Mysteries of glaciation
An alternate theory of origin, to wit, that ice sheets came from highly abnormal snowfalls which embraced the entire glaciated areas, will acquire irresistible appeal, provided an adequate source for such unearthly precipitation can be disclosed, together with the revelation of conditions and natural laws which made such precipitation inevitable. Such an alternate theory of origin will be expounded later herein.
Climate in Past Ages
Now let us inquire what actual evidence exists to support the hypothesis that glacial ice accumulated slowly because of gradual deterioration of climate. Today there appears to be unanimous conviction among leaders in the field of paleontology that during by far the greater portion of time since the Azoic era, mild, benign climatic conditions have existed. It is also the concensus that, astonishinglv and inexplicably, such conditions were comparatively uniform over most of Earth’s surface; that temperate climate extended both north and south to within both polar circles. It is also believed that, amazingly, seasonal effects during most of geological time have been much less pronounced than they are now.
It is the concensus among leading scientists that such usually mild climatic conditions have been interrupted only occasionally, only at irregular intervals, only for comparatively brief periods, and only during glacial epochs. Many quotations could be given to support these statements. Space permits only a few.
Dr. F. H. Knowlton, in Relations of Paleobotany to Geology, says:
Relative uniformity, mildness and comparative equability of climate, accompanied by high humidity, have prevailed over the greater part of the Earth, extending to or into polar circles, during the greater part of geologic time since at least the Middle Paleozoic. This is the regular, the ordinary, the normal condition.
Edward H. Colbert, in his paper Vertebrate Paleoecology, as reported by Howard Shapely in Climatic Change, says (p. 269):
So far as past climates can be interpreted from the record of fossil vertebrates, it would appear that during much of Earth history the world has enjoyed uniformly warm, equable climate over most of its surface . . . the general picture of past vertebrate life is that of warmth-loving animals living over wide ranges of latitude, from the southern tips of the continental land masses through the middle latitudes to regions as far north as the Arctic Circle.
John Wolbach, previously quoted, says:
Periods of widespread glaciation, separated by longer periods of mild climate, have apparently characterized the climate of the Earth for nearly two billion years.
Dr. Bell, also previously quoted, speaks of
the problem of the warm polar climate of non-glaciated periods, when temperate life forms flourished well within the Arctic Circle. . . .
She says further:
. . . the climate of the Tertiary began warm and mild, with temperate-type life far within the Arctic Circle . . . and coal-forming vegetation flourished on the continent of Antarctica.
Hardwoods in Polar Regions
Elso S. Barghoorn, in Geologic Record of Plant Life, writes:
The luxuriant growth of broad-leaf hardwood forests in high Arctic latitudes persisted from the Cretaceous into the Eocene and probably the Oligocene, indicating a prolonged continuation of humid, warm temperature, or at least temperate forest climate in polar regions. Evidence for this may be found in both Arctic and Antarctic regions. . . . The greater part of climatic history, evidenced by extinct floras and their distribution, appears to have been characterized by more equable distribution of temperature and also of rainfall. This geologically “normal” climate has been altered at long intervals by far briefer periods of polar ice and glaciation of the continents, even into middle and lower latitudes.
Admiral Byrd, writing in National Geographic, October 1935, about fossils he found on a mountain during one of his expeditions to Antarctica, says:
The rock fragments from this mountainside invariably included plant fossils, leaf and stem impressions, coal and fossilized wood. Here at the southernmost known mountain in the world, scarcely two hundred miles from the South Pole, was found conclusive evidence that the climate of Antarctica was once temperate or even sub-tropical.
While there is general agreement that throughout geologic time “the definitely zoned climatic belts, so familiar to us at the present time, apparently did not exist” (Colbert), every writer remains silent when it comes to offering an explanation for that mysterious anomaly. Later herein a precise explanation will be presented.
Is it not strange, that if glacial episodes developed because of slow, gradual deterioration of climate, their duration in every instance was so short and that usual conditions of warm, temperate, uniform climate returned so quickly?
As has been pointed out herein before, the aim of every theory about ice ages has been to discover changed circumstances which could have caused climate to grow colder. To be tenable, any theory based upon colder climate must account for world-wide refrigeration affecting all zones of climate in both the northern and southern hemispheres at the same time; it must explain recurrence of cold-climate time and again at irregularly spaced intervals; it must account for the greatest accumulations of ice in specific regions; and it must account for the rapid return of temperate climate following each glaciation. Every theory thus far propounded has failed to meet these requirements.
Are widely held assumptions that climate grew gradually colder and that as a result ice sheets accumulated from winter snowfall, supported by actual, visible, concrete evidence? Or are the assumptions sustained only by longing and hope to verify them because they envision the one and only explanation of ice ages which anybody has been able to conceive?
Changes in Life Forms
It is evident that life forms changed radically at, or near, times of glaciation. It seems to be unanimously assumed that such changes took place prior to arrival of each ice episode. The theory that ice ages resulted because climate had deteriorated, obviously rules out any other conclusion. Three of the four major ice ages listed before, seem to have been dated fairly close to, if not in fact precisely at, the close of one era and the beginning of the next. The first major glaciation occurred between the Archeozoic and the Proterozoic. The second, between the Proterozoic and the Paleozoic. The third, between the Paleozoic and the Mesozoic. There appears to have been only a minor glaciation between the Mesozoic and Cenozoic. The fourth major glaciation, the Pleistocene, occurred only recently, late in the Cenozoic.