Grain-Size Data

Note: Sample preparation, processing, and grain-size analysis procedures are described in the Methods section ("Grain-size Analysis").

---

   Sediment samples from the 07SCC04 and 07SCC05 vibracores were analyzed using a Beckman Coulter LS 200 particle-size analyzer to measure the size distribution of sedimentary particles ranging from 0.4 m to 2 mm in diameter. The grain-size data were saved as Microsoft Excel (XLS) spreadsheets. These spreadsheets include a data sheet with the averages of three sub-sampled replicates, reported as a single result for each interval followed by the LS 200 output data sheets for sub-sampled intervals including each replicate or "run" performed for accuracy. The output data for each sub-sample interval are organized by the attribute classes (red numbers) described below. A sample spreadsheet is shown below (click to enlarge):

1. Sample identification number.

2. Sample depth down core in feet and meters.

3. A series of columns representing the samples' cumulative weight percents between 0 and 100 percent in approximately 5-percent intervals in millimeter and phi units.

4. Each sub-samples calculated moments for: mean (Inman, 1952), standard deviation (phi units), and percent sand, silt, and clay in each sub-sample. 

Cruises 07SCC04 and 07SCC05:

• All grain-size data spreadsheets are available for the 07SCC04 and 07SCC05 cores.

Cruise 87039

• No grain-size data analyses exist for the CI_87 cores.

Note: To view the grain-size data, a text editor (TXT) and (or) Microsoft Excel (XLS) is needed. Files may also be viewed online with free Google Docs, if connected to the Internet. If you are unable to open any of these files, please contact Chandra Dreher (cdreher@usgs.gov).

Accessing the Data

   To access the data for each core simply click on the Study Area Map (above) and navigate to the section that contains the desired core. Right-click (to open page in a new window) on a core or core ID label to activate the Core Data Table. The table contains a column entitled Grain-Size Data that presents thumbnail previews of individual cores and links to the downloadable XLS files.