Meagan Eagle Gonneea
Jennifer A. O'Keefe Suttles
Kevin D. Kroeger
2018
Collection, Analysis, and Age-Dating of Sediment Cores from Salt Marshes on the South Shore of Cape Cod, Massachusetts, From 2013 Through 2014
1.0
Tabular digital data
Reston, VA
U.S. Geological Survey
Suggested citation: Gonneea, M.E., O'Keefe Suttles, J.A., and Kroeger, K.D., 2018, Collection, analysis, and age-dating of sediment cores from salt marshes on the south shore of Cape Cod, Massachusetts, from 2013 through 2014: U.S. Geological Survey data release, https://doi.org/10.5066/F7H41QPP.
https://doi.org/10.5066/F7H41QPP
https://www.sciencebase.gov/catalog/item/5a748e35e4b00f54eb19f96c
The accretion history of fringing microtidal salt marshes located on the south shore of Cape Cod, Massachusetts, was reconstructed from sediment cores collected in low and high marsh vegetation zones. The location of these marshes within protected embayments and the absence of large rivers on Cape Cod result in minimal sediment supply and a dominance of organic matter contribution to sediment peat. Age models based on 210-lead and 137-cesium were constructed to evaluate how vertical accretion and carbon burial rates have changed over the past century. The continuous rate of supply age model was used to age date 11 cores (10 low marsh and 1 high marsh) across four salt marshes. Both vertical accretion rates and carbon burial increased from 1900 to the years of collection, 2013 and 2014. Elevation of the marsh surface was measured to evaluate where the marsh falls within the current tidal frame. The historic marsh surface elevation was then reconstructed from the calculated age of each depth interval and its elevation, assuming that elevations within this shallow zone (less than 30 centimeters) have been preserved for the past century.
These cores were collected, age dated, and their elevation measured to determine what elevation trajectories salt marsh surfaces have followed over the past century as sea level has risen at a rate of 2.8 mm/yr. In addition, carbon burial was evaluated to determine what rates were over the past century.
20131204
20140117
20140604
20140616
20140701
20140805
Ground Condition. These are the dates when the cores were collected.
None planned
-70.556945801557
-70.496520996872
41.584306748081
41.543205912373
USGS Metadata Identifier
USGS:5a748e35e4b00f54eb19f96c
USGS Thesaurus
soil chemistry
radiometric dating
piston coring
carbon isotope analysis
carbon
nitrogen
sea-level change
sedimentation
ISO 19115 Topic Category
geoscientificInformation
location
elevation
oceans
None
high marsh
low marsh
210-lead
137-cesium
accretion rate
carbon burial
salt marsh elevation
Geographic Names Information System (GNIS)
Cape Cod
Barnstable County
Falmouth
Sage Lot Pond
Great Pond
Hamblin Pond
Eel Pond
Waquoit Bay
Commonwealth of Massachusetts
United States of America
none
none
Meagan Eagle Gonneea
U.S. Geological Survey
mailing and physical
384 Woods Hole Rd.
Woods Hole
MA
02543
USA
508-457-2280
mgonneea@usgs.gov
https://www.sciencebase.gov/catalog/file/get/5a748e35e4b00f54eb19f96c/?name=Saltmarsh_AR.jpg
Browse graphic showing a plot of the accretion rates at each of the core locations.
JPEG
Radionuclides (210Pb, 226Ra, 137Cs, 7Be) were measured on planar gamma counters that were standardized to an EPA standard pitchblende ore in the same geometry as the samples. Suppression of low energy peaks by self-adsorption was corrected according to Cutshall and others (1983).
Weight percent carbon and nitrogen and the isotopic signature of carbon and nitrogen in organic matter was analyzed at the U.C. Davis Stable Isotope Facility with an Elementar Vario EL CUbe or MIcro Cube elemental analyzer interfaced to a PDZ Europa 20-20 isotope ratio mass spectrometer. Long-term standard deviation is 0.2 permil for 13C and 0.3 per mil for 15N.
Any value below detection is given the numerical value of 0. Any attribute that wasn't measured for a specific sample is listed as -99999. Each sample was treated in the same manner for each analysis.
Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. All sample measurements are reported.
Latitude and Longitude was measured with a handheld Garmin 76Cx GPSmap unit in the field at time of collection. The GPS unit indicated accuracy was within 3 meters. No formal positional accuracy tests were conducted.
