Cores from Searsville Lake within Stanford University’s Jasper Ridge Biological Preserve, California, USA, are examined to identify a potential GSSP for the Anthropocene: core JRBP2018-VC01B (944.5 cm-long) and tightly correlated JRBP2018-VC01A (852.5 cm-long). Spanning from 1900 CE ± 3 years to 2018 CE, a secure chronology resolved to the sub-annual level allows detailed exploration of the Holocene-Anthropocene transition. We identify the primary GSSP marker as first appearance of 239,240Pu (372–374 cm) in JRBP2018-VC01B and designate the GSSP depth as the distinct boundary between wet and dry season at 366 cm (6 cm above the first sample containing 239,240Pu) and corresponding to October-December 1948 CE. This is consistent with a lag of 1–2 years between ejection of 239,240Pu into the atmosphere and deposition. Auxiliary markers include: first appearance of 137Cs in 1958; late 20th-century decreases in δ15N; late 20th-century elevation in SCPs, Hg, Pb, and other heavy metals; and changes in abundance and presence of ostracod, algae, rotifer, and protozoan microfossils. Fossil pollen document anthropogenic landscape changes related to logging and agriculture. As part of a major university, the Searsville site has long been used for research and education, serves users locally to internationally, and is protected yet accessible for future studies and communication about the Anthropocene. Plain Word Summary: The Global Boundary Stratotype Section and Point (GSSP) for the proposed Anthropocene Series/Epoch is suggested to lie in sediments accumulated over the last ~120 years in Searsville Lake, Woodside, California, USA. The site fulfills all of the ideal criteria for defining and placing a GSSP. In addition, the Searsville site is particularly appropriate to mark the onset of the Anthropocene, because it was anthropogenic activities–the damming of a watershed–that created a geologic record that now preserves the very signals that can be used to recognize the Anthropocene worldwide.
Bibliographical noteFunding Information:
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by Haus der Kulturen der Welt, Jasper Ridge Biological Preserve, Stanford University, the Howard Hughes Medical Institute, and the United States Geological Survey.
We thank the Haus der Kulturen der Welt (HKW, Berlin) for collaborating with the Anthropocene Working Group in the assessment of the candidate GSSP-sites. The collaboration was realized in the framework of HKW’s long-term initiative Anthropocene Curriculum, an international project for experimental forms of Anthropocene research and education developed by HKW and the Max Planck Institute for the History of Science (MPIWG, Berlin) since 2013. We are grateful to Dan Powers and Pete dal Ferro (USGS Marine Facilities) for critical assistance collecting the cores; to Brandon Nasr (USGS), Steven Gomez (JRBP), and JRBP staff for logistical support in the field; Stanford Environmental Measurements Facility for use of shared equipment; the National Lacustrine Core Facility (LacCore) for diatom sample processing; Monique Belanger (NAU) for pollen processing; and to Clarke Knight (USGS) and two anonymous reviewers for manuscript review. Thanks also to Nona Chiariello (JRBP), Trevor Hébert (JRBP), David Mucciarone (Stanford SIBL), and the Hadly Lab. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by Haus der Kulturen der Welt, Jasper Ridge Biological Preserve, Stanford University, the Howard Hughes Medical Institute, and the United States Geological Survey.
© The Author(s) 2023.
- elemental analyses
- heavy metals
Continental Scientific Drilling Facility tags
PubMed: MeSH publication types
- Journal Article