Authigenic mineral matter

Coal contains detrital minerals that were deposited along with the plant material, and authigenic minerals that were formed during coalification. The abundance of mineral matter in coal varies considerably with its source, and is reported to range between 9.05 and 32.26 wt% (Valkovic 1983). Minerals found in coal include (Table 2) aluminosilicates, mainly clay minerals carbonates, such as, calcite, ankerite, siderite, and dolomite sulphides, mainly pyrite (FeS2) chlorides and silicates, principally quartz. Trace elements in coal are commonly associated with one or more of these minerals (see Table 2). 

Heterotrophic respiration fueled by the rain of organic matter from the surface ocean is ubiquitous in marine sediments. Its rate determines one of the important characteristics of the sedimentary environment the depth of redox horizons below the sediment-water interface. Heterotrophic respiration is the process by which carbon and nutrients are returned to the water column it is important in the marine fixed nitrogen and sulfur cycles and the accumulation of metabolic products sets the conditions for the removal of phosphorus from the oceans in authigenic minerals. A great deal of effort has been directed toward quantifying the rates, pathways, and effects of metabolism in sediments. 

The Maastrichtian (latest Cretaceous) Israeli oil shales consist of four main groups of components organic matter biogenic calcite and apatite detrital clay minerals and quartz, with a little amount of authigenic pyrite and feldspar. The main chemical characteristics of the oil shales are reviewed,with an emphasis on those which may affect future utilization techniques. 

The sample suite from each core can be divided into four factors on the basis of similarities in chemical compositions as defined by Q-mode factor modeling. Factor-1 samples are rich in trace metals due to adsorption onto clay, altered tuffaceous material, and (or) organic matter and precipitation as sulfides. The relatively high concentration of boron is probably related to its inclusion in authigenic feldspars. Factor-2 samples are rich in elements commonly associated with minerals of detrital or volcanic origin. These samples contain relatively high concentrations of analcime, dawsonite, and (or) potassium feldspar, all of which are associated with alteration of tuffaceous material. Siderite and ferroan or ankeritic... 

---