Chiloe and Concepcion, without the possible identity ever having occurred
to me. At last there was no resisting the conclusion. I could not expect
shells, for they never occur in this formation; but lignite or carbonaceous
shale ought to be found. I had previously been exceedingly puzzled by
meeting in the sandstone, thin layers (few inches to feet thick) of a
brecciated pitchstone. I strongly suspect the underlying granite has
altered such beds into this pitchstone. The silicified wood (particularly
characteristic) was yet absent. The conviction that I was on the Tertiary
strata was so strong by this time in my mind, that on the third day in the
midst of lavas and [? masses] of granite I began my apparently forlorn
hunt. How do you think I succeeded? In an escarpement of compact greenish
sandstone, I found a small wood of petrified trees in a vertical position,
or rather the strata were inclined about 20-30 deg to one point and the
trees 70 deg to the opposite one. That is, they were before the tilt truly
vertical. The sandstone consists of many layers, and is marked by the
concentric lines of the bark (I have specimens); 11 are perfectly
silicified and resemble the dicotyledonous wood which I have found at
Chiloe and Concepcion (6/2. "Geol. Obs." page 202. Specimens of the
silicified wood were examined by Robert Brown, and determined by him as
coniferous, "partaking of the characters of the Araucarian tribe, with some
curious points of affinity with the yew."); the others (30-40) I only know
to be trees from the analogy of form and position; they consist of snow-
white columns (like Lot's wife) of coarsely crystalline carb. of lime. The
largest shaft is 7 feet. They are all close together, within 100 yards,
and about the same level: nowhere else could I find any. It cannot be
doubted that the layers of fine sandstone have quietly been deposited
between a clump of trees which were fixed by their roots. The sandstone
rests on lava, is covered by a great bed apparently about 1,000 feet thick
of black augitic lava, and over this there are at least 5 grand
alternations of such rocks and aqueous sedimentary deposits, amounting in