Stratigraphy & Sedimentology
-Sedimentology and carbon isotope stratigraphy of the Toarcian (Lower Jurassic)
(e.g., Izumi et al., 2012; Kemp and Izumi, 2014)
-Sedimentology of the Lower-Middle Pleistocene
(e.g., Nishida, Kazaoka, Izumi et al., 2015)
Paleoceanography
-Toarcian (Early Jurassic) oceanic anoxic (T-OAE) event recorded in shallow-marine deposits of Japan
(e.g., Izumi et al., 2012; Kemp and Izumi 2014)
Ichnology
-Application of isotopic, mineralogical, and geochemical approaches in ichnology to reveal the paleoecology of the trace-makers
(e.g., Izumi 2012; Izumi 2014, Spanish Journal of Palaeontology; Izumi 2014, Ichnos)
-Paleoecology and paleobiology of trace fossils, especially using the ichnogenus Phymatoderma
(e.g., Izumi 2013; Izumi in press, Acta Palaeontologica Polonica; Izumi et al. 2014; Izumi and Yoshizawa in press, Journal of Paleontology; Izumi, 2015, Palaeo3; Izumi, 2015, Geobios)
-Application of trace fossils to interpret sedimentary environments
(e.g., Nishida, Kazaoka, Izumi et al., 2015)
-Ichnofabric analysis
Paleontology
-Marine vertebrate coprolites
(e.g., Nakajima and Izumi, 2014)