═══════════════════════════════════╤═════════════╤═════════════
Present American classification │Conybeare and│ C. & P.
│Phillips 1822│ orders
───────────────────────────────────┼─────────────┼─────────────
│ │ Superior
Psychozoic or Recent │Alluvial │ Order
│ │
───────────┬───────────────────────┼─────────────┼─────────────
Cenozoic │Pleistocene │Diluvial │ „
│ │ │Upper Marine │
│ │ │ formation │
│ │ │ (Crag, │
„ │Pliocene │Neogene │ Bagshot │ „
│ │ │ sand, and │
│ │ │ Isle of │
│ │ │ Wight) │
„ │Miocene │ „ │ „ │ „
„ │ │Fresh-water │ „
│ │ formations │
„ │Oligocene │Paleogene │London Clay │ „
„ │Eocene │ „ │Plastic Clay │ „
───────────┼────────────┴──────────┼─────────────┼─────────────
│ │ │
│ │ │ Supermedial
Mesozoic │Cretaceous │Chalk │ Order
│ │ │
│ │ │
│ │Beds between │
│ │ Chalk and │
│ │ Oolite │
│ │ Series │
„ │Comanchian 1887 │ (Chalk │ „
│ │ Marle, │
│ │ Green Sand,│
│ │ Weald Clay,│
│ │ Iron Sand) │
───────────┼───────────────────────┼─────────────┼─────────────
│ │Upper Oolitic│
│ │ division │
│ │ (Purbeck │
„ │Jurassic 1829 │ beds, │ „
│ │ Portland │
│ │ Oolite, │
│ │ Kimmeridge │
│ │ Clay) │
│ │Middle │
│ │ Oolitic │
„ │ „ │ division │ „
│ │ (Coral Rag,│
│ │ Oxford │
│ │ Clay) │
│ │Lower Oolitic│
│ │ division │
│ │ (Cornbrash │
│ │ Stonesfield│
│ │ Slate, │
│ │ Forest │
│ │ Marble, │
„ │ „ │ Great │ „
│ │ Oolite, │
│ │ Fullers’ │
│ │ Earth, │
│ │ Inferior │
│ │ Oolite, │
│ │ Sand and │
│ │ Marlestone)│
„ │ „ │Lias │ „
───────────┼───────────────────────┼─────────────┼─────────────
„ │Triassic 1834 │New Red │ „
│ │ Sandstone │
───────────┼───────────────────────┼─────────────┼─────────────
Paleozoic │Permian 1841 │Magnesian │ „
│ │ Limestone │
───────────┼───────────────────────┼─────────────┼─────────────
│ │ │ Medial or
„ │ │Coal Measures│Carboniferous
│ │ │ Order
„ │Pennsylvanian 1891 │ │ „
│ │Millstone │
„ │Mississippian 1869 │ Grit and │ „
│ │ Shale │
„ │ │Old Red │ „
│ │ Sandstone │
„ │Devonian 1839 │ │ „
───────────┼───────────────────────┼─────────────┼─────────────
│ │Unresolved │
│ │ Submedial │
„ │Silurian 1835 │ and │
│ │ Inferior │
│ │ Orders │
„ │Ordovician 1879 │ „ │
„ │(=Lower Silurian 1835) │ „ │
„ │Cambrian 1833 │ „ │
───────────┼────────────┬──────────┼─────────────┼─────────────
Proterozoic│Keweenawan │Huronian │ „ │
│ │ 1852 │ │
„ │Animikian │ „ │ „ │
„ │Huronian │ „ │ „ │
„ │Sudburian │ „ │ „ │
───────────┼────────────┼──────────┼─────────────┼─────────────
Archeozoic │Keewatin │Laurentian│ „ │
│ │ 1853 │ │
„ │Coutchiching│ „ │ „ │
───────────┴────────────┴──────────┴─────────────┴─────────────
═══════════════════════════════════╤══════════╤════════════
Present American classification │Wernerian │ Other
│ orders │ writers
───────────────────────────────────┼──────────┼────────────
│ Newest │ Tertiary
Psychozoic or Recent │ Floetz │ Class
│ Class │
───────────┬───────────────────────┼──────────┼────────────
Cenozoic │Pleistocene │ „ │ „
│ │ │ │
│ │ │ │
│ │ │ │
„ │Pliocene │Neogene │ „ │ „
│ │ │ │
│ │ │ │
│ │ │ │
„ │Miocene │ „ │ „ │ „
„ │ │ „ │ „
│ │ │
„ │Oligocene │Paleogene │ „ │ „
„ │Eocene │ „ │ „ │ „
───────────┼────────────┴──────────┼──────────┼────────────
│ │Primitive │ Primitive
│ │Transition│Intermediate
Mesozoic │Cretaceous │and Floetz│ and
│ │ Classes │ Secondary
│ │ │ classes
│ │ │
│ │ │
│ │ │
│ │ │
„ │Comanchian 1887 │ „ │ „
│ │ │
│ │ │
│ │ │
│ │ │
───────────┼───────────────────────┼──────────┼────────────
│ │ │
│ │ │
│ │ │
„ │Jurassic 1829 │ „ │ „
│ │ │
│ │ │
│ │ │
│ │ │
│ │ │
│ │ │
„ │ „ │ „ │ „
│ │ │
│ │ │
│ │ │
│ │ │
│ │ │
│ │ │
│ │ │
│ │ │
│ │ │
│ │ │
„ │ „ │ „ │ „
│ │ │
│ │ │
│ │ │
│ │ │
│ │ │
│ │ │
│ │ │
„ │ „ │ „ │ „
───────────┼───────────────────────┼──────────┼────────────
„ │Triassic 1834 │ „ │ „
│ │ │
───────────┼───────────────────────┼──────────┼────────────
Paleozoic │Permian 1841 │ „ │ „
│ │ │
───────────┼───────────────────────┼──────────┼────────────
│ │ │
„ │ │ „ │ „
│ │ │
„ │Pennsylvanian 1891 │ „ │ „
│ │ │
„ │Mississippian 1869 │ „ │ „
│ │ │
„ │ │ „ │ „
│ │ │
„ │Devonian 1839 │ „ │ „
───────────┼───────────────────────┼──────────┼────────────
│ │ │
│ │ │
„ │Silurian 1835 │ „ │ „
│ │ │
│ │ │
„ │Ordovician 1879 │ „ │ „
„ │(=Lower Silurian 1835) │ „ │ „
„ │Cambrian 1833 │ „ │ „
───────────┼────────────┬──────────┼──────────┼────────────
Proterozoic│Keweenawan │Huronian │ „ │ „
│ │ 1852 │ │
„ │Animikian │ „ │ „ │ „
„ │Huronian │ „ │ „ │ „
„ │Sudburian │ „ │ „ │ „
───────────┼────────────┼──────────┼──────────┼────────────
Archeozoic │Keewatin │Laurentian│ „ │ „
│ │ 1853 │ │
„ │Coutchiching│ „ │ „ │ „
───────────┴────────────┴──────────┴──────────┴────────────
_Early Geology in Philadelphia._—The oldest scientific society is the
American Philosophical Society of Philadelphia, started by the
many-sided Benjamin Franklin in 1769, and which has published since
1771. Up to the time of the founding of the Journal in 1818, there had
appeared in the publications of this society thirteen papers of a
geologic nature, nearly all small building stones in the rising geologic
story of North America. The only fundamental ones were Maclure’s
Observations of 1809 and 1817. Later, in this same city, there was
organized another scientific society that came to be for a long time the
most active one in America. This was the Academy of Natural Sciences,
started in 1812 with seven members, but it was not until 1817 and the
election of William Maclure as its first president that the work of the
Academy was of a far-reaching character. Here was built up not only a
society for the advancement of the natural sciences and publications for
the dissemination of such knowledge, but, what is equally important, the
first large library and general museum.
