The weekly democratic statesman. [volume] (Austin, Tex.) 1871-1883, 1875-11-11

seoiOBlCaA UGlS, uoNu " tuc lower sluFlufii
leaving a void, or geological blank, tina
must have covered an immense period O
{ NE, including all those geological era
when the upper silurian, devonian, carboni
ferrous, Permean and jnrassic formation
successfully made their appearances as par
of the earth's surface. Throughout the ere
taceous region we notice that the hills ar
terraced in water-leveI lines, showing th
results of denudation, but nothing of up
heaval and fracture from internal forces
And we can seem 10 lCok back tn that pc
riod long ago, when the tops of these hill
were being gradually elevated above th'
surrounding sea of waters, when terrace az
ter terrace was sueeessiyeiy washed by the
retreating waves, until finally that which
was once an ocean became dry land. Bu
when We strike the lower slIurian all l.
changed. Here the rocky strata, once il
horizontal position, have been curved and
broken in all directions by violent interna
forces, frequently showing unmistaElabi,
evidences of having undergone the infiu
ence of intense heat. In the cretaceou,
we find an immense quantity Of fossils,
showing that nature was already actively a
work in the production of animal life, but
scarcely trace OF mineral deposit. Al
tous bluff exposes the strata in perpendic
ular height of about one hundred feet, neal
the case. and underlying the solid rocks
above, / noticed strata of rotten lime
mari, in which are the best preserved and
most easily obtained fossil shells, some oi
them weighing several pounds, ever saw,
[ couldaha picked up ten wagon-load:
Within distance of ten rods, of extinct
species of bivalves. The shells had become
completely transformed to solid calcareous
matter, preserving their exact form, while
the mari stratum in which they had been
imbedded remained almost unchanged, very
pulverulent and easily detached from the
fossils.
Then we reach the. silurian system-the
lower limestone and Potsdain sandstone,w we
see far less evidence of organic remains,
bus many indications of metalliferous, de
posit. Leaving the Perdinsles, We pass
over the red sandy soil of the Potsdarn
saCistt,ias st,ae me rreeeion for some distance, when,
at Hudson Mount, we again come to to q 9 sud
den and decided change in all tue .geolog-
ical features of the surface. Here l first
saw the granite Immediately underlying the
silurian system, the metamorphic or lau-
rentian system being wanting. The coun-
ravine and valley, and a far more frequent
exposure of rough, rocky bluffs and hill.
sides. And here we see still greater evi
denceof upheayaland breakage of the earth:
crust. The landscape becomes more va lei
and picturesque, and as we pass on and down
into Cole Creek valley we soon observe
that we are in an exclusively primitive re,
gion, surrounded az various distances By
n ifxhn ..f lrx. sl,r
rian system. The rocks are all azoic--crys s.
taline in structure and unstratifed-and
either granite or some variety of trachytic,
the latter appearing in the beds of branches
for some distance in the descent toward
the Sandy. Here observed numerous
dikes of the finest soapstone (steatite), very
white when pulverized, free from grit,
and in unlimited amount. As we pass
on in northerly direction down
Cole creek valley, towards its junction with
the Sandy, the laurentian or metsmorphiC
system begins to appear, consisting of va
rious we'll defined strata of shales, states and
crystalline limestones, and continues, with
an occasional exposure of granite, unti
near the Llano river Along Honey creek,
and upon the smaller branches emptying into
it, these strata, lying at high angle of IN.
clination, rapidly succeed each other, SC
that at some points within the. distance o.
one mile, we may. find an expS sure of ten o
twenty entirely different strata, and in tn,
beds of these streams a greater variety o
rlck may be picked up than in any p ace
ever saw--a fine place for the geological
and meteorological student to accumulate
specimens and examine the phenomena o.
qualification, breakage and upheaval, al
well as those of abrasion and denudatior
from the action of aqueous and atmosphe
neal influences. West of this val
ley, and separating it from HondC
and Legend vallies, is an extensive
range OF lower silurian hills, from
three to five miles IN width, connecting
with the limestone region to the west o
the head waters of Cole creek, and extend
ing in a north easterly direction to near th,
Llano river. IT is known as Cedar Noun
tain on the south of the Sandy, as Riley
Mountain on the north to Waters creek
and as Cap Mountain between there and tn,
Llano river. / notice that along the base o
this range, the metamorphic rocks iinmedi
ately underiie the Pvtsdam sandstone Of th,
lower saluriln and crop out with an upward
incl nation on either side. The slluriaI
hills seem to have settled down into an ex
tensive metamorphic basin, depressing j
by superincumbent weight. The loves
point of depression seems to have been a
Honey Geek Cove, basin OF several mile
in circumference, surrounded on all sides
excepting the outlet for Honey creek on th
east, by high bills OF the lower siiuriai
limestone and sandstone. Here the uppe
strata of the hills dip rapidly IN all direction
toward the Cove, and disappear beneath
series of the lower car5oniferous formations
as though an enormous vortex had one
opened and they had disappeared into tn
bowels of the earth. just at the mouth o
the Cove, near Honey Creek, an enormou
mass of rock seems TO have been detache'
from the adjacent mountain and dumps
edgewise into huge hole that was opene'
to receive it, where it still prUtfudes, tn
strata in perpendicular. position. This
one OF the most interesting geological Il
calities anywhere to be met with, and yer
forcibly conveys the idea that at one tim
since the formation Of the silurian strata
the whole primitive or azoic formatians ha
been broken up and fioated about upon th
sea OF molten fluid upon which it rested
carrying upon its surface, like hoodwoo
upon pond of broken ice, the silurian hill
that thus became isolated from each Other
On the northwestern limits Of this cove 9
basin, from the bed of . branch of Hone
creek, Just at the point where tn
upper stratum Of silurian limeston
dips under the carbonlferous, good btu
minous coal is often washed out, and / hav
seen one piece picked up just below there
after freshet, that was abont one foe
square and from fonr 70 Fix inches thick
Above the position Of this coal stratum Al
two of carboniferous limestone, separate
/ by one Of dark bituminous shale, and sii
above the upper limestone is another Of sol
zrgilIaceous sIiale, very pulverulsnt on e,
posure, forming clay that / think woul
make line fire-brick. Overlying this shsl
| is couglomerate rock, composed Of angus
pieces OF limestone aud Il at. firmly bOur
together by cAicaFeous cement. Upon thii
OF directly upon the upper shale, rests II
surface soil OF aiiusium II the basin, wiiic
/ is OF variable depths at different points
The upper shale appears in many places
the beds OF the water courses. DR.. G.
smith, of Llana, has made some explon
tions here for coal, but so far ] Think viii
mt sncress. Yet it is probable that goo