Temporal changes in grain size and organic-mineral aggregates in surficial sediments near the Massachusetts Bay Outfall Site, Appendix 1

Open File Report 01-499, Temporal Changes in Grain Size and Organic-Mineral Aggregates

Title Page

Abstract

Introduction

Geologic Environment

Methods

Results/Discussion
Station2
Station 3

Conclusions
Station2
Station 3

Acknowledgments

References

Appendix 1

Table 1

Table 2

APPENDIX 1 Flow chart detailing the Massachusetts Bay textural analysis procedure of the 0-0.5 cm surficial interval as sampled from Hydrodynamic Gravity Cores

Using nested stainless steel sieves of mesh size -1 phi (2.0 mm) and 4 phi (0.0625 mm), gently wet sieve a split of wet sediment, using aliquots of 0.2 um filtered seawater with 80ml formalin diluted to 20 liters. The fine fraction is retained in a mason jar. Transfer the coarse fraction retained on the 4 phi sieve to a 100 ml beaker (dry and weigh any gravels retained on the 2.0 mm sieve) and proceed with the analyses for each fraction as outlined below:

Coarse Fraction

Fine Fraction

transfer the sediment from the beaker and gently re-sieve through a set of nested 2 phi and 4 phi sieves using filtered sea water and add the wash to the fine fraction in the mason jar

Determine sieved volume using a graduated cylinder, Record and return solution to the mason jar

examine the sediment retained on each sieve using a light microscope; characterize particles as to detrital,aggregates, fecal pellets, etc. and, qualitatively, determine relative percentages of each.

transfer contents from each sieve to a 100 ml glass beaker with filtered seawater and sonify in a sonic bath for 30 minutes

Homogenize solution with a stir bar and extract 10-20 ml with a pipette; transfer to a millipore rig using a pre-weighed 47 mm diameter/0.4 um nucleopore filter; filter solution and rinse five times with fdw-record both volumes

re-sieve contents through a 4 phi sieve using a 200 ml tall-boy beaker as a catch pan.....................

Return sediment retained on 4phi sieve for standard size analysis

using whole phi nested sieves (include -1 phi fraction as well)

dry filter overnight under a laminar flow hood; determine weight of sediment (g)- this is weight of fines in the (silts-clays) sample

resuspend the filtrate with a motorized stirrer and transfer an aliquot of sieved solution with a pipette and filter through a standard millipore filtration rig using a pre-weighed 47 mm diameter/0.4 um nucleopore filter; rinse filter and sediment 5 times with filter distilled water and record volume of aliquot filtered and final volume collected in the flask with a graduated cylinder;

analyze the solution in the mason jar by standard coulter counter methods- this will determine the distribution of silt and clay sized particles within the sample

transfer filter to a petrie dish and dry overnight under a laminar flow hood; record weight of filter and determine weight of sediment normalized to grams. This is an operationally defined measure of the weight of aggregates within the sample.

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