Samples from Oven 3.1 were examined to establish the nature and
origin of the fuels used. Macerations of unburnt coal fragments
yielded abundant megaspores and miospores (Table 6.21 provides
definitions of terms perhaps unknown to most readers). The assemblages
obtained were typical of the lower part of the Middle Coal
Measures of early Westphalian B age (Duckmantian). Lycopsid
megaspores of the genera Tuberculatisporites and Rotatisporites
were abundant and lycopsid microspores of Densosporites and
Lycospora were equally abundant in miospore preparations.
Durain lithotypes occurred together with clarain, vitrain and shaley
coals. Vitrinite reflectance measurements (mean random) gave
values of 0.49–0.62Ro indicating a high volatile bituminous rank.
A lower Middle Coal Measure origin from the Yorkshire coalfield
is the most likely source of the coal indicating potential transport
from the south of Leeds via York. Coke from the oven was abundant
and some incorporated iron. Petrography and reflectance of
the coke indicates high temperatures greater than 1200°C were
used during the operations of the oven.