Abstract DISTRIBUTION AND AGE OF UPPER PALEOZOIC VOLCANIC ROCKS Volcanic rocks of Upper Paleozoic age are widespread throughout Europe, where they range from alkaline basalts through arc-type calc-alkaline basalts and andesites, to ophiolites and to acid ignimbrites. In Ireland and the UK, volcanic rocks consist of mildly alkaline basalts and their derivatives. The two greatest thicknesses of volcanic rocks occur in the Midland Valley of Scotland and in the Limerick Syncline, Ireland. In Ireland, Lower Carboniferous volcanic rocks are found on the margins of both the Shannon Trough (Strogen, 1988) and the Dublin Basin. Coarse volcanic breccias, in most cases occupying vents, are found scattered across the Irish Midlands e.g., Croghan Hill, southeast of Lough Ennell and near Edenderry (the last two known from boreholes; Fig. 1). Float of similar breccias is found widely within areas of Courceyan rocks e.g. around Moate (Strogen, 1974a). Thin ash-fall tuffs occur across the west Midlands (Fig. 1). and intrusive, tuffisites are also common

Abstract For any consideration of the organic matter in intimate association with the surface of soil clays it is appropriate to consider first the totality of the organic matter in the soil. The term “soil organic matter” (SOM), according to Stevenson (1994) , refers to “the whole of the organic matter in soils, including the litter, the light fraction, the microbial biomass, the water-soluble organics, and the stabilized organic matter (humus)”. Nowadays, the term natural organic matter (NOM) is widely used for the natural organic components in soils, sediments, and waters. On the basis of earlier definitions by Kononova (1966) , Hayes and Swift (1978) considered the complete soil organic fraction to be made up of live organisms and plants within the soil, and their undecomposed, partly decomposed, and completely transformed remains. However, they regarded SOM to be a more specific term for the non-living components that may be described as “a heterogeneous mixture composed largely of products resulting from microbial and chemical transformation of organic debris.” The transformation, or the humification process, gives rise to the final product, humus , a mixture of substances with some resistance to further degradation. This definition is similar to that of Stevenson who considered humus to be the total of organic compounds in soil exclusive of undecayed plant and animal tissues, their partial ‘decomposition’ products, and the soil biomass. Stevenson partitioned SOM into the “active” (or labile) and the “stable” pools. The “active fraction” contains the macro-organic (or particulate) matter and the

Abstract The South Central Ireland region extends from the South Munster Basin north to the southern margin of the Dublin Basin and from Wexford in the SE to the Burren in the NW (Fig. 59). The region is dominated by strata of Mississippian age, with Pennsylvanian strata preserved in boreholes in south Co. Wexford and in the upper part of the Leinster and Kanturk coalfields. Throughout the South Central region, the Tournaisian strata present below the Waulsortian mud-bank limestones, which form a continuous thick unit of massive pale grey limestone across most of the region, are represented by the Lower Limestone Shale and Ballysteen Limestone groups (Brück 1985) of the Limerick Province (see Philcox 1984; Sevastopulo & Wyse Jackson 2009). The Lower Limestone Shale Group is related to a northward-directed marine transgressive event across the North Munster shelf. The deepening trend, which started during the deposition of the Ballysteen Limestone Group, continued with the Waulsortian facies on the distal part of a ramp. From the latest Tournaisian time and throughout the Visean there is widespread development of shallow-water marine carbonate platform sediments with only localized deeper-water ramp and basinal facies (mostly in the Shannon Basin) (Somerville et al. 1992b; Strogen et al. 1996; Sevastopulo & Wyse Jackson 2009). The greatest areal extent and stratigraphic thickness (c. 2 km) of Namurian rocks occurs in the Shannon Basin, centred on counties Clare and Limerick.