Alexander Winchell.

Geological excursions; or, The rudiments of geology for young learners online

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UNIVERSITY OF CALIFORNIA
LOS ANGELES




The RALPH D. REED LIBRARY

-c

DEPARTMENT OF GEOLOGY-
UNIVERSITY OF CALIFORNIA
LOS ANGELES, CALIF.



GEOLOGICAL EXCURSIONS;



OR,



THE RUDIMENTS OF GEOLOGY



FOR YOUNG LEARNERS.



BY ALEXANDER WINCHELL, LL.D.,

PROFESSOR OF GEOLOGY AND PALAEONTOLOGY IN THE UNIVERSITY OF MICHIGAN.

FORMERLY DIRECTOR OF THE GEOLOGICAL SURVEY OF MICHIGAN.

AUTHOR OF "SKETCHES OF CREATION," "WORLD LIFE,"

BTC., ETC.



Science-teaching should begin early in the school-course.

PRESIDENT ELIOT, Harvard University.



FiFTIl'E'DITYdN.



CHICAGO:
S. C. GRIGGS AND COMPANY.

1889.



COPYRIGHT, 1884,
JY S. C. GRIGGS AND COMPANY.



I KKISHT a LEONARD!"



CONTENTS.



PAGB
PREFATORY NOTE , 1

A WORD WITH THE TEACHER * 5

SOME PRACTICAL SUGGESTIONS &

STANDARD SAMPLES OF MINERALS AND ROCKS ... 11

EXCURSION L In the Garden.

ORGANIC AND INORGANIC 13

EXCURSION II. In the Garden and Field.

BOULDERS AND SAND 1&

EXCURSION III. To the Gravel Bank.

THE DRIFT 21

EXCURSION IV. To Another Gravel Bank.

SPRINGS AND WELLS . . . ...... 26

EXCURSION V. To Our Laboratory.

How THINGS ARE PUT TOGETHER 30

EXCURSION VI. To the Field.

QUARTZ 36-

iii






iv CONTENTS.

EXCURSION VII. To the Field

THE FELDSPARS 40

EXCURSION VIII. To the Field.

CALCITE 46

EXCURSION IX. To the Field,

THE MICAS, HORNBLENDE AND TALC 50

EXCURSION X. Among the Boulders.

QUARTZOSE ROCKS 54

EXCURSION 'SI. Among the Boulders.

MICACEOUS ROCKS 57

EXCURSION XIL With the Stone Cutter.

HORNBLENDIC ROCKS 62

EXCURSION XI II. To the Marble Yard.

CALCAREOUS ROCKS 69

EXCURSION XIV. To the Clay Pit and the Field.

ARGILLACEOUS ROCKS 74

EXCURSION XV. To the Specimen Drawers.

EXERCISES IN IDENTIFICATIONS 78

EXCURSION XVI. .By the Waterside.

SEDIMENTS 81

EXCURSION XVII. In the Gorge.

DECAY AND EROSION OF ROCKS 87



CONTENTS. V

EXCURSION XVIIL At the Rocky Ledge.

STRATA AND SYSTEMS OF STRATA 95

.EXCURSION XIX. To the Diagrams.

How THE STRATA ENWRAP THE EARTH .... 101

EXCURSION XX. To the Geological Map.

How TO UNDERSTAND A GEOLOGICAL MAP . . . 109

EXCURSION XXL To the Geological Map.

GEOLOGICAL SECTIONS 116

EXCURSION XXII. To the White Mountains.

THE Eozoic ROCKS 123

EXCURSION XXIII. To the Upper Mississippi.

CAMBRIAN (OR LOWER SILURIAN) ROCKS AND HISTORY 131

EXCURSION XXIV. To Niagara Falls.

SILURIAN ROCKS AND HISTORY 140

EXCURSION XXV. To Mackinac.

DEVONIAN ROCKS 146

EXCURSION XXVI. To Burlington, Iowa.

THE LOWER CARBONIFEROUS ROCKS 153

EXCURSION XXVII. To the Coal Mines.

THE COAL MEASURES 160

EXCURSION XXVIII. To Selma, Alabama.

THE MESOZOIC ROCKS ... 168



vi CONTENTS.

EXCURSION XXIX. To Claiborne, Alabama.

THE TERTIARY FORMATIONS ....... 173



EXCURSION XXX. TotheJtiver Valley.

QUATERNARY FORMATIONS ....... .178

EXCURSION XXXI. To Switzerland.

ABOUT GLACIERS ........... 185

EXCURSION XXXII. Through the Ages.