William Maclure (1763–1840), correctly named by Silliman the “father of
American geology,” was born and educated in Scotland, and died near
Mexico City. A merchant of London until 1796, when he had already
amassed “a considerable fortune,” he made a first short visit to New
York City in 1782. In 1796 he again came to America, this time to become
a citizen of this country and a liberal patron of science.
About 1803, single-handed and unsustained by government patronage,
Maclure interested himself most zealously and efficiently in American
geology. In 1809 he published his Observations on the Geology of the
United States, Explanatory of a Geological Map. This work he revised “on
a yet more extended scale,” issuing it in 1817 with 130 pages of text,
accompanied by a large colored geological map.
_Silliman, the Pioneer Promoter of Geology._—In 1806 when Benjamin
Silliman (1779–1864) began actively to teach chemistry and mineralogy,
all the sciences in America were in a very backward state, and the earth
sciences were not recognized as such in the curricula of any of our
colleges. Silliman gave his first lecture in chemistry on April 4, 1804.
In the summer of that year, Yale College asked him to go to England to
purchase material for the College, and great possibilities for
broadening his knowledge now loomed before him. As Silliman himself
(=43=, 225, 1842) has told the interesting story of his sojourn in
England and Scotland, it is worth while to restate a part of it here.
“Passing over to England in the spring of 1805, and fixing my
residence for six months in London, I found there no school, public or
private, for geological instruction, and no association for the
cultivation of the science, which was not even named in the English
universities.” In geology “Edinburgh was then far in advance of
London.... Prof. Jameson having recently returned from the school of
Werner, fully instructed in the doctrines of his illustrious teacher,
was ardently engaged to maintain them, and his eloquent and acute
friend, the late Dr. John Murray, was a powerful auxiliary in the same
cause; both of these philosophers strenuously maintaining the
ascendancy of the aqueous over the igneous agencies, in the geological
phenomena of our planet.
On the other hand, the disciples and friends of Dr. Hutton were not
less active. He died in 1797, and his mantle fell upon Sir James Hall,
who, with Prof. Playfair and Prof. Thomas Hope, maintained with signal
ability, the igneous theory of Hutton. It did not become one who was
still a youth and a novice, to enter the arena of the geological
tournament where such powerful champions waged war; but it was very
interesting to view the combat, well sustained as it was on both
sides, and protracted, without a decisive issue, into a drawn
battle....
The conflicts of the rival schools of Edinburgh—the Neptunists and the
Vulcanists, the Wernerians and the Huttonians, were sustained with
great zeal, energy, talent, and science; they were indeed marked too
decidedly by a partisan spirit, but this very spirit excited untiring
activity in discovering, arranging, and criticising the facts of
geology. It was a transition period between the epoch of geological
hypotheses and dreams, which had passed by, and the era of strict
philosophical induction, in which the geologists of the present day
are trained....
I was a diligent and delighted listener to the discussions of both
schools. Still the igneous philosophers appeared to me to assume more
than had been proved regarding internal heat. In imagination we were
plunged into a fiery Phlegethon, and I was glad to find relief in the
cold bath of the Wernerian ocean, where my predilections inclined me
to linger.”
_Silliman’s Students and Their Publications._—Silliman’s first student
to take up geology as a profession was Denison Olmstead (1791–1859),
educator, chemist, and geologist, who was graduated from Yale in 1813.
Four years later he was under special preparation with Silliman in
mineralogy and geology, and in that year was appointed professor of
chemistry in the University of North Carolina. In 1824–1825 Olmstead
issued a Report on the Geology of North Carolina, which is the first
official geological report issued by any state in America, “a
conspicuous and solitary instance,” according to Hitchcock’s review of
it (=14=, 230, 1828), “in which any of our state governments have
undertaken thoroughly to develop their mineral resources.”
Amos Eaton (1776–1842), lawyer, botanist, surveyor, and one of the
founders of American geology, was a graduate of Williams College in the
class of 1799. He studied with Silliman in 1815, attending his lectures
on chemistry, geology, and mineralogy. He also enjoyed access to the
libraries of Silliman and of the botanist, Levi Ives, in which works on
botany and materia medica were prominent, and was a diligent student of
the College cabinet of minerals. He settled as a lawyer and land agent
in Catskill, New York, and here in 1810 he gave a popular course of
lectures on botany, believed to have been the first attempted in the
United States.
In 1818 appeared Eaton’s first noteworthy geological publication, the
Index to the Geology of the Northern States, a text-book for the classes
in geology at Williamstown. The controlling principle of this book was
Wernerism, a false doctrine from which Eaton was never able to free
himself. This book was “written over anew” and published in 1820.
While at Albany in 1818, Governor De Witt Clinton asked Eaton to deliver
a course of lectures on chemistry and geology before the members of the
legislature of New York. It is believed that Eaton is the only American
having this distinction, and because of it he became acquainted with
many leading men of the state, interesting them in geology and its
application to agriculture by means of surveys. In this way was sown the
idea which eventually was to fructify in that great official work: The
Natural History of New York. (See =43=, 215, 1842; and Youmans’ sketch
of Eaton’s life, Pop. Sci. Monthly, Nov. 1890.)
Edward Hitchcock (1793–1864), reverend, state geologist, college
president, and another of the founders of American geology, was largely
self-taught. Previous to 1825, when he entered the theological
department of Yale College, he had met Amos Eaton, who interested him in
botany and mineralogy, and between 1815 and 1819 he had made lists of
the plants and minerals found about his native town, Deerfield,
Massachusetts. Therefore, while studying theology at Yale it was natural
for him also to take up mineralogy and geology with Silliman, whose
acquaintance he had made at least as early as 1818.
