THE RAPID PREPARATION OF STRUCTURAL IMAGES FROM UNDISTURBED, NONCOHESIVE MATERIAL (MILLED PEAT)

A new method for the acquisition of undisturbed in situ samples of mil led peat (non-cohesive particulate material) suitable for image analys is was developed. Samples were obtained in the field by dripping Endur a epoxy resin onto a stockpile surface. Blocks of material (160 mm x 1 20 mm) with original pore structure up to 140 mm deep were removed to the laboratory and re-impregnated with Crystic resin from which polish ed blocks and thin sections were produced. All resins were mixed with fluorescent dye so that when viewed under ultraviolet light, a resolut ion of ca. 20 mu m was possible from only partially polished faces. Ca reful observation in the field indicated that few (if any) particles w ere not bound by the initial impregnation. When prepared as thin secti ons (without a dehydration period), the two impregnants could be disti nguished within the pore space under crossed polarised light. It can b e concluded that the method permits observation of undisturbed macro, meso and some micro pores (> 75 mu m, 75-30 mu m and 30-5 mu m diamete r, respectively [Soil Science Society of America, 1997. Glossary of So il Science Terms. Soil Science Society of America, WI, USA, 134 pp.]). (C) 1998 Elsevier Science B.V. All rights reserved.