Computed Tomography: Application in Studying Biogenic Structures in Sediment Cores

Abstract

The study of biogenic structures in cores is hampered by the facts that the structures are generally exposed only on vertical surfaces, and that the area available for study is limited by typically small core diameter. Computed tomography (CT) gives a three-dimensional picture by producing a series of bedding-parallel sections. It thus provides a technique that gleans the maximum information possible from the limited volume of sediment without destroying the core. Enhanced images of beddingparallel traces in cores of unconsolidated sediments in CT images will facilitate the comparison of traces in modern and ancient deep-sea deposits. This comparison has been limited previously by the fact that horizontal traces, which are dominant in deep-water deposits, are poorly expressed on conventional vertically oriented X-radiographs of unconsolidated sediments. The detailed serial sectioning of cores by CT will also allow reconstruction of the tiering relationships of deep-water trace producers.