Maryland Coastal Bays Sediment Mapping Project: RSA Sediment Size Data

Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: Darlene Wells and Robert Conkwright, Maryland Geological Survey, Maryland Department of Natural Resources
Originator: Assateague Island National Seashore, Resource Management GIS
Publication_Date: September 1999
Title:
Maryland Coastal Bays Sediment Mapping Project: RSA Sediment Size Data
Geospatial_Data_Presentation_Form: vector digital data
Other_Citation_Details:
Data files may be accessed from Coastal and Estuarine Geology Program File Report 99-5, released on CD-ROM.
Online_Linkage: http://science.nature.nps.gov/nrdata
Description:
Abstract:
This data set contains location and textural parameters for 411 surface sediment samples collected in Maryland's Coastal Bays. The location parameters include UTM zone 18 North coordinates, as well as Maryland State Plane Grid (in meters), and latitude and longitude for sediment sample locations. Textural parameters from the Rapid Sediment Analysis (RSA) include cumulative weight percentages for quarter phi size class between -1 phi and 4 phi, phi values for 5, 16, 50, 84, and 95 cumulative percentiles, Folk graphic mean and sorting (standard deviation) for sediments consisting of greater than 75 percent sand.
Purpose:
These data were collected to map the sedimentological characteristics of the surficial sediments and to provide a base line data set for Maryland's coastal bays.
Supplemental_Information:
The data was produced over a multi-year period, each year focusing on a portion of the coastal bays. Data included textural components. Data for each portion of the bays were presented in a year-end final report submitted to the funding agency in fulfillment of the contact. A total of five reports (not including the final synthesis report and atlas) were submitted to the U.S. Minerals Management Service, Continental Margins Program, and to the University of Texas at Austin, Bureau of Economic Geology in fulfillment of Contract #14-35-0001-30643 and to the Coastal Zone Management Program of the Maryland Department of Natural Resources pursuant to National Oceanic and Atmospheric Administration awards #NA47OZ0132, #NA57OZ0301, and #NA67OZ0302. For the final year, the total data was compiled into a final data base and presented in tabular form as part of synthesis report and digital atlas, submitted to the Coastal zone Management Program of the Maryland Department of Natural Resources pursuant to National Oceanic and Atmospheric Administration awards #NA77OZ0188. 

Wells, D.V., Conkwright, R.D., and Park, J., 1994, Geochemistry and geophysical framework of the shallow sediments of Assawoman Bay and Isle of Wight Bay in Maryland: Maryland Geological Survey Open File Report No. 15, Baltimore, Md., 125 pp.
Wells, D.V., Conkwright, R.D. ,Hill, J.M., and Park, J., 1994, The surficial sediments of Assawoman Bay and Isle of Wight Bay in Maryland: physical and chemical characteristics: Coastal and Estuarine Geology File Report No. 94-2, Maryland Geological Survey, Baltimore, Md.., 99 pp.
Wells, D.V., Conkwright, R.D., Gast, R., Hill, J.M., and Park, J., 1996, The shallow sediments of Newport Bay and Sinepuxent Bay in Maryland: physical and chemical characteristics: Coastal and Estuarine Geology File Report No. 96-2, Maryland Geological Survey, Baltimore, Md.., 116 pp.
Wells, D.V.,Harris, S.M., Hill, J.M., Park, J., and Williams, C.P., 1997, The shallow sediments of upper Chincoteague Bay area in Maryland: physical and chemical characteristics: Coastal and Estuarine Geology File Report No. 97-2, Maryland Geological Survey, Baltimore, Md.., 90 pp.
Wells, D.V.,Harris, S.M., Hill, J.M., Park, J., and Williams, C.P., 1998, The shallow sediments of middle Chincoteague Bay area in Maryland: physical and chemical characteristics: Coastal and Estuarine Geology File Report No. 98-1, Maryland Geological Survey, Baltimore, Md.., 104 pp.
Wells, D.V., and Conkwright, R.D., 1999, Maryland Coastal Bays Sediment Mapping Project: Physical and chemical characteristics of the shallow sediments- Synthesis Report and Atlas: Coastal and Estuarine Geology Program File Report 99-5, 1st Edition, Maryland Geological Survey, Baltimore, Md., HTML format contained on a Compact Disk (CD).