Hitchcock, who was destined to be one of the most prominent figures of
his time, was appointed in 1825 to the chair of chemistry and natural
history at Amherst College. His first geologic paper, one of five pages,
appeared in 1815. Three years later appeared his more important paper on
the Geology and Mineralogy of a Section of Massachusetts, New Hampshire,
and Vermont (=1=, 105, 436, 1818). This is also noteworthy for its
geological map, the next one to be published after those of Maclure of
1809 and 1817. In 1823 came a still greater work, A Sketch of the
Geology, Mineralogy, and Scenery of the Regions contiguous to the River
Connecticut (=6=, 1, 200, 1823; =7=, 1, 1824). Here the map above
referred to was greatly improved, and the survey was one of the most
important of the older publications.
Youmans in his account of Hitchcock (Pop. Sci. Monthly, Sept. 1895)
says:
“The State of Massachusetts commissioned him to make a geological
survey of her territory in 1830. Three years were spent in the
explorations, and the work was of such a high character that other
States were induced to follow the example of Massachusetts.... The
State of New York sought his advice in the organization of a survey,
and followed his suggestions, particularly in the division of the
territory into four parts, and appointed him as the geologist of the
first district. He entered upon the work, but after a few days of
labor he found that he must necessarily be separated from his family,
much to his disinclination. He also conceived the idea of urging a
more thorough survey of his own State; hence he resigned his
commission and returned home. The effort for a resurvey of
Massachusetts was successful, and he was recommissioned to do the
work. The results appeared in 1841 and 1844.”
Oliver P. Hubbard was assistant to Silliman in 1831–1836, and then up to
1866 taught chemistry, mineralogy, and geology at Dartmouth College.
James G. Percival was graduated at Yale in 1815, and in 1835 he and C.
U. Shepard of Amherst College were appointed state geologists of
Connecticut. Their report was issued in 1842.
James Dwight Dana (1813–1895) was undoubtedly the ablest of all of
Silliman’s students. Graduated at Yale in 1833, he spent fifteen months
in the United States Navy as instructor in mathematics, cruising off
France, Italy, Greece, and Turkey. In 1836 he was assistant to Silliman,
and in 1837, at the age of twenty-four years, he published his widely
used System of Mineralogy. Two years later Dana joined the Wilkes
Exploring Expedition as mineralogist, returning to America in 1842; his
geological results of this expedition were published in 1849. In 1863,
during the Rebellion, he published his Manual of Geology, and through
four editions it remained for forty years the standard text-book for
American geologists.
_First American Geological Society._—The founding in 1807 of the
Geological Society of London, the parent of geological societies,
undoubtedly had its stimulating effect on Silliman, and with his marked
organizing ability he began to think of forming an American society of
the same kind. This he brought about the year following the appearance
of the Journal, that is, in 1819. The American Geological Society, begun
in 1819 (=1=, 442, 1819), was terminated in 1830 (=17=, 202, 1830). The
first meeting (September 6, 1819) and all the subsequent ones were held
in the cabinet of Yale College. The brief records of the doings of this
society are printed in volumes =1=, =10=, =15=, and =18= of the Journal.
Silliman was the attraction at the meetings, surrounded by his mineral
cabinet, and he gave “the true scientific dress to all the naked
mineralogical subjects” discussed.
_Wernerian Geology in North America._
_The Father of American Geology._—Historical Geology begins in America
with William Maclure’s Observations on the Geology of the United States,
issued in 1809. This was the first important original work on North
American geology, and its colored geological map was the first one of
the area east of the Mississippi River. The classification was
essentially the Wernerian system. All of the strata of the Coastal
Plain, now known to range from the Lower Cretaceous to Recent, were
referred to the Alluvial. To the west, over the area of the Piedmont,
were his Primitive rocks, while the older Paleozoic formations of the
Appalachian ranges were referred to the Transition. West of the folded
area, all was Floetz or Secondary, or what we now know as Paleozoic
sedimentaries. The Triassic of the Piedmont area and that of Connecticut
he called the Old Red Sandstone, and the coal formations of the interior
region he said rested upon the Secondary. The second edition of the work
in 1817 was much improved, along with the map, which was also printed on
a more correct geographic base. (For greater detail, see Merrill,
Contributions to the History of American Geology, 1906.)
Even though Maclure’s geologic maps are much generalized, and the scheme
of classification adopted a very broad one, they are in the main
correct, even if they do emphasize unduly the rather simple geologic
structure of North America. This fact is patent all through Maclure’s
description. Cleaveland also refers to it in his treatise of 1816, and
Silliman in the opening volume of the Journal (=1=, 7, 1818) says: “The
outlines of American geology appear to be particularly grand, simple,
and instructive.” Then, all the kinds of rocks were comprehended under
four classes, Primitive, Transition, Alluvial, and Volcanic. It is also
interesting to note here that in 1822 Maclure had lost faith in the
aqueous origin of the igneous rocks and writes of the Wernerian system
as “fast going out of fashion” (=5=, 197, 1822), while Hitchcock said
about the same thing in 1825 (=9=, 146).
_The Work of Eaton._—Amos Eaton, after traveling 10,000 miles and
completing his Erie Canal Report in 1824, “reviewed the whole line
several times,” and published in 1828 in the Journal (=14=, 145) a paper
on Geological Nomenclature, Classes of Rocks, etc. The broader
classification is the Wernerian one of Primitive, Transition, and
Secondary classes. Under the first two he has fossiliferous early
Paleozoic formations, but does not know it, because he pays no attention
anywhere to the detail of the entombed fossils, and all of his Secondary
is what we now call Paleozoic. The correlations of the latter are faulty
throughout.
Then came his paper of 1830, Geological Prodromus (=17=, 63), in which
he says: “I intend to demonstrate ... that all geological strata are
arranged in five analogous series; and that each series consists of
three formations; viz., the Carboniferous [meaning mud-stones],
Quartzose, and Calcareous.” We seem to see here expressed for the first
time the idea of “cycles of sedimentation,” but Eaton does not emphasize
this idea, and the localities given for each “formation” of “analogous
series” demonstrate beyond a doubt that he did not have a sedimentary
sequence. The whole is simply a jumble of unrelated formations that
happen to agree more or less in their physical characters.
“I intend to demonstrate,” he says further, “that the detritus of New
Jersey, embracing the marle, which contains those remarkable fossil
relics, is antediluvial, or the genuine Tertiary formation.” This
correlation had been clearly shown by Finch in 1824 (=7=, 31) and yet
both are in error in that they do not distinguish the included
Cretaceous marls and greensands as something apart from the Tertiary.
