Geomorphic Mapping of Garner Run, Susquehanna Shale Hills ... · Geomorphic Mapping of Garner Run,...
1
Geomorphic Mapping of Garner Run, Susquehanna Shale Hills Critical Zone Observatory (SSHCZO), Central, PA Sarah B. Granke 1 , Joanmarie Del Vecchio 2 , Roman A. DiBiase 2 1 Department of Geology, Pomona College, Claremont, CA 2 Department of Geosciences, The Pennsylvania State University, State College, PA 3: Open boulder field, no soil 1.5: Intermediate 1: Soil mantled with boulders 2: Canopied boulders, no soil Degree of Rockiness Road Existing Instrumented Soil Pits Garner Run SfM Site Channel Heads Shallow Soil Pits Point Counts Convergent swales/ intermittent channels 0: Fully soil-mantled N 100 m • Surface rockiness and grain size decrease downslope which could be a function of downslope being less steep and therefore unable to facilitate the transport of largeer clasts. Statistical breakdowns sug- gest a decrease in rockiness coinciding with a decrease in slope on both hillslopes. • Strong asymmetry in degree of rockiness between Tussey Mountain and Leading Ridge suggests an aspect related relationship in landscape development. Aspect differences would cause Tussey to experi- ence greater freeze-thaw cycles and enable more extensive solifluction to occur as compared to Leading Ridge. • Clay content is higher in the low-sloping bench at the foot of Tussey Mountain possibly suggesting a difference in underlying parent material (sandstone vs shale). Further investigation into clay contents via deeper pits and hydrometer work would be beneficial in getting more precise clay content percentages. 4. Results and Interpretations: Figure 3: Plot of average slopes for each surface class. Circles are plotted at the average value and whiskers extend to +/- 1 standard deviation. open boulder (3) boulder canopy (2) intermediate (1.5) bouldery soil (1) soil-mantled (0) Tussey Mountain slope Leading Ridge slope 30 10 20 Slope (º) References: Brantley, S. L., DiBiase, R., Russo, T., Shi, Y., Lin, H., Davis, K. J., Kaye, M., Hill, L., Kaye, J., Neal, A. L., Eissenstat, D., Hoagland, B., Dere, A., (2015): Designing a suite of measurements to understand the critical zone. Earth Surface Dynam- ics (submitted). Acknowledgements:: This project would not have been possible without financial support from NSF EAR 1263212. This project also was aided tremendously with the help of Brandon Forsythe and Dave Pederson in soil pit digging. Thank you. 1m Millimeter resolution orthophoto of open boulder field on Tussey Moun- tain slope made from SfM photo- grammetric survey. Figure 2: Plot of grain sizes of boulders as a function of distance from the Tussey Mountain ridgeline, color coded by surface unit. The dashed blue line shows location of Garner Run stream channel relative to boulder point count locations. open boulder fields with no soil; orange on map canopied boulder fields; yellow on map soil mantled with emergent boulders; green on map Maximum grain diameter D84 D50 (median grain diameter) D16 Minimum grain diameter 0 20 40 60 80 100 120 140 100 200 300 400 500 600 700 800 900 1000 Distance from Tussey Mt Ridgeline (m) Grain Diameter (cm) Tussey Mountain Leading Ridge (Garner run) NW # # ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ " " " " ? ? ? ? ? ? ? 0 50 100 150 200 25 Meters 3. Methods and Approach: • Field mapping of surface features: spatial distribution of boulder fields, variations in ground cover - 11 days total (300 m x 1000 m area, mapped at 10 m resolution) • Surface clast grain size measurement - 19 point counts (n = 100 for each) across mapping area - Structure from motion photogrammetry survey of boul- der field to characterize surface roughness • Soil descriptions - 6 shallow pits dug (average depth of 30 cm) in Tussey Mountain slope - described depth, color, and texture of horizons Digital elevation model of Shavers Creek Watershed (Brantley et al. 2015) PENNSYLVANIA SSHCZO N AcD BxD HTF HsB MkD Ru HTD AoB 200 m Garner Run subcatchment showing distribution of soil series (SSURGO database) Soil Series 2. Garner Run Study Area 1. Motivation Investigating the physical properties of the soil mantle and surface morphology is necessary to model the processes linked to mass fluxes--water, energy, gas, sediment, and solutes (WEGSS)--in the landscape. Existing data on these properties are in- adequate for the purpose of model building because the resolution does not account for the complex surface heterogene- ities present in Garner Run. Previous work is also inadequate for geomorphic interpretations of past processes and climate of the landscape because it fails to capture details like spatial variability of lobate features, as well as surface roughness. This study aims to produce high resolution surficial mapping for future model building and studies of past processes. Figure 1: Characteristic photo of each mapping class with degree of rocki- ness specified. SE 0: Fully soil-mantled 3: Open boulder field with no soil 1: Mostly soil-mantled, some emergent boulders 2: Canopied Boulders with no soil
Transcript of Geomorphic Mapping of Garner Run, Susquehanna Shale Hills ... · Geomorphic Mapping of Garner Run,...