ABOUT THE PLANTS AND ANIMALS OF THE PAST . 191

QUESTIONS ON THE TEXT



PEEFATOEY



ADDRESSED TO TEACHERS AND SCHOOL OFFICERS.

THAT the elements of geology are so seldom taught either in
our primary or secondary schools is a circumstance to be
regretted. No tendency seems manifest toward any improvement
in this particular. -In Michigan, which enjoys a justly high repu-
tation for the excellence of its schools and teaching, even less
geology is studied in school than was customary a dozen years
ago. No knowledge whatever of this subject is required for
entrance into the University of Michigan in the " Classical
Course," nor in the " Scientific Course," nor in the so-called
" English Course " though in the last two courses the candidate
is given his option between preparation in Chemistry, Geology,
Zoology and Physiology. Of necessity, Physiology, which is
generally taught in the schools, is almost always the chosen sub-
ject, though next to this stands Chemistry. Practically, there-
fore, the study of geology in the University begins with the
elements in every course. A similar state of things exists in
most of our colleges. There is no course where geology is a
prerequisite, so that the student on entering may find himself in
position to push on to some advanced knowledge of the subject.
One would anticipate that a course specifically denominated
" Scientific," would demand a more extended scientific prepara-
tion than the old " Classical " course, and that a science which
has done as much for industry, civilization and culture as geology
has, would not fail to be enumerated among the requirements.

Since geology is not so required for entrance into college, it
has ceased to be taught in the schools as if geology had no



2 PREFATORY NOTE.

uses if not demanded as a preparation for college. This seems
to the present writer a greater mistake than the other. For
assuredly, the large majority of pupils, not expecting the oppor-
tunity for collegiate study of the science, have reason to com-
plain that they must be deprived altogether of the opportunity
to learn even the nature of the subject. When they enter upon
the affairs of adult life, and especially, if they mingle in the
intellectual life of the age, they find living questions agitating
the world, before which they must remain dumb and uninformed,
because their merits are rooted in the great facts of the earth's
history and the history of life.

Such life-long ignorance of geology is quite as unnecessary as
deplorable. The elements of the science are not a body of
principles difficult to master, nor encumbered with a greater
number of scientific terms than the sciences of physiology,
chemistry and botany. The data of geology, moreover, lie all
about us, and are the most obtrusive and noticeable of all the
objects which we daily encounter. Stones and rocks never fail
to awaken the curiosity of the boy or girl; and there are few
children who have not made collections of stones, distinguishing
their varieties by precisely the same characters as the most expert
student. Assuredly, it seems a dictate of educational philosophy
to take a hint from these childish predispositions and aptitudes,
and shape the child's education with some regard to what he
seems peculiarly fitted to study.

But, however appropriate and useful this study, where are the
teachers who will properly lead the pupil ? They are exceedingly
few in number. As geology is not taught in the schools, and as
nineteen-twentieths of our teachers have not studied it in college,
there is almost no preparation among the teachers of primary
and secondary grades to induct a pupil into an elementary knowl-
edge of the subject. In this state of the case, it would seem
very difficult to begin the desired improvement.

To the writer, the only hope of early reform seems to lie in
furnishing teachers with a text book so framed as to be capable



PEEFATOEY NOTE.

of successful use by a teacher without previous acquaintance
with the subject. Certainly, no such text books exist; for,
though there are several which might be employed by teachers
thoroughly disciplined by previous study, the large majority of
our teachers are not so disciplined, and it may not be necessary;
and these text, books, moreover, are too much conformed to the
dogmatic or didactic method telling about things which are far
away, or, if near at hand, are not identifiable by the aid of the
book. Due discrimination is not observed between those concep-
tions of the subject which are abstract and beyond the reach of
the young pupil, or older novice, and those which can be attained
through accessible concrete illustrations. Many of them are
good systematic presentations of the subject, but they are pro-
nounced " dry " and unintelligible. They are, in truth, too sys-
tematic and too complete.

The present author has pursued a fundamentally different
plan, and hopes he has prepared a primer of geology so simple
and so intelligible that no previous preparation of the teacher
will be needed. Hence any teacher who will pursue the method
will obtain an insight into the subject, and will be able, also, to
lead pupils of very tender years. One lesson which the author
has learned from much experience is here applied. The beginner,
especially if young, retains, as the result of his first course of
study in any subject, a surprisingly small amount of tangible and
available information. This is the author's first principle of pro-
cedure. His second is, to enlist the senses and the sentiments.
Hence the method is essentially inductive; the book speaks to
the pupil in the second person; it leads to the application of each
item of knowledge in some useful or interesting relation, and
seeks to awaken the thought of the learner.