One gets impatient with the later writings of Eaton, because he does not
become liberalized with the progressive ideas in stratigraphic geology
developing first in Europe and then in America, especially among the
geologists of Philadelphia. Therefore it is not profitable to follow his
work further.
_Early American Text-books of Geology._—The first American text-book of
geology bears the date of Boston 1816 and is entitled An Elementary
Treatise on Mineralogy and Geology, its author being Parker Cleaveland
of Bowdoin College. The second edition appeared in 1822. It also had a
geologic map of the United States, practically a copy of Maclure’s. To
mineralogy were devoted 585 pages, and to geology 55, of which 37
describe rocks and 5 the geology of the United States. The chronology is
Wernerian. Of “geological systems” there are two, “primitive and
secondary rocks.”
In 1818 appeared Amos Eaton’s Index to the Geology of the Northern
States, having 54 pages, and in 1820 came the second edition, “wholly
written over anew,” with 286 pages. The theory of the later edition is
still that of Werner, with “improvements of Cuvier and Bakewell,” and
yet one sees now-a-days but little in it of the far better English
text-book. Eaton did very little to advance philosophic geology in
America. What is of most value here are his personal observations in
regard to the local geology of western Massachusetts, Connecticut,
southwestern Vermont, and eastern New York (=1=, 69, 1819; also Merrill,
p. 234).
We come now to the most comprehensive and advanced of the early
text-books used in America. This is the third English edition of Robert
Bakewell’s Introduction to Geology (400 pages, 1829), and the first
American edition “with an Appendix Containing an Outline of his Course
of Lectures on Geology at Yale College, by Benjamin Silliman” (128
pages). Bakewell’s good book is in keeping with the time, and while not
so advanced as Conybeare and Phillips’s Outlines of 1822, yet is far
more so than Silliman’s appendix. The latter is general and not specific
as to details; it is still decidedly Wernerian, though in a modified
form. Silliman says he is “neither Wernerian nor Huttonian,” and yet his
summary on pages 120 to 126 shows clearly that he was not only a
Wernerian but a pietist as well.
_Unearthing of the Cenozoic and Mesozoic in North America._
_The Discerning of the Tertiary._—The New England States, with their
essentially igneous and metamorphic formations, could not furnish the
proper geologic environment for the development of stratigraphers and
paleontologists. So in America we see the rise of such geologists first
in Philadelphia, where they had easy access to the horizontal and highly
fossiliferous strata of the coastal plain. The first one to attract
attention was Thomas Say, after him came John Finch, followed by Lardner
Vanuxem, Isaac Lea, Samuel G. Morton, and T. A. Conrad. These men not
only worked out the succession of the Cenozoic and the upper part of the
Mesozoic, but blazed the way among the Paleozoic strata as well.
Thomas Say (1787–1834), in 1819, was the first American to point out the
chronogenetic value of fossils in his article, Observations on some
Species of Zoophytes, Shells, etc., principally Fossil (=1=, 381). He
correctly states that the progress of geology “must be in part founded
on a knowledge of the different genera and species of reliquiæ, which
the various accessible strata of the earth present.” Say fully realizes
the difficulties in the study of fossils, because of their fragmental
character and changed nature, and that their correct interpretation
requires a knowledge of similar living organisms.
The application of what Say pointed out came first in John Finch’s
Geological Essay on the Tertiary Formations in America (=7=, 31, 1824).
Even though the paper is still laboring under the mineral system and
does not discern the presence of Cretaceous strata among his Tertiary
formations, yet Finch also sees that “fossils constitute the medals of
the ancient world, by which to ascertain the various periods.”
Finch now objects to the wide misuse in America of the term alluvial and
holds that it is applied to what is elsewhere known as Tertiary. He
says:
“Geology will achieve a triumph in America, when the term alluvial
shall be banished from her Geological Essays, or confined to its
legitimate domain, and then her tertiary formations will be seen to
coincide with those of Europe, and the formations of London, Paris,
and the Isle of Wight, will find kindred associations in Virginia, the
Carolinas, Georgias, the Floridas, and Louisiana.”
The formations as he has them from the bottom upwards are: (1)
Ferruginous sand, (2) Plastic clay, (3) Calcaire Silicieuse of the Paris
Basin, (4) London Clay, (5) Calcaire Ostrée, (6) Upper marine formation,
(7) Diluvial.
The grandest of these early stratigraphic papers, however, is that by
Lardner Vanuxem (1792–1848), of only three pages, entitled “Remarks on
the Characters and Classification of Certain American Rock Formations”
(=16=, 254, 1829). Vanuxem, a cautious man and a profound thinker, had
been educated at the Paris School of Mines. James Hall told the writer
in a conversation that while the first New York State Survey was in
operation, all of its members looked to Vanuxem for advice.
In the paper above referred to, Vanuxem points out in a very concise
manner that:
“The alluvial of Mr. Maclure ... contains not only well characterized
alluvion, but products of the tertiary and secondary classes. Littoral
shells, similar to those of the English and Paris basins, and pelagic
shells, similar to those of the chalk deposition or latest secondary,
abound in it. These two kinds of shells are not mixed with each other;
they occur in different earthy matter, and, in the southern states
particularly, are at different levels. The incoherency or earthiness
of the mass, and our former ignorance of the true position of the
shells, have been the sources of our erroneous views.”
The second error of the older geologists, according to Vanuxem, was the
extension of the secondary rocks over “the western country, and the back
and upper parts of New York.” They are now called Paleozoic. Some had
even tried to show the presence of Jurassic here because of the
existence of oölite strata. “It was taken for granted, that all
horizontal rocks are secondary, and as the rocks of these parts of the
United States are horizontal in their position, so they were supposed to
be secondary.” He then shows on the basis of similar Ordovician fossils
that the rocks of Trenton Falls, New York, recur at Frankfort in
Kentucky, and at Nashville in Tennessee.
“It is also certain that an uplifting or downfalling force, or both,
have existed, but it is not certain that either or both these forces
have acted in a uniform manner.... Innumerable are the facts, which have
fallen under my observation, which show the fallacy of adopting
inclination for the character of a class,” such as the Transition class
of strata. He then goes on to say that in the interior of our country
the so-called secondary rocks are horizontal and in the mountains to the
east the same strata are highly inclined. “The analogy, or identity of
rocks, I determine by their fossils in the first instance, and their
position and mineralogical characters in the second or last instance.”
It appears that Isaac Lea (1792–1886) in his Contributions to Geology,
1833, was the first to transplant to America Lyell’s terms, Pliocene,
Miocene, and Eocene, proposed the previous year. The celebrated
Claiborne locality was made known to Lea in 1829, and in the work here
cited he describes from it 250 species, of which 200 are new. The
horizon is correlated with the London Clay and with the Calcaire
Grossier of France, both of Eocene time (=25=, 413, 1834).
