Post by Lorenzo Luciani

HESS PART 1 “I shall consider this paper an essay in geopoetry.” So said the author of the most cited work in solid-earth geophysics between 1966 and 1968, entitled “History of Ocean Basins,” published in 1962. Harry Hammond Hess (1906–1969) was responsible for introducing this neologism to define the spreading of the ocean floor, characterized by the birth and destruction of the Earth’s crust: a context that inspired his poetic vision. Born in New York, Hess entered Yale University in 1923 as an electrical engineering student, but soon turned to geology. After graduating in 1927, he undertook two arduous years of geological surveying in Northern Rhodesia, now Zambia. In 1929, he began his doctoral studies at Princeton University, culminating in 1932 with a dissertation summarizing his field and laboratory work on a body of altered peridotite outcropping at Schuyler, Virginia. Together with William Maurice Ewing (1906–1974), Hess had participated the previous year aboard a submarine in a submarine gravity survey in the West Indies, under the supervision of Felix Andries Vening Meinesz (1887–1966). This experience would lead to the publication in 1938 of his first major work, on island arcs and their origin, and the rank of lieutenant. For twenty years, beginning as a doctoral candidate, Hess conducted detailed mineralogical studies of pyroxenes in mafic and ultramafic magmas, clarifying their paragenetic relationships and introducing unit-cell analysis of orthopyroxenes and clinopyroxenes by X-ray diffractometry. Peridotite was always the object of his profound scientific devotion, as he immediately realized that this mantle-derived rock held the key to understanding the deep structure of the Earth's crust and recognizing ancient mountain ranges. At the 17th International Geological Congress held in Moscow in 1939, Hess presented a paper on the relationships between island arcs, gravity anomalies, and peridotite. During the farewell banquet, a fearful silence fell over those present when, referring to the Ural Mountains, he curtly uttered the words: "Here is the revolution...", later specifying "the Hercynian revolution." This was followed by a wave of relief and cheers, as Stalinist dogma had not been challenged by his wit. Many of the conclusions of this report were later abandoned, but the central role of peridotite never faded in subsequent theories on the nature and behavior of the oceanic crust.