There is an additional metadata document, entitled 'MdCBSeds_meta.doc' that should be located in the same folder as this dataset.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 199107
Ending_Date: 199712
Currentness_Reference:
ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: As needed
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -75.357252
East_Bounding_Coordinate: -75.064579
North_Bounding_Coordinate: 38.451530
South_Bounding_Coordinate: 38.023599
Keywords:
Theme:
Theme_Keyword_Thesaurus: ASIS Keyword Thesaurus
Theme_Keyword: estuaries
Theme_Keyword: beach dynamics
Theme_Keyword: sedimentation
Theme_Keyword: Grain Size
Theme_Keyword: chemistry
Theme_Keyword: Organic Carbon
Theme_Keyword: Surficial Sediments
Theme_Keyword: water quality
Theme_Keyword: Sulfur
Theme_Keyword: Nitrogen
Theme_Keyword: Phosphorous
Theme_Keyword: Metals
Theme_Keyword: coastal dynamics
Theme_Keyword: carbon
Theme:
Theme_Keyword_Thesaurus: National Park Service Theme Category Thesaurus
Theme_Keyword: Geology
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: geoscientificInformation
Place:
Place_Keyword_Thesaurus: Geographic Locations
Place_Keyword: Assateague Island National Seashore
Place_Keyword: USA East Coast
Place_Keyword: Maryland
Place_Keyword: Worcester County
Place_Keyword: Assawoman Bay
Place_Keyword: Isle of Wight Bay
Place_Keyword: Sinepuxent Bay
Place_Keyword: Newport Bay
Place_Keyword: Chincoteague Bay
Place_Keyword: Ocean City, Maryland
Place_Keyword: Fenwick Island
Place:
Place_Keyword_Thesaurus: National Park System Unit Name Thesaurus
Place_Keyword: Assateague Island National Seashore
Place:
Place_Keyword_Thesaurus: National Park System Unit Code Thesaurus
Place_Keyword: ASIS
Temporal:
Temporal_Keyword: Holocene
Access_Constraints: None
Use_Constraints:
Acknowledgment of the Maryland Geological Survey, and Darlene Wells and Robert Conkwright shall be made in products derived from these data. The Maryland Geological Survey (MGS) makes no warranty, either express or implied, as to the use or appropriateness of the data, and there are no warranties of merchantability or fitness for a particular purpose or use. MGS may not be subject to liability for human error, defect, or failure of machines, or any material used in connection with the machines, including tapes, disks, punch card and energy. MGS may not be liable for any lost profits, consequential damages, or claims against the user by third parties.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Assateague Island National Seashore
Contact_Position: GIS Specialist
Contact_Address:
Address_Type: mailing and physical address
Address:
7206 National Seashore Lane
City: Berlin
State_or_Province: MD
Postal_Code: 21811
Contact_Voice_Telephone: 410-641-1443
Contact_Facsimile_Telephone: 410-641-4158
Contact_Electronic_Mail_Address: asis_gis@nps.gov
Hours_of_Service: Mon - Fri 9:00 am - 4:00 pm
Data_Set_Credit:
Acknowledgment of the Maryland Geological Survey, and Darlene Wells and Robert Conkwright shall be made in products derived from these data.
Native_Data_Set_Environment:
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.2.0.1324
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Data_Quality_Information:
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Over the course of the project, several navigational systems were used during the collection of samples.  A Loran-C navigation system was used to locate sampling sites during the collection of the cores 9101 through 9114 and for surficial samples 91003 through 91008 ( in Isle of Wight and Assawoman Bays).  The accuracy of this system is ± 50 meters.  Loran coordinates were converted to Latitude and Longitude coordinates using correction technique described in Halka, J.P., 1987, LORAN-C Calibration in Chesapeake Bay: Maryland Geological Survey Report of Investigation No. 47, Baltimore, Maryland, 34 pp.

For the collection of cores 9501 through 9510, and 9601 through 9606, and for surficial sediment samples 95001 through 95302, a Garmin GPS 45 unit interfaced with a Garmin GBR 21 Beacon Receiver was used.  The report accuracy of this system is ± 5 to 10 meters.   A Magnavox MX300 GPS system with MX 50R DGPS Beacon (U.S. Coast Guard) Receiver was used for navigation during the collection of surficial sediment samples 93001 through 94178 and cores.  The reported accuracy of the system is ± 3 to 5 meters.

An Ashtech ACA-12 GPS receiver interfaced with a Starlink MRB-2A MSK Radiobeacon DGPS receiver was used to collect cores 9701 through 9705, and surficial samples 96003 through 96353.  The reported accuracy of the Ashtech DGPS system is ± 2 to 4 meters.
Quantitative_Horizontal_Positional_Accuracy_Assessment:
Horizontal_Positional_Accuracy_Value: Variable positional accuracy, see accuracy report.
Horizontal_Positional_Accuracy_Explanation:
Variable positional accuracy, see accuracy report.
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
Water depths recorded at each sampling site were not adjusted for tide level.
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator: Darlene Wells, Maryland Geological Survey
Publication_Date: September 1999
Title:
The Maryland Coastal Bays Sediment Mapping Project
Geospatial_Data_Presentation_Form: spreadsheet
Publication_Information:
Publication_Place: Baltimore, MD
Publisher: Maryland Geological Survey, Maryland Department of Natural Resources
Other_Citation_Details:
This study was conducted by the Maryland Geological Survey, Darlene Wells, Principle Investigator; and funded in part by the U.S. Minerals Management Service, Continental Margins Program, and the University of Texas at Austin, Bureau of Economic Geology contract #14-35-0001-30643, and by the Coastal Zone Management Program of the Maryland Department of Natural Resources pursuant to National Oceanic and Atmospheric Administration awards # NA47OZ0132, #NA57OZ0301, #NA67OZ0302, and #NA77OZ0188.
Source_Contribution:
This study was conducted by the Maryland Geological Survey, Darlene Wells, Principle Investigator; and funded in part by the U.S. Minerals Management Service, Continental Margins Program, and the University of Texas at Austin, Bureau of Economic Geology contract #14-35-0001-30643, and by the Coastal Zone Management Program of the Maryland Department of Natural Resources pursuant to National Oceanic and Atmospheric Administration awards # NA47OZ0132, #NA57OZ0301, #NA67OZ0302, and #NA77OZ0188.
Process_Step:
Process_Description:
Textural analyses-Overview- The grain size composition of each sample was determined for sand-, silt-, and clay-sized particles, ranging in diameter from 0.00006 to 2 mm.  Particle size, expressed as cumulative weight percent, was measured on a logarithmic scale and grouped into dimensionless phi intervals: phi = negative log to the base 2 of the particle diameter in mm.  Example: 4 phi is equivalent to  1 / (2 to 4th power) mm or 0.0625 mm.