Elevation was measured with a Trimble Real-Time Kinematic (RTK) GPS after core collection. Accuracy was 2-3 cm according to instrument corrections. No formal positional accuracy tests were conducted.
Eleven sediment cores were collected in coastal salt marshes between 12/4/2013 and 8/5/2014. All cores were collected in the low marsh except SLPB, which was collected in the high marsh. A piston coring system was used, where the core liner (diameter 11 cm, 1-2 m in length) was fitted with a gasketed piston that was placed on the sediment surface. The clear, sharpened core liner was pushed down into the marsh subsurface, while the piston was maintained at the marsh surface via tension on the piston. We visually observed the sediment surface to ensure that the soil column did not compact during collection. Once the core reached the underlying coarse sediment interface (except at Hamblin Pond, where the depth to the peat base was >2 m), the core liner and piston were removed from the marsh with a pulley system. The process date reflects the last occurrence of the work. This process step and all subsequent steps were performed by the same people, Meagan E. Gonneea and Jennifer O'Keefe Suttles, unless otherwise noted.
20140805
Meagan E Gonneea
U.S. Geological Survey
mailing and physical
384 Woods Hole Road
Woods Hole
MA
02543
United States
508-457-2280
mgonneea@usgs.gov
After each core collection, the sediment cores were immediately returned to the Woods Hole Coastal and Marine Science Center. They were placed in a refrigerator for 1 to 3 days, then split vertically, sectioned at 1 or 2 cm intervals, frozen, and then freeze dried for 7 days, until sediment weights did not change further. Dry bulk density was determined as the dry weight of a known volume of sample. Approximately 5 g of dried sediment sample was blended and homogenized prior to sealing in a jar for a minimum of three weeks and then placed on a planar-type gamma counter for 24 to 48 hours to measure 7Be, 137Cs, 210Pb, and 226Ra at 477, 661.6, 46.5 and 352 kiloelectronvolts (KeV) energies respectively (Canberra Inc., USA). Detector efficiency was determined from EPA standard pitchblende ore in the same geometry as the samples. Activities of 7Be, 137Cs, and 210Pb were decay corrected to time of collection. Suppression of low energy peaks by self-absorption was corrected for according to Cutshall and others, 1983. Detection limit for excess 210Pb was 0.05 dpm/g (disintegrations per minute per gram). Sediment ages and accretion rates were calculated with the continuous rate of supply 210Pb age model, a variant on the advection-decay equation (Appleby and Oldfield, 1978; Goldberg, 1963). This model assumes that 210Pb supply to the sediment surface is constant through time, but allows for changing sedimentation rates, in addition to decay, to control the down-core activity of 210Pb. The common form of the CRS (constant rate of 210Pb supply) model as derived by Appleby and Oldfield (1978) solves for age based on the distribution of 210Pb in the sediment record. Prior to application of the age model, 210Pb profiles were evaluated to ensure they were sufficiently resolved to apply the CRS model without bias towards to ages that are too old or accretion rates that are too low at depth (Binford, 1990). All gamma analyses were ongoing from 2014 and completed in 2016.
Appleby, P.G., and Oldfield, Frank, 1978, The calculation of lead-210 dates assuming a constant rate of supply of unsupported 210Pb to the sediment: Catena, v. 5, issue 1, p. 1–8, https://doi.org/10.1016/S0341-8162(78)80002-2.
Binford, M.W., 1990, Calculation and uncertainty analysis of 210 Pb dates for PIRLA project lake sediment cores: Journal of Paleolimnology, v. 3, issue 3, p. 253-267, https://doi.org/10.1007/BF00219461.
Cutshall, N.H., Larsen, I.L., and Olsen, C.R., 1983, Direct analysis of 210 Pb in sediment samples—Self-absorption corrections: Nuclear Instruments and Methods in Physics Research, v. 206, issues 1–2 , p. 309–312, https://doi.org/10.1016/0167-5087(83)91273-5.
Goldberg, E.D, 1963, Geochronology with 210 Pb, in Miller, J.A., convener, Radioactive dating: International Atomic Energy Agency Symposium on Radioactive Dating, Athens, Greece, November 19-23, 1962, [Proceedings], p. 121-131.
