1. The document analyzes organic geochemical evidence from marine and non-marine records to understand the relationships between terrestrial ecosystem collapse, soil erosion, and the end-Permian marine extinction. 2. Results show the onset of plant extinction preceded the end-Permian marine extinction in both the non-marine Xiaohebian section and marine Shangsi section by dozens of thousands of years, and was accompanied by a soil erosion event. 3. Bacteria flourished during the plant extinction in the non-marine section and during the marine extinction in the marine section. A proto-recovery of herbaceous plants occurred later and coincided with global warming.

1. Terrestrial Ecosystem Collapse and Soil
Erosion
before the End-Permian Marine Extinction:
Organic Geochemical Evidence
from Marine and Non-Marine Records
Raman Kumar Biswas
Supervisor: Prof.Kunio Kaiho
Introductio
n
Geological
setting
Method
s
Results
Discussi
on
Conclusion

2. Research Highlights
Biswas, R., K., Kaiho. K., Saito, R.,Tian, L., Shi, Z., 2020.
Terrestrial ecosystem collapse and soil erosion before the
end-Permian marine extinction: Organic geochemical
evidence from marine and non-marine records. Global and
Planetary Change. (in Press)
All the findings written in this thesis is going to be published in Biswas et al. (2020 in press, GPC).
1. Plant extinction was followed by soil erosion and the end-Permian marine extinction.
2. Bacteria flourished during the plant extinction in the non-marine section.
3. Bacteria flourished during the end-Permian marine extinction in the marine section.
4. Proto-recovery of vegetation coincided with global warming and oceanic euxinia.

3. Acknowledgeme
nts
Prof. Yasufumi Iryu; For the academic and research support
Prof. Kunio Kaiho; Research design, laboratory experiment, reviewing, overall guideline
Dr. Ryosuke Saito; Identify biomarkers, teaching on biomarkers, reviewing
Dr. Tian Li; Reviewing and providing the rock sample. Zhiqiang Shi; Rock sample
Prof. Takeshi Kakegawa; For supporting me with the C/N data in his laboratory.
Dr. Megumu Fujibayashi; Organic carbon content and its isotopes.
Dr. Hideko Takayanagi; Carbonate carbon isotope data.
Dr. Noritoshi Suzuki; Microscopic thin section preparation and fossil analysis.
Technical staff; Preparation of thin section and other technical support.
IGPAS Program, Tohoku University.
I express my deepest gratitude to my laboratory members and all well-wishers.
I thank,

4. The Permian–Triassic (P–Tr) mass extinction occurred approximately 252 Ma.
Approx. 90% of marine species, 70% of terrestrial vertebrate eliminated (Erwin, 1994,
Nature; Shen et al., 2011a, Science; Benton, 2018, Philosophical transactions of the
royal society A).
1. Introduction
Terrestrial devastation is demonstrated globally by the mass disappearance of the
Glossopteris and Gigantopteris megaflora (Hochuli et al., 2010, Glob. Planet.
Chang.).
There was a major loss of terrestrial flora, mostly coinciding with the end-
Permian extinction of terrestrial and marine fauna (Twitchett et al., 2001,
Geology; Ward et al., 2005, Science; Hochuli et al., 2010, Glob. Planet. Chang.).

5. Wildfire indicated by increased charcoal followed by high mercury (Hg)
concentrations from southwestern China coincided with the end-Permian plant
extinction and end-Permian terrestrial ecosystem devastation event (EPTD), which
occurred prior to the EPE and the peak of volcanism (Chu et al., 2020, Geology).
The soil erosion event is demonstrated by the high excursions of inorganic
weathering indices (Chemical Index of Alteration [CIA], Plagioclase Index of
Alteration, and Chemical Index of Weathering) spanning the end-Permian plant
extinction (Cao et al., 2019, Palaeogeogr. Palaeoclimatol. Palaeoecol.)
Paired coronene (high-temperature combustion proxy)–mercury spikes as a refined
proxy for LIP emplacement indicate that discrete volcanic eruptions could have caused
the terrestrial ecosystem crisis followed by the marine ecosystem crisis
(Kaiho et al., 2020 in press, Geology).