Rapid Sediment Analysis
The sand components of surficial sediment samples classified as Sand (i.e., sediment comprise of >75% by weight of sand size particles) were analyzed with a rapid sediment analyzer (RSA).  The RSA is a settling tube operating on the principle of settling velocity, insofar as larger particles fall faster than smaller ones.  Stoke's law, however, is invalid for particle sizes coarser than 4? due to the turbulence that develops in a particle's wake as it descends through a column of water.  Instead, velocities for sand-sized spheres have been determined from direct observations of falling particles, and empirical equations have been developed to predict fall velocities for different particle sizes and water temperatures.

The RSA developed by MGS is based on a microbalance system designed by R.J. Gibbs (1974) and modified by the Coastal Engineering Research Center (CERC) of the U.S. Army Corps of Engineers.  The Survey has further refined the CERC system: large scale oscillations due to coarse sediment striking the balance pan have been reduced; undesirable vibration noise has been decreased; accurate timing of sample introduction has been achieved; and the apparatus has been interfaced with a dedicated PC, permitting fast, accurate data reduction and calculation of statistical parameters.

The RSA was calibrated with glass beads of known size, density, and sphericity.  The accuracy of the instrument was tested by inter-calibration with one of similar design.  Both yielded similar values for the particle size distribution of sediments.  Design, operation, and calibration of the RSA are described more fully by Halka and others (1980).
The apparatus consists of (1) a vertical plexiglass tube - 175 cm long and 15 cm in diameter, (2) a sediment injection system directly above the tube, and (3) a circular plexiglass weighing pan suspended 150 cm below the water surface on a fine wire attached to an electrobalance.  The injector and the electrobalance are interfaced with the calculator.

The first step in operating the RSA was checking and recording the temperature of the water column.  A maximum difference between top and bottom temperatures of 1oC was permitted.  A larger differential produces convection currents, which interfere with particle settling.  Actual temperatures in the RSA ranged from 19-23oC and remained constant over the average working period.  The recorded temperature was entered into the data reduction program to compensate for viscosity and density changes in the water column due to temperature variations.
 
The RSA sampling and statistical analysis programs were loaded into the calculator, then activated.  The electrobalance and strip chart recorder were zeroed.  A microsplitter was used to obtain a 0.4-0.6 g aliquot of the sand fraction.  The grains were sprinkled evenly over the face of the sample introduction plate, which had been previously wetted with a solution of Kodak Photoflow (1 ppt).  This solution causes the sample to adhere to the plate when it is inverted and placed in the injector.  It also breaks the surface tension of the water when the sample makes contact.  After insertion into the injection assembly, the introduction plate was gently lowered to the water surface, simultaneously releasing the sand grains and activating the calculator.

The calculator immediately began recording the weight of the sediment accumulating on the weighing pan, taking a reading every 0.2675 seconds.  Because the time interval between successive readings was known, the cumulative weight of the sediment through time could be determined.  The standardized fall time for each ¼ phi class in the sand-sized range was calculated, and the cumulative weight at that time was computed.  These values were stored on a computer tape indexed by sample location coordinates.  The tape served as input for additional statistical manipulations and as a permanent record of each sample's grain size distribution.
The amount of time required to complete an analysis varied, depending on the grain size distribution of the sand; finer samples took longer to settle than coarser ones.  Maximum run time per sample was 8.5 minutes for settling and 4 minutes for data processing.

The cumulative weight percentages greater than for the ¼ phi classes were combined with the 8 phi and 10 phi weights to obtain a cumulative grain size distribution from -1 phi (2 mm) to 14 phi (< 0.00001 um) for the sediment sample.  Percentiles for 5%, 16%, 50%, 84% and 95%, and Folk mean and standard deviation were calculated from this distribution.
Process_Date: 1991-1998
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Maryland Geological Survey
Contact_Position: Coastal Geologist
Contact_Address:
Address_Type: mailing and physical address
Address:
2300 St. Paul Street
City: Baltimore
State_or_Province: Maryland
Postal_Code: 21218-5210
Country: USA
Contact_Voice_Telephone: (410) 554-5518
Contact_Facsimile_Telephone: (410) 554-5502
Hours_of_Service: 8:30 am - 5:00 pm EST
Process_Step:
Process_Description:
Water content- The procedure for measuring water content consisted of weighing a 25-50 g split of the homogenized sample, drying the split at 65oC, and reweighing it.  Water content, in percent, was calculated as:
(water weight (g)/ wet weight of sediment (g)) x 100
where water weight is the difference between the wet and dry weights of the sample.
The procedure is based on the assumption that the sediment is 100% saturated with free water (water that is not bound up in the crystalline lattice of clay minerals).
Process_Date: 1991-1998
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Maryland Geological Survey
Contact_Position: Coastal Geologist
Contact_Address:
Address_Type: mailing and physical address
Address:
2300 St. Paul Street
City: Baltimore
State_or_Province: Maryland
Postal_Code: 21218-5210
Country: USA
Contact_Voice_Telephone: (410) 554-5518
Contact_Facsimile_Telephone: (410) 554-5502
Hours_of_Service: 8:30 am - 5:00 pm EST
Process_Step:
Process_Description:
Bulk density
Bulk density, in g/cm3, was calculated from the weights used in determining water content, as:
wet weight of sediments (g)/((dry weight of sediment (g)/2.72 (g/cm3)) + water weight (g))
The calculation is based on the assumption that the average grain density of the particulate matter is 2.72 g/cm3 and that all voids in the sediment are completely saturated with water.
Process_Date: 1991-1997
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Maryland Geological Survey
Contact_Position: Coastal Geologist
Contact_Address:
Address_Type: mailing and physical address
Address:
2300 St. Paul Street
City: Baltimore
State_or_Province: Maryland
Postal_Code: 21218-5210
Country: USA
Contact_Voice_Telephone: (410) 554-5518
Contact_Facsimile_Telephone: (410) 554-5502
Hours_of_Service: 8:30 am - 5:00 pm EST
Process_Step:
Process_Description:
Textural analyses-
Overview- 
The grain size composition of each sample was determined for sand-, silt-, and clay-sized particles, ranging in diameter from 0.00006 to 2 mm.  Particle size, expressed as cumulative weight percent, was measured on a logarithmic scale and grouped into dimensionless phi intervals: phi = negative log to the base 2 of the particle diameter in mm.  Example: 4 phi is equivalent to  1 / (2 to 4th power) mm or 0.0625 mm
Sediment samples were analyzed for water content and grain size (sand, silt, clay content).  Water content was calculated as the percentage of water weight to the weight of the wet sediment.  Water content was determined by weighing 30 to 50 grams of sediment, drying the sediment at 65°C, and then re-weighing the dried sediment.  Dried sediments were saved for chemical analyses. Sand, silt and clay contents were determined using the following process.  Sediment samples were first treated with 10% solution of hydrochloric acid (HCl) to remove carbonate material such as shells and then treated with a 6 or 15% solution of hydrogen peroxide (H2O2) to remove organic material.  The sediments were then passed through a 62 micron mesh sieve separating sand from the mud (silt + clay) fraction.  Mud fractions were analyzed using a pipette technique to determine silt and clay contents.  Weights of the sand, silt and clay fractions were converted to relative proportions (weight percentages).  The distribution of the sand fraction, in quarter-phi intervals, was determined using a rapid sediment analyzer (RSA), a settling tube that measures particle size based on settling velocity.