Timothy A. Conrad began to write about the American Tertiary in 1830,
and his more important publications were issued at Philadelphia. His
papers in the Journal begin with 1833 and the last one on the Tertiary
is in 1846.
The Tertiary faunas and stratigraphy have been modernized by William H.
Dall in his monumental work of 1650 pages and 60 plates entitled
“Contributions to the Tertiary Fauna of Florida” (1885–1903). Here more
than 3160 forms of the Atlantic and Gulf deposits are described, but in
order to understand their relations to the fossil faunas elsewhere and
to the living world, the author studied over 10,000 species. Since then,
many other workers have interested themselves in the Tertiary problems.
Much good work is also being done in the Pacific States where the
sequence is being rapidly developed.
_The Discerning of the Eastern Cretaceous._—The Cretaceous sequence was
first determined by that “active and acute geologist,” Samuel G. Morton
(1799–1851), but that these rocks might be present along the Atlantic
border had been surmised as early as 1824 by Edward Hitchcock (=7=,
216). Vanuxem, as above pointed out, indicated the presence of the
Cretaceous in 1829. In this same year Morton proved its presence before
the Philadelphia Academy of Natural Sciences.
Between 1830 and 1835 Morton published a series of papers in the Journal
under the title “Synopsis of the Organic Remains of the Ferruginous Sand
Formation of the United States, with Geological Remarks” (=17=, 274, _et
seq._). In these he describes the Cretaceous fossils and demonstrates
that the “Diluvial” and Tertiary strata of the Atlantic border also have
a long sequence of Cretaceous formations. In the opening paper he
writes: “I consider the marl of New Jersey as referable to the great
ferruginous sand series, which in Prof. Buckland’s arrangement is
designated by the name of green sand.... On the continent this series is
called the ancient chalk ... lower chalk,” etc. Again, the marls of New
Jersey are “geologically equivalent to those beds which in Europe are
interposed between the white chalk and the Oölites.” This correlation is
with the European Lower Cretaceous, but we now know the marls to be of
Upper Cretaceous age. Although Eaton objected strenuously to Morton’s
correlation, we find M. Dufresnoy of France saying, “Your limestone
above green sand reminds me very much of the Mæstricht beds,” a
correlation which stands to this day (=22=, 94, 1832). In 1833 Morton
announces that the Cretaceous is known all along the Atlantic and Gulf
border, and in the Mississippi valley. “The same species of fossils are
found throughout,” and none of them are known in the Tertiary. He now
arranges the strata of the former “Alluvial” as follows:
Modern │Alluvial.
„ │Diluvial.
─────────┼─────────────────────────────────────────────────────────────
Tertiary │Upper Tertiary (Upper Marine).
„ │Middle Tertiary (London Clay).
„ │Lower Tertiary (Plastic Clay).
─────────┼─────────────────┬───────────────────────────────────────────
Secondary│Calcareous Strata│Cretaceous group, or Ferruginous Sand
│ │ series (=24=, 128).
„ │Ferruginous Sand │ „
_Western Cretaceous._—In 1841 and 1843 J. N. Nicollet announced the
discovery of Cretaceous in the Rocky Mountain area. Of 20 species of
fossils collected by him, 4 were said to occur on the Atlantic border,
and of the 200 forms of the Atlantic slope only 1 was found in Europe.
Here we see pointed out a specific dissimilarity between the continents,
and a similarity between the American areas of Cretaceous deposits
(=41=, 181; =45=, 153).
The Cretaceous of the Rocky Mountains was clearly developed by F. V.
Hayden in 1855–1888 and by F. B. Meek (1857–1876). Other workers in this
field were Charles A. White (1869–1891), and R. P. Whitfield
(1877–1889). Since 1891 T. W. Stanton has been actively interpreting its
stratigraphy and faunas.
_Cretaceous and Comanche of Texas._—The broader outlines of the
Cretaceous of Texas had been described by Ferdinand Roemer in 1852 in
his good work, Kreidebildungen von Texas, but it was not until 1887 that
Robert T. Hill showed in the Journal (=33=, 291) that it included two
great series, the Gulf series, or what we now call Upper Cretaceous, and
a new one, the Comanche series. This was a very important step in the
right direction. Since then the Comanche series has been regarded by
some stratigraphers as of period value, while others call it Lower
Cretaceous; the rest of the Texas Cretaceous is divided by Hill into
Middle and Upper Cretaceous. On the other hand, Lower Cretaceous strata
had been proved even earlier in the state of California, for here in
1869 W. M. Gabb (1839–1878) and J. D. Whitney (1819–1896) had defined
their Shasta group, which was wholly distinct faunally from the Comanche
of Texas and the southern part of the Great Plains country.
_Jurassic and Triassic of the West._—In 1864, the Geological Survey of
California proved the presence of marine Upper Triassic in that State,
and since then it has been shown that not only is all of the Triassic
present in Idaho (where it has been known since 1877), Oregon, Nevada,
and California, but that the Upper Triassic is of very wide distribution
throughout western North America. Jurassic strata, on the other hand,
were not shown to be present in California until 1885, while in the
Rocky Mountain area of the United States there was long known an
unresolved series of “Red Beds” situated between the Carboniferous and
Cretaceous. This gave rise to the “Red Bed problem,” the history of
which is given by C. A. White in the Journal (=17=, 214, 1879). In 1869,
F. V. Hayden announced the discovery of marine Jurassic fossils in this
series, and since then they have come to be known as the Sundance fauna,
extending from southern Utah and Colorado into Alaska. Above lie the
dinosaur-bearing fresh-water deposits, since 1894 known as the Morrison
beds. In 1896, O. C. Marsh (1831–1899) announced the presence of
Jurassic fresh-water strata along the Atlantic coast (=2=, 433), but
to-day only a small part of them are regarded as of the age of the
Morrison, while the far greater part are referred to the Comanche or
Lower Cretaceous. The red beds below the Jurassic of the Rocky Mountain
area have during the past twenty years been shown to be in part of Upper
Triassic age and of fresh-water origin, while the greater lower part is
connected with the Carboniferous series and is made up of brackish— and
fresh-water deposits of probable Permian time.
_Triassic of Atlantic States._—The fresh-water Triassic of the Atlantic
border states was first mentioned by Maclure (1817), who regarded it as
the equivalent of the Old Red Sandstone of Europe. In this he was
followed by Hitchcock in 1823 (=6=, 39), the latter saying that above it
lies “the coal formation,” which is true for Europe, but in America the
coal strata are older than these red beds, now known to be of Triassic
age.
