{"id":557,"date":"2021-01-13T18:00:00","date_gmt":"2021-01-13T23:00:00","guid":{"rendered":"https:\/\/ajeziorski.ca\/podcast\/?p=557"},"modified":"2022-07-27T20:19:14","modified_gmt":"2022-07-28T00:19:14","slug":"25-defining-the-anthropocene","status":"publish","type":"post","link":"https:\/\/ajeziorski.ca\/podcast\/25-defining-the-anthropocene\/","title":{"rendered":"25: Defining the Anthropocene"},"content":{"rendered":"\n

\u201cExtraordinary claims demand extraordinary evidence\u201d – Carl Sagan<\/em><\/p>\n\n\n\n

Our next episode on Topical Paleolimnology<\/a> examines the proposed new geological epoch<\/a> in the history of the Earth – the Anthropocene<\/a> (or “Age of Humans”). The definition of an epoch is complex, and paleolimnology may be fundamental to this one.<\/p>\n\n\n\n

The “official” timeline of Earth history is defined by the International Commission on Stratigraphy<\/a>, a subcommittee of the International Union of Geological Sciences (IUGS)<\/a>. <\/p>\n\n\n\n

\"The
The International Chronostratigraphic Chart<\/a><\/figcaption><\/figure><\/div>\n\n\n\n

Two key questions must be answered to define a stage on the geologic time scale<\/a>:<\/p>\n\n\n\n

1) \u201cWhen did the stage begin?\u201d 
2) \u201cWhat is the geologic marker that defines the beginning of the stage?\u201d<\/p>\n\n\n\n

Stages are defined either \u201cchronometrically\u201d at a specific time (e.g. 4.6B years ago), or based on a stratigraphic marker associated with paleontological changes (mostly marine fossils). These definitions are referred to as a Global Boundary Stratotype Section and Point<\/a> (GSSPs), or more colloquially as \u201cgolden spikes”, as they are locations where a literal golden spike is hammered into the rock.<\/p>\n\n\n\n

\"Photo<\/a>
GSSP (or golden spike) marking the Ediacaran Period<\/a><\/figcaption><\/figure><\/div>\n\n\n\n

To date, more than 60 golden spikes have been placed. Two are located in Canada, both in Newfoundland, Fortune Head<\/a> (the boundary between the Precambrian Era and the Cambrian Period) and Green Point<\/a> (the boundary between the Cambrian Period and the Ordovician Period).<\/p>\n\n\n\n

For now, we continue to reside in the Holocene<\/a> Epoch (i.e. the past 10,000 years since the last glacial period). The Anthropocene has not yet been formally recognised, and a Anthropocene Working Group<\/a> has been tasked with identifying a suitable marker to define a new golden spike.<\/p>\n\n\n\n

The criteria used to establish a GSSP include:<\/p>\n\n\n\n