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.