More specifically, it directs a large amount of attention to the
pebbles and stones so abundant everywhere in the drift of the
northern states; and to the phenomena of sedimentation and
erosion everywhere accessible. From these most familiar illus-
trations, it passes to the phenomena of stratified rocks and the



4 PREFATORY NOTE.

way they are arranged upon the earth. Here much use is made
of maps and sections, as these train the learner to the indispen-
sable conceptions of superposition, succession, continuity and
discontinuity. Not much is said about purely systematic geology,
and still less about palaeontology and geological theory. These
divisions of the subject are more abstract and complicated, and
ought to be deferred till some familiarity is acquired with the
conceptions capable of illustration from familiar facts and
phenomena. Then much stress is laid upon the " Exercises."
These are not mere questions on the text. The answers to many
of the questions are only inferences from statements in the text.
Some are practical applications. Frequently the question leads
to an extension of knowledge. Some questions are asked which
will require considerable reflection some even, which cannot be
answered categorically. It is intended that the pupil shall keep
the question in mind, and search for the proper answer bv asking
his elders, by consulting books or by exploring in collections of
specimens. It is profitable to have something to ponder over.

There is not a great amount of science imparted. It is sur-
prising often discouraging, to observe how limited is the total
amount of exact knowledge acquired even by older students after
a more thorough course. It is also an interesting fact that a
very little knowledge, if it is fundamental, and fully mastered by
viewing it from all sides, will serve to answer a very large number
of common inquiries.- It is also true that a good deal of verbiage
is employed. Many sentences add nothing to the statement of
facts. They are intended simply to control attention and keep
alive the pupil's interest.

The very gist of the method is, that the pupil shall do all that
is indicated, and positively see every thing that is described, as
far as possible. Great efforts must be made to render this pos-
sible. Just so far as anything must be studied about, without
the opportunity to handle and examine it, and make drawings of
it, so far the pupil is unfortunate; so far the plan of the book is
not brought into practice.



A WORD WITH THE TEACHER. 5

A large part of these " Excursions " has been used in actual
trials by actual teachers, while yet in manuscript. The result
encourages' the hope that they may be found suited to the object
set forth, and may thus become instrumental in diffusing knowl-
edge and appreciation of a branch of science as accessible as any,
and as fruitful as any in results of high value in the industries
and culture of modern civilization.

This primer is, therefore, commended to the candid considera-
tion of teachers and school officers, in the hope that they already
feel the desirability of early instruction in geology, and may be
disposed to join with the author in testing the value of the method
which is here proposed.



A WORD WITH THE TEACHER.

Here, ladies, is a little book in which I hope you will be
interested. I address you, because nearly all the teachers of
those for whom the book is suitable are women; and also because
I have found women especially interested and apt in the studies
which are here introduced. The book is thought to be so simple
that it will literally " teach of itself," if you let it have its way.
So you need not be deterred from forming a little class in
" geology " in consequence of having geology omitted from your
own education. It is, I confess, too childish in style for your
own use as a learner ; but please consider that you are not the
pupil only so far as you may find it desirable to become a
pupil.

Now, please permit me to note concisely what seem to me
the points most essential in making this little book a success :

1. Positively do and have done everything indicated in the
text. Do not say some of these things are so simple or so
obvious that the doing would be a mere form. Probably some-
thing will turn up which you or your pupils could riot anticipate.



6 A WORD WITH THE TEACHER.

Do not be afraid to take hammers and collecting bags or baskets
into the garden or the field, and actually break the rocks and
study them and bring them home. No matter about keeping
quiet in this class. The very study requires talking and move-
ment. The novelty of the method and its conformity with the
impulses and instincts of the child's nature will assuredly make
it the favorite class of the school.

2. Should you happen to be located in a large city or upon
a prairie or other section of the country where boulders are not
easily accessible, the best recourse will be to a wagon load or
two of boulders brought from some boulder region and thrown
down in the school yard. These may be broken into moderate-
sized fragments by any man with a large-sized stone hammer.
All teachers, as a provision against rainy days, might have a
large lot of fragments placed under a shed. Even teachers in
states south of the boulder-covered regions of our country
might get a supply by the cheap help of a freight car from
the North.

3. A day or two before the class is taken on an " Excursion,"
read it over yourself so as to know what to expect, and be
prepared for its requirements. When the excursion is taken,
you may let every pupil carry a book; or if you think better,
only carry one yourself, and read aloud from it, giving the
pupils time to examine and think and respond.

