Location and Processed results (XLS format) from surface grain size analysis of sediment grab samples, Long Island Sound mapping project Phase II

Sediment grab samples were taken in summer of 2017 and 2018 using a modified van Veen grab sampler. A sub-sample of the top two centimeters was 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 weighed. If there was sufficient fine material (< 64 µm), 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 were 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 is presented here as an Excel spreadsheet. There is an accompanying ESRI shapefile. Funding was provided by the Long Island Sound Mapping Fund administered cooperatively by the EPA Long Island Sound Study and the Connecticut Department of Energy and Environmental Protection (DEEP).