 28.61 9.59 0.9177 60.37 45.89

120-140 20.63 31.15 10.52 30.94 10.31 0.9800 60.14 49.00

140-160 21.64 31.26 9.62 30.81 9.17 0.9532 63.70 47.66

160-180 21.25 32.78 11.53 31.73 10.48 0.9089 69.48 45.45

180-200 19.17 29.59 10.42 29.17 10.00 0.9597 59.98 47.98

Table 5. Moisture correction factor and corrected weights for sample B4.

Hydrometer Texture Analysis for Sample Core B1

37

Sample (cm)CorrectedWeight (g)

6 hour 52Minute

Reading (g/L)

BlankSolution

(g/L)

Corrected6 hour 52

MinuteReading

(g/L)

Sand Fraction Weight

(g)PercentSand

PercentSilt

PercentClay

0-20 60.27 40 4 36 20.03 33 7 6020-40 66.80 30 4 26 23.86 36 25 3940-60 66.99 31 4 27 20.28 30 29 4060-80 66.79 31 4 27 21.06 32 28 4080-100 64.40 30 4 26 19.73 31 29 40100-120 61.63 29 4 25 19.65 32 28 41120-140 61.02 29 4 25 18.69 31 28 41140-160 62.68 29 4 25 20.07 32 28 40160-180 62.15 30 4 26 19.82 32 26 42180-200 64.93 28.5 4 24.5 20.99 32 30 38200-220 64.60 28 4 24 19.46 30 33 37220-240 65.14 26 4 22 21 32 34 34240-260 62.97 25 4 21 20.5 33 34 33260-280 58.93 22 4 18 19.16 33 37 31280-300 61.16 22 4 18 20.48 33 37 29300-320 60.48 23 4 19 20.01 33 35 31320-340 63.19 25 4 21 20.12 32 35 33

Table 6. Particle size analysis of B1 showing percent sand, silt, and clay in core samples from B1.

38

Hydrometer Texture Analysis for Sample Core B4

Sample (cm)

CorrectedWeight (g)

6 hour 52Minute

Reading (g/L)

BlankSolution

(g/L)

Corrected6 hour 52

MinuteReading

(g/L)

Sand Fraction Weight

(g)PercentSand

PercentSilt

PercentClay

0-20 49.95 19 3 16 30.67 61 7 3220-40 49.80 25 3 22 27.17 55 1 4440-60 49.77 26 3 23 21.69 44 10 4660-80 49.40 21 3 18 20.04 41 23 3680-100 49.59 16 3 13 28.86 58 16 26100-120 45.89 21 3 18 23.57 51 9 39120-140 49.00 17.5 3 14.5 20.75 42 28 30140-160 47.66 21 4 17 1.21 3 62 36160-180 45.45 15.5 4 11.5 25.86 57 18 25180-200 47.98 20 4 16 20.63 43 24 33

Table 7. Particle size analysis of B4 showing percent sand, silt, and clay in core samples from B4.

Percent Sand by Weight for Core Sample B139

Sample

BeakerWeight

(g)

Sample Plus

Beaker Weight (g)

SandWeight (g)

CorrectedTotal Sample

Weight (g)Percent

Sand

0-20 110.34 130.37 20.03 60.55 33.08

20-40 112.19 136.05 23.86 66.93 35.65

40-60 114.09 134.37 20.28 66.99 30.27

60-80 113.11 134.17 21.06 66.79 31.53

80-100 113.16 132.89 19.73 64.40 30.64

100-120 106.16 125.81 19.65 61.63 31.88

120-140 110.34 129.03 18.69 61.02 30.63

140-160 112.19 132.26 20.07 62.68 32.02

160-180 114.09 133.91 19.82 62.09 31.92

180-200 113.11 134.1 20.99 64.93 32.33

200-220 113.16 132.62 19.46 65.44 29.74

220-240 106.16 127.16 21 65.20 32.21

240-260 113.11 133.61 20.5 63.09 32.49

260-280 113.16 132.32 19.16 59.40 32.26

280-300 112.19 132.67 20.48 61.50 33.30

300-320 114.09 134.1 20.01 60.59 33.03

320-340 110.34 130.46 20.12 63.31 31.78

Table 8. Percent sand by mass for sample B1.