4. Make yourself sure that every pupil sees and does and
understands everything which is required, and does the best he
can in answering all questions. Be deliberate enough to render
this possible. Sometimes the lesson will need to be divided.
With some classes it will be best to devote an hour to the
excursion proper, and then the " Exercises " may occupy the
time on the next day. This may be the best method with all
classes. Sometimes the whole must be twice gone over. In
almost every lesson the positions of localities mentioned will
have to be studied from the School Atlas.

5. Accustom yourself and your pupils to copying the figures



A WORD WITH THE TEACHER. 7

in the book; and practise still more in making drawings of
other things not figured, such as gravel banks, boulders, cliffs,
ravines, landscapes. Do not say, " I never took a lesson in
drawing," for the most finished draughtsmen were once in the
same situation. Try. Try again, and so continue. If you are
already somewhat practised in drawing, you will find your skill
extremely useful. The geological sections required, and the
other exercises on the geological map may be troublesome at
first, but no exercises can be more profitable.

6. Lay much stress on the "Jl/xercises," and invent addi-
tional ones. Some of them are merely intended to set pupil
and teacher to thinking and investigating. Some of the ques-
tions cannot be definitely answered. When a question is pro-
posed which you cannot answer at once, say so frankly. We
all have to confess ignorance. I think the " Exercises " will
awaken much interest. You will, of course, have to ask many
questions on the text and its subject matter; but these you will
frame for yourself or find at the end of the book.

?. -Adhere strictly to the method indicated in the book;
but vary the details according to the circumstances, and extend
the instruction and the observations according to your own
judgment.

8. Have every pupil collect, preserve and label specimens.
A good plan to pursue is the following: To each specimen
attach a little circular bit of white paper to receive the " school
number." Let each different species or variety of minerals and
rocks receive a separate number. Those which are the same
species or variety will receive the same number. In a little
book write the numbers, and the names of the specimens cor-
responding to them. Let each pupil also attach to each of his
own specimens, a little colored paper each pupil choosing
some different bright color; or, if the same color as that of
another pupil, let it be cut oval or square or diamond shaped;
so that each pupil's specimens can be picked out when all are
placed in a pile together. Have each pupil also keep a cata-



8 A WOED WITH THE TEACHEE.

logue. Then the number on the white ticket stuck to each of
his specimens will give the name of the specimen as soon as
he refers to his list. You will find, a little beyond, some
practical directions for this work.

9. Use other specimens additional to those collected by the
class if it is possible to do so. By this means you will get
for study more species and varieties. There may be some
small, neglected collections or single specimens in your neigh-
borhood, lying on dusty mantels, what-nots and 6tageres. Look
them up and press them into service. I am sure you will find
many sorts which are not mentioned in this little book, because
the book mentions the most common things, which it is most
important to know something about; while people generally
seek to lay up rare things from distant regions. But use all
that you can. Besides this, there ought to be a small labelled
collection obtained from some reliable dealer, furnishing true
examples of the more common minerals and rocks. Such a
collection can be purchased for two or three dollars, or a
better one for five dollars.

All that may be learned by the aid of this little book will
only conduct the pupil over the threshold of the subject. But
even so much may be made highly interesting and indeed very
useful. Beyond this threshold are departments of the subject
not mentioned here, and a whole range of ideas and conclusions
about the history of the world, and of other worlds, which would
not be appropriate here, but which, nevertheless, are extremely
fascinating to the student, and tend greatly to enlarge and
ennoble his intelligence.

Now, I wish to feel in communication with all the teachers
who try to use this primer. Please exercise the freedom to
write on any point which you think may require further eluci-
dation from the author.

ALEXANDER WINCHELL.

UNIVERSITY OF MICHIGAN,
ANN ARBOR.



SOME PRACTICAL SUGGESTIONS.



FOR STUDENTS OF ALL GRADES.

1. Hammers and some other instruments best suited for
breaking and studying rocks are described in Excursions VI
and VII.

2. For making the little circular or oval tickets, white or
colored, a saddler's or tinner's " punch " is suitable. One which
will cut tickets three-sixteenths of an inch in diameter is large
enough for small specimens. If many tickets stick together as
they come from the punch, place a lot in one hand and rub them
with the fingers of the other hand. Fold the paper so as to
punch through several thicknesses at each blow. Use a thin
quality of paper.

3. For attaching the tickets do not use common mucilage,
but prepare a cement as follows:

Clear Gum Arabic, 2 oz.

Fine Starch, U oz.

White Sugar, i oz.

