Excerpt from Silurian Radiolarian Zonation for the Caballos Novaculite, Marathon Uplift, West Texas Since fossils could not be observed in the field, a variety of sampling strategies were employed to max imize fossil recovery. Some sections were sampled in great detail on a bed-by-bed basis over several meter intervals Payne Hills 11 section) and other sections were sampled by collecting composite samples of two to four adjacent beds at 50 cm intervals to increase chances of recovery. Composite samples are indicated by a c following the sample number (text-figure Some of the productive sections that were sampled by the composite method were later re-sampled for single bed samples Monument Creek). Access to parts of the field area became restricted in 1989 and limited the amount of re-sampling. Limited access was allowed for a finite number of excursions in 1990, during which I focused on collecting from unsampled and under sampled localities. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

This paper presents a local biozonation for Silurian radiolarians recovered from the Caballos Novaculite, Marathon uplift, Texas. Six measured sections representing 25-30 m of strata from the western half of the uplift have yielded abundant and moderately well-preserved radiolarian assemblages that can be subdivided into six biozones. The Rotasphaerid Superzone (Ro), contains the four oldest zones 1, 2, 3, and 4, and is defined by the first and last appearances of the superfamily Rotasphaeracea. The base of this superzone has not yet been determined in the Marathon uplift. All taxa chosen for this biozonation are commonly occurring, distinctive, robust forms that can be correlated from section to section, thereby meeting the criteria for establishing a practical and widely applicable biostratigraphic scheme.