STUDY OF RADIOLARIA CONTAINED WITHIN CALCIUM PHOSPHATE CONCRETIONS IN PENNSYLVANIAN AGE ANNA, EXCELLO, MUNCIE CREEK AND OAKLEY BLACK SHALES FROM MISSOURI, KANSAS AND OKLAHOMA

There has been insufficient study of radiolarian faunas and other fossils in Pennsylvanian phosphorite concretions over the last 50 years since they were first studied. The aim of this paper is to examine, identify and study radiolarian microfaunas contained within selected Pennsylvanian age phosphorite concretions. We selected the following units due to ease of collection; Anna, Muncie Creek, Excello, and Oakley black shales. Calcium phosphate concretions from these deep water black shales contain a diverse fauna of macroscopic and microscopic organisms. Macrofaunas range from fish dermal denticles, teeth, coprolites, cartilage, bellerophontid gastropods, inarticulate brachiopods, ammonoid and nautiloid fragments. Microfaunas include foraminifera, siliceous sponge spicules, condonts and radiolaria. The overwhelming majority of radiolaria specimens that have been found in the collected phosphate concretions are spherical forms, possibly entactinids. Radiolarian tests which were originally silica (opal-A) have been replaced by calcium phosphate (phosphorite). Tests from these radiolarians have been preserved with and without their inner shells and are often very abundant, being preserved on top of each other with a variety of external spines. Concretions collected from the neostratotype and other Excello Shale localities preserved the most diverse and abundant radiolarian faunas. The lack of Pseudoabaillella spp., Albaillella spp., and triangular radiolarian forms in phosphate concretions from all localities was noted. The lack of these radiolarian types in these assemblages suggests they were not living at these locations, were minor components of the assemblages, or were not encountered during the thin sectioning process. Some concretions (from Lee’s Summit, MO) were collected from a skeletal packstone (probably Raytown Limestone Member of the Iola Formation) instead of a phosphatic black shale where they normally form authigenically at the surface water interface in intergranular pore space. These concretions are weathered and highly abraded suggesting reworking from an older deep water black shale (possibly Muncie Creek Member) and deposition in a shoal water environment during the Pennsylvanian.