Definition of 'paleosol', and 'soil', and comments on 'geosol'
Posted by Donald L. Johnson 07 Oct 1999 11:58:45
Colleagues: Somebody once said "He who shouts loudest gets the attention". Well, lets hope not. We all have a voice. So, with all due respect, here's mine. I suggest that the term 'paleosol' be used ONLY for buried soils, because this concept is consistent with first usage (Erhart, 1932, 1940), it honors priority, and most importantly it is most LOGICAL. To formally define 'paleosol' as "soils developed on landscapes of the past", as often has been done, and as has recently AGAIN been proposed, will guarantee -- I submit -- permanent and continued confusion. The "landscapes of the past" definition is what has embroiled the term 'paleosol' in controversy and confusion in the FIRST place -- even among practioners in the field! Do not institutionalize and codify the confusion by adopting this conceptually flawed definition for the Glossary of Paleopedology. Soils at the present land surface receive modern pedogenic imprints regardless of their genetic nature, or whether one pronounces them as relict, exhumed, old, very old, fossil, or whatever. In addition, all soils (pedons, polypedons, or whatever) have a different genetic history; they intuitively HAVE to have different histories! Somebody once said that Entisols "grow up" to be Ultisols, or Oxisols, or whatever. But, Oxisols can also "grow down", or change (evolve, regress, whatever) to Entisols when stability is replaced by denudation (by stream capture, baselevel changes, tectonics, or whatever). Pedogenesis moves in both directions, progressive and regressive. All soils have experienced changes and have theoretically imprinted the evolved conditions of all or most elements of the immediate and ambient environment (and not JUST climate). In other words, soils evolve due to the constantly changing multitudinous elements of the endogenous and exogenous environments, pure and simple. From this perspective, all soils are polygenetic. And if all soils are polygenetic, then the term "polygenesis" as applied to soils is probably unnecessary, other than to emphasize the point that all soils ARE polygenetic. If soil needs to be defined, it is best defined in very general terms, and one that seems to cover all cases is one that was suggested some years ago: "soil is material at the surface of planets and similar bodies altered by biologic, chemical, and/or physical agents". The definition is universal in scope, and calls attention to the apparent fact that pedogenesis on planet Earth is unique inasmuch as it is the only one with biologic agents. Notice that the term "soil" has been used in this discussion thus far, and in the discussions of all others who have contributed to this ongoing conceptual and terminological dialog, including those who protest its use, without much anxiety about what the hell soil is. Yet, it has been argued that the term "soil" is confusing, that it has varied and ambiguous meanings, and that in buried contexts it should be replaced with "geosol". I submit that this is pure nonsense. We all use the terms "soil" and "buried soil" regularly, and we understand what we mean as those terms are used in context. This is true with many words, in any language. Many textbooks contain "soil" in the title without making editors, publishers or readers the slightest bit nervous. "Buried soil" has been used well over a hundred years, a use begun by early giants in the field (e.g., McGee, Powell, and Leverett, among others). How many times has the term soil been used in this ongoing dialog where you have been confused about its meaning in context, about what the writer meant?
I do not agree with everything Vance Holliday wrote in his Newsletter note, but I do agree with most of it. I especially agree with what he said about "geosol", that it is an unnecessary and superfluous term regardless of the fact that it has been codified as a basic pedostratigraphic term in the North American Stratigraphic Code, where it replaced the time-honored "soil" (a mistake in my opinion). The expressions "buried soil" and "paleosol" are synonyms, and can replace "geosol" in every case without loss of understanding. Thanks for your attention, and thanks, Vance, for initiating this discussion. Confucious, or somebody (Aristotle?), said, "know thyself and nothing in excess" Hmmmm!
Attachment: See also: CELEBRATING 50 YEARS OF GEOGRAPHY AT ILLINOIS--1949-1999!
|