Upper Jurassic Kimmeridge clays

The crude oil used by Bennett and Barter (1997) was a typical North Sea oil generated from Upper Jurassic, Kimmeridge clay formation source rocks. The alkylphenol distribution in a sample of (Miller) crude oil, determined using solid phase extraction (SPE), is shown in Fig. 16.21. The crude oil is dominated by phenol and cresol and contains appreciable quantities of dimethylphenols. The concentrations of 2,3-, 3,4-, and 3,5-dimethylphenol also include a contribution from 2-, 3-, and 4-ethylphenols, because they coelute under the conditions employed (Bennett et ah, 1996). 

The 24 samples chosen (for which summary data are given) range in age from the Cambrian (Sweden) deposit (Camb 1) to the Upper Jurassic Kimmeridge clays (K series) their sources are shown in Figure 1, From Bitterli (JL), and other literature reports, they can generally be classed as marine (Camb, LL, UL,... 

Matthews A, Morgans-Bell HS, Emmanuel S, Jenkyns HC, Erel Y, Halicz L (2004) Controls on iron-isotope fractionation in organic-rich sediments (Kimmeridge Clay, Upper Jurassic, southern England). Geochem Cosmochim Acta, in press... 

Raiswell R., Newton R., and WignaU P. B. (2001) An indicator of water-column anoxia resolution of biofacies variations in the Kimmeridge Clay (Upper Jurassic UK). J. Sedim. Res. 71, 286-294. 

Generation and expulsion. In the western source kitchen, petroleum generation from Upper Jurassic source rocks commenced towards the end of the Cretaceous (56.5 Ma bp) and was almost complete by mid Miocene times (10.4 Ma bp) when transformation ratios of 0.9 were reached. In the easterly kitchen, generation from the Kimmeridge Clay Formation (KCF) source rock was only just starting at this time (TR<0.3). At 10.4 Ma bp, no generation has occurred from Upper Jurassic... 

Kiln Scum or Kiln White. See scum. Kimmeridge Clay. A clay of the Upper Jurassic system used as a raw material for building bricks in Dorset and Oxford the lower beds often contain gypsum and lime, the upper beds are shaly and bituminous. 

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