Re: paleonet Sample preparation: Rewoquat

["chris king" <chrking@xxxxxxxxxxxxxxx>]

Thanks very much Bruno..its a very useful reference and I will follow it up.
Best wishes
Chris
--
Chris King
16A Park Road, Bridport, Dorset
DT6 5DA   UK
Phone 01308 459225
Email chrking@globalnet.co.uk
----- Original Message ----- 
From: "Bruno GRANIER" <bruno-granier@wanadoo.fr>
To: <paleonet@nhm.ac.uk>; <paleonet@nhm.ac.uk>
Sent: 30 June 2006 22:02
Subject: Re: paleonet Sample preparation: Rewoquat


This product was also used recently by Moullade M., Tronchetti G. & Bellier 
J.-P. (2005)

Here is the reference of their paper (available online):

The Gargasian (Middle Aptian) strata from Cassis-La Bédoule (Lower Aptian 
historical stratotype, SE France): planktonic and benthic foraminiferal 
assemblages and biostratigraphy.- Carnets de Géologie / Notebooks on 
Geology, Brest, Article 2005/02 (CG2005_A02)

and an excerpt of the paper:

"The samples collected in the sixties were prepared for examination using 
the Averburg (1962), method. This involves a soaking in sodium thiosulphate 
followed by the addition of hydrogen peroxide. The washed residue is then 
processed in Bradosol (cationic moistening; see details in Carbonnel et 
alii, 1965; Moullade, 1966). Unfortunately, these samples were sieved 
through an 80 µm mesh screen, thought to be sufficient at that time. Our 
current knowledge about the size of the smallest planktonic foraminifera 
requires that sediments be sieved through a finer mesh of at least 63 µm, or 
even of 45 µm.
After having been crushed and oven-dried, the samples collected at the turn 
of the century were soaked for a minimum of several days in Rewoquat W 3690 
(cationic tenside), then sieved at 45 µm using warm water and rinsed with 
hydrogen peroxide. This procedure is time consuming but gives excellent 
results, for both concentrating and cleaning microfaunas."

You should contact these people ... they'll be please to give you more 
information.
;)
BG