:55lj THE GEOLOGIST, 
NOTES AND QUERIES. 
PissuRES IN PoiiTLAND STRATA. — lu your review of the proceedings of 
tlie Geologists' Association, in your last November number, you have noticed 
some remarks of Mr, Gray on tlie bone fissures in the Isle of Portland. I ch 
not tlvink you have quite caught the meaning he intended to convey. 
The Island of Portland consists of a base of Kimmeridge clay, covered by 
by strata of Portland sand and Portland oolite, and capped in some parts of 
the Island by a few feet of calcareous slate belonging to the lower Purbeck. 
Pissures occur in tlie oolite, caused apparently by the shrinking of the stone 
in tlie act of consolidation. There is an excellent woodcut representing one 
of these fissures in Mr. Damon's " Geology of Weymouth and the Isle of 
Portland," page 73. It will there be seen that the fissure affects all tlie beds 
beneath the dirt bed, as far as the sand. Now, the facts that the roots of tlie trees 
which grew in the dirt bed penetrated the stone beneath, and that the calcareous 
slate was deposited around the stumps of those trees before petrefaction, show 
that the slate was deposited before the stone was consolidated. The subse- 
quent shrinking of the stone, which is pale, crystalline, and rings beneath tlie 
liammer, seems to have caused the fissures in the stone beds tliat do not pass 
upwards into the calcareous slate. Not that the slate has not likewise con- 
tracted in hardening, but its contraction has caused a multitude of small in- 
terstices at short intervals, whilst the insterstices between the blocks of solid 
stone have occurred at greater distances from each other, and, therefore, taken 
singly, are of greater width, and have 
no corresponding fissures above them 
on the slate. Now, what Mr. Gray 
means with respect to the human 
bones, which have been occasionally . 
found in the fissures, is this— viz., C 
that they have only iDeen found in 
those parts of the Island wliich are _^ — 
capped by the calcareous slate, and , 
not where the stone is immediately 
subjacent to the vegetable soil. 
Prom what you have quoted from his paper, I would conclude that, where 
this is the case, the fissures are not vacant, as in the other parts of the Island, 
but filled with rubble from above, and, therefore, parts of skeletons interred 
above them would not fall down into them. 
Mr. Damon has expressed the same opiuion as Mr. Gray — that tlie human 
bones in these fissures have fallen from graves in the soil above. He says 
they "are interred remains, and found a few feet beneath the surface in the 
rubble bed (that is the calcareous slate), though a stray bone or two may 
find its way down a fissure where the bones of these animals mav have been 
deposited.'' (p. 130). 
Of course ihis does no more at the most than show- that no fossil remains 
of man have hitherto been found in Portland, but in no respect affects the 
question — whether or not they have been found elsewhere ? 
There are some curious questions connected with the occurrence of mam- 
malian ];onrs of fissures in small islands like Portland and the Isle of Caldy- 
