Dr. Inga Köhler

Inga Köhler works on the topic of Early life and Archean Banded Iron Formations

Dr. Dipl.-Geol.


Inga Köhler
Postal Address: Friedrich Schiller University of Jena
Institute of Geosciences
Burgweg 11
07743 Jena
Office: Room H309B
Phone: +49 3641 948 636
Fax: +49 3641 948 622

Since 04/2014

Research Associate at the Institute of Earth Sciences, University of Jena


PhD in Geomicrobiology at the Centre of Applied Geosciences, Eberhard-Karls University of Tübingen

PhD Thesis: Simulating diagenesis in Precambrian Banded Iron Formations


Diploma in Geology and Paleontology at the Friedrich-Alexander University Erlangen/Nürnberg

Diploma thesis: Growth banding in Silurian Stromatoporoids on Gotland

Diploma mapping: Facies mapping of the western Rhatsberg near Erlangen

Lectures and exercises

Eberhard Karls UniversityTübingen (2008-2011):

  •  Laboratory course Geomicrobiology (Shortcourse)
  • Geomicrobiology for Geologists (Exercise)

Friedrich Schiller University Jena (since 2014):

  •  Sedimentology (Exercise): 1SWS, Summersemester 2014 and 2015
  •  Introduction into Geosciences: 2SWS, Wintersemester 2014 and 2015
  •  Historical Geology: 3SWS, Wintersemester 2014, 2015 and 2016 with C. Heubeck and P. Frenzel
  •  Sedimentpetrology (Shortcourse): 2SWS, Wintersemester 2015 and 2016 with S. Henkel

Field training & Fieldtrips

Friedrich Schiller University Jena (since 2014):

  •  Fieldseminar Sedimentology (2014): 5 days



Moodies Group, Barberton Greenstone Belt, South Africa

The Moodies Group (ca. 3.2 Ga) of the Barberton Greenstone Belt, South Africa host nearshore depositional environments with structures that resemble microbial mats. The biogenicity of these structures has yet to be confirmed, however, isotopically light kerogen and remains of cellular structures strongly suggest a biological origin.

One goal of my work is therefore to verify the biogenicity of these presumed microbial mats by additional analysis of:

  • Fossil structures by microscopy, SEM, CLSM and nano-SIMS, etc.
  • Kerogen by C-Isotope, Raman spectroscopy and biomarker, etc.

In case biogenicity can be verified, the internal complexity as well as the metabolism and ecology of these microbial mats will further be studied in order to constrain early metabolic pathways and better understand early strategies of life.

Their age, abundance, diverse morphology, good preservation and well-defined paleoenvironments make these mats an ideal object to expand our knowledge of early life and to contribute to our knowledge of biologic diversification, and the rise of oxygen on early earth.


Biogenicity of Precambrian Banded Iron Formations

Furthermore, I am interested in the biological mediated formation of Precambrian Banded Iron Formation (BIFs).

My PhD work involved the simulation of diagenesis in BIFs through temperature and pressure induced iron mineral transformation in high pressure- high temperature autoclaves. I development a suitable experimental system for the laboratory study of biogenic mineral diagenesis and a protocol to identify and quantify gaseous, dissolved and mineral products formed during diagenesis and metamorphism.

In the future I will focus on biological structures and signatures in BIFs of the Moodies and Fig Tree Group of the Barberton Greenstone Belt.



Children's Book/ Kinderbuch

How Earth became habitable- A journey through the Precambrian

Goldschmidt_2018_v1 Kopie

Wie die Erde bewohnbar wurde- Eine Reise durch das Präkambrium

Poster Kopie

Publications and Conference contributions


Koehler, I., Konhauser, K.O., Kappler, A. (2010). Role of microorganisms in Banded Iron Formations. Geomicrobiology: Molecular and Environmental Perspective. Larry Barton, Martin Mandl and Alexander Loy (Editors). 485p

Koehler, I., Konhauser, K.O., Papineau, D., Kappler, A., (2013). Biological carbon precursor to diagenetic siderite spherulites in  iron formations. Nature Communications, 4, 1741.

