Evening star. [volume] (Washington, D.C.) 1854-1972, 1891-08-28
TIE GEOLOGICAL CONGRESS.


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THE QUESTION OF CORRELATION II GEOLOGICAL
FORMATION DBcrsskp AT LkxoTu-Pnors.
GILBERT, MARSH, zrrrKL AND BARON De Gkkn
PARTICIPATING IN THE DEBATE.
The main lecture hall Of Columbian Univer-
sity was again this morning crowded with dis
tinRuished scientists from all portions of the
globe, wearing pretty little medalious fastsns 4
with bright red ribbons and inscribed
with the legends Of the International
congress Of geolosists. II may be Of inter-
est to know that this congress contains
delegates from the following countries: United
States. Austria, Belgium. Chilli, France, Mexico.
Peru. Roumania, Russia. Switzerland. Canada,
Germany. Great Britain and Sweden. The
work Of the congress, il will therefore be seen,
has most wide-spreading influence and the
results reached at these congresses are accepted
as authority by geolosists the world over.
PLErsTocESK CLASSIFICATION.
Al stated in The STAR yesterday afternoon,
the dfscussion OF a classification Of pleistocene
formation was continued and the general adj
vantsges OF the genetic or chronological CLASH
hcation discussed.
DIR. MCGEE of this city proposed a classifica-
ZION OF all pleistocsHe deposits, with five gem
erai heads: A. AqueOn. at base level, above
base level B. Glacial. direct and indirect. G..
Aqueo-glacial. ID. Eolic. E. Volcanic, direct
and indirect.
Vice President lie Conte again presided at
the morning session today. The secretary of
the Congress before the session commenced
made several statements. He made the state
ments first in English and afterward in French.
Inc Appalachian excursion, he said, had been
given up, while tickets for the Potomac excur-
sion were ready for distribution.
CORRELATION IN GEOLOGICAL Forms.
The question for discussion today was on cor
relation in geological forms and the question
was opened by Mr.. G. X. Gilbert of the geo.
logical survey, who has made this question a
subject Of great thought and who recently has
published a mastery paper on the subject.
Mr.. Gilbert said he had only recently been
informed OF the necessity for his opening. the
discussion. He thought the scientists from
abroad should bear the main brunt Of the
fight In regard to classification OF de
posts. He referred first to local methods.
then stepped in. Physical continuity was a
means of correlation and perhaps the best
method. There were, however. limitations to
this method Traces we're rarely possible for
great distances. Indirect methods must be
resorted to. Beds of similar ithologic fOrma-
tion could be construed as chronoiogically
similar.
Another method referred to the sequence
with which the deposits we're laid. Layers
following in sequence In different localities ar
gued the same conditions. Limitations OF large
extent, however, must be put on both these
methods.
PHYSICAL BREAKS.
Physical breaks afforded fourth method for
correlation. The limitation here would prob
ably be distance. Simultaneous relations of
bod 10
method OF correlation. This method has been
found useful, both at Salt Lake and on the
Atlantic coast The relation of deposits
to some geological climate, said Mr..
Gilbert, often affords means fer correlation.
Another physical method Of correlation, ac-
cording to the speaker. arose from similar
physical changes. The similar action of gases
In different beds showed chronological SINH
larity. This method, however, was largely
limited by local climatic changes. The physi-
cal methods mentioned above were all valuable
at short range. but Of little use at long range.
FLORA AND ANIMAL CLASSIFICATION.
Mr. Gilbert then referred to more Theoretical,
and perhaps more accurate methods of classif-
cation, taking the fora and animal life into
question. the first being what he termed
matching by species. as a lady would match a
piece OF cloth IN dry goods store.
divergence from status at q fixed date
affords method of correlation of great benefit
in the newer spec es.
The relation to the fauna contained in the
deposits to climate affords another method.
The last few methods all have relation to the
Gilbert gave in q few words few Of the limita-
tons.
In regard to the value of fossils in correla-
ton Mr.. Gilbert laid down the proposition that
the value Of species for this purpose was
greatly dependent on the length Of its life and
m ga of in II ~,
back making the correlation vague.
TWO GERMAN PROFESSORS
The discussion was then taken up by Prof
Won Attell Of the University at Munich. who
devoted his attention to the methods Of cor
relation by plants and animals. He did not
think the method by plants at all accurate In
animals he thought the land animals most valu-
able in correlation and spoke Of the difficulty of
correlation in some countries where vertebrate
animals were not found in many of the de-
posits.
The discussion was continued in the same
line by Baron Gerard de Geer.
PROF.. MARSH OF YALE.
Prof. Othniel c. Marsh. the well-known pro-
lessor Of geology at Yale. followed briefly
Prof. Marsh Is a thick-set man with q good
looking English cast Of countenauce.
Prof. Marsh described difficulties he had had
In the Rocky mountains in endeavorinG TO cor
relate by fossils. He agreed with the other
speakers that vertebrate animals afforded the
best and most accurate material for correla-
ton.
Referring to the Rocky mountains Prof
Marsh remarked that every one knew that
there were to be found the greatest and most
beautiful geological SUGGESTIONS to be found
In the world. He referred to a classification
he had made taking the Rocky mountains as q
starting point. The mollusks and invertebrates
Afforded no definite information. Lately. said
Mr.. Marsh, some lucky discoveries in several
series of rocks Of vertebrate animals had been
OF immense value in tho correlation of deposits.
He gave descriptions Of some OF the marvellous
animals whose existence had lately been clearly
proved by the discovery OF fossil forms.
At this point the congress took q recess for
lunch and this afternoon continued the dis
cussion on the same question.
This evening the National Museum will be
open to members Of the congress for an in
spection of the collections
ToMoRnows OUTING
On Sunday number Of the members Of the
congress will go on an all-day excursion down
the river to view the geologic formations and
also spend pleasant day.
AN EXTENDED TRIP WEST.
How the Foreign Biologists win He Enter.
tanned Alter the Congress Closes.
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