Rapid Sediment Analysis
The sand components of surficial sediment samples classified as Sand (i.e., sediment comprise of >75% by weight of sand size particles) were analyzed with a rapid sediment analyzer (RSA).  The RSA is a settling tube operating on the principle of settling velocity, insofar as larger particles fall faster than smaller ones.  Stoke's law, however, is invalid for particle sizes coarser than 4 phi due to the turbulence that develops in a particle's wake as it descends through a column of water.  Instead, velocities for sand-sized spheres have been determined from direct observations of falling particles, and empirical equations have been developed to predict fall velocities for different particle sizes and water temperatures.

The RSA developed by MGS is based on a microbalance system designed by R.J. Gibbs (1974) and modified by the Coastal Engineering Research Center (CERC) of the U.S. Army Corps of Engineers.  The Survey has further refined the CERC system: large scale oscillations due to coarse sediment striking the balance pan have been reduced; undesirable vibration noise has been decreased; accurate timing of sample introduction has been achieved; and the apparatus has been interfaced with a dedicated PC, permitting fast, accurate data reduction and calculation of statistical parameters.

The RSA was calibrated with glass beads of known size, density, and sphericity.  The accuracy of the instrument was tested by inter-calibration with one of similar design.  Both yielded similar values for the particle size distribution of sediments.  Design, operation, and calibration of the RSA are described more fully by Halka and others (1980).
The apparatus consists of (1) a vertical plexiglass tube - 175 cm long and 15 cm in diameter, (2) a sediment injection system directly above the tube, and (3) a circular plexiglass weighing pan suspended 150 cm below the water surface on a fine wire attached to an electrobalance.  The injector and the electrobalance are interfaced with the calculator.

The first step in operating the RSA was checking and recording the temperature of the water column.  A maximum difference between top and bottom temperatures of 1oC was permitted.  A larger differential produces convection currents, which interfere with particle settling.  Actual temperatures in the RSA ranged from 19-23oC and remained constant over the average working period.  The recorded temperature was entered into the data reduction program to compensate for viscosity and density changes in the water column due to temperature variations.
 
The RSA sampling and statistical analysis programs were loaded into the calculator, then activated.  The electrobalance and strip chart recorder were zeroed.  A microsplitter was used to obtain a 0.4-0.6 g aliquot of the sand fraction.  The grains were sprinkled evenly over the face of the sample introduction plate, which had been previously wetted with a solution of Kodak Photoflow (1 ppt).  This solution causes the sample to adhere to the plate when it is inverted and placed in the injector.  It also breaks the surface tension of the water when the sample makes contact.  After insertion into the injection assembly, the introduction plate was gently lowered to the water surface, simultaneously releasing the sand grains and activating the calculator.

The calculator immediately began recording the weight of the sediment accumulating on the weighing pan, taking a reading every 0.2675 seconds.  Because the time interval between successive readings was known, the cumulative weight of the sediment through time could be determined.  The standardized fall time for each ¼ phi class in the sand-sized range was calculated, and the cumulative weight at that time was computed.  These values were stored on a computer tape indexed by sample location coordinates.  The tape served as input for additional statistical manipulations and as a permanent record of each sample's grain size distribution.
The amount of time required to complete an analysis varied, depending on the grain size distribution of the sand; finer samples took longer to settle than coarser ones.  Maximum run time per sample was 8.5 minutes for settling and 4 minutes for data processing.

