The Great Carbon Machine
Source Institution: Smithsonian National Museum of Natural History
Source Exhibit: David H. Koch Hall of Fossils - Deep Time
Source Url: https://naturalhistory.si.edu/visit/virtual-tour/current-exhibits/deep-time-virtual-tour-fossil-list
Source Kind: interpretive_topic_or_panel
Use: research inspiration only; SAGE will write original interpretation
Dossier Status: scientifically_enriched_concept_room_01
Plain Language Explanation: Carbon continually moves among Earth's atmosphere, oceans, living organisms, soils, sediments and rocks. Some exchanges happen quickly through photosynthesis, feeding, respiration and decomposition. Other carbon moves through slow geological pathways involving weathering, burial, carbonate formation, subduction and volcanism. Over deep time, this cycling links life, climate, oceans and the solid Earth.
Evidence: Carbon occurs in atmospheric carbon dioxide, living tissue, dissolved ocean chemistry, soils and rocks.; Photosynthesis transfers atmospheric or dissolved carbon into biological material.; Burial and mineral formation can store carbon in sediments and rocks over geological time.; Volcanism and other geological processes return carbon from Earth's interior to the surface system.
Examples From Collection: Quercus sp. petrified wood; Pinophyta indet. mineralized wood; Pecopteris strongii leaf; Plant fossils demonstrate that carbon once held in living tissue can become part of the geological record.
Common Misconception: The carbon cycle is not only an atmospheric process. Most of Earth's long-term carbon story involves oceans, sediments, rocks and geological processes operating across enormous spans of time.
What Scientists Still Debate: The major carbon reservoirs and pathways are well established, but scientists continue to refine how quickly carbon moved through ancient Earth systems and how those changes affected past climates and ecosystems.
Sources: https://www.usgs.gov/media/images/usgs-carbon-cycle; https://www.usgs.gov/science/science-explorer/natural-hazards/how-the-earth-moves
Enrichment Method: SAGE original interpretive concept; source title retained; evidence separated from reconstruction and open questions