2016
Meagan E Gonneea
U.S. Geological Survey
mailing and physical
384 Woods Hole Road
Woods Hole
MA
02543
United States
508-457-2280
508-457-2310
mgonneea@usgs.gov
A subsample of freeze dried sediment was combined from two consecutive depths (for example, 0 to 1 and 1 to 2) to represent the mixed interval for elemental analysis. For this sample, 0.5 g of the sediment was ball-milled to a fine powder and packaged for carbon and nitrogen analysis at the U.C. Davis Stable Isotope Facility. There carbon and nitrogen content and isotopic ratio of the sediment organic matter was measured with an Elementar Vario EL Cube or Micro Cube elemental analyzer interfaced to a PDZ Europa 20-20 isotope ratio mass spectrometer. Carbon isotopic ratios are reported relative to Pee Dee Belemnite (PDB) and nitrogen isotopic ratios relative to air. These analyses occurred concurrently with analyses in the previous process step.
2015
Meagan E Gonneea
U.S. Geological Survey
mailing and physical
384 Woods Hole Road
Woods Hole
MA
02543
United States
508-457-2280
mgonneea@usgs.gov
The marsh surface elevation at the core collection sites were surveyed with a Trimble Real-Time Kinematic Geographic Positioning System (RTK GPS) shortly after collection. All data were projected in NAD 1983 Massachusetts State Plane FIPS 2001 and elevations are given relative to NAVD88. The elevation accuracy is 2-3 cm relative to NAVD88. This process step took place over time, with the last measurement in 2014.
2014
Meagan E Gonneea
U.S. Geological Survey
mailing and physical
384 Woods Hole Road
Woods Hole
MA
02543
United States
508-457-2280
mgonneea@usgs.gov
The Excel spreadsheet was exported as a CSV file from Excel for Mac version 15.33.
2018
Meagan E Gonneea
U.S. Geological Survey
mailing and physical
384 Woods Hole Rd.
Woods Hole
MA
02543
United States
508-457-2280
mgonneea@usgs.gov
Added keywords section with USGS persistent identifier as theme keyword.
20200807
U.S. Geological Survey
VeeAnn A. Cross
Marine Geologist
Mailing and Physical
384 Woods Hole Road
Woods Hole
MA
02543-1598
508-548-8700 x2251
508-457-2310
vatnipp@usgs.gov
Point
Point
549
1.0E-5
1.0E-5
Decimal degrees
North American Datum of 1983
Geodetic Reference System 80
6378137.0
298.257222101
NAVD88
1.0
centimeters
Explicit depth coordinate included with horizontal coordinates
South Shore Cape Cod Salt Marsh Core Data
Core location, elevation, radiochemistry results, age model, and carbon and nitrogen results
Meagan E. Gonneea
Core ID
ID: Each core is assigned an alphabetical ID to indicate which marsh it was collected at (defined below) and a secondary qualifier of A, B or C, indicating the order of core collection over time.
Producer defined.
SLP
Sage Lot Pond
Meagan E. Gonneea
EP
Eel Pond
Meagan E. Gonneea
HB
Hamblin Pond
Meagan E. Gonneea
GP
Great Pond
Meagan E. Gonneea
Collection Date
Date: A numeric identifier of the date the core was collected in the format of month/day/year.
Producer defined.
12/4/2013
8/5/2014
Latitude
Lat: Latitude decimal degrees north, NAD83.
Producer defined.
41.55445
41.47671
Longitude
Lon: Longitude decimal degrees west, NAD83.
USGS
70.50044
70.58044
Depth from sediment surface, interval mean (cm)
Depth: A numeric identifier of the interval mid-point depth below the sediment interface in centimeters.
Producer defined.
0
159
Elevation relative to NAVD88, interval mean (cm)
Elevation: A numeric identifier of interval mid-point elevation relative to NAVD88 datum in centimeters. Calculated by subtracting the mid-interval depth from the NAVD88 elevation of the core location (depth = 0).
Producer defined.
-144
24
Dry bulk density (g/cm3)
DBD: A numeric identifier of the sediment dry bulk density in grams per cubic centimeter (g/cm3). Values of -99999 indicate this measurement was not performed.
Producer defined.
0.02
1.87
210-Lead total (dpm/g)
210Pb: A numeric identifier of the sediment total 210-lead activity in decays per minute per gram (dpm/g). Measured at 46.6 kiloelectronvolt (KeV) on a planar gamma counter. Values of -99999 indicate this measurement was not performed.
Producer defined.
