W. M. Davis

The Geographical Cycle

All the varied forms of the lands are dependent on—or, as the mathematician would say, are functions of—three variable quantities, which may be called structure, process, and time. In the beginning, when the forces of deformation and uplift determine the structure and attitude of a region, the form of its surface is in sympathy with its internal arrangement, and its height depends on the amount of uplift that it has suffered. If its rocks were unchangeable under the attack of external processes, its surface would remain unaltered until the forces of deformation and uplift acted again; and in this case structure would be alone in control of form. But no rocks are unchangeable; even the most resistant yield under the attack of the atmosphere, and their waste creeps and washes downhill as long as any hills remain; hence all forms, however high and however resistant, must be laid low, and thus destructive process gains rank equal to that of structure in determining the shape of a land mass. Process cannot, however, complete its work instantly, and the amount of change from initial form is therefore a function of time. Time thus completes the trio of geographical controls, and is, of the three, the one of the most frequent application and of a most practical value in geographical description.

Sheetfloods and streamfloods

Repeated excursions in the Mohave Desert region of southeastern California have led to this comprehensive summary of the work of sheetfloods and streamfloods in arid physiographic cycles. Comparisons are also made with accounts of a few other arid regions, especially those in which better examples of external drainage or locally degrading base levels have been observed. In regard to the controversial question of the importance of lateral erosion in deserts, it is concluded, at least for the region under observation, that lateral erosion is of practically no importance, except in the mountains and in the few other places where there are well-developed washes or water courses. Sheetfloods, not streamfloods, normally grade piedmont slopes and the fan bays where desert mountain valleys open out between diminishing spurs. The areas subject to sheetfloods there are enlarged mainly by back-weathering subaerial degradation of the mountain and spur slopes, essentially in the manner analyzed by Lawson (1915). Where gradual uplift, degrading base levels, or other moderate changes allow streamfloods to take mild possession of these graded areas, their work too is almost entirely down-wearing rather than lateral cutting.

Bufo alvarius: a potent hallucinogen of animal origin

Anthropologists have long speculated that ancient peoples of Mesoameria used a toad, Bufo marinus, as a ritual intoxicant. This hypothesis rests on many iconographic and mythological representations of toads and on a number of speculative ethnographic reports. The authors reject B. marinus as a candidate for such use because of the toxicity of its venom. A more likely candidate is the Sonoran desert toad, Bufo alvarius, which secretes large amounts of the potent known hallucinogen, 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT). The authors demonstrate that the venom of B. alvarius, although known to be toxic when consumed orally, may be safely smoked and is powerfully psychoactive by that route of administration. These experiments are the first documentation of an hallucinogenic agent from the animal kingdom, and they provide clear evidence of a psychoactive toad that could have been employed by Precolumbian peoples of the New World.

Identity of a New World Psychoactive Toad

Anthropologists have long speculated that ancient peoples of Mesoamerica used a toad, Bufo marinus , as a ritual intoxicant. This hypothesis rests on many iconographic and mythological representations of toads and on a number of speculative ethnographic reports. We reject B. marinus as a candidate for such use because of the toxicity of its venom. A more likely candidate is the Sonoran desert toad, Bufo alvarius , which secretes large amounts of the potent, known hallucinogen, 5-methoxy-N, N-dimethyltryptamine (5-MeO-DMT). We demonstrate that the venom of B. alvarius , though known to be toxic when consumed orally, may be safely smoked and is powerfully psychoactive by that route of administration. These experiments are the first documentation of a hallucinogenic agent from the animal kingdom, and they provide clear evidence of a psychoactive toad that could have been employed by Precolumbiae peoples of the New World.

Report of the Committee on the Nomenclature of Faults

Introduction The great inconsistency in the use of terms relating to faults, and especially the lack of uniformity when dealing with faults in which there is a component of displacement parallel with the fault strike, 2 led to the appointment by the Council of the Geological Society of America at the Baltimore meeting, December, 1908, of a Committee on the Nomenclature of Faults. This Committee was charged with recommending a proper nomenclature. A preliminary report was made at the Washington meeting, December 30, 1911, and was printed as a special brochure by order of the Council, under the title “Proposed Nomenclature of Faults.” Copies were sent to all Fellows of the Society and a few other geologists with the request that it be freely criticised. The Committee received a number of letters containing apt criticisms and making useful suggestions. As a result of these letters and the discussion at the New . . .