The first one to question this correlation was Alexandre Brongniart, who
had received from Hitchcock rock specimens and a fossil fish which he
erroneously identified with a Permian species, and accordingly referred
the strata to the Permian (=3=, 220, 1821; =6=, 76, pl. 9, figs. 1, 2,
1823). The discerning Professor Finch in 1826 remarked that the red beds
of Connecticut appear to belong “to the new or variegated sandstone,”
because of eight different criteria that he mentions. Of these, but two
are of value in correlation, their “geological position” and the
presence of bones other than fishes. In the Connecticut area, however,
the geological position cannot be determined even to-day, and in Finch’s
time the bones of dinosaurs were unknown. Finch then goes on to point
out the occurrences of Old Red Sandstone in Pennsylvania, but all of the
places he refers to are either younger or older in time. Here we again
see the fatality of trying to make positive correlations on the basis of
lithology and color (=10=, 209, 1826). In 1835, however, Hitchcock
showed that the bones that had been found in 1820 were those of a
saurian, and accordingly referred the strata of the Connecticut valley
to the New Red Sandstone, a term that then covered both the Permian and
the Triassic. In 1842, W. B. Rogers referred the beds to the Jurassic,
on the basis of plants from Virginia. In 1856, W. C. Redfield
(1789–1857), because of the fishes, advocated a Lias, or Jurassic age,
and proposed the name Newark group for all the Triassic deposits of the
Atlantic border. More recently, on the basis of the plants studied by
Newberry, Fontaine, Sturr, and Ward, and the vertebrates described by
Marsh and Lull, the age has been definitely fixed as Upper Triassic (see
Dana’s Manual of Geology, 740, 1895).
_Unearthing of the Paleozoic in North America._
_Permian of the United States._—In Europe, previous to 1841, the
formations now classed as Permian were included in the New Red
Sandstone, and with the Carboniferous were referred to the Secondary. In
that year Murchison proposed the period term Permian. In 1845 came the
classic Geology of Russia in Europe and the Ural Mountains, by
Murchison, Keyserling, and De Verneuil. In this great work the authors
separated out of the New Red the Magnesian Limestone of Great Britain
and the Rothliegende marls, Kupferschiefer, and Zechstein of Germany,
and with other formations of the Urals in Russia, referred them to the
Permian system. This step, one of the most discerning in historical
geology, was all the more important because they closed the Paleozoic
era with the Permian, beginning the Secondary, or Mesozoic, with the New
Red Sandstone or the Triassic period. There is a good review of this
work by D. D. Owen (1807–1860) in the Journal for 1847 (=3=, 153).
Owen, though accepting the Permian system, is not satisfied with its
reference to the Paleozoic, and he sets the matter forth in the Journal
(=3=, 365, 1847). He doubts “the propriety of a classification which
throws the Permian and Carboniferous systems into the Paleozoic period.”
This is mainly because there is no “evidence of disturbance or
unconformability” between the Permian and Triassic systems. Rather
“there is so complete a blending of adjacent strata” that it is only in
Russia that the Permian has been distinguished from the Triassic. This
view of Owen’s was not only correct for Russia but even more so for the
Alps and for India, and it has taken a great deal of work and discussion
to fix upon the disconformable contact that distinguishes the Paleozoic
from the Mesozoic in these areas. In other words, there was here at this
time no mountain making. Then Owen goes on to state that because the
Permian of Europe has reptiles, he sees in them decisive Mesozoic
evidence. “These are certainly strong arguments in favor of placing, not
only the Permian, but also the Carboniferous group in the Mesozoic
period, and terminating the Paleozoic division with the commencement of
the coal measures.” To this harking backward the geologists of the world
have not agreed, but have followed the better views of Murchison and his
associates.
In 1855 G. G. Shumard discovered, and in 1860 his brother B. F. Shumard
(1820–1869) announced, the presence of Permian strata in the Guadalupe
Mountains of Texas, and in 1902 George H. Girty (=14=, 363) confirmed
this. Girty regards the faunas as younger than any other late Paleozoic
ones of America, and says: “For this reason I propose to give them a
regional name, which shall be employed in a force similar to
Mississippian and Pennsylvanian.... The term Guadalupian is suggested.”
G. C. Swallow (1817–1899) in 1858 was the first to announce the presence
of Permian fossils in Kansas, and this led to a controversy between
himself and F. B. Meek, both claiming the discovery. It is only in more
recent years that it has been generally admitted that there is Permian
in that state, in Oklahoma, and in Texas. This admission came the more
readily through the discovery of many reptiles in the red beds of Texas,
and through the work of C. A. White, published in 1891, The Texan
Permian and its Mesozoic Types of Fossils (Bull. U. S. Geological
Survey, No. =77=).
[Illustration: James Hall]
_Carboniferous Formations._—The coal formations are noted in a general
way throughout the earliest volumes of the Journal. The first accounts
of the presence of coal, in Ohio, are by Caleb Atwater (=1=, 227, 239,
1819), and S. P. Hildreth (=13=, 38, 40, 1828). The first coal plants to
be described and illustrated were also from Ohio, in an article by
Ebenezer Granger in 1821 (=3=, 5–7). The anthracite field was first
described in 1822 by Zachariah Cist (=4=, 1) and then by Benjamin
Silliman (=10=, 331–351, 1826); that of western Pennsylvania was
described by William Meade in 1828 (=13=, 32).
The Lower Carboniferous was first recognized by W. W. Mather in 1838
(=34=, 356). Later, through the work of Alexander Winchell (1824–1891),
beginning in 1862 (=33=, 352) and continuing until 1871, and through the
surveys of Iowa (1855–1858), Illinois (essentially the work of A. H.
Worthen, 1858–1888), Ohio (1838, Mather, etc.), and Indiana (Owen, etc.,
1838), there was eventually worked out the following succession:
Permian period.
Upper Barren series.
Dunkard group.
Washington group.
Pennsylvanian period.
Upper Productive Coal series. Monongahela series.
Lower Barren Coal Measures. Conemaugh series.
Lower Productive Coal Measures. Allegheny series.
Pottsville series.
_The New York System._—We now come to the epochal survey of the State of
New York, one that established the principles of, and put order into,
American stratigraphy from the Upper Cambrian to the top of the
Devonian. No better area could have been selected for the establishing
of this sequence. This survey also developed a stratigraphic
nomenclature based on New York localities and rock exposures, and made
full use of the entombed fossils in correlation. Incidentally it
developed and brought into prominence James Hall, who continued the
stratigraphic work so well begun and who also laid the foundation for
paleontology in America, becoming its leading invertebrate worker.
