New Application Note – Micropalaeontology

A new application info sheet use the use of electric pulse fragmentation (EPF) in liberation of foraminafera can be downloaded from our Resources section.

Recent testwork with researchers from the Camborne School of Mines, University of Exeter, UK, has shown the efficacy of EPF in the separation and liberation of foraminafera (forams) from hardened host rock.

foraminafera
Jebel Hafeet sample 1

 

Forams are an extremely useful micro-fossil that can both act as a palaeo-proxy for ocean chemistry, including temperature and isotopic composition, but also can act as a biostratigraphic marker for distinct horizons within a petroleum drilling campaign.

To properly identify the species, the forams must be removed from the host rock then correctly aligned on a thin section plate to give a cross section of the fossil. This poses a problem as mechanical methods of rock crushing can damage the specimens and don’t guarantee liberation of forams, while other methods such as dissolution of the matrix in acid, or freeze-thaw fracturing, are both time intensive and do not guarantee fossil preservation.

 

foraminafera
Images of Jebel Hafeet sample 1. Left: Close up of hand specimen; Right: images of forams from polished thin sections.

 

The sample was treated in the Lab system using the open vessel with 10 mm internal screen. 50 discharges were administered at 5 per second for a total of 10 seconds processing time. As the sample was fragmented, liberated forams fell through the screen and were protected from further treatment. Forams were quickly libertaed from the rock matrix, and intact specimens were shown to outnumber fractured by a considerable margin, with little remaining matrix material attached.

 

foraminafera
Liberated forams from sample 1. Field of view is 12mm.