The cumulative weight percentages greater than for the ¼ phi classes were combined with the 8 phi and 10 phi weights to obtain a cumulative grain size distribution from -1 phi (2 mm) to 14 phi (< 0.00001 um) for the sediment sample.  Percentiles for 5%, 16%, 50%, 84% and 95%, and Folk mean and standard deviation were calculated from this distribution.
Process_Date: 1991-1998
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Maryland Geological Survey
Contact_Position: Coastal Geologist
Contact_Address:
Address_Type: mailing and physical address
Address:
2300 St. Paul Street
City: Baltimore
State_or_Province: Maryland
Postal_Code: 21218-5210
Country: USA
Contact_Voice_Telephone: (410) 554-5518
Contact_Facsimile_Telephone: (410) 554-5502
Hours_of_Service: 8:30 am - 5:00 pm EST
Process_Step:
Process_Description:
Nitrogen, carbon, sulfur (NCS) analyses-  Total nitrogen, carbon and sulfur, and organic and reactive carbon contents was determined using a Carlo Erba NA1500 analyzer.  All surficial and cores samples (except for some coarse sand samples) were analyzed for total NCS.  One hundred seventy-five sediment samples were selected for organic and reactive carbon analyses. A split of each dried sample was treated with 10% hydrochloric acid (HCl) to remove inorganic carbon (i.e., CaCO3 from carbonaceous minerals such as marble and limestone).   This treated sample was redried, reground, and analyzed for organic carbon content.  A second split of  dried sample (for fifty-five samples)  was treated with 30% hydrogen peroxide (H2O2) to remove "reactive" carbon.  This peroxide treated sample was redried, reground and analyzed for non-reactive carbon.

Dried sediments were pulverized in tungsten-carbide vials using a ball mill.  Approximately 10 to 15 mg of dried sediment were weighed into a tin capsule.  The exact weight (to the nearest ?g) of the sample was recorded.  To enhance complete combustion during the analysis, 15 to 20 mg of vanadium pentoxide (V2O5) were added to the sediment.  The sediment sample, contained in a tin capsule, was dropped into a combustion chamber where the sample was oxidized in an atmosphere of pure oxygen.  The resulting combustion gases, along with pure helium used as a carrier gas, were passed through a reduction furnace to remove free oxygen and then through a sorption trap to remove water.  Separation of the gas components was achieved by passing the gas mixture through a chromatographic column.  A thermal conductivity detector was used to measure the relative concentrations of the gases.
Process_Date: December 1998
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Maryland Geological Survey
Contact_Position: Coastal Geologist
Contact_Address:
Address_Type: mailing and physical address
Address:
2300 St. Paul Street
City: Baltimore
State_or_Province: Maryland
Postal_Code: 21218-5210
Country: USA
Contact_Voice_Telephone: (410) 554-5518
Contact_Facsimile_Telephone: (410) 554-5502
Hours_of_Service: 8:30 am - 5:00 pm EST
Process_Step:
Process_Description:
Metal analyses-  Dried sediment samples were  prepared for elemental analysis (Cd, Cr, Cu, Fe, Mn, Ni, P, Pb, and Zn) using the following microwave digestion technique modified from EPA Method #3051 (Soil Sample Digestion Procedure for Floyd Digestion Vessels).  Approximately 0.5 g dried, ground sediment, 2.5 ml concentrated HNO3, and 7.5 ml concentrated HCl were placed in the teflon digestion vessel. Digestion vessel was capped and placed in microwave.  The sediment and acid mixture was digested by irradiating the vessel according to the programmed steps recommended for the number of vessels in the microwave.  The vessel was allowed to cool to room temperature before opening.  The contents of the vessel was transferred to 100 ml volumetric flask and diluted with high purity water to 75 ml.  The resulting digestates were then analyzed using a Thermo Jarrel-Ash Atom Scan 25 sequential ICAP (Inductively Coupled Argon Plasma) unit. The wavelengths and conditions selected for the metals of interest were determined using digested bottom sediments from the selected sites in Maryland's Coastal Bays and reference materials from the National Institute of Standards and Technology (NIST SRM #1646 and #1646a--Estuarine Sediment; NIST SRM #2704--Buffalo River Sediment) and the National Research Council of Canada (PACS-1 and PACS-2--Marine Sediment).

Monosulfide analyses- Monosulfides (acid volatile sulfides) were determined using a method adapted from Berner, R.A., 1970, Sedimentary pyrite formation: Amer. Jour. Sci, vol. 268, p. 1-23.  Wet sediment samples were acidified to produce hydrogen sulfide (H2S), purged with oxygen-free nitrogen gas (N2), and trapped in a solution of zinc sulfate-ammonium hydroxide which converted the H2S to zinc sulfide (ZnS).  The ZnS was then re-acidified, producing H2S, the amount of which was determined by iodometric titration.

