Fig. 6: Spatial and temporal distribution of organic-rich shales and coals during the late Paleozoic.
From: Tectonic–astronomical interactions in shaping late Paleozoic climate and organic carbon burial
a The distribution of organic-rich shales and coals across different paleolatitudes and time periods during the late Paleozoic. Each point represents a deposit from a marine, marginal, or lacustrine environment, with the color-coded dots corresponding to different depositional environments: blue for marine, green for MNT (Marine-nonmarine transition zone), and orange for lacustrine. Horizontal bars indicate age uncertainty associated with each deposit. The top histogram shows the frequency of organic-rich sediment deposition over time, while the side histogram shows their distribution by paleolatitude. The denser accumulation of deposits in tropical to subtropical regions (0° to 40° paleolatitude) is evident, especially during tectonically relatively stable periods such as Phase II. b The spatial distribution of organic-rich shales and coals during different tectonic phases. The majority of organic-rich deposits during Phase II are located in tropical and subtropical latitudes, with a relatively high density compared to the more broadly distributed records in Phases I and III (See Fig. S9 for details).
