Most pre-Quaternary palynology samples are currently prepared by demineralisation of the sediment/sedimentary rock matrix using hydrochloric and hydrofluoric acids (HCl and HF respectively). If a consistently effective alternative to this procedure can be developed, palynological processing will be made significantly less hazardous to both laboratory personnel, and to the wider environment. Furthermore, most non-acid processing methods are normally quicker and cheaper than matrix dissolution using acid. Some authors have previously used hydrogen peroxide (H 2 O 2 ) to extract palynomorphs by the physico-chemical disaggregation of the clay fraction. However, H 2 O 2 is a powerful oxidizing agent and hence can potentially destroy sedimentary organic material, including palynomorphs. A new method using hot H 2 O 2 , where exposure of the sample material to the H 2 O 2 is minimised, has been developed. Crushed sample material in a suitable vessel is placed on a hot plate for one minute, treated with 15-30% H 2 O 2 for 10 minutes, then the residue is diluted with cold distilled water. Disaggregated sample material tends to float, and is decanted into a large vessel containing distilled water to further dilute the H 2 O 2 . If any undisaggregated sample remains, the procedure is repeated several times if necessary. Relatively indurated sedimentary lithotypes normally require several treatments. The reason for this stepwise treatment is that the organic material is not exposed to H 2 O 2 for sustained periods, thereby reducing the possibility of palynomorph damage/degradation due to oxidation. When the sample matrix has been fully disaggregated, the residue can be further processed as appropriate.In this study, eight samples of Carboniferous, Jurassic, Paleogene, and Quaternary age were prepared quantitatively using the new H 2 O 2 method. These were all prepared using 30% H 2 O 2 . For comparison, they were also prepared quantitatively using HCl/HF and/or sodium hexametaphosphate [(NaPO 3 ) 6 ]. Quantitative preparations allow the concentration of palynomorphs extracted to be determined, and therefore the effectiveness of the techniques used can be compared objectively. The palynomorph residues derived from these three techniques varied markedly. The H 2 O 2 method does not consistently disaggregate all the sample material, particularly the older and more indurated lithotypes. Some evidence of oxidation effects was observed. Two samples of Mississippian mudstone from the U.S.A. were prepared using H 2 O 2 and (NaPO 3 ) 6 . Both methods produced abundant miospores, however the H 2 O 2 procedure yielded far higher palynomorph concentrations than the (NaPO 3 ) 6 2 technique. Minor degradation of palynomorphs in the H 2 O 2 preparation was noted. The H 2 O 2 and HCl/HF methods were compared directly on a palynomorph-rich sample of Upper Carboniferous mudstone from offshore Scotland. Both preparations produced abundant miospores. The HCl/HF method had significantly higher recovery levels than the H 2 O 2 procedure....

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11 12 A sample of palynomorph-rich Upper Carboniferous mudstone from Scotland 13 was separately pre-treated overnight with acetone, two detergent solutions, formic 14 acid, household bleach (two methods), methylated spirits and white spirit prior to 15 palynological preparation using sodium hexametaphosphate [(NaPO3)6]. The aim of 16 this study was to identify effective methods of pre-treatment that would increase 17 palynomorph yields using the (NaPO3)6 method. Pre-treatment generally increased the 18 mass of sample that was broken down by the (NaPO3)6 technique. Detergent one 19 (carpet cleaner), formic acid, household bleach and white spirit allowed the 20 disaggregation of more rock than without any pre-treatment. However, formic acid 21 produced a lower concentration of yield of Carboniferous miospores than with no pre-22 treatment. Pre-treatment with acetone, detergent two (industrial detergent) and 23 methylated spirits actually decreased the weight of rock that was disaggregated with 24 (NaPO3)6. Despite this, all these three pre-treatments improved the palynomorph yield 25 as compared to with no pre-treatment. Moreover, all the pre-treatments except formic 26 acid improved palynomorph productivity. The effectiveness of pre-treatments was 27 demonstrated by the increased absolute numbers of indigenous palynomorphs 28 extracted. However, the concentrations of miospores per gram of rock are more 29 significant. Acetone, both detergent solutions, methylated spirit and white spirit 30 significantly improved the amounts of palynomorph extracted. Household bleach was 31 found to lighten and selectively destroy relatively delicate palynomorphs; this reagent 32 should be used with caution, and only with robust material. In the subsample soaked 33 overnight in 5% bleach solution, all the exotic Lycopodium spores added were 34 destroyed. By contrast in the subsample treated with 2.5% bleach solution for six 35 hours, a small proportion of the exotic Lycopodium spores survived. This study 36indicates that the (NaPO3)6 method using either detergent or white spirit as a pre-37 treatment is highly effective at extracting palynomorphs from clay-rich lithotypes. 38However the concentration of palynomorphs obtained is generally lower than those 39 from mineral acid digestions. 40 41

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...

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