Exploration of the Red River of Louisiana, in the year 1852 / by Randolph B. Marcy ; assisted by George B. McClellan. Page: 167 of 368
xv, 286 p., [65] p. of plates (1 fold.) : ill., maps ; 24 cm.View a full description of this book.
Extracted Text
The following text was automatically extracted from the image on this page using optical character recognition software:
APPENDIX D.--GEOLOGY.
151
From your description, especially in your leeture before the American
Geographical and Statistical Society, it is manifest that the character o
the rocks changes on the northwest of the gypsum formation, and near
the head of the south branch of Red river. The red clay and gypsum
have disappeared, and sandstone succeeds; but of what age I have no
means of judging.
Another interesting mineral found by you in the red clay and gypsum
formations above described, is copper. The specimens were put into
the hands of Professor Charles U. Shepard, who has analyzed them, as
well as several other specimens, in the laboratory of Amherst College
and whose report I annex to my own. You will see that he has made
free use of your name by attaching it to a new ore of copper, found on
Red river near the Witchita mountains; and that he describes three or
four other species of copper ore from the same region. For a particular
description I refer you to his report, while I confine myself to a few remarks
as to the geology of the deposite.
On section V, Dr. Shumard has shown the geological position of this
ore, viz: near the bottom of, and in the red clay, and more than one
hundred feet from the surface. We hence see that the ore was deposited
from water, although some specimens from Cache creek of calcareous
amygdaloid seem to have been melted. But if, as has been suggested,
the gypsum was produced by the joint action of submarine volcanoes
and water the copper may have had the same origin, and this would
explain the presence of chlorine in the Marcylite.
How much copper may be expected in such a region as that on Red
river, I have no means of judging, because I know of no analogous
formation. But as we have proof that it is an aqueous deposite, and
that igneous agency has been active not far off, it would not be
strange if the vicinity of the Witchita mountains should prove a prolific
locality.
The oxide of manganese described by Professor Shepard may, perhaps,
be found abundant and more pure. And the iron-sand, so common
in some of the creeks, indicates the existence of magnetic oxide of iron
in the mountains.
Whether the red clay formation and the gypsum formation that have
been described are of the cretaceous age or not, there can be no doubt
as to the deposites passed over from July 20 to Fort Washita, for among
the specimens are two species of Gryphcea, and one echinoderm, much
mutilated, but evidently of that period. On the 27th, a "bluish gray,
highly crystallized limestone" was observed, which cropped out beneath
the sandstone, and which Dr. Shumard says was " non fossil
Upcoming Pages
Here’s what’s next.
Search Inside
This book can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Book.
Marcy, Randolph Barnes. Exploration of the Red River of Louisiana, in the year 1852 / by Randolph B. Marcy ; assisted by George B. McClellan., book, 1854; Washington, DC. (https://texashistory.unt.edu/ark:/67531/metapth6105/m1/167/: accessed April 25, 2024), University of North Texas Libraries, The Portal to Texas History, https://texashistory.unt.edu; crediting UNT Libraries Special Collections.