Lead-210 (210 Pb) activity analysis- A two gram subsample was split from the dried water content sample taken from the cores, and sent to the University of Maryland, Horn Point Environmental Laboratory.  The samples were analyzed by Dr. Jeffrey Cornwell.  The measurement of 210 Pb (T ½ = 22.3 yrs.) was carried out by the analysis of its daughter radionuclide, 210 Po (T ½ = 138 days).  The extraction procedure for 210 Po generally followed that of Sugai, S.F., 1990, Transport and sediment accumulation of 210 Pb and 137 Cs in two southeast Alaska fjords: Estuaries: vol. 13, p. 380-392.  Briefly, approximately 1 g of dried sediment was added to a beaker along with NIST-traceable 209 Po as a yield tracer.  The sediment was digested a 70 degrees C, with 10 ml of HCl and 10 ml HNO3, centrifuged to remove particulates, and the acid was evaporated to near dryness overnight.  After a small additional evaporation of added HCl, 100 ml of 0.01 N HCl and ~0.25 g of ascorbic acid was added to the sediment in the beaker.  The 210 Po and 209 Po was plated onto silver overnight and counted in alpha spectrometers.  The activity values (reported as disintegrations per minute per gram or dpm/g) represent that of 210Po which is in secular equilibrium with 210 Pb.  The standard error is the counting error based on the total number of counts and is generally larger than that observed with repeated analyses.  The absolute activity is determined using a 209Po solution as a yield tracer, which, in turn, is calibrated against NIST standards.  Unsupported 210Pb activity was determined from the asymptote of the 210Po downcore profile.
Process_Date: 1991-1999
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Maryland Geological Survey
Contact_Position: Coastal Geologist
Contact_Address:
Address_Type: mailing and physical address
Address:
2300 St. Paul Street
City: Baltimore
State_or_Province: Maryland
Postal_Code: 21218-5210
Country: USA
Contact_Voice_Telephone: (410) 554-5518
Contact_Facsimile_Telephone: (410) 554-5502
Hours_of_Service: 8:30 am - 5:00 pm EST
Process_Step:
Process_Description:
Results of previous process steps were all incorporated into the same table, with each sediment sample location stored in a record.  Each record contained location information and results of sediment analyses.  The UTM coordinates were then used to import the table into ArcMap, using the Import X/Y Data tool.  The resulting event theme was then converted into a shapefile, and metadata created by the Maryland Geologic Survey was appended to the shapefile using ArcCatalog.
Process_Date: 200706
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Assateague Island National Seashore
Contact_Position: GIS Specialist
Contact_Address:
Address_Type: mailing and physical address
Address:
7206 National Seashore Lane
City: Berlin
State_or_Province: MD
Postal_Code: 21811
Country: USA
Contact_Voice_Telephone: 410-641-1443
Contact_Facsimile_Telephone: 410-641-1099
Contact_Electronic_Mail_Address: asis_gis@nps.gov
Hours_of_Service: Mon - Fri 8:00am - 4:00pm
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Spatial_Data_Organization_Information:
Indirect_Spatial_Reference_Method:
This data set contains a listing of sediments and associated characteristics. The locations (points) where these sediments were collected are designated by Maryland State Plane Grid coordinates and latitude and longitude coordinates, both referenced to North America Datum of 1983.
Direct_Spatial_Reference_Method: Vector
Point_and_Vector_Object_Information:
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: Entity point
Point_and_Vector_Object_Count: 411
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Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Grid_Coordinate_System:
Grid_Coordinate_System_Name: Universal Transverse Mercator
Universal_Transverse_Mercator:
UTM_Zone_Number: 18
Transverse_Mercator:
Scale_Factor_at_Central_Meridian: 0.999600
Longitude_of_Central_Meridian: -75.000000
Latitude_of_Projection_Origin: 0.000000
False_Easting: 500000.000000
False_Northing: 0.000000
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: coordinate pair
Coordinate_Representation:
Abscissa_Resolution: 0.000000
Ordinate_Resolution: 0.000000
Planar_Distance_Units: meters
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: Geodetic Reference System 80
Semi-major_Axis: 6378137.000000
Denominator_of_Flattening_Ratio: 298.257222
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Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Entity_Type_Label: Sediment
Entity_Type_Definition:
Solid material, both mineral and organic, that has come to rest on the earth's surface below sea level.
Entity_Type_Definition_Source:
American Geological Institute, Dictionary of Geological Terms, 1962, New York, Doubleday and Co., Inc.
Attribute:
Attribute_Label: STA
Attribute_Definition:
Identification number for the surficial sediment or core station.  Core stations are identified by 4 digit number with first two digit designating the year of collection and last two designating the sequence of collection for that year.  Surficial stations are identified by 5 digit number with the first two designating the year of collection and last three designating the sequence or order in which the sample was collected for that year.  Generally, stations were numbered across the bays from north to south and from downstream to upstream.
Attribute_Definition_Source:
NONE
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 9101
Range_Domain_Maximum: NA
Attribute_Units_of_Measure: Dimensionless
Attribute:
Attribute_Label: EASTING_MS
Attribute_Definition:
Distance, in meters, east of origin for Maryland State Plane Coordinate System, NAD83
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 542783
Range_Domain_Maximum: 568989
Attribute_Units_of_Measure: meters
Attribute:
Attribute_Label: NORTHING_M
Attribute_Definition:
Distance, in meters, north of origin for Maryland State Plane Coordinate System, NAD83
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 40052
Range_Domain_Maximum: 89792
Attribute_Units_of_Measure: meters
Attribute:
Attribute_Label: Easting_UT