Posth, N.R., Köhler, I., Swanner, E., Schröder, C., Wellmann, E., Binder, B., Konhauser, K.O., Neumann, U., Berthold, C., Nowak, M., Kappler, A. (2013). Simulating Precambrian banded iron formation diagenesis. Chemical Geology, 362, 131-142.


Conference contributions

2008 Kalkowsky Symposium in Göttingen, Talk:

Long term diagenetic fate of Fe mineral/cell organic matter aggregates formed

during the deposition of Precambrian Banded Iron Formations


2009 Goldschmidt Conference in Davos, Talk:

Lab simulations of long term diagenetic fate of biomass in Banded Iron



2011 Quenstedt- Feier, Tübingen, Poster:

Effects of pressure and temperature on biogenic iron minerals and organic

compounds- Did Fe(II)- oxidizing bacteria deposit Banded Iron Formations?


2011 Invited talk at the Albert Ludwigs Universität Freiburg

Simulating diagenesis in Precambrian Banded iron formations

2015 Goldschmidt Conference in Prague, Poster:

Biological carbon precursor to diagenetic siderite with spherical structures in iron formations

2016 SPP Building a Habitable Earth Meeting in Cologne, Poster:

DIfferent phases of carbonaceous matter in microbial mats of the Moodies Group in the Barberton Greenstone Belt, South Africa

2016 Invited talk at the European Institute for Marine Studies in Brest

Banded Iron Formations- a picnic with evolution

2016 Goldschmidt Conference in Yokohama, Talk:

DIfferent phases of carbonaceous matter in microbial mats of the Moodies Group in the Barberton Greenstone Belt, South Africa



Research interests

  • Archean Geomicrobiology
  • Fossil microbial mats of the Moodies Group, South Africa
  • Formation of Banded Iron Formations in the Precambrian
  •  Astrobiology

Further information can be found via my Research Gate, XING and LinkedIn Profils:




Private interests and experience

  • Sweden and the swedish language
  • Star Trek and Firefly, Gyllene Tider and Roxette
  • Professional experience in Photoshop
  • Popular scientific presentations on Origin of Life on Earth, Life on other Planets and the Archean Ecosystem

Building a Habitable Earth

Origin of coastal facies Banded Iron Formation, Barberton Greenstone Belt (3.2 Ga)


The existence of oxygen in our atmosphere is something that we take for granted in everyday life. The onset of an oxygenated atmosphere however, was a complex and protracted process. Oxygen literally had to fight its way to the top until it became one of the integral elements of earth's atmosphere after the Great Oxidation Event (GOE) at 2.4 Ga. Pyrite oxidation in oxygenic benthic microbial ecosystems could be a possible reason for this delay since the oxygen would have been immediately consumed by the oxidation.
The well-preserved sedimentary successions of the Moodies Group in the Barberton Greenstone Belt (BGB), South Africa, may not only present a unique evidence for oxygenic photosynthesis at 3.2 Ga but also document the immediate oxygen consumption by oxidation of pyrite.
Moodies Banded Iron Formations are found in close association with microbial mats and largely silicified gypsum concretions. We propose that oxygen generated in the benthic biomats oxidized abundant detrital pyrite to form sulphates and iron oxides. While the sulphates were transported to sandy floodplains, iron oxides were washed into the prodelta and lagoonal-facies to form Moodies BIF.
In this proposal, the plausibility of such a mechanism will be tested by an interdisciplinary approach, involving geochemistry, geomicrobiology and applied petrology. Our goal is to: (1) find evidence for pyrite oxidation and bacterial remains of oxygen producing bacteria. (2) Test how oxygen producing bacteria respond to the acidic conditions created during pyrite oxidation under Archean conditions. (3) Test the fossilisation potential of bacteria grown un-der acidic conditions during metamorphism. (4) Test whether the banding of Moodies BIFs was created by pH changes in biomats. To this end we intent to perform analysis of specific isotope and trace element signatures, analyse Moodies biomats for remains of microfossils, carry out eco-physiological experiments with cyanobacteria under acidic, Archean conditions and subject these bacteria to P/T conditions relevant for the BGB.
We expect that the results of our study will help to connect evidence for pre-GOE oxidative weathering with the history of atmospheric chemistry, and support the plausible antiquity of oxygenic photosynthesis well before the GOE.