East Shetland Basin

Fig. 2. General Jurassic stratigraphy of the East Shetland basin in the northern North Sea (simplified after Brown,...

At temperatures above c,100°C steroidal aromatization occurs at an increasingly faster rate than sterane isomerization. As a result, in young extensional basins in which there is a high heat flow, such as the Pannonian Basin in Hungary, aromatization can be virtually complete while sterane isomerization is at an early stage (Fig. 5.53a). In older basins with more moderate heat flows, such as the East Shetland Basin (northern North Sea Fig. 5.53b), the steroid isomerization and... 

Fig. 5.53 Plots of depth versus isomerization of steranes at C-20 and aromatization of C-ring monoaromatic steroids in the Pannonian Basin (Pliocene deposits, geothermal gradient >50°Ckm-1) and East Shetland Basin (Jurassic, geothermal gradient c.30°C km-1).The broken line represents the approximate depth of onset of oil generation. (Data after Mackenzie McKenzie 1983 Mackenzie 1984.)...

The immature character and limited source volume in Kitchen 1 makes migration from the west unlikely, thereby suggesting an alternative source for parts of the petroleum population 2, which the authors suggest is dominantly sourced from the East Shetland Basin. 

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