Copyright
James W. (James William) Head.

History and comprehensive description of Loudoun County, Virginia [electronic resource] online

. (page 4 of 15)
Online LibraryJames W. (James William) HeadHistory and comprehensive description of Loudoun County, Virginia [electronic resource] → online text (page 4 of 15)
Font size
QR-code for this ebook


planes to the folds can not be discovered.



44 HISTORY OF

Parallel with the micas that cause the schistosity, the
growth of the quartz and epidote lenses took place. These,
too, have been deformed by crushing and stretching along
Bull Run Mountain and the south part of Catoctin Mountain.
From this fact, taken in connection with the folding of the
schistose planes at Point of Rocks, it would appear that the
deforrdation was not a single continuous effort.

The ratios of schistose deformation in the igneous rocks are
as follows: diabase, with unstable mineral composition and
small mechanical strength, has yielded to an extreme degree;
granite, with stable composition and moderate mechanical
strength, has yielded to the more pronounced compression.



MINERAL AND KINDRED DEPOSITS.

In point of mineral wealth I^oudoun ranks with the foremost
counties of the State. Iron, copper, silver, soapstone, asbes-
tos, hydraulic limestone, barytes, and marble are some of the
deposits that have been developed and worked with a greater
or lesser degree of success.

A large bed of compact red oxide of iron lies at the eastern
base of the Catoctin Mountain, on the margin of the Potomac
River. I


1 2 4 6 7 8 9 10 11 12 13 14 15

Online LibraryJames W. (James William) HeadHistory and comprehensive description of Loudoun County, Virginia [electronic resource] → online text (page 4 of 15)