Richmond dispatch. [volume] (Richmond, Va.) 1884-1903, 1899-11-26
THE RICHMOND BASIN.

Geology of the Richmond Basin" 10y
Nathaniel Southgate shaler and Jay
Backus Woodwork. is tho title OF on
extract from the nineteenth annual re-
port of the United states Survey. 1897 'gS.
Part II. and SIS just to- hand
This extract comes from the Govern
mcnt Printing once at Washington. IN
~ royal octave. PACED 3s7-5l9 and s. "A
pamphlet replete with beautiful illustra-
lions Of natural features and numerous
figures. II contains, also. two colored
maps The first one pictures a portion Of
the Midlothian District; the other IS q
preliminary geologic map Of the Rich-
mond area. Taken as a whole, the work
will be considered as q trustful contribu-
ton 90 the geological literature OF The
Richmond basin. 1t is understood chat
the reporters-Messrs. Shaler and Wood
worth-have famiiarized themselves with
the most remarkable features of this
basin by frequent visits TO it and a tenn
porary residence at one or the other of
it's salient points. Biologists Of admitted
eminonce had already observed this phe-
nomenal product of the middle geologic
age. and in making known their views.
laid as it were. no mean foundation for a
comparative study of their conclusions.
Little more than birds-eye view can
bo given by the writer of the geographi-
cal position Of the Richmond basin and
the topography of its area. These are
best expressed by the reporters who say
I Il fr.f
the former:
THE area described I'm this report lies
within the region known as the Piedmont
District, which forms the Atlantic face
~ the ancient Appalachian ranges This
| bench, as is well known, begins at the
eastward at line indicated by the falls.
or rapids, of many streams which how
into the Atlantic. having along this line
| an altitude OF about 100 feet, and rises
| thence in a gradual manner TO height
of 500 TO l,0oJ feet. when II meets the cs-
| carpment OF the Blue Ridge. This rise is
not perfectly uniform. but IS divided into
several indstinct steps. The Richmond
area lies on the eastern edge of this dis
| trict, on either side of the James river
| The total length Of the area in a nearly
north and south direction is thirty three
miles. and its maximum width is 9.5 miles.
| its area being about 100 square miles"
The topography Of the area is thus set
forth:
Although, geologically. a very evident
basin, having a maximum depth OF 5000
| feet the Richmond area has not a dis
| tinct Topographic character such as the
| geologist H. accustomed 10 associate with
mOuntain-built rocks. It's surface IS that
Of a roughened plain. or low table-land.
| which is somewhat intersected by the
| lesser streams and is divided by the rela-
! lively broad and deep gorge OF The James
river. The ancient GRANTEES and gneisses
| OF the periphery of the area, as well as
| the mum lous dikes within its limits are
| all worn down 10 about the same level
with the deposits OF the basin itself. The
| materials OF which are relatively more
liable 10 decay and erosion. only here
and there Is ii possible for even the
trained observer 10 trace any very cis-
| tinct topographic indications Of the con-
| tact between the sedimentarv deposits
contaired IN the trough and the igneous
and crystalline rocks Of the surrounding
country Except In certain rare local.
ties. the surface in no wise reveals their
! juxtapOsition.'
The economic importance OF the area
OF the Richmond basin will probably in
terest the general reader.
IT contains the only freely burnable