Environmental changes and global recovery of primary producers after the Cretaceous/Paleogene boundary (KPgB): A molecular fossil approach

Informations projet

EPROAMA

N° de convention de subvention: 101022128

DOI

10.3030/101022128

Projet clôturé

Date de signature de la CE 17 Mars 2021

Date de début 1 Janvier 2022

Date de fin 31 Decembre 2023

Financé au titre de

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Coût total

€ 224 933,76

Contribution de l’UE

€ 224 933,76

Coordonné par

UNIVERSITY OF BRISTOL
United Kingdom

Periodic Reporting for period 1 - EPROAMA (Environmental changes and global recovery of primary producers after the Cretaceous/Paleogene boundary (KPgB): A molecular fossil approach)

Période du rapport: 2022-01-01 au 2023-12-31

Résumé du contexte et des objectifs généraux du projet

I used this fellowship to study the environmental changes and global recovery of primary producers after the Cretaceous/Paleogene boundary (K-Pg): A molecular fossil approach (EPROAMA). This fellowship was carried out at the University of Bristol (UoB-UK) under the supervision of Prof. Richard D. Pancost.
The K-Pg (≈66.02 Ma ago). It represents the last of the five major mass extinctions in Earth´s history. Determining the nature of the associated rapid environmental change and biotic recovery is critical for understanding the cause and effects of this event, a key event in the history of life on our planet and potentially relevant for future biotic events.

My results show, the non-fossilising phytoplankton community was impacted at K-Pg event, as was reflected in the source and character of organic matter reached the seafloor. But in addition, the recovery time of this community (algae, bacteria, and archaea.) was very different depended to the distant to the impact site (distal and proximal sections).

1 Objectives

My EPROAMA proposal had the following specific research objectives, which were cut across 5 work packages (WP1-WP5):
1. Determine changes in algal organic matter (OM) inputs and their timing relative to the ejecta release and anoxia across the KPg section (Caracava) (WP3 and WP4).
2. Determine how long it took for pre-event distributions and conditions to return (WP3 and WP4).
3. Determine the carbon isotopic composition of n-alkanes (inferred to derive from leaf waxes), yielding one of the first and highest resolution terrestrial (atmospheric) records of carbon cycle disruption (WP4).

2. Explanation of the work carried per WP

-WP1: Management. Deliverables (D1.1 and D.1.2) were performed.
-WP2: Field work for sampling the Caravaca section from K-Pg. Deliverable D.2.1 was performed and a core from Caravaca section was recovery, but in addition, we also made another fieldtrip to take samples from other two outcrops located in USA. The Risk Management RM1 projected wasn't happened and the Milestone M1 was obtained perfectly.
-WP3: Analysis of organic compounds from K-Pg in the Caravaca section. Deliverable D.3.1 was performed and all extraction and analyses from Caravaca samples were finished. In addition, we also analyzed the samples from the others USA K-Pg sections. The Risks Management RM2 and RM3 projected weren't happened and the Milestone M3 was performed. I wrote 3 papers, 1 was published and 2 are under revision.
-WP4: Analysis of carbon isotopic composition of n-alkanes from Caravaca section. Deliverable D.4.1 was performed and all stable carbon isotopic composition on n-alkanes from Caravaca section and USA section were finished. The Risks Management RM2 and RM3 projected weren't happened and the Milestone M4 was in progress, I am writing 2 papers more.
-WP5: Disseminations and communications. Deliverables D.5.1 D.5.2 D.5.5 D.5.6 D.5.7 and D5.8 were performed. D.5.3 I am working on it, I bought the dominion, and I am working in the design and content of the webpage, and D.5.4 wasn´t performed for technical problems.

All lab work was carried out in the Organic Geochemistry Unit (OGU), based within the Schools of Earth Science and Chemistry at the UoB-UK,

Travail effectué depuis le début du projet jusqu’à la fin de la période considérée dans le rapport et principaux résultats atteints jusqu’à présent

During this project (January 2022 to December 2023), I performed several works:
I started with several fieldtrips to take a core/samples from Spain and USA K-Pg sections. Once obtained, samples were sealed and stored in a cold room and it was sub-sampled (at centimetres resolution).
The approach broadly encompassed the following methods. First, I determined total organic carbon contents to provide a record of OM burial and the context for changes in OM inputs. Second, ground Caravaca/USA samples were extracted by Soxlhet Extraction. The resulting total lipid extracts were separated by silica chromatographic column into apolar and polar fractions to allow their subsequent analysis. Third, the key biomarker abundances and distributions were determined by GC and GC-MS in the apolar fraction and by HPLC/APCI-MS for GDGTs (in the polar fraction), to ascertain changes in OM source, algal assemblages (steranes), terrestrial biomarker (n-alkanes), redox state (pristane/phytane ratio; homohopane index; gammacerane; Isorenieratene), microbial inputs (hopanes) and GDGTs characterization (BIT index, terrestrial and sea surface Temperature (SSTTEX86). I also explored changes in ‘apparent thermal maturity’ which could reflect changes in re-worked, sedimentary OM inputs, e.g. changes in C31 hopane ratio. Finally, I determined compound specific isotope analysis of stable carbon in lipid biomarkers (n-alkanes, acyclic isoprenoids, and hopanes), to obtain novel and high-resolution records of terrestrial (atmospheric) and marine carbon cycle disruption, used highly specialised GC-IRMS.

The dissemination of my results within a scientific and international audience, was via three ways:
• By published (1), submitted (4) my research results in SCI-journals, all of them were first authored by myself, in international and national peer review journals.
• By attending targeted international and national conferences (5) such as, BOGS July 2022 (Southhampton-UK) and July 2023 (Durham-UK); Gordon Research Conference (GRC) and Gordon research seminar (GRS) in Organic geochemistry (New Hamshire-USA) July-August 2022; IMOG 2023 (Montpellier-France) Septamber 2023.
• By attending targeted international Workshops (2) such us, UK-IODP Workshop, November 2022 (Southampton-UK); 2nd International Workshop on GDGTs, September 2023 (Zurich-Switzerland).
For the non-specialized sector, I intend to use a social media supported website, as well as press releases associated with my publications, as effective ways to disseminate results and progress. Furthermore, the UoB supports Gender Equality in RRI terms and I also took into account the possible gender differences in the innovation content and dissemination activities throughout my research.

My main research topic is very interesting for a wider type audience, so I participated in several outreach activities:
• Festival of Nature 2022 and 2023.
• European Researchers’ Night in September 2022and 2023.

Finally, I used social media platforms like ResearchGate, Facebook or LinkedIn as tools of research dissemination and public engagement.

Progrès au-delà de l’état des connaissances et impact potentiel prévu (y compris l’impact socio-économique et les conséquences sociétales plus larges du projet jusqu’à présent)

At present, there is strong agreement that we need to enhance our knowledge of the inter-linked climate-biotic system. In particular, climatic system and biodiversity research are priorities at the European/Global level and are one of the United Nations Sustainable Development Goals (Goal 13-climatic action). Future projections require past analogues to understand climate responses. In this context, the study of past climate variability and biotic consequences can provide relevant insights into future scenarios, as well as for climate modellers that can incorporate paleoclimate data in models for predictions/perspectives on how the Earth’s climate will change and the biological recovery from environmental crises. The innovative application of both organic and inorganic proxies of this proposal brings together two different research fields with a common objective and wider perspective. Other than the scientific impact, my interesting results from this work, could contribute in a soon future to an EU-scale conversation about climate change, both in the public and governance arenas.

Outcrops analysed from K-Pg boundary at this MCSA fellowship