A review and field guide for the standardized description and sampling of paleosols

Abstract

Paleosols are unrivaled terrestrial archives of paleoclimatic, paleoecological, and paleoenvironmental conditions, yet their full utility and potential for unlocking critical information about past ecosystems, as well as their comparability with other records, is dependent upon the quality and thoroughness of such studies. To help standardize communication and compatibility in and between paleopedology studies, a systematic review was conducted with the goal of providing a “field-guide” for helping investigators approach paleosol identification, description, classification. A paleosol logging sheet template was developed to help standardize field data collection and note taking, which includes a list of 30 items that should ideally be described. An accompanying sample log sheet was also developed to assist with collection of key data during the sampling phase of paleosol investigations. Based on this review, we conclude that examination of fresh surfaces focusing on horizonation, color, structure (peds), pedogenic features, mineral accumulations, and bioturbation (burrows/chambers and root traces) is critical to all paleosol investigations and standard field testing should include color of the paleosol matrix and mottles present, carbonate content, redoximorphic conditions, and presence of organic matter. To further facilitate this work, we have illustrated and tabulated key paleosol features and classification schemes, including horizon determination and classification; ped determination and classification; mottle description; mineral accumulation description/morphology; burrow/chamber morphology and description; and rhizolith morphology and classification. In addition, a review of best practices in the collection of samples for subsequent laboratory analyses and paleoenvironmental interpretations is presented.