This work is reviewed at great length in the Journal in the volumes for
1844–1847 by D. D. Owen. Evidently it followed too new a plan to receive
fulsome praise from conservative Owen, as it should have. He remarks
that the volumes “are not a little prolix, are voluminous and expensive,
and do not give as clear and connected a view of the geological features
of the state as could be wished.... We are of the opinion that before
this work can become generally useful and extensively circulated, it
must be condensed and arranged into one compendious volume” (=46=, 144,
1844). This was never done and yet the work was everywhere accepted at
once, and to this end undoubtedly Owen’s detailed review helped much.
The Natural History Survey of New York was organized in 1836 and
completed in 1843. The state was divided into four districts, and to
these were finally assigned the following experienced geologists. The
southeastern part was named the First District, with W. W. Mather
(1804–1859) as geologist; the northeastern quarter was the Second
District, with Ebenezer Emmons (1799–1863) in charge; the central
portion was the Third District, under Lardner Vanuxem (1792–1848); while
the western part was James Hall’s (1811–1898) Fourth District.
Paleontology for a time was in charge of T. A. Conrad (1830–1877); the
mineralogical and chemical work was in the hands of Lewis C. Beck; the
botanist was John Torrey; and the zoologist James DeKay.
The New York State Survey published six annual reports of 1675 pages
octavo, and four final geological reports with 2079 pages quarto.
Finally in 1846 Emmons added another volume on the soils and rocks of
the state, in which he also discussed the Taconic and New York systems;
it has 371 pages. With the completion of the first survey, Hall took up
his life work under the auspices of the state—his monumental work,
Paleontology of New York, in fifteen quarto volumes of 4539 pages and
1081 plates of fossils. In addition to all this, there are his annual
and other reports to the Regents of the State, so that it is safe to say
that he published not less than 10,000 pages of printed matter on the
geology and paleontology of North America.
In regard to this great series of works, all that can be presented here
is a table of formations as developed by the New York State Survey.
Practically all of its results and formation names have come into
general use, with the exception of the Taconic system of Emmons and the
division terms of the New York system. (See p. 88.)
The New York State Survey, begun in 1836, was continued by James Hall
from 1843 to 1898. During this time he was also state geologist of Iowa
(1855–1858) and Michigan (1862). Since 1898, John M. Clarke has ably
continued the Geological Survey of New York, the state which continues
to be, in science and more especially in geology and paleontology, the
foremost in America.
_Western Extension of the New York system._—Before Hall finished his
final report, we find him in 1841 on “a tour of exploration through the
states of Ohio, Indiana, Illinois, a part of Michigan, Kentucky, and
Missouri, and the territories of Iowa and Wisconsin.” This tour is
described in the Journal (=42=, 51, 1842) under the caption “Notes upon
the Geology of the Western States.” His object was to ascertain how far
the New York system as the standard of reference “was applicable in the
western extension of the series.” In a general way he was very
successful in extending the system to the Mississippi River, and he
clearly saw “a great diminution, first of sandy matter, and next of
shale, as we go westward, and in the whole, a great increase of
calcareous matter in the same direction.” He also clearly noted the
warped nature of the strata, the “anticlinal axis,” since known as the
Cincinnati and Wabash uplifts and the Ozark dome.
Hall, however, fell into a number of flagrant errors because of a too
great reliance on lithologic correlation and supposedly similar
sequence. For instance, the Coal Measures of Pennsylvania were said to
directly overlap the Chemung group of southern New York, and now he
finds the same condition in Ohio, Indiana, and Illinois, failing to see
that in most places between the top of the New York system and the Coal
Measures lay the extensive Mississippian series, one that he generally
confounded with the Chemung, or included in the “Carboniferous group.”
He states that the Portage of New York is the same as the Waverly of
Ohio, and at Louisville the Middle Devonian waterlime is correlated with
the similar rock of the New York Silurian. Hall was especially desirous
of fixing the horizon of the Middle Ordovician lead-bearing rocks of
Illinois, Wisconsin, and Iowa, but unfortunately correlated them with
the Niagaran, while the Middle Devonian about Columbus, Ohio, and
Louisville, Kentucky, he referred to the same horizon. The
Galena-Niagaran error was corrected in 1855, but the Devonian and
Mississippian ones remained unadjusted for a long time, and in Iowa
until toward the close of the nineteenth century.
_The Geological Column of the New York Geologists of 1842–1843,
according to W. W. Mather 1842._
Quaternary system │Alluvial division.
„ │Quaternary division.
„ │Drift division.
────────────────────────────┼────────────────────────────┬────────────
Tertiary system │These strata are included in│
│ the next lower division. │
────────────────────────────┼────────────────────────────┼────────────
│Long Island division. Equals│New Red
│ the Tertiary and │ system of
Upper Secondary system │ Cretaceous marls, sands, │ Emmons and
│ and clays of the coastal │ Hall.
│ plain of New Jersey. │
„ │Trappean division. The │ „
│ Palisades │
„ │Red Sandstone division. │ „
Coal system of Mather, and Carboniferous system of Hall.
Old Red system of Catskill Mountains of Emmons; Catskill division of
Mather and Hall; and Catskill group of Vanuxem.
_According to Hall 1843, and essentially Vanuxem 1842._
│Chemung, Portage or Nunda (divided into
│ Cashaqua, Gardeau, Portage), Genesee,
Erie division [Devonian] │ Tully, Hamilton (divided into
│ Ludlowville; Encrinal, Moscow), and
│ Marcellus.
────────────────────────────┼────────────────────────────────────────
│Corniferous, Onondaga, Schoharie,
Helderberg series │ Cauda-alli, Oriskany, Upper
[Devonian-Silurian] │ Pentamerus, Encrinal, Delthyris,
│ Pentamerus, Waterlime, Onondaga salt
│ group.
────────────────────────────┼────────────────────────────────────────
Ontario division [Silurian] │Niagara, Clinton, and Medina.
────────────────────────────┼────────────────────────────────────────
│Oneida or Shawangunk, Grey sandstone,
Champlain division │ Hudson River group, Utica, Trenton,
[Silurian-Ordovician-Upper│ Black River including Birdseye and
Cambrian] │ Chazy, Calciferous sandrock, and
│ Potsdam.
_According to Emmons 1842, Mather 1843, Vanuxem 1842, Hall 1843._
Taconic System [Ordovician │Granular quartz, Stockbridge limestone,
and Lower Cambrian] │ Magnesian slate, and Taconic slate.
────────────────────────────┼────────────────────────────────────────
Primary or Hypogene system │Metamorphic and Primary rocks.