0.21
36.94
210-Lead total error (dpm/g)
210Pb_e: A numeric identifier of the measurement error in sediment total 210-lead activity in decays per minute per gram (dpm/g). Values of -99999 indicate this measurement was not performed.
Producer defined.
0.06
3.73
226-Radium (dpm/g)
226Ra: A numeric identifier of the sediment total 226-radium activity in decays per minute per gram (dpm/g). Measured at 352 kiloelectronvolt (KeV) on a planar gamma counter. Values of -99999 indicate this measurement was not performed.
Producer defined.
0.14
3.32
226-Radium error
226Ra_e: A numeric identifier of the measurement error in sediment total 226-radium activity in decays per minute per gram (dpm/g). Values of -99999 indicate this measurement was not performed.
Producer defined.
0.01
0.79
210-Lead excess (dpm/g)
210Pbex: A numeric identifier of the sediment excess 210-Lead activity in decays per minute per gram (dpm/g). Calculated as the difference between total 210-Lead and total 226-Radium activities. Values of -99999 indicate this measurement was not performed.
Producer defined.
-0.13
36.30
210-Lead excess error (dpm/g)
210Pbex_e: A numeric identifier of the propagated measurement error in sediment excess 210-Lead activity in decays per minute per gram (dpm/g). Values of -99999 indicate this measurement was not performed.
Producer defined.
0.07
3.81
137-Cesium (dpm/g)
137Cs: A numeric identifier of the sediment total 137-Cesium activity in decays per minute per gram (dpm/g). Measured at 662 kiloelectronvolt (KeV) on a planar gamma counter. Values of -99999 indicate this measurement was not performed, zero values are below detection limit.
Producer defined.
0.00
2.96
137-Cesium error (dpm/g)
137Cs_e: A numeric identifier of the measurement error in sediment total 137-Cesium activity in decays per minute per gram (dpm/g). Values of -99999 indicate this measurement was not performed, zero values are below detection limit.
Producer defined.
0.00
0.33
7-Beryllium (dpm/g)
7Be: A numeric identifier of the measurement error in sediment total 7-Beryllium activity in decays per minute per gram (dpm/g). Measured at 447 kiloelectronvolt (KeV) on a planar gamma counter. Values of -99999 indicate this measurement was not performed, zero value are below detection limit.
Producer defined.
0.00
12.54
7-Beryllium error (dpm/g)
7Be_e: A numeric identifier of the measurement error in sediment total 7-Beryllium activity in decays per minute per gram (dpm/g). Values of -99999 indicate this measurement was not performed, zero values are below detection limit.
Producer defined.
0.00
2.00
Weight percent carbon
wtC: Total amount of carbon by weight percent in soil as measured with an Elementar Vario EL Cube or Micro Cube elemental analyzer at University of California at Davis Stable Isotope Facility. This value was measured on combined consecutive samples, for example 0 to 1 cm and 1 to 2 cm, were combined for a sample from 0 to 2 cm. Values of -99999 indicate this measurement was not performed.
Producer defined.
0.4
42.5
Weight percent nitrogen
wtN: Total amount of nitrogen by weight percent in soil as measured with an Elementar Vario EL Cube or Micro Cube elemental analyzer at University of California at Davis Stable Isotope Facility. This value was measured on combined consecutive samples, for example 0 to 1 cm and 1 to 2 cm, were combined for a sample from 0 to 2 cm. Values of -99999 indicate this measurement was not performed.
Producer defined.
0.02
2.66
Carbon 13/12 ratio
13C: The carbon isotopic signature of the soil sample relative to Pee Dee Belemnite (PDB) standard as measured with an Elementar Vario EL Cube or Micro Cube elemental analyzer interfaced to a PDZ Europa 20-20 isotope ratio mass spectrometer at University of California at Davis Stable Isotope Facility. This value was measured on combined consecutive samples, for example 0 to 1 cm and 1 to 2 cm, were combined for a sample from 0 to 2 cm. Values of -99999 indicate this measurement was not performed.
Producer defined.
-27.75
-12.54
Nitrogen 15/14 ratio
15N: The nitrogen isotopic signature of the soil sample relative to air as measured with an Elementar Vario EL Cube or Micro Cube elemental analyzer interfaced to a PDZ Europa 20-20 isotope ratio mass spectrometer at University of California at Davis Stable Isotope Facility. This value was measured on combined consecutive samples, for example 0 to 1 cm and 1 to 2 cm, were combined for a sample from 0 to 2 cm. Values of -99999 indicate this measurement was not performed.
