Professor Gastaldo’s research focuses on several key paleontological and sedimentological questions. These include: (1) the nature of the terrestrial fossil record over deep time; (2) the taphonomic processes (death, decay, disarticulation) involved in preserving the biosphere in the sedimentary record; (3) the nature of coal and coal-bearing systems; and (4) how fossil assemblages are used to understand ecosystem stability, perturbation (short- and long-term disturbance), turnover, extinction, and replacement.
Over the course of his career, he has undertaken both macrofossil and microfossil studies in, and published results with a wide variety of collaborators on:
- Modern (Holocene) coastal plain and deltaic, plant-and-peat accumulating regimes primarily in the: (1) Mobile-Tensaw River Delta, Alabama, USA; (2) Mahakam River Delta, Kalimantan, Indonesia; and (3) Rajang River Delta, Sarawak, East Malaysia.
- The application of plant-fossil proxies to understanding and interpreting deep time climate states.
- Paleogene (66—23 mya) and Neogene (23—2.6 mya) coal-bearing intervals of central Europe, concentrating on Braunkohle (lignite-grade coal) and the landscapes in which they formed prior to, and including, the Miocene Thermal Optimum.
- Permian to Early Triassic (290—248 mya) rocks of the Karoo Basin, South Africa, testing the hypothesis of synchronous ecosystem collapse in response to the End Permian Mass Extinction (252.2 mya).
- Late Carboniferous (Pennsylvanian; 323 mya) to Early Permian (290 mya) ecosystems of the paleotropical equatorial belt in North America (Illinois, Black Warrior, Maritime basins), Europe, and China.
- Early Carboniferous (Mississippian; 330—323 mya) coal-bearing ecosystems in the Silesian Coal Basin of the Czech Republic and Poland.
- Early to Middle Devonian (408—388 mya) terrestrial and coastal ecosystems in Maine, New Brunswick, and the Canadian Maritimes.