A Perspective on Stratigraphic, Vertically-Upward “Displacements or Dislocations” of Conodont-Elements: An Example From the Upper Devonian, Pre-Lithified, Black Shales of the Chattanooga Shale Formation In Tennessee, USA

Abstract

Stratigraphic “displacements or dislocations” are coarse clasts and / or objects (such as unaltered remains or conodont-elements) slowly mobilizing or migrating vertically upward through a fine-grained matrix by a cryogenetic process known as “upfreezing” due to freezing temperatures. The process was originally established by periglaciologists and cold-climate geomorphologists who applied it only to unconsolidated, sedimentary deposits. In this study, the process is applied to the marine, pre-lithified, black shales of the Upper Devonian, Chattanooga Shale Formation, specifically in Tennessee, USA. The importance of this recognition is to alert paleontologists and stratigraphers about the strong possibility of inaccurate age-determinations made concerning coarse objects such as a conodont-element (denticles) (but not fossilized molds) because of their fossilized presence in age-determined, stratigraphic, rock levels when the apatite-composed denticles may have instead been initially deposited at a lower stratigraphic level during pre-lithification of the fine-grained, host-rock (shale) before the paleo-upfreezing process mobilized the denticles upwards. Many lines of evidences are given in this study towards apparent, predominant, freezing temperatures in the pre-existing, Chattanooga Sea of the Appalachian Basin, including particular, supposed, bioturbated, pre-lithified, organic black shale that is reinterpreted here as cryoturbated, pre-lithified, organic, black shale.