New Haven: 1907. 1st Edition. FIRST EDITION OF THE 1st PUBLISHED DESCRIPTION OF THE USE OF RADIOMETRIC DATING (Boltwood) & THE FIRST IDENTIFICATION OF THE 1st GREAT GLACIATION OF EARTH (Coleman).
BOLTWOOD: Boltwood’s use of radiometric dating remains “the principal source of information about the absolute age of rocks and other geological features, including the age of fossilized life forms or the age of the Earth itself, and can also be used to date a wide range of natural and man-made materials" (Wikipedia). The paper offered is the first appearance of his work.
In 1902 Rutherford & Soddy discovered radioactive elements, then “broke them down into other elements in a predictable sequence or series. Boltwood studied this concept of "radioactive series," and found that lead was always present in uranium and thorium ores. He believed that lead must be the final product of the radioactive decay of uranium and thorium. A few years later, in 1907, he reasoned that since he knew the rate at which uranium breaks down (its half-life), he could use the proportion of lead in the uranium ores as a kind of meter or clock. The clock would tell him how long that ore -- and by extension, the earth's crust -- had existed. His observations and calculations put Earth's age at 2.2 billion years. This was a dramatic increase in the estimate of Earth's age for the time” (PBS, People and Discoveries).
COLEMAN: In the paper offered here, Coleman identifies the "Huronian glaciation," the first great glaciation of the Earth, which took place 2.4 Gya to 2.1 Gya, resulting from the "Great Oxidation Event." Geologists were startled when, in this paper, Coleman announced that he had discovered glacial deposits in the Precambrian of Cobalt, Ontario. His discovery, The Huronian glaciation “is the oldest series of protracted climatic refrigeration events that extensively affected Earth. It occurred between 2.45 and 2.22 Ga in association with the rise of atmospheric oxygen. Three glaciations of that series, the classical Huronian ice ages, are bracketed in time between ~2.45 and 2.32 Ga; the fourth event, recognized so far only in South Africa, is ~2.22 Ga in age. During these events, glaciers covered continents, extended to low latitudes, and reached to sea level. The ice ages were followed by a protracted time interval with greenhouse (warm and humid) conditions. The name is derived from the Huronian Supergroup exposed on the north shore of Lake Huron in Ontario, Canada, between Sault Ste. Marie, Sudbury, and Cobalt” (Bekker, Huronian Glaciation, Encyclopedia of Astrobiology, 2015). Item #1384
CONDITION & DETAILS: First edition bound in old, pebbled buckram that, save for slight scuffing at the edge tips, is in almost perfect condition. Library plate on front paste-down and stamp on title from Case School of Applied Science; almost invisible “CSAC” at base of spine; pages somewhat tanned throughout. Clean throughout. A handsome volume.