Characteristics and Genesis of the Parleys and Mendon Soils Series in Northern Utah

Khalid I. Al-Amin, Utah State University


The study was designed to test the genetic theory of soil development of two soils derived from different geological material, but developed under conditions of similar climate , topography, biological activity, and age. An attempt wa s made to relate the soils charac teristics to their present classification . Parleys and Mendon series which developed from Bonneville and Salt Lake Formation , respectively, were selected for that purpose. Along the east side of Cache Valley, two pedons representing each of the studied series were sel ected to have si~ilar soil formers except for their parent material.

Evidently, the se studied soils have been developed from di.ff erent heterogenous sediments . Mendon soils have been developed from Salt Lake Formation to at l east 51 em depth, ~vhereas, the solum horizons are a tt ributed to the Bonneville Formation. The Parleys soil seems to be n.J ·inJy Jevel(,)ped from Bonneville Formation. But the upper solum horizons are rrobably inte rlaye red with fine deposits of Holocene age . Those soils which de rived from differe nt geologica] dcposi ts sl!mv .J high degree of similarity between them. Heterogenlty and the nature of the soil parent mat e rial, and similarity of their climatic and developmental conditions are believed to be the major causes to inhibit many genetic variables between them.

In Northern Utah, the Mendon soils are classified as Calcic Pachic Argixerolls , at the subgroup level. This study has shown that most of the Mendon pedons do not have a Pachic epipedon. Therefore , these s tudi ed soil s could he gr ouped toge ther in one subgroup. The result is Calcic Argixerolls in fine-silty, mixed, mesic family. Re-examining Mendon series in Cache Valley and reclassifying them on the basis of Pachic epipedon would be an interesting Subject for further study.