Producer defined.
-0.82
5.33
Sediment age (years)
Age: A numeric identifier for the age in years from the collection date of the core interval based on the Continuous Rate of Supply 210-Lead age model. Values of -99999 indicate this measurement was not performed.
Producer defined.
1.1
103.8
Sediment Age Error (years)
Age_e: A numeric identifier for the age model uncertainty in years of the core interval based on the Continuous Rate of Supply 210-Lead age model. Error is propagated through the model. Values of -99999 indicate this measurement was not performed.
Producer defined.
0.1
18.2
Vertical Accretion Rate (mm/y)
VAR: A numeric identifier for the vertical accretion rate of the sediment in millimeters per year (mm/y). Calculated as the difference in interval midpoint divided by the difference in ages of those adjacent sediment intervals. Values of -99999 indicate this measurement was not performed.
Producer defined.
1.0
9.7
Mass Accumulation Rate (g/m2/y)
MAR: A numeric identifier for the mass accumulation rate of the sediment in grams per square meter per year (g/m2/y). Calculated by multiplying dry bulk density times vertical accretion rate. Values of -99999 indicate this measurement was not performed.
Producer defined.
104
1285
Carbon accumulation rate (gC/m2/y)
CAR: A numeric identifier for the carbon mass accumulation rate of the sediment in grams of carbon per square meter per year (gC/m2/y). Calculated by multiplying the average mass accumulations rate for the combined depth interval of the elemental sample times weight percent carbon. Values of -99999 indicate this measurement was not performed.
Producer defined.
19
380
Any value below detection is given the numerical value of 0, with the exception of surface elevation, which is 0. Any attribute that wasn't measured for a specific sample is listed as -99999. The data are available in both XLSX and CSV formats. The attribute label in the detailed description above is the first row of the Excel spreadsheet. The first part of the attribute definition (before the colon) indicates the abbreviated label for that column and is on the second row of the Excel spreadsheet. The abbreviated column heading is provided as a convenience for using the data in other software packages that might have difficulty with the longer label.
U.S. Geological Survey - Meagan E. Gonneea
ScienceBase
U.S. Geological Survey - ScienceBase
mailing and physical
Denver Federal Center, Building 810, Mail Stop 302
Denver
CO
80225
United States
1-888-275-8747
sciencebase@usgs.gov
This data release contains the core location, elevation, radiochemistry results, age model, and carbon and nitrogen results in an Excel spreadsheet (Waquoit_Core_data_release.xlsx), CSV file (Waquoit_Core_data_release.csv) and browse graphic (Saltmarsh_AR.jpg). FGDC CSDGM metadata (Waquoit_Core_data_release_meta.xml) accompanies the data.
Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
XLSX
Excel for Mac 15.33
The dataset contains the Excel spreadsheet, the CSV file, the browse graphic, and the CSDGM metadata in XML format.
1
https://www.sciencebase.gov/catalog/file/get/5a748e35e4b00f54eb19f96c
https://www.sciencebase.gov/catalog/file/get/5a748e35e4b00f54eb19f96c?name=Waquoit_Core_data_release.xlsx
https://www.sciencebase.gov/catalog/item/5a748e35e4b00f54eb19f96c
The first link downloads all the files on the landing page to a zip file, the second link downloads the Excel spreadsheet only, and the third link takes you to the landing page of the data.
CSV
Excel for Mac 15.33
The dataset contains the Excel spreadsheet, the CSV file, the browse graphic, and the CSDGM metadata in XML format.
1
https://www.sciencebase.gov/catalog/file/get/5a748e35e4b00f54eb19f96c
https://www.sciencebase.gov/catalog/file/get/5a748e35e4b00f54eb19f96c?name=Waquoit_Core_data_release.csv
https://www.sciencebase.gov/catalog/item/5a748e35e4b00f54eb19f96c
The first link downloads all the files on the landing page to a zip file, the second link downloads the CSV version of the data only, and the third link takes you to the landing page of the data.
none
20200807
Meagan E Gonneea
U.S. Geological Survey
mailing and physical
384 Woods Hole Rd.
Woods Hole
MA
02543
USA
508-457-2280
mgonneea@usgs.gov
Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998