Rub them together in a mortar; add as much water as the laun-
dress would use for that amount of starch, and wait till the gum
arabic is well dissolved; then cook the solution in a vessel sus-
pended in boiling water until the starch becomes clear. The
cement must be nearly as thick as tar. Keep it in a wide-
mouthed bottle stoppered by a cork having a small round bristle
brush passing through it. Drop in a small lump of gum camphor
to prevent souring and mouldiness. It will keep a year or more.
When too much dried away add a little water. This cement is
strong, and is good for repairing breakages of specimens, and
also for attaching specimens to cards for exhibition.



10 SOME PRACTICAL SUGGESTIONS.

4. When many specimens are to be ticketed at once, spread
them on a table and touch each one in a proper place with the
tip of the brush, leaving a little cement, but not too much,
Spread a quantity of well separated tickets on the table; moisten
the tip of your finger on the tongue or a damp towel, and pick up
a ticket and press it firmly on one of the gummed spots; then,
as some of the cement probably adheres to your finger, remove
it on your tongue or the damp towel, and pick up another ticket
and attach it in the same way. This method is rapid. After
a half hour the tickets will be dry enough to receive the num-
bers. Use only the blackest and best ink in writing them, with
a fine-pointed steel pen, and make the figures perfect as possible.

5. Good cabinet rock specimens are generally dressed to a
rectangular shape if possible. For a school cabinet they may be
about two and a quarter by three inches square, and one or two
inches thick. But it is better to have a shapeless specimen than
none at all. Most of the pupils will probably be suited with
mere fragments. But in all cases, some approach may be made
to the standard form. Mere minerals must be preserved as
we can get them. When a specimen is reduced nearly to the
requisite size, the trimming may be best done while holding the
specimen in the left hand and striking a quick blow with a light
hammer, so as to chip off small pieces. Remember, the sharper
the blow, the less liable is the specimen to shatter. The last of
the dressing may be done by striking the specimen square on the
edge. This is especially practicable with quartzose and all crys-
talline rocks. Fossils should be worked out of the rock with
hammer and chisels and other appropriate tools, or at least the
adhering rock should be as much removed as possible.

6. When specimens are to be boxed for transportation, wrap
each separately in paper, and use enough packing material of
paper, hay or straw, to prevent rubbing against each other.
Always fill the box as full as possible. If the specimens will
not do it, use waste paper, sawdust or anything even fine
chips to fill all the empty spaces.



STANDARD SAMPLES OF MINERALS AND ROCKS.

[To illustrate Winchell's "Geological Excursions."]

The whole list forms "Collection No. 1." The list omitting the
starred names forms " Collection No. 2."



1. Quartz (at least one crystal with

termination).

2. Chalcedony or Agate.

3. Red Jasper.

4. Hornstone or Chert.

5. Orthoclase, showing crystalline

form.

6. Labradorite.

7. *Albite, or at least some third

feldspar.

8. Muscovite (common mica), show-

ing crystalline form.

9. Hornblende. Dark variety, show-

ing crystalline form.

10. *Actinolite.

11. Augite, common variety, show-
ing crystalline form.

12. Talc, foliated variety.

13. Calcite, rhombohedral and dog-
tooth varieties.

14. *Pyrites.

15. *Selenite.

16. *Hematite.

17. *Magnetite.

18. *Limonite.

19. Quartzite, vitreous.

20. Quartzite, granular.

21. Quartzose Conglomerate.

22. Sandstone, gray.

23. *Sandstone, red.

24. Granulite (Quartz and Feldspar).

25. Granite (Quartz, Feldspar and
Mica), strictly unstratifled.



26. Gneiss, distinctly stratified.

27. Mica Schist.

28. Hydromica Schist,

29. Hornblende Rock (Amphibolite).

30. Hornblende Schist.

31. Syenite (Quartz, Feldspar and
Hornblende) strictly unstratified.

32. Syenitic Gneiss, distinctly strati-
fied.

33. Hyposyenite (Orthoclase and
Hornblende).

34. Diorite (Plagioclase and Horn-
blende).

35. Diabase (Plagioclase and Augite).

36. *Dolerite.

37. *ModernLava.

38. *Epidote Rock (or Epidotic
Rock).

39. *Talc Rock or Steatite.

40. Serpentine.

41. Argillite or Slate.

42. Shale, argillaceous.

43. *Kaolin.

44. *Petrosilex (Cryptocrystalline,
Quartz and Orthoclase).

45. Felsite (Cryptocrystalline, Quartz
and Plagioclase).

46. Porphyritic Rock.

47. *Marl.

48. Common Limestone, with Fos-
sils.


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Online LibraryAlexander WinchellGeological excursions; or, The rudiments of geology for young learners → online text (page 1 of 15)