_Correlations with Europe._—The first effort toward correlating the New
York system with those of Europe was made by Conrad in his Notes on
American Geology in 1839 (=35=, 243). Here he compares it on faunal
grounds with the Silurian system. A more sustained effort was that of
Hall in 1843 (=45=, 157), when he said that the Silurian of Murchison
was equal to the New York system and embraced the Cambrian, Silurian,
and Devonian, which he considered as forming but one system. Hall in
1844 and Conrad earlier were erroneously regarding the Middle Devonian
of New York (Hamilton) as “an equivalent of the Ludlow rocks of Mr.
Murchison” (=47=, 118, 1844).
In 1846 E. P. De Verneuil spent the summer in America with a view to
correlating the formations of the New York system with those of Europe.
At this time he had had a wide field experience in France, Germany, and
Russia, was president of the Geological Society of France, and
“virtually the representative of European geology” (=2=, 153, 1846).
Hall says, “No other person could have presented so clear and perfect a
coup d’oeil.” De Verneuil’s results were translated by Hall and with his
own comments were published in the Journal in 1848 and 1849 under the
title “On the Parallelism of the Paleozoic Deposits of North America
with those of Europe.” De Verneuil was especially struck with the
complete development of American Paleozoic deposits and said it was the
best anywhere. On the other hand, he did not agree with the detailed
arrangement of the formations in the various divisions of the New York
system, and Hall admitted altogether too readily that the terms were
proposed “as a matter of concession, and it is to be regretted that such
an artificial classification was adopted.” De Verneuil’s correlations
are as follows:
The Lower Silurian system begins with the Potsdam, the analogue of the
Obolus sandstone of Russia and Sweden. The Black River and Trenton hold
the position of the Orthoceras limestones of Sweden and Russia, while
the Utica and Lorraine are represented by the Graptolite beds of the
same countries. Both correlations are in partial error. He unites the
Chazy, Birdseye, and Black River in one series, and in another the
Trenton, Utica, and Lorraine. Of species common to Europe and America he
makes out seventeen.
In the Upper Silurian system, the Oneida and Shawangunk are taken out of
the Champlain division, and, with the Medina, are referred to the
Silurian, along with all of the Ontario division plus the Lower
Helderberg. The Clinton is regarded as highest Caradoc or as holding a
stage between that and the Wenlock. The Niagara group is held to be the
exact equivalent of the Wenlock, “while the five inferior groups of the
Helderberg division represent the rocks of Ludlow.” We now know that
these Helderberg formations are Lower Devonian in age. De Verneuil
unites in one series the Waterlime, Pentamerus, Delthyris, Encrinal, and
Upper Pentamerus. Of identical species there are forty common to Europe
and America.
The Devonian system De Verneuil begins, “after much hesitation,” with
the Oriskany and certainly with the five upper members of Hall’s
Helderberg division, all of the Erie and the Old Red Sandstone. He also
adjusts Hall’s error by placing in the Devonian the Upper Cliff
limestone of Ohio and Indiana, regarded by the former as Silurian. The
Oriskany is correlated with the grauwackes of the Rhine, and the
Onondaga or Corniferous with the lower Eifelian. Cauda-galli, Schoharie,
and Onondaga are united in one series; Marcellus, Hamilton, Tully, and
Genesee in another; and Portage and Chemung in a third. Of species
common to Europe and America there are thirty-nine.
The Waverly of Ohio and that near Louisville, Kentucky, which Hall had
called Chemung, De Verneuil correctly refers to the Carboniferous, but
to this Hall does not consent. De Verneuil points out that there are
thirty-one species in common between Europe and America. “And as to
plants, the immense quantity of terrestrial species identical on the two
sides of the Atlantic, proves that the coal was formed in the
neighborhood of lands already emerged, and placed in similar physical
conditions.”
An analysis of the Paleozoic fossils of Europe and America leads De
Verneuil to “the conviction that identical species have lived at the
same epoch in America and in Europe, that they have had nearly the same
duration, and that they succeeded each other in the same order.” This he
states is independent of the depth of the seas, and of “the upheavings
which have affected the surface of the globe.” The species of a period
begin and drop out at different levels, and toward the top of a system
the whole takes on the character of the next one. “If it happens that in
the two countries a certain number of systems, characterized by the same
fossils, are superimposed in the same order, whatever may be, otherwise,
their thickness and the number of physical groups of which they are
composed, it is philosophical to consider these systems as parallel and
synchronous.”
Because of the dominance of the sandstones and shales in eastern New
York, De Verneuil holds that a land lay to the east. The many fucoids
and ripple-marks from the Potsdam to the Portage indicated to him
shallow water and nearness to a shore.
_The Oldest Geologic Eras._—We have seen in previous pages how the
Primitive rocks of Arduino and of Werner had been resolved, at least in
part, into the systems of the Paleozoic, but there still remained many
areas of ancient rocks that could not be adjusted into the accepted
scheme. One of the most extensive of these is in Canada, where the
really Primitive formations, of granites, gneisses, schists, and even
undetermined sediments, abound and are developed on a grander scale than
elsewhere, covering more than two million square miles and overlain
unconformably by the Paleozoic and later rocks. The first to call
attention to them was J. I. Bigsby, a medical staff officer of the
British Army, in 1821 (=3=, 254). It was, however, William E. Logan
(1798–1875), the “father of Canadian geology,” who first unravelled
their historical sequence. At first he also called them Primary, but
after much work he perceived in them parallel structures and
metamorphosed sediments, underlain by and associated with pink granites.
For the oldest masses, essentially the granites, he proposed the term
Laurentian system (1853, 1863) and for the altered and deformed strata,
the name Huronian series (1857, 1863). Overlying these unconformably was
a third series, the copper-bearing rocks. Since his day a great host of
Canadian and American geologists have labored over this, the most
intricate of all geology, and now we have the following tentative
chronology (Schuchert and Barrell, =38=, 1, 1914):
Late Proterozoic era.
Keweenawan, Animikian and Huronian periods.
Early Proterozoic era.
Sudburian period or older Huronian.
Archeozoic era.
Grenville series, etc.
Cosmic history.
_The Taconic System Resurrected._
The Taconic system was first announced by Ebenezer Emmons in 1841, and
clearly defined in 1842. It started the most bitter and most protracted
discussion in the annals of American geology. After Emmons’s subsequent
publications had put the Taconic system through three phases, Barrande
of Bohemia in 1860–1863 shed a great deal of new and correct light upon
it, affirming in a series of letters to Billings that the Taconic
fossils are like those of his Primordial system, or what we now call the
Middle Cambrian (=31=, 210, 1861, _et seq._).
In a series of articles published by S. W. Ford in the Journal between
1871 and 1886, there was developed the further new fact that in
Rensselaer and Columbia counties, New York, the so-called Hudson River
group abounds in “Primordial” fossils wholly unlike those of the
Potsdam, and which Ford later on spoke of as belonging to “Lower
Potsdam” time.