These different forms of fossilisation may easily be understood if we examine the mud recently thrown out from a pond or canal in which there are shells.
"The Student's Elements of Geology"
Sir Charles Lyell
The perplexity in which we are involved when we attempt to solve this problem may be owing partly to our want of diligence as collectors, but still more perhaps to ignorance of the laws which govern the fossilisation of land-animals, whether of high or low degree.
"The Student's Elements of Geology"
Sir Charles Lyell
In some of the associated carboniferous shales, ferns and calamites occur, and all the phenomena of the successive buried forests remind us of the sections in Figures 439 and 440 of the Nova Scotia coal-measures, with this difference only, that in the case of the South Joggins the fossilisation of the trees was effected without the eruption of volcanic matter.
"The Student's Elements of Geology"
Sir Charles Lyell