The Monterey Event and the Paleocene‐Eocene Thermal Maximum

Abstract

The Columbia River Flood Basalts and the North Atlantic Igneous Province are two of the youngest Large Igneous Provinces (LIPs) and both are associated with perturbations of the global carbon-cycle. Here we explore the link between the emplacement and eruption of LIPs and their associated carbon-cycle and climatic responses. The emplacement of both LIPs are associated with two well-known climate events: the Monterey Carbon Isotope Excursion (MCIE; ~17-13.5 Ma) and the Paleocene-Eocene Thermal Maximum (PETM; ~56 Ma) characterized by a positive 1‰ and negative 3-5‰ carbon isotope excursion, respectively. Both are also associated with signifi cant global warming. However, despite these contrasting timescales and carbon isotope trends, boron-based proxy records indicate a similar surface ocean carbonate system response. In both cases, elevated LIP derived carbon dioxide emissions led to oceanic absorption of the carbon released causing a decline of surface ocean pH and an increase in dissolved inorganic carbon. We conclude that, although similar underlying carbon-cycle processes are at play during both events, their specific behavior is somewhat different as the magnitude, carbon emissions rate (slow vs. fast), and background climate state (icehouse vs. greenhouse) conspire to cause distinct carbon isotope expressions in the sedimentary record and variable climatic responses to each LIP emplacement.

Assessing Volcanic Controls on Miocene Climate Change

“…It has been proposed that MMCO length was extended by a delayed silicate weathering feedback (Babila & Foster, 2021), but our model results suggest the warm interval length is consistent with the single injection of mantle CO 2 , with no clear requirement for a delay in the onset of CRBG weathering to reproduce proxy data (Figure 2). Additionally, the scale of sequestration associated with silicate weathering of the CRBG does not appear to be sufficient to drive the transition to cooler climate after ∼13.9 Ma, the end of the MMCO (Steinthorsdottir et al., 2020), with proxy evidence suggesting a much more rapid shift to cooler temperatures than the SCION reconstruction (Figure 2g).…”

“…The CRBG represents the effusive phase of a Large Igneous Province (LIP) which erupted between 17 and 6 Ma (Barry et al., 2013; Kasbohm et al., 2021; Kasbohm & Schoene, 2018). Recent research indicates ∼95% of the CRBG was emplaced in a 750 kyr period from 16.7 Ma onwards (Kasbohm & Schoene, 2018), supporting the theory that volcanic greenhouse gas release may have led to the MMCO (Armstrong McKay et al., 2014; Babila & Foster, 2021).…”

Вспышки Численности Диатомовых Водорослей В Неогеновых Озерах Приморского Края: Причины И Последствия

“…Со среднемиоценовым временем, отметившимся углеродным событием Монтерей, во время которого содержание такого парникового газа, как СО 2 , в атмосфере повышалось до 470-630 ppm (Babbila, Foster, 2021), в отличие от со-ppm (Babbila, Foster, 2021), в отличие от со- (Babbila, Foster, 2021), в отличие от со-Babbila, Foster, 2021), в отличие от со-, Foster, 2021), в отличие от со-Foster, 2021), в отличие от со-, 2021), в отличие от современного, составляющего 300-450 ppm, связано формирование новокачалинского диатомита. Именно для этого диатомита была отмечена максимальная концентрация диатомей в осадках.…”