Attribute_Definition:
The easting is abscissa of coordinate pair in NAD83 Universal Transverse Mercator (UTM) coordinate system, Zone 18.  Easting is the eastward projected distance, in meters, of the position from the central meridian (W75 degree meridian, give a false easting value of 500,000) for zone 18 of UTM.
Attribute:
Attribute_Label: Northing_U
Attribute_Definition:
Northing is ordinate of coordinate pair in UTM coordinate system, Zone 18.  Northing is the northward projected distance of the point from the equator.
Attribute:
Attribute_Label: Phi_ng1
Attribute_Definition:
Cumulative percent of grain size distribution coarser than -1 phi ( 2 mm)
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 100
Attribute_Units_of_Measure: percent
Attribute:
Attribute_Label: Phi_ng0_75
Attribute_Definition:
Cumulative percent of grain size distribution coarser than  -0.75 phi ( 1.68 mm)
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 100
Attribute_Units_of_Measure: percent
Attribute:
Attribute_Label: FID
Attribute_Definition:
Internal feature number.
Attribute_Definition_Source:
ESRI
Attribute_Domain_Values:
Unrepresentable_Domain:
Sequential unique whole numbers that are automatically generated.
Attribute:
Attribute_Label: Shape
Attribute_Definition:
Feature geometry.
Attribute_Definition_Source:
ESRI
Attribute_Domain_Values:
Unrepresentable_Domain:
Coordinates defining the features.
Attribute:
Attribute_Label: Phi_ng0_5
Attribute_Definition:
Cumulative percent of grain size distribution coarser than  -0.5 phi (1.41 mm)
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 100
Attribute_Units_of_Measure: percent
Attribute:
Attribute_Label: Phi_ng0_25
Attribute_Definition:
Cumulative percent of grain size distribution coarser than  -0.25 phi (1.19 mm)
Attribute:
Attribute_Label: Phi_0
Attribute_Definition:
Cumulative percent of grain size distribution coarser than  0.0 phi (1.00 mm)
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 100
Attribute_Units_of_Measure: percent
Attribute:
Attribute_Label: Phi_0_25
Attribute_Definition:
Cumulative percent of grain size distribution coarser than  0.25 phi (0.84 mm)
Attribute:
Attribute_Label: Phi_0_5
Attribute_Definition:
Cumulative percent of grain size distribution coarser than  0.5 phi (0.71 mm)
Attribute:
Attribute_Label: Phi_0_75
Attribute_Definition:
Cumulative percent of grain size distribution coarser than  0.75 phi (0.59 mm)
Attribute:
Attribute_Label: Phi_1
Attribute_Definition:
Cumulative percent of grain size distribution coarser than  1.0 phi (0.50 mm)
Attribute:
Attribute_Label: Phi_1_25
Attribute_Definition:
Cumulative percent of grain size distribution coarser than  1.25 phi (0.42 mm)
Attribute:
Attribute_Label: Phi_1_5
Attribute_Definition:
Cumulative percent of grain size distribution coarser than  1.5 phi (0.35 mm)
Attribute:
Attribute_Label: Phi_1_75
Attribute_Definition:
Cumulative percent of grain size distribution coarser than  1.75 phi (0.30 mm)
Attribute:
Attribute_Label: Phi_2
Attribute_Definition:
Cumulative percent of grain size distribution coarser than  2.0 phi (0.25 mm)
Attribute:
Attribute_Label: Phi_2_25
Attribute_Definition:
Cumulative percent of grain size distribution coarser than  2.25 phi (0.21 mm)
Attribute:
Attribute_Label: Phi_2_5
Attribute_Definition:
Cumulative percent of grain size distribution coarser than  2.5 phi (0.177 mm)
Attribute:
Attribute_Label: Phi_2_75
Attribute_Definition:
Cumulative percent of grain size distribution coarser than  2.75 phi (0.149 mm)
Attribute:
Attribute_Label: Phi_3
Attribute_Definition:
Cumulative percent of grain size distribution coarser than  3.0 phi (0.125 mm)
Attribute:
Attribute_Label: Phi_3_25
Attribute_Definition:
Cumulative percent of grain size distribution coarser than  3.25 phi (0.105 mm)
Attribute:
Attribute_Label: Phi_3_5
Attribute_Definition:
Cumulative percent of grain size distribution coarser than  3.5 phi (0.088 mm)
Attribute:
Attribute_Label: Phi_3_75
Attribute_Definition:
Cumulative percent of grain size distribution coarser than  3.75 phi (0.074 mm)
Attribute:
Attribute_Label: Phi_4
Attribute_Definition:
Cumulative percent of grain size distribution coarser than
Attribute:
Attribute_Label: Phi_8
Attribute_Definition:
Cumulative percent of grain size distribution coarser than  8.00 phi (0.0039 mm)
Attribute:
Attribute_Label: Phi_14
Attribute_Definition:
Cumulative percent of grain size distribution coarser than  14.0 phi (0.000061 mm)
Attribute:
Attribute_Label: Pctil_5
Attribute_Definition:
phi class corresponding to 5% on cumulative weight curve
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -1.0
Range_Domain_Maximum: 14
Attribute_Units_of_Measure: phi unit
Attribute:
Attribute_Label: Pctil_16
Attribute_Definition:
phi class corresponding to 16% on cumulative weight curve
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -1.0
Range_Domain_Maximum: 14
Attribute_Units_of_Measure: phi unit
Attribute:
Attribute_Label: Pctil_50
Attribute_Definition:
phi class corresponding to 50%, or median, on cumulative weight curve
Attribute:
Attribute_Label: Pctil_84
Attribute_Definition:
phi class corresponding to 84% on cumulative weight curve
Attribute:
Attribute_Label: Pctil_95
Attribute_Definition:
phi class corresponding to 95% on cumulative weight curve
Attribute:
Attribute_Label: Mean
Attribute_Definition:
Graphic mean (Folk): Graphic mean = (phi 16 + phi 50 + phi 84) / 3 ; best graphic measure for determining overall size; corresponds very closely to mean as computed by the method of moments; superior to median because it is based on three points and gives a better overall picture
Attribute_Definition_Source:
Folk, R.L., 1974, Petrology of Sedimentary Rocks: Austin, TX, Hemphill Publishing Co., 182 p.
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -1.0
Range_Domain_Maximum: 14
Attribute_Units_of_Measure: Phi
Attribute:
Attribute_Label: Sorting
Attribute_Definition:
Inclusive graphic standard deviation (Folk): Inclusive graphic standard deviation = [(phi 84   phi 16) / 4] + [(phi 95   phi 5) / 6.6] ; best overall measure of sorting; Inclusive graphic standard deviation:
