180 The American Oeologist. March is90. 
Bank. The one occurs in every vai-iety of the early Cretaceous 
(Neocomian) rocks, including unaltered sandstones, and metamorphic 
phthanite, pseudo-diabase, pseudo-diorite, glaucophane schists, and 
serpentine. The most important deposits are found in the metamor- 
phosed rooks, but this seems to be duo only to their hardness. Chico 
sandstones, the uppermost Cretaceous formation of California, contain 
cinnabar at New Idria. Elsewhere this ore is found in sandstones that 
are believed to bo Miocene, in Pliocene and post-Pliocene andesite, 
and in recent basalt. 
Great similarity of all these quicksilver deposits indicates that they 
were not derived from the enclosing diverse rock formations, and that 
they have had a common history, which in two places has been con- 
tinued to the present time. The process of deposition of cinnabar from 
heated waters holding soluble double sulphides, issuing from great 
depths, is still going forward at Steamboat Springs and Sulphur Bank, 
where, as well as in the laboratory, Mr. Becker has carefully studied 
the chemical conditions of the solution and precipitation of this ore. 
He concludes that the enclosing rocks have been without effect upon 
the deposits, since they occur in nearly all the rocks of the Coast 
Ranges. The origin of the quicksilver is shown to be probably by 
leaching from the underlying granite, which the author believes to be 
the first-formed crust of the globe, still in many places exposed to 
view and forming its surface. 
Deposition of cinnabar appears to have taken place through 
the agency of hot sulphur springs, which were probably in all 
cases of volcanic origin. Basalt of Quaternary age is the lava usually 
associated with the deposits ; but at New Almadenit is a rhyolite dike, 
which is probably Quaternar}' or late Pliocene. The author shows 
that after the close of the Jurassic no eruptions seem to have taken 
place in the Coast Ranges until the close of the Miocene or a little 
later. Andesites were then ejected at intervals until the close of the 
Pliocene. Younger andesites, which seem to be early Quaternary, 
constitute a natural group of trachyte -like rocks, for which the name 
asperites is proposed in this report. These fo.rm Mt. Shasta and the 
surrounding country, and are extensively developed at Clear lake, 
thence southward to the bay of San Francisco, and at Steamboat 
Springs. Still later, during the Quaternary and down to very recent 
times tliore have been many basalt eruptions. The date of the latest 
in the vicinity of Sulphur Bank was probably within a thousand years 
or less ; and in northern California there is good reason for believing 
that there has been a small basaltic eruption within forty years. From 
these records of volcanic activity it appears that the age of the cinna- 
bar deposits is limited to post-Miocene time, and there is little doubt 
that nearly all the ore has been deposited since the end of the Pliocene. 
On new plants from the Erian and Carboniferous, and on the characters 
and affinities of paJxozoic gijmnosperms. By Sir J. William Dawson, 
LL.D., F.R.S., F.G.S., &c. (From the Canadian Record of Science, 
