Description: Processed results from of surface grain size analysis of the sediment grab samples recovered as part of the Long Island Sound mapping project Phase II.Sediment grab samples have been taken in summer of 2017 and 2018 using a modified van Veen grab sampler. A sub-sample of the top two centimeter was taken and stored in a jar. Dried sub-samples samples were analyzed for grain size. First the samples were treated with hydroperoxide to remove organic components. Then the sample was passed through a series of standard sieves representing Phi sizes with the smallest being 64 µm. The content of each sieve was dried and weight. If there was sufficient fine material (< 64 µm), then this fine fraction was further analyzed using a Sedigraph system. The results of sieving and sedigraph analysis have been combined and the percentages for gravel, sand, silt and clay are determined following the Wentworth scale. In addition, other statistics including mean, median, skewness and standard deviation are calculated using the USGS GSSTAT program. The results of the LDEO/Queens College grain size analysis have been combined with data collected by the LISMARC group and analyzed by USGS. Based on the different percentages sediment classifications are determined following the Schlee and the Falk systems. These results are also translated into the CMACS systems. The data are presented as Excel spreadsheet and ESRI shapefile.Time period of content: 2017-08-01 to 2022-11-16Attribute accuracy: The attribute accuracy has not been determined, but standard practices have been followed.Completeness: The dataset is mostly complete. Several samples had too little material to perform analyze the fine fraction in the sedigraph. The fines of these are distributed over the fine grain scale. These samples are dominated by sand and/or gravel and, therefore, the remaining fines do not really influence the classification.Positional accuracy: Locations are based on DGPS using the ship GPS antenna for most cores resulting +/- 5 m accuracy.Attributes: Sample_ID: Text describing the Name of the grab sampleLab: Text indicating if the sample was analyzed at the LDEO core Lab, Queens College, or by USGSProject: indicating the phase of the Long Island Sound Mapping Project (LIS2 is Phase 2)Latitude: Latitude of grab sample stationLongitude: Longitude of grab sample stationPHI_13: percent of the sample mass that was falls into the grain size category Phi 13PHI_12: percent of the sample mass that was falls into the grain size category Phi 12PHI_11: percent of the sample mass that was falls into the grain size category Phi 11PHI_10: percent of the sample mass that was falls into the grain size category Phi 10PHI_9: percent of the sample mass that was falls into the grain size category Phi 9PHI_8: percent of the sample mass that was falls into the grain size category Phi 8PHI_7: percent of the sample mass that was falls into the grain size category Phi 7PHI_6: percent of the sample mass that was falls into the grain size category Phi 6PHI_5: percent of the sample mass that was falls into the grain size category Phi 5PHI_4: percent of the sample mass that was falls into the grain size category Phi 4PHI_3: percent of the sample mass that was falls into the grain size category Phi 3PHI_2: percent of the sample mass that was falls into the grain size category Phi 2PHI_1: percent of the sample mass that was falls into the grain size category Phi 1PHI_0: percent of the sample mass that was falls into the grain size category Phi 0PHIM1: percent of the sample mass that was falls into the grain size category Phi -1PHIM2: percent of the sample mass that was falls into the grain size category Phi -2PHIM3: percent of the sample mass that was falls into the grain size category Phi -3PHIM4: percent of the sample mass that was falls into the grain size category Phi -4PHIM5: percent of the sample mass that was falls into the grain size category Phi -5gravel_pct: Percent of the sample mass that falls into the gravel categorysand_pct: Percent of the sample mass that falls into the sand categorysilt_pct: Percent of the sample mass that falls into the silt categoryclay_pct: Percent of the sample mass that falls into the clay categorymud_pct: Percent of the sample mass represents silt plus claymedian: calculated median grain size (in Phi)mean: calculated mean grain size (in Phi)stddev: Standard deviation of grain size around the mean (Phi)skewness: calculated skewness of grain size distribution in samplekurtosis: calculated kurtosis of gain size samplegs_schlee: grain size classification following the Schlee classification schemags_falk: grain size classification following the Falk classification schemaCMECS_sub_orig: CMECS substrate origin CMECS_sub_class: CMECS substrate classCMECS_sub_subclass: CMECS substrate subclassCMECS_sub_group: CMECS substrate group classification
Copyright Text: Timothy C. Kenna, Frank O. Nitsche, Cecilia McHugh, Long Island Sound Cable Fund Steering Committee