Submarine Fracture Zones, Aseismic Ridges and the International Council of Scientific Unions Line: Proposed Western Margin of the East Pacific Ridge in Nature, 207, 5000, pp. 907-911, Aug. 28 1965

London: Macmillan, 1965. 1st Edition. FIRST EDITION IN ORIGINAL WRAPS of the last of four papers by John Tuzo Wilson providing evidence to buttress the idea of both transform faults and the Vine-Matthews hypothesis that the sea floor is spreading, here arguing "how mutually supportive these two concepts were" (Frankel, The Continental Drift Controversy, 294). Reinforcing this, Wilson's paper points "out the existence of submarine fracture zones, which transversely cut the oceanic ridges - the transform faults - showed large-scale deformation of the oceans along these narrow mobile belts that form a network between the rigid plates offsetting the ocean ridges as a result of differential movement of the plates" (Valdiya, Aspects of Tectonics, 81). [Note that we offer a number of other Wilson papers separately as well as the Vine-Matthews paper].

Wilson's contributions to the theory of plate tectonics "introduced to the mainstream the idea that continents and oceans are in continuous motion over our planet's surface" and in so doing, revolutionized the ways we understand the Earth (Heron, Plate Tectonics, The Conversation, July 4, 2016). Scientific American counts Wilson's discoveries as one of the century's five major advances in science.

In this paper, "Wilson thought about the mutual consequences of transform faults and aseismic ridges, and the generally inactive ridges that extended out from mid-ocean ridges and are occasionally topped by volcanic islands. Working from the idea that aseismic ridges are formed over hot spots, he proposed... that horizontal crustal motions relative to Earth's mantle are determinable by looking at the trends of island chains with the expectation that the age of islands along each chain increases with distance from its associated spreading ridge. He also claimed that the position of ridge-offsets relative to each other should be reflected both by the magnetic pattern and by the position of aseismic ridges on adjacent blocks between fracture zones.

"Using these guidelines, he argue[s] [again in this paper, p. 910], that the ‘floor of the Pacific is moving northwards like that of the Atlantic Ocean and several southern continents'. Returning to the issue of whether the great fracture zones are related to the East Pacific Rise or to the Darwin Rise, he argued that the fracture zones and aseismic ridges (Emperor Seamounts, Line Islands Ridge, Hawaiian Islands, Tuamotu Islands, Society and Ustral islands, Tehuantepec Ridge, Cocos Ridge, and Nazca Ridge) are associate with the East Pacific Rise. Given the close association of all these, excepting Hawaiian Islands, with the East Pacific Rise, he claimed that their westerly extension forms the western margin of the East Pacific Rise. He named this margin the ICSU Line in honor of the International Council of Scientific Unions. He imagined the western flank of the East Pacific Rise to extend at least to the middle of the Pacific Ocean. Then [p. 908], assuming that spreading rates had been the same on either flank of the East Pacific Rise, inferred that ‘its eastern margin and northern crest' must ‘have been overridden by the Americas' (Frankel, The Continental Drift Controversy, 294).

ALSO INCLUDED: Joseph Altman and Gopal D. Das's "Post-Natal Origin of Microneurones in the Rat Brain, pp. 953-956. "Using radioactively-tagged thymidine, Altman suggested that new neurons were added into several regions of the adult rat brain, including into the olfactory bulb (OB) and dentate gyrus (DG)" (Lois, Adult Neurogenesis, Frontiers in Neuroscience, 8, 2014, 165). CONDITION & DETAILS: London: Macmillan & Co., Ltd. Complete issue. 4to. (11 x 8 inches). Light institutional stamp on front and rear wrap; slight edge wear. Otherwise bright and very clean throughout.