Further Testing of a Non-Acid Palynological Preparation Procedure

Abstract

The extraction of palynomorphs from sedimentary rocks and unconsolidated sediments has traditionally used hydrochloric acid (HCl) and hydrofluoric acid (HF) to remove the matrix by dissolution. The use of these, and other, acids in palynological preparation requires significant laboratory infrastructure, and may produce hazardous and potentially environmentally damaging waste. An effective technique of palynomorph preparation using sodium hexametaphosphate [(NaPO 3 ) 6 ] was recently developed. This technique was initially demonstrated on a suite of samples of Early Jurassic to Quaternary age. In this study, non-acid preparation techniques were tested on 11 samples of Ordovician, Carboniferous, Jurassic and Paleogene age from the UK. In four of the six case studies described herein, the rock was prepared quantitatively using both the traditional mineral acid technique and the (NaPO 3 ) 6 procedure. In the Carboniferous case study, the two samples were prepared quantitatively using HCl/HF, (NaPO 3 ) 6, and hydrogen peroxide (H 2 O 2 ). In the quantitative preparations, the concentrations of palynomorphs can be directly compared. Two nonquantitative case studies were undertaken using (NaPO 3 ) 6 only, in order to demonstrate that this method is of practical utility.The (NaPO 3 ) 6 and H 2 O 2 methods generally proved to be as effective as the mineral acid procedure. However the results from the three Paleozoic samples proved somewhat variable. The Early Ordovician sample 1 did not break down in (NaPO 3 ) 6 , and consequently the palynomorph yield from this sample was extremely poor, compared to the acid preparation. Two Lower Carboniferous samples were prepared using all three methods. In sample 2, all the methods were effective, although the H 2 O 2 technique proved less effective than those using mineral acids and (NaPO 3 ) 6 . In this sample, both the non-acid methods produced palynomorph assemblages cleaner of extraneous woody material than the residue produced by the acid digestion method. By contrast, in Carboniferous sample 3, the acid preparation was far better than those from the two non-acid preparations. It appears that mudrocks which are relatively indurated are not consistently disaggregated using (NaPO 3 ) 6 and/or H 2 O 2 . It may be possible to adapt these nonacid techniques so that they are more efficient on these relatively hard lithotypes. The samples would need to be softened prior to treatment with (NaPO 3 ) 6 and/or H 2 O 2 . Even on relatively hard lithotypes, some palynomorphs were extracted using (NaPO 3 ) 6 and H 2 O 2 . This confirms that non-acid methods can be used on harder rocks if a preliminary age assessment is required and/or the full laboratory facilities are unavailable.The (NaPO 3 ) 6 technique proved extremely effective in the two quantitative Jurassic case studies. These were on the Oxford Clay and Kimmeridge Clay formations (Callovian-Oxfordian and Kimmeridgian respectively). In samples 4, 6 and 7, both methods gave similar palynomorph yields. However in sample 5 from the Oxf...

Pleistocene till provenance in east Yorkshire: reconstructing ice flow of the British North Sea Lobe

“…The 8-16 mm and >16 mm size fractions were categorised in terms of lithology and stratigraphic age, and hence regions of likely provenance through correlation with reported outcrop occurrences. The allochthonous palynomorph content was extracted from two 50 g sub-samples of the bulk material through non-acid palynological preparation techniques (Riding & Kyffin-Hughes, 2004. Three slide fractions were prepared from each residue through swirling and heavy liquid separation (Riding & Kyffin-Hughes, 2004), representing a light, heavy and centrifuged sub-sample.…”

“…The allochthonous palynomorph content was extracted from two 50 g sub-samples of the bulk material through non-acid palynological preparation techniques (Riding & Kyffin-Hughes, 2004. Three slide fractions were prepared from each residue through swirling and heavy liquid separation (Riding & Kyffin-Hughes, 2004), representing a light, heavy and centrifuged sub-sample. The palynomorphs were grouped according to stratigraphic ranges, thus indicating their likely provenance.…”

Nonpollen palynomorphs: Indicators of salinity and environmental change in the Caspian–Black Sea–Mediterranean corridor

“…The low recovery of dinocysts in cores 72 and 1461 (probably also in Lake Durankulak, Table 1) refl ects processing with the traditional KOH and acetolysis methods of Faegri and Iversen or Birks (Bryant and Wrenn, 1998) in contrast to the other samples that were processed by sieving, followed by chemical digestion with cold 10% HCL and warm 52% HF (e.g., Mudie et al, 2004). Other new methods use only sodium hexametaphosphate (NaPO 3 ) 6 , as described by Riding and Kyffi n-Hughes (2006), or dilute KOH (Bryant and Wrenn, 1998). Extraction using heavy liquid separation (e.g., Wood et al, 1996) is satisfactory in preventing oxidation damage of thin-walled palynomorphs, but it needs careful application to avoid loss of specimens by settling after coagulation of clumped grains.…”

Interlobate ice‐sheet dynamics during the Last Glacial Maximum at Whitburn Bay, County Durham, England

“…Samples were prepared using the sodium hexametaphosphate method outlined by Riding & Kyffin-Hughes (2006). Heavy minerals were obtained by density separation using full freezing in accordance with techniques outlined by Gale & Hoare (1991), Mange & Maurer (1992), Walden (2004) and Mange & Otvos (2005).…”