Anthropocene + Anthropogenic rocks

What is the Anthropocene?

It is an unofficial unit of geologic time, used to describe the most recent period in Earth’s history when human activity started to have a significant impact on the planet’s climate and ecosystems

What is it a formal Anthropocene defined by?

A Global Boundary Statotype Section and Point (GSSP)

A designated time boundary (a Global Standard Stratigraphic Age)

The beginning of the Anthropocene is most generally considered to be the year 1800 CE, around the beginning of the Industrial Revolution in Europe

What are other alternatives for the start of the Anthropocene?

Atomic bomb - creation of spike in rare radioisotopes which could be preserved in the geological record

Widespread creation of anthropogenic materials (e.g. concrete, plastics), widespread movement of material around the Earth’s surface

What is the point of the Anthropocene?

A new geological period gives focus to the challenges and impacts created by humans upon the Earth. Although it is extremely short compared to the geolocial timescales

What is artificial ground?

It is areas where the ground surface has been significantly modified by human activity.

It is unconsolidated sediment and in order for it to be a marker of the Antrhopocene, it must be preserved in the rock record by being consolidated and lithified.

What is made ground?

It is a type of artifical ground.

It can be made of:

Natural materials shifted by humans e.g waste rock from mining dumped in spoil heaps

Wholly anthropogenic materials e.g. concrete, slag and plastics

What’s an example of lithified artificial ground?

Coastal slag heap, Carnforth, Lancashire. It is slag from iron works.

The coastal side of the slag bank is clearly lithified. Can see clasts of slag but they are fused together by a cream coloured mineral material, hypothesised to be a mineral cement

Using an example describe how anthropogenic rocks can form

Concrete is an anthropogenic rock. It isn’t loose sediment and has all the properties of a rock. Could potentially survive into the rock record

Plastiglomerate. A sedimentary composed of clasts of natural beach pebbles, fused together with melted plastic.

Lithified colliery spoil by coast in northumbria. Sediment from coal mining has been deposited but subsequently thru interactions with sea water has become lithified.

Are anthropogenic rocks markers for the Anthropocene?

Lithification of artificial ground and creation of anthropogenic rocks with wholly anthropogenic materials in them could be preserved in the rock record. HOWEVER very little naturally deposited sediment is lithified.

it is often re eroded and retransported before lithification. so chances are LOW.

esp when considering all the other possiblities such as atomic bomb radioisotopes and microplastics.