A comparison of HF-based and non-HF-based palynology processing techniques in clay-rich lignites from the Claiborne Group, upper Mississippi Embayment, United States

Abstract

Organic and clay-rich lignite samples from the upper Mississippi Embayment, United States, are known from organic petrography to be extremely palynomorph-rich; however, they are notoriously difficult to process. This leads to difficulty in determining the biostratigraphic placement of individual deposits and in interpreting depositional environments. Six ‘standard’ and non-standard processing techniques for extracting palynomorphs from these samples are presented and the results of each methodology analyzed. Results of these experiments led to the development of a new, hydrofluoric-acid-free processing technique which is presented, along with subsequent refinements to this technique. Samples processed with the new technique, referred to as the ‘O'Keefe technique’, are extremely palynomorph-rich and contain biostratigraphically significant taxa. These taxa allow the deposit to be placed within the middle Eocene Claibornian Stage, and show that it is likely correlative with NP 15.

Keywords:

• palynology processing
• maceration
• clay-rich lithotypes
• Claiborne Group
• Eocene