Wilmington expositor. (Wilmington, Del.) 1831-18??, 1831-12-02
Synopsis OF a course Of lectures
ON Natural Science.


ON Natural Science.
TO BE DELIVERED BY DIR. HENRY GIBBONS.
LECTURES 1. & IL.
Distinction between Mineralogy proper and
Geology, the former relating to individual min.
erals, and may be studied separately--the lat
ter, relating to the structure of the Earth, and
requiring some knowledge of the former Some
Minerals more important in Geology than 9th
ers, constituting the Geological Alphabet: viz.
Quartz. Feldspar, Mica, Hornblend, Carlo
nate of lime, Gypsum, slate, Falc and Chlorate !:
their leading characters &c.
Surface of the Earth stratihed like an onions
strata only partial, broken by mountains-o.
horizontal. but now otherwise, and
uniform in relative position--im-
portant application of this principle--Depth to
which the Geologist has explored, only 4 or $
beneath supposed to be Granite
Symmes' theory &c.
Mountains, structure of-deepest rock in
the valley. becomes the highest on mountains,
and why q Theory of the formation of noun
tains--method of ascertaining the Geology Of
a mountain and adjacent valley,
Necessary differences drawn from inspection
of strata, forming Geological history of Gre
alton. which accords with the Mosaic history.
Principal Glasses of strata. Primitive, Tran
sition. Secondary and Tertiary.
1. Primitive. crystalline, and without frag-
ments-contain no fossils--their position
why called Observation-Disclosures drawn from
these features solution and suspension defined.
Q: Transition, why SO called. differ from
Primitive-contain fragments; fossils--their
position: deductions.
s. Secondary-their structure-fossils:'u PUP
per secondary strata, decentralization
Mineral veins found in Primitive. Transit
on, and secondary rocks: consist of various
substances; contain metals: Theory of their
formation-GaDgue; definition of. depth of its
veins--Bohemia mine: vein of silver in Andes:
Botallack mine--Theories of Hutton and Wer-
ner on veins.
Werner and Hutton's Theories of Valleys
objection to their formation by rivers and by
subsistence: correct theory: Passage of Poto-
mac through blue ridge: Wind gap of Delaware
river.
a. Tertiary partial-deposted from sea or
lakes-abouDd in fossils, some species of
which still lve-deductions.
Rocks formed in succession--order in which
animals were created--no remains of human
species except or skeletons in recent lime
stone.
.. Miner classes; /, Volcanic and Basaltic
IL, DeluYial and Alluvlal.
1. Ancient Volcanoes-Basaltic rocks very
Iirregularly deposited and at what time their o
Irigin.
2: Deluvial formed by deluges, and Alluvi
| al by rivers.
| Primitive Rivers onsidered-Granite: deep
est rock-its name how derived-3 Ingredient
Quartz, Feldspar Mica, form the top of mos
mountains Volcanic--Moun
Blanc assembled by Saussure with difficulty
prospect from it-Granite needles, and the ar
/ ruments founded on them--Granite used TO
| luilding--Roman Obelisks-Egyptian Pyra
lnids-Bunker-hilI monument.
Gneiss and Mica Slate-composition Of
only varieties of Granite:
i Primitive limestone: found in Delaware
forms statuary marble when hne-Serpantine
why SO called-found in Delaware-preciou
erpantine--Porphyry-o of its ingredient
! rystallized-very hard
II Transition Rocks-Slate--its uses for wri
lting, roofing, &C.. Slate mountains not so at
lrupt and barren as Granite-abounds in til
Observation-Disclosures.
: Grauwacke or Gray-wacke--composed {
!, fragments.
Il Transition Investigations some mour
! Itains in Europe--beautiful variegated marble
/ contains precious metals and tin. lead &c
j Caverns washed in it--subterraneous rivers
!, Swallow holes of acknowledgements the IT
mains of ANIMALS, in abundance.