Brownsville herald. [volume] (Brownsville, Tex.) 1910-current, 1924-08-15
Is 1t "Delta"
---Of-.-
Is 1t "Valley?"


under the mistaken impression that The
Herald is attempting TO foist a new
name upon this section; that is, 70 call
IL "Rio Grandc Delta" instead Of Low
er Rio Grande Valley"
The Herald has endeavorcd all along
TO make clear the fact that il has mere
" placed this matter a bit prominently
before its readers for their considera-
tion. only as a suggestion. II its sug
gestion has done nothing else, it a,
least has brought forth a number Of in.
teresting letters on the subject, among
the most interesting of which is one by
Dr. J. J.. Workman Of Brownsville. geo
logist and mining engineer, formerly r
professor in oae Of the country's great
est universities. and man OF many col
ltRe degrees.
Other letters have been received by
The Herald. and they will appear from
time to time. IN the meantime. If any
other reader has a thought on the sub
ject. The Herald will be glad TO receive
il.
DR.. Wortman's letter follows:
To the Editor of The Herald:
have been considerably interested in
the discussion that has been going on in
your paper for severak days past, in re
gard TO whether this immediate vicinity
In which we live, Is to be called the
Lower Rio Grande Valley or the RIO
Grande Delta. What I shall here say
does not take into consideration hy wha'
name the region may have been pre-
viously known 70 either Indians. Mex
leans or whites, or whether il has ac-
quired a trade name" which il would
be wise or unwise to attempt to change.
shall limit myself simply TO the facts.
Sinoe the whole matter turns upon
what valley is. and what delta is, as
usually employed and understood by the
geographer or the gcologist. il woulf
seem to me that il can be quickly dis
posed of. To the geologst. a river val
ley is longitudinal depression. result,
ing from erosion or otherwise, occupied
by a river. with higher land upon eitn-
er side Of it. rising either by a grad
nal slope. abrupt hills. or bordercd by
bluffs or escarpmonts. 1t may vary
much in width, and IL frequently divid
ed into terraces, benches or levels.
which. under normal conditions. always
present definite slope towards the
stream bed. We are thus cften enabled
TO distinguish a first or lower bottom.
second bottom or even a third bottom
in many valleys. 1t likewise happens
that river in its course frequently en-.
ters canyon. in which the bordering
higher land upon either side comes
abruptly TO the edge Of the water and
the more or less level stretches Of land
upon either side Of the stream com
pletely disappear. In all such eases
the valley above the canyon is termed
the upper valley" and that below the
canyon is called the "lower valley"
A delta, on the other hand. is a more
or less level stretch Of land found
where a river enters a lake, gulf or sea,
and results from the gradual accumula.
tion Of silt or sediment brought down
by the stream and spread out on the
bottom Of the lake or gulf into which IL
mouths, until the mass is built up into a
dry land plain. Such plain il then spok-
en- Of as a delta plain for the reason
that IL has been formed BY the accumu.
latian of the sediments Of the delta. The
term delta" il may be remarked in
passing takes its name from the Greek
letter ID, which IL a perfect triangle
the head Of the delta being represented
by thu apex Of the triangle. and the foot
of the delta by the base Of the triangle
When a river arrives az its final dcs-
tination and begins to form delta
plain. il l. said to have reached "bas-
level" and one Of the high characterist-
les Of such stream. as il proceeds
through the plain thus formed. is tha,
IL becomes exceedingly tortuous ard be-
gins TO build up its bed higher than the
surrounding land. This results from
the sudden decrease in the slope of the
stream bed. and the difficulty il has in
discharging its load Of sediment. For
this reason, especially in flood time. the
usual channel OF exit Is insufficient or
unable to carry off the flood waters
fast enough, and as result additional
outlets are formed on either side Of the
main channel and then the whole stream
spreads out fan-wiso. discharrinr BY
many mouths Thus the delta" as
above stated is formed
With this understanding before us.
what does one find upon careful cxami-
nation Of the region around about tho
mouth OF the Rio Grandc? The first
thing 10 be noted is that it consists or
broad. almost level pIain. with de-
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