Hornblende etching and quartz/feldspar ratios as weathering and soil development indicators in some Michigan soils

Abstract Weathering can be used as a highly effective relative age indicator. One such application involves etching of hornblende grains in soils. Etching increases with time (duration) and decreases with depth in soils and surficial sediments. Other variables, related to intensity of weathering and soil formation, are generally held as constant as possible so as to only minimally influence the time-etching relationship. Our study focuses on one of the variables usually held constant-climate-by examining hornblende etching and quartz/feldspar ratios in soils of similar age but varying degrees of development due to climatic factors. We examined the assumption that the degree of etching varies as a function of soil development, even in soils of similar age. The Spodosols we studied form a climate-mediated development sequence on a 13,000-yr-old outwash plain in Michigan. Their pedogenic development was compared to weathering-related data from the same soils. In general, soils data paralleled weathering data. Hornblende etching was most pronounced in the A and E horizons, and decreased rapidly with depth. Quartz/feldspar ratios showed similar but more variable trends. In the two most weakly developed soils, the Q/F ratio was nearly constant with depth, implying that this ratio may not be as effective a measure as are etching data for minimally weathered soils. Our data indicate that hornblende etching should not be used as a stand-alone relative age indicator, especially in young soils and in contexts where the degree of pedogenic variability on the geomorphic surface is large

Saline soils: a potentially significant geoheritage of the Vojvodina region, Northern Serbia

Halomorphic (or saline) soils, are characterized by high concentrations of soluble salts or sodium, or both. Saline soils have unfavorable agricultural properties but provide the natural habitats for a variety of highly specialized plants, animals, and other organisms. It is these special interactions that create the typical landscape of saline soils, known as “slatina”. The aim of this study is to assess and evaluate the geotouristic potential of six of the most attractive slatina sites in the Vojvodina region, Northern Serbia: Jegrička, Slano Kopovo, Rusanda, Okanj, Pečena slatina, and Pašnjaci Velike Droplje. Overall, all analyzed sites have significant tourism potential, based on both natural and tourist values. In addition to the tourism potentials, analyzed sites have high value as a natural endemic ecosystem inhabited with highly specialized plants and birds

Mapping the physiography of Michigan with GIS

Abstract: We present a new physiographic map of Michigan, that is also available interactively, online. Only four, small-scale physiographic maps of Michigan had been previously published. Our mapping project made use of a wide variety of spatial data, in a GIS environment, to visualize and delineate the physical landscape in more detail than has been done previously. We also examined many of the unit boundaries in the field, using a GIS running on a GPS-enabled laptop. Unlike previous physiographic maps, the online version of the map enables users to query the criteria used to define each of the 224 boundaries of its 10 major and 91 minor physiographic units. The interactive nature of the online version of the map is a unique enhancement to physiographic maps and mapping. Our study also provides data on the number and types of criteria used to define each of the 224 unit boundaries within the map. Most of our unit boundaries are based on data derived from 10-m raster elevation data and NRCS soils data, e.g., relief, soil wetness, escarpments, landscape fabric, and parent material characteristics. Data gleaned from NRCS SSURGO county-scale soil maps were a strength of the project

Approaches and challenges to the study of loess—Introduction to the LoessFest Special Issue

In September 2016, the annual meeting of the International Union for Quaternary Research's Loess and Pedostratigraphy Focus Group, traditionally referred to as a LoessFest, met in Eau Claire, Wisconsin, USA. The 2016 LoessFest focused on thin loess deposits and loess transportation surfaces. This LoessFest included 75 registered participants from 10 countries. Almost half of the participants were from outside the United States, and 18 of the participants were students. This review is the introduction to the special issue for Quaternary Research that originated from presentations and discussions at the 2016 LoessFest. This introduction highlights current understanding and ongoing work on loess in various regions of the world and provides brief summaries of some of the current approaches/strategies used to study loess deposits

Soils: genesis and geomorphology

The book's introductory chapters in soil morphology, mineralogy, chemistry, physics, and organisms prepare the reader for the more advanced treatment that follows. Unlike its competitors, this textbook devotes considerable space to discussions of soil parent materials and soil mixing, along with dating and paleoenvironmental reconstruction techniques applicable to soils. Although introductions to widely used soil classification systems are included, theory and processes of soil genesis and geomorphology form the backbone of the book. Replete with more than 550 high-quality figures and photos and a detailed glossary, this book will be invaluable for anyone studying soils, landforms, and landscape change anywhere on the globe

Spodosol development as affected by geomorphic aspect

ABSTRACT In midlatitude locations with steep slopes, geomorphic aspect can be an important factor in determining spatial variations in soil development. This study examines the influence of aspect on soil development in Baraga County, Michigan, as a means of explaining within-landform variability. The soils are sandy and have spodic morphologies. All are located on steep slopes (45-73%) of contrasting aspect. Ten pedons each from backslopes on north-to-northeast-(N-NE) and south-tosouthwest-(S-SW) facing slopes were described, sampled, and compared using standard techniques. Variation in slope gradient was not, statistically, a determining factor in the differential soil development found here. Aspect has strongly influenced soil development, however, with soils more strongly developed (i.e., more podzolized) on 1N-NE slopes than on S-SVV slopes. Several soil characteristics indicative of strong podzolization were found on N-NE slopes, including higher values of solum thickness and POD index, greater losses of extractable Fe and Al from E horizons and concomitant gains in B horizons, and darker and redder B horizon colors. Soils were generally cooler on N-NE slopes in summer, with essentially similar temperatures under snowpacks in winter. Cooler temperatures and greater amounts of infiltrating water in soils with N-NE aspects may have accelerated podzolization by allowing more organo-metallic complexes to be formed and translocated. Podzolization driven by translocation of amorphous, inorganic compounds appears, however, to be nearly equivalent on sites of differing aspect. Of the ten pedons on N-NE slopes, nine classified as Spodosols (Entic or Typic Haplorthods) and the other was an Entisol. Seven of the 10 pedons on S-SW slopes classified as Entisols (Udipsamments or Udorthents), and the remaining three were Spodosols