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: < 0.35 phi
Enumerated_Domain_Value_Definition:
very well sorted
Enumerated_Domain_Value_Definition_Source:
Folk, R.L., 1974, Petrology of Sedimentary Rocks: Austin,
TX, Hemphill Publishing Co., 182 p.
Enumerated_Domain:
Enumerated_Domain_Value: 0.35 to 0.50 phi
Enumerated_Domain_Value_Definition:
well sorted
Enumerated_Domain_Value_Definition_Source:
Folk, R.L., 1974, Petrology of Sedimentary Rocks: Austin,
TX, Hemphill Publishing Co., 182 p.
Enumerated_Domain:
Enumerated_Domain_Value: 0.50 to 0.71 phi
Enumerated_Domain_Value_Definition:
moderately well sorted
Enumerated_Domain_Value_Definition_Source:
Folk, R.L., 1974, Petrology of Sedimentary Rocks: Austin,
TX, Hemphill Publishing Co., 182 p.
Enumerated_Domain:
Enumerated_Domain_Value: 0.71 to 1.00 phi
Enumerated_Domain_Value_Definition:
moderately sorted
Enumerated_Domain_Value_Definition_Source:
Folk, R.L., 1974, Petrology of Sedimentary Rocks: Austin,
TX, Hemphill Publishing Co., 182 p.
Enumerated_Domain:
Enumerated_Domain_Value: 1.00 to 2.00 phi
Enumerated_Domain_Value_Definition:
poorly sorted
Enumerated_Domain_Value_Definition_Source:
Folk, R.L., 1974, Petrology of Sedimentary Rocks: Austin,
TX, Hemphill Publishing Co., 182 p.
Enumerated_Domain:
Enumerated_Domain_Value: 2.00 4.00 phi
Enumerated_Domain_Value_Definition:
very poorly sorted
Enumerated_Domain_Value_Definition_Source:
Folk, R.L., 1974, Petrology of Sedimentary Rocks: Austin,
TX, Hemphill Publishing Co., 182 p.
Enumerated_Domain:
Enumerated_Domain_Value: > 4.00 phi
Enumerated_Domain_Value_Definition:
extremely poorly sorted
Enumerated_Domain_Value_Definition_Source:
Folk, R.L., 1974, Petrology of Sedimentary Rocks: Austin,
TX, Hemphill Publishing Co., 182 p.
Overview_Description:
Entity_and_Attribute_Overview:
This data set contains selected textural information on 411 surficial sediment samples.  These sediment samples were collected from the Maryland's coastal bays during a  period between 1991 and 1997.  Each sediment sample is identified by a station number, basin code, and coordinates for both geographic (lat and long) and Maryland state plane system, in NAD83.  Textural data also are listed for each sediment sample. Textural data include cumulative weight. percentages for quarter phi class (for surficial sediments comprised of >75% sand size particles).
Entity_and_Attribute_Detail_Citation:
A description of the surficial sediments and explanation of the specific textural and chemical parameters measured for sediment samples  are detailed in the following interpretive report describing the study from which these data originated: Wells, D.V., and Conkwright, R.D.,  1999, Maryland Coastal Bays Sediment Mapping Project: Physical and chemical characteristics of the shallow sediments- Synthesis Report and Atlas: Coastal and Estuarine Geology Program File Report 99-5, 1st Edition, Maryland Geological Survey, Baltimore, Md., HTML format contained on a Compact Disk (CD).
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Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Assateague Island National Seashore
Contact_Position: GIS Specialist
Contact_Address:
Address_Type: mailing and physical address
Address:
7206 National Seashore Lane
City: Berlin
State_or_Province: MD
Postal_Code: 21811
Contact_Voice_Telephone: 410-641-1443
Contact_Facsimile_Telephone: 410-641-4158
Contact_Electronic_Mail_Address: asis_gis@nps.gov
Hours_of_Service: Mon - Fri 9:00 am - 4:00 pm
Resource_Description: Downloadable Data
Distribution_Liability:
The National Park Service shall not be held liable for improper or incorrect use of the data described and/or contained herein. These data and related graphics ("GIF" format files) are not legal documents and are not intended to be used as such. The information contained in these data is dynamic and may change over time. The data are not better than the original sources from which they were derived. It is the responsibility of the data user to use the data appropriately and consistent within the limitations of geospatial data in general and these data in particular. The related graphics are intended to aid the data user in acquiring relevant data; it is not appropriate to use the related graphics as data. The National Park Service gives no warranty, expressed or implied, as to the accuracy, reliability, or completeness of these data. It is strongly recommended that these data are directly acquired from an NPS server and not indirectly through other sources which may have changed the data in some way. Although these data have been processed successfully on a computer system at the National Park Service, no warranty expressed or implied is made regarding the utility of the data on another system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. This disclaimer applies both to individual use of the data and aggregate use with other data.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: SHP
Transfer_Size: 0.011
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name: http://nrdata.nps.gov/asis/asisdata/mcb_sediment_data.zip
Fees: None
Custom_Order_Process:
Data files may be accessed from Coastal and Estuarine Geology Program File Report 99-5, released on CD-ROM.
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Metadata_Reference_Information:
Metadata_Date: 19941011, Revised 20070529
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Assateague Island National Seashore
Contact_Position: GIS Specialist
Contact_Address:
Address_Type: mailing and physical address
Address:
7206 National Seashore Lane
City: Berlin
State_or_Province: MD
Postal_Code: 21811
Country: USA
Contact_Voice_Telephone: 410-641-1443
Contact_Facsimile_Telephone: 410-641-1099
Contact_Electronic_Mail_Address: asis_gis@nps.gov
Hours_of_Service: Mon-Fri 0900-1600
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
Metadata_Extensions:
Online_Linkage: http://nrdata.nps.gov/profiles/nps_profile.xml
Profile_Name: NPS Metadata Profile
Metadata_Extensions:
Online_Linkage: http://www.esri.com/metadata/esriprof80.html
Profile_Name: ESRI Metadata Profile
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