From fordj@UCS.ORST.EDUTue Apr 29 15:21:55 1997 Date: Fri, 31 Jan 1997 11:12:48 -0800 From: Jesse Ford To: Multiple recipients of list PALEOLIM Subject: Battarbee plates I had so many requests for the info on Battarbee plates that I thought I would just post directly to the list. For those of you wondering what Battarbee plates are, they are used to settle out diatoms from sediment digests onto cover slips for mounting directly onto slides. Because the area of the cover slips and the area of the plate can be calculated, and the original volume of sediment digest is known, it is a (semi-) quantitative method. Rick Battarbee developed this approach: Battarbee 1973 Limnology & Oceanogr 18:647-653. Herewith the comments (below my signature field). One got added as part of the queries I received last night.... ****************************** Dr. Jesse Ford Dept. Fisheries and Wildlife 104 Nash Hall Oregon State University Corvallis, OR 97331-3803 Ph: 541-737-1960 FX: 541-737-1980 fordj@ucs.orst.edu ***************************** I had some made from Lexan (polycarbonate) which solves any metal oxidation problems, but they all warped slightly while being turned on the lathe resulting in a very slight convexity to the circular settling chamber. I tend to get annual rings of microfossils as the sample gradually dries from center to margin. Craig Sandgren ****************** I have had lots of precipitates using aluminum and other alloy plates so now I am sticking with acrylic plates. They seem to work better and are cheap to make. Here at the Univ. of Washington they can make them out of just about any material you want (they work with lots of exotic plastics for the surgical tools they make) -metal or plastic. You may want to check out Richard Laws paper in Micropaleontology (vol 29, 1983). He uses a different techniques withbeakers that works great with the materials I have been prepping. The slide tray he uses is very easy to build. Brian Sherrod Department of Geological Sciences/USGS University of Washington, Box 351310 Seattle, Washington 98195 bsgeol@u.washington.edu (206)685-1960 ******************************** I had mine made out of solid pvc. It seems to work really well. I gave the spec.'s to our Biology Department machinist and he did a great job. The biggest problem I had was finding coverslips to fit (mine are 22mm dia.) Cori L. Barraclough Department of Biology University of Victoria CBARR@UVVM.UVIC.CA ********************************** I have had Battarbee trays made of plexiglass and have had pretty good success. I place a large box over them with a few holes - I think this helps to keep a wet atmosphere directly above the plates and maybe cuts down on the charge?? Anyway, the box has helped us. Peter Siver *********************************** My recommendation is NOT TO USE TRAYS, but invest in a good calibrated spike, pollen or spheres. True, it is a pain to calibrate (by heamocytometer) but I think your results will be better. In fact, I have a paper submitted and accepted by JOPL that details an experiment on concentrations. The choice is partially personal, but even Battarbee is using spikes these days... Alex Wolfe From rbattarb@GEOGRAPHY.UCL.AC.UKTue Apr 29 15:25:45 1997 Date: Sun, 9 Feb 1997 18:45:39 GMT From: Rick Battarbee To: Multiple recipients of list PALEOLIM Subject: "Battarbee" trays Dear all, Nice to know those old trays had some use! I found they needed to be made from plexiglass and that they worked really well with some but not all sediments (good with silty sediments) - but I abandoned them about 20 years ago in favour of a microsphere spike method (Battarbee & Kneen 1982, L&O). The micospheres we use are divinylbenzene ones (stable in organic solvents) with a mean diameter of 6.7 um, and we calibrate them quite quickly and easily with an electronic particle counter. We have had few problems, and hold calibrated stock suspensions, that we can sell to anyone interested - #100.00 for 50 ml (contact vjones@geog.ucl.ac.uk). Rick Battarbee ----------------------------------------------- Professor R.W. Battarbee rbattarb@ucl.ac.uk Environmental Change Research Centre Tel: 44 (0)171 380 7582 University College London Office: 44 (0)171 380 7575 26 Bedford Way Fax: 44 (0)171 380 7565 London WC1H 0AP