Percent Sand by Weight for Core Sample B4

40

Sample

BeakerWeight

(g)

Sample Plus

Beaker Weight (g)

SandWeight (g)

CorrectedTotal Sample

Weight (g)Percent

Sand

0-20 111.98 142.57 30.59 49.95 61.24

20-40 113.22 140.39 27.17 49.80 54.56

40-60 114.03 135.72 21.69 49.77 43.58

60-80 111.13 131.17 20.04 49.40 40.57

80-100 114.71 143.57 28.86 49.59 58.20

100-120 106.16 129.73 23.57 45.89 51.37

120-140 112.19 132.94 20.75 49.00 42.35

140-160 106.16 107.37 1.21 47.66 2.54

160-180 114.03 139.89 25.86 45.45 56.90

180-200 111.13 131.76 20.63 47.98 42.99

Table 9. Percent sand by mass for sample B4.

B1 Sieve size (Phi) 10 14 18 25 35 45 60 80 120 170 230 Pan Total

41

Sample Weight (g)

0-20 0 0.5 0.8 0.8 1.2 1.5 2.2 2.1 3.2 2.7 3.3 0.9 19.2

20-40 0 0.3 0.6 1 1.7 2.3 3.5 2.9 3.9 2.6 3 1.3 23.1

40-60 0 0.3 0.7 0.7 1.1 2.2 2.2 3.3 2.8 3.4 3.4 1.3 21.4

60-80 0 0.5 0.7 0.8 1.1 1.5 2.2 2.2 3.5 3.1 3.8 1.3 20.7

80-100 0 0.5 0.5 0.8 1.1 1.4 2 2 3.3 2.8 3.7 1.1 19.2

100-120 0 0.3 0.6 0.7 1.1 1.4 2 2 3.3 2.9 3.6 0.7 18.6

120-140 0 0.3 0.5 0.7 1 1.4 2 2 3.3 2.9 3.4 0.7 18.2

140-160 0 0.5 0.5 0.6 1 1.3 2 2 3.3 2.9 3.7 1.8 19.6

160-180 0 0.5 0.6 0.7 1 1.3 2 2 3.5 3 3.7 1.3 19.6

180-200 0 0.3 0.6 0.8 1.2 1.4 2.1 2.1 3.6 3 3.9 1.4 20.4

200-220 0 0.3 0.5 0.7 1 1.3 2 2 3.3 2.8 3.5 0.8 18.2

220-240 0 0.4 0.6 0.8 1.1 1.4 2 2.1 3.6 3.2 3.9 1.3 20.4

240-260 0 0.5 0.6 0.7 1 1.3 2 2 3.4 3 3.8 1.9 20.2

260-280 0 0.4 0.6 0.7 0.9 1.3 1.9 1.9 3.3 2.8 3.5 1.2 18.5

280-300 0 0.5 0.6 0.6 1 1.3 2 2 3.4 2.9 3.7 1.7 19.7

300-320 0 0.4 0.6 0.8 1.1 1.4 2 2 3.3 2.9 3.7 1.8 20

320-340 0 0.5 0.7 0.9 1.1 1.4 2.1 2.1 3.4 3 3.8 1.1 20.1

Table 10. Sand mass of each 0.5 phi interval for core sample B1.

B4 Sieve size (Phi) 10 14 18 25 35 45 60 80 120 170 230 Pan Total

42

Sample Weight (g)

0-20 0 1 1.7 2.1 3 3.6 4.8 3.6 4.2 2.4 2.6 0.6 29.6

20-40 0 1 1.7 2.3 3.2 3.8 4 2.4 2.8 1.9 2.4 0.7 26.2

40-60 0 0.5 0.8 1 1.6 1.9 2.4 2.2 3.4 2.8 3.4 1.1 21.1

60-80 0 0.3 0.4 0.6 1 1.2 2 2 3.6 3 3.8 1.2 19.1

80-100 0 0.6 1.2 1.4 2 2.4 3 2.6 4.1 3.7 4.7 2.4 28.1

100-120 0 0.5 0.7 0.9 1.3 1.7 2.6 2.5 4.2 3.4 4.2 1.1 23.1

120-140 0 0.5 0.6 0.6 1 1.3 2 2 3.5 3.3 4.3 1.2 20.3

140-160 0 0 0 0 0 0 0 0 0.1 0.1 0.8 0.3 1.3

160-180 0 0.2 0.3 0.3 0.5 0.7 1.4 2.1 5.4 5.4 6.9 1.5 24.7

180-200 0 0.3 0.6 0.7 1.1 1.6 2.6 2.4 3.6 2.7 3.1 0.7 19.4

Table 11. Sand mass for each 0.5 phi interval for core sample B4.

43