Geomorphic Mapping of Garner Run, Susquehanna Shale Hills Critical Zone Observatory (SSHCZO), Central, PA
Sarah B. Granke1, Joanmarie Del Vecchio2, Roman A. DiBiase2
1Department of Geology, Pomona College, Claremont, CA2Department of Geosciences, The Pennsylvania State University, State College, PA
3: Open boulder �eld, no soil
1.5: Intermediate
1: Soil mantled with boulders
2: Canopied boulders, no soil
Degree of Rockiness
Road
Existing Instrumented Soil Pits
Garner Run
SfM Site
Channel Heads
Shallow SoilPits
Point Counts
Convergent swales/ intermittent channels
0: Fully soil-mantled
N
100 m
• Surface rockiness and grain size decrease downslope which could be a function of downslope being less steep and therefore unable to facilitate the transport of largeer clasts. Statistical breakdowns sug- gest a decrease in rockiness coinciding with a decrease in slope on both hillslopes. • Strong asymmetry in degree of rockiness between Tussey Mountain and Leading Ridge suggests an aspect related relationship in landscape development. Aspect di�erences would cause Tussey to experi- ence greater freeze-thaw cycles and enable more extensive soli�uction to occur as compared to Leading Ridge. • Clay content is higher in the low-sloping bench at the foot of Tussey Mountain possibly suggesting a di�erence in underlying parent material (sandstone vs shale). Further investigation into clay contents via deeper pits and hydrometer work would be bene�cial in getting more precise clay content percentages.
4. Results and Interpretations:
Figure 3: Plot of average slopes for each surface class. Circles are plotted at the average value and whiskers extend to +/- 1 standard deviation.
open boulder (3)
boulder canopy (2)
intermediate (1.5)
bouldery soil(1)
soil-mantled(0)
Tussey Mountain slopeLeading Ridge slope
30
10
20
Slop
e (º
)
References:Brantley, S. L., DiBiase, R., Russo, T., Shi, Y., Lin, H., Davis, K. J., Kaye, M., Hill, L., Kaye, J., Neal, A. L., Eissenstat, D., Hoagland, B., Dere, A., (2015): Designing a suite of measurements to understand the critical zone. Earth Surface Dynam-ics (submitted).
Acknowledgements:: This project would not have been possible without �nancial support from NSF EAR 1263212. This project also was aided tremendously with the help of Brandon Forsythe and Dave Pederson in soil pit digging. Thank you.
1m
Millimeter resolution orthophoto of open boulder �eld on Tussey Moun-tain slope made from SfM photo-grammetric survey.
#
#
^
^
^
^
^
^
^
^
^
^
^
^
^
^
^
^
^
^^
"
"
"
"
?
?
? ?
?
?
?
TMMS
LRRT
LRMS
LRVF
100
Meters
Figure 2: Plot of grain sizes of boulders as a function of distance from the Tussey Mountain ridgeline, color coded by surface unit. The dashed blue line shows location of Garner Run stream channel relative to boulder point count locations.
open boulder �elds with no soil; orange on map
canopied boulder �elds; yellow on map
soil mantled with emergent boulders; green on map
Maximum grain diameter
D84
D50 (median grain diameter)
D16
Minimum grain diameter
0
20
40
60
80
100
120
140
973 895 791 682 888 780 676
Grai
n Si
ze (c
m)
100 200 300 400 500 600 700 800 900 1000
Distance from Tussey Mt Ridgeline (m)
Gra
in D
iam
eter
(cm
)
Tussey Mountain Leading Ridge
(Gar
ner r
un)
NW
#
#
^
^
^
^
^
^
^
^
^
^
^
^
^
^
^
^
^
^^
"
"
"
"
?
?
? ?
?
?
?
0 50 100 150 20025Meters
3. Methods and Approach: • Field mapping of surface features: spatial distribution of boulder �elds, variations in ground cover - 11 days total (300 m x 1000 m area, mapped at 10 m resolution) • Surface clast grain size measurement - 19 point counts (n = 100 for each) across mapping area - Structure from motion photogrammetry survey of boul- der �eld to characterize surface roughness • Soil descriptions - 6 shallow pits dug (average depth of 30 cm) in Tussey Mountain slope - described depth, color, and texture of horizons
Digital elevation model of Shavers Creek Watershed (Brantley et al. 2015)
PENNSYLVANIA
SSHCZO
N
AcD
BxD
HTFHsB
MkD
RuHTD
AoB200 m
Garner Run subcatchment showing distribution of soil series (SSURGO database)
Soil Series
2. Garner Run Study Area 1. MotivationInvestigating the physical properties of the soil mantle and surface morphology is necessary to model the processes linked to mass �uxes--water, energy, gas, sediment, and solutes (WEGSS)--in the landscape. Existing data on these properties are in-adequate for the purpose of model building because the resolution does not account for the complex surface heterogene-ities present in Garner Run. Previous work is also inadequate for geomorphic interpretations of past processes and climate of the landscape because it fails to capture details like spatial variability of lobate features, as well as surface roughness. This study aims to produce high resolution sur�cial mapping for future model building and studies of past processes.
Figure 1: Characteristic photo of each mapping class with degree of rocki-ness speci�ed.
SE
0: Fully soil-mantled
3: Open boulder �eld with no soil
1: Mostly soil-mantled, some emergent boulders
2: Canopied Boulders with no soil
