Voice from the Past (the DELTA Newsletter)

The Voice from the Past is the official DELTA newsletter. Published quarterly the "Voice" is the best way to keep up with the many and varied activities of DELTA members, including research project progress reports, development reports for DELTA databases, announcements, grant opportunities, perspectives, and lists of current publications. The newsletter is free to everyone and can either be downloaded directly from this web page or sent to you as an e-mail attachment if you are a Voice from the Past subscriber. Subscription details are provided below following a few highlights from the current "Voice".

Volume 1, Issue 4 Highlights

Stacks Image 621

New geochemical identification fingerprints of volcanism during the Ordovician-Silurian transition

Shengchao Yang
School of Earth Sciences and Engineering, Nanjing University

Volcanism has a significant influence on the environmental and biological evolution in geological history, usually recorded by volcanic ash layers (bentonites). However, most volcanic eruption materials were dispersed and mixed with sediments as cryptotephra (invisible volcanic ash layers), unrecognisable by the naked eye, making the role of volcanism in major geological events obscure. Therefore, identification of cryptotephra and reconstruction of the volcanic activities are critical for understanding its influence on the environmental and biological evolution during major geological periods.

At present, volcanism identification methods are classified into the following three aspects: First, empirical visual recognition, a method useful for describing visible bentonites, but it is not suitable for the thin ash layers. Second, mineral composition and morphological characteristics, a method used to distinguish dispersed volcanic shards from aeolian minerals within ice cores, but it is difficult to apply to sediments due to the complex composition of sediments and the diagenesis. Third, special elements and their related isotopic signatures, such as Hg and Δ199Hg. However, volcanism is not the only cause of Hg anomalies, and the mismatching between the isotopic signatures and volcanic ash occurrence suggest this method requires further assessment. Is there a widely comparable indicator that identifies the volcanic material and thus indicates volcanism? Via analysis and correlation of the sources, diagenetic processes, and geochemical features of bentonites, we established a set of new geochemical fingerprints for cryptotephra identification within shales.

Our results demonstrate that Zr, Hf, Zr/Cr, Zr/Al2O3, Cr/Al2O3, V/Al2O3, Ni/Al2O3, SiO2/Al2O3, and K2O/Rb were relatively reliable geochemical fingerprints of volcanic material input within shales, and useful in reconstructing the volcanic activities in the Lower Yangtze region during the O/S transition. These fingerprints indicate two stages of intensive volcanisms, during the middle–late Katian and at the Hirnantian/Rhuddanian transition, which were tightly coupled with the rapid biodiversity decline during middle- late Katian and the second pulse of the Late Ordovician mass extinction (LOME), respectively. The relationship between intensive volcanism and the two pulses of the LOME further supports a volcanic stressor for the biotic crises (Figure 1).


Yang, S.C., Hu, W.X., Fan, J.X., Deng, Y.Y. 2022. New geochemical identification fingerprints of volcanism during the Ordovician-Silurian transition and its implications for biological and environmental evolution. Earth-Science Reviews 228, 104016.

NSFC Excellent Young Scientists Fund (Overseas)

The Excellent Young Scientists Fund aims to attract and encourage overseas outstanding young scholars (including non-Chinese expatriates) who have made great achievements in the natural sciences, engineering, technology, and other similar fields to work in the PRC. The fund encourages young talent to conduct innovative research in their respective research direction, promotes the rapid growth of young scientific talent, cultivates a number of outstanding scholars in the frontiers of science and technology in the world, contributes to building the PRC’s strength in science and technology.

The funding amount is RMB 1-3 million for 3 years.

Applicants of Excellent Young Scientists Fund (Overseas) should meet the following qualifications:
  • Abide by the laws and regulations of the People's Republic of China, have good scientific ethics and consciously practice the scientific spirit in the new era;
  • Have a date of birth on or after January 1, 1983;
  • Have a doctorate degree;
  • The research mainly focuses on natural science, engineering technology, etc.;
  • Before March 15, 2023, the applicant should have obtained a formal teaching or research position in an overseas university, scientific research institution, or corporate R&D institution, with work experience of more than 36 consecutive months; for those who have obtained a doctorate degree overseas with particularly outstanding performance, the limitation of work experience may be appropriately relaxed;
  • The applicant shall have obtained the achievement of scientific research or technology recognized by peer experts, and have the potential of becoming an academic leader or outstanding talent in related fields;
  • The applicant who has not yet returned (or come) to work in China on a full- time basis, or returned (came) to work in China after January 1, 2022, must resign from the overseas work or have no work overseas after being notified of the grant of funding and return (come) to work in China full-time for at least 3 years.

Qualified applicants can sign a work contract or an agreement of intent with supporting institutions (including Nanjing University) in accordance with the requirements of the programme guidelines, and log in the information system(https://isisn.nsfc.gov.cn/) after January 15, 2023 to fill out the application form.
For more information, please contact Ms. Ariana Xu (ariana.xu@nju.edu.cn).


You may use this form to notify me of your subscription request; or you can e-mail your request to me at: ariana.xu@nju.edu.cn.