Structure and Origin of Glacial Sand Plains

External Form and Internal Structure .—Plains of stratified gravelly sand, half a mile or more in diameter, standing mesa-like above the adjacent valley ground, are common in many parts of New England. They lie on striated ledges and till, and hence are at most not older than the closing stages of the latest glacial epoch. Their distinct marginal slopes give no indication of more than a small measure of erosion, and hence their present form may be taken as essentially equivalent to their initial constructional form. They are well stratified throughout, and this, along with their definite marginal slope, indicates them to be deposits made in bodies of standing water. The general surface of these sand plains is very even, but fails of being level by reason of a gentle slope, generally to the south, of ten, twenty, of thirty feet to the mile. Their margins are in most cases . . .

Glacial Erosion in France, Switzerland and Norway

Eighteen years ago I presented to this Society an essay on Glacial Erosion, in which my own observations were supplemented by a review of all that I could find written on the subject in the hope of reaching some safe conclusion regarding what was then (as it is still) a mooted question. Although recognizing effective erosion to depths of ‘a moderate number of feet’ where ice pressure was great and motion was rapid, in contrast to deposition where pressure and motion were reduced and where the amount of subglacial drift was excessive, I could not at that time find evidence to warrant the acceptance of great glacial erosion, such as was advocated by those who ascribed Alpine lakes and Norwegian fiords to this agency. In a retrospect from the present time, it seems as if one of the causes that led to my conservative position was the extreme exaggeration of some glacialists, who found in glacial erosion a destructive agency competent to accomplish any desired amount of denudation — an opinion from which I recoiled too far. Since the publication of my previous essay I had gradually come to accept a greater and greater amount of glacial erosion in the regions of active ice motion; but in spite of this slow change of opinion, the maximum measure of destructive work that, up to last year, seemed to me attributable to glaciers was moderate; and it was therefore with great surprise that I then came upon certain facts in the Alps and in Norway which demanded wholesale glacial erosion for their explanation.

The physical geography (geomorphology) of William Morris Davis

Canadian north and centre, an area larger than that of Quebec and the Maritime Provinces combined. Their depth is variable but may extend to about 100 feet (c. 30 m). Muskeg is thus a significant feature of the landscape and is also an important organic resource, so that the problem of its wise development is associated with many other aspects of the northern environment, such as water supplies, forest resources and the exploitation of petroleum, natural gas and other mineral deposits. The scope of this multidisciplinary work is extensive: there are papers dealing with the post-glacial history and origin ofthe muskeg, the classification ofthe different types of ecosystems, their chemistry and physical properties, their hydrology and soils. Further contributions discuss industrial utilization and the impact of economic development, particularly the effect of pipeline construction and human settle ents. A final section considers the wildlife of muskeg in relation to conservation and recreation. Each chapter reviews what is known, draws attention to limitations in knowledge and contains an extensive bibliography. The book is illustrated by many photographs, both ground and aerial, and also maps, diagrams and tables and is an essential reference text for all students of the physical environment ofthe Canadian north. W. W. Newey

The structure of the Triassic formation of the Connecticut Valley

CONTENTS: The physical problem-Limitation of acceptable hypothesis-Disturb. ance has taken place-Its date is after the pedod of deposition-It was Dot can sed by overfiow or intrusion of trap-sheets-It was not a simple monoclinal tilting-~;vidence for occurrence of unseen faults-Their systematic positionTheir control of the topography-Crescentic ridges-Area and depth of disturb· ance-Probable character of disturbing force-Its action on the funclameutal schists-Consequent monoclinal faulting of overlying Triassic strata-Strike of faults determined by strike of schists.

In the Shadow of Red Cedar

a constellation of life unique on earth, they spread between sea and mountain peak, reaching across and defying national boundaries as they envelop all who live within their influence in an unrivaled frontier of the spirit. It is a world anchored in the south by giant sequoias (Sequoiadendron giganteum), the most massive of living beings, and coast redwoods (Sequoia sempervirens) that soar 300 feet above the fogbanks of Mendocino. In the north, two trees flourish: western hemlock (Tsuga heterophylla), with its delicate foliage and finely furrowed bark; and Sitka spruce (Picea sitchensis), most majestic of all, a stunningly beautiful species with blue-green needles that are salt tolerant and capable of extracting minerals and nutrients from sea spray. In between, along the silent reaches of the midcoast of British Columbia, behind a protective veil of Sitka spruce, rise enormous stands of Douglas fir (Pseudotsuga menziesii). Intermingled with hemlock and fir, growing wherever the land is moist and the rains abundant, is perhaps the