6. Yet, the relationships of land plant devastation, massive soil and rock erosion, and the
end-Permian extinction both in marine and non-marine environment have not been
clarified hence conducted this study.
Evidence from δ18O values of conodont apatite in the Shangsi and Meishan sections
indicates a ~10°C increase in surface seawater across the end-Permian crisis
(Joachimski et al., 2012, Geology; Sun et al., 2012, Science; Chen et al., 2016,
Palaeogeogr. Palaeoclimatol. Palaeoecol; Shen et al., 2018, Gelogical Society of
America Bulletin; Petsios et al., 2019, Palaeogeogr. palaeoclimatol. palaeoecol.).
The erosion event led to an algal bloom, the release of toxic components,
asphyxiation, and oxygen-depleted near-shore bottom seawater, which served as
environmental stresses for near-shore marine animals (Kaiho et al., 2016, Helion; Xie
et al., 2017, Ear. Planet. Sci. Lett.).
Soil erosion at the end of the End Permian Terrestrial Devastation (EPTD) impacted
the marine ecosystem during the P–Tr transition (Kaiho et al., 2016, Helion; 2020 in
press, Geology).

7. Chinahe;Fluvial-coastal
swamp
Depositional Environments
Meishan: Outer Shelf
Shangsi; Shelf Edge-upper
slope
Xiaohebian; Brackish
onshore lagoon
Xuanwei Formation
Bed 5
Kayitou Formation
Bed 6
Bed 8-volcanic
ash

8. 2. Geological Setting

9. 3. Method
2. n-C17/ n-C14-C19 as a cyanobacterial proxy
3. Dibenzofuran/Phenathrene (DBF/Phe) as a soil
erosion index
1. Long chain n-alkane
[(n-C27+C29)/ (n-C17+C19+C27+C29)] proxy for higher plant collapse
(Sachse, et al., 2004; Williams, 2012)
4. The moretane/hopane
(C30M/C30HP) ratio
proxy for the soil input
5. The hopane/sterane index
for the bacteria/ eukaryotes
6. C32 2α- methyl hopane Index
for Stress Environments
7. Isorenieratane/TOC (m/z; 134)
proxy for Photic zone euxinia

10. Introduction
Geographical
Methods
Results
Discussi
on
Conclusio
n 3. Methods

11. Introducti
Geological
setting
Method
s
Result
Discussi
on
Conclusio
n
4. Results 4.1 Basic Information

12. Introducti
Geological
setting
Discussi
on
Conclusio
n
End
Permian
Plant
Extinction
Results

13. Introducti
Geological
setting
Method
s
Results
Discussi
on
Conclusio
n
Marine Extinction
Horizon

14. Method
Results
Discussio
n
Conclusio
n
The CPI values (<1;
this study) reflect the
fact that exterior
sediments could not
have been contaminated
with petrogenic recent
hydrocarbons, as CPI
values <3 indicate oiled
sediments (Farmington and
Tripp, 1977, Geochim.
Cosmochim. Act.).
Contamination
check and
maturity

15. Method
Results
Discussi
on
Conclusio
n 4.2. Bio-environmental events at Xiaohebian

16. 4.3. Bioenvironmental
events at Shangsi
Microcoleus chthonoplastes, Oscillatoria spp.,
and Spirulina spp. (Winters et al., 1969; Paoletti
et al., 1976) [ 0.01- 0.7]

17. Method
Results
Discussi
on
Conclusio
n

18. Method
Results
Discussi
on
Conclusio
n
Comparison of geochemical indicators
of the Xiaohebian and Shangsi sections
The soil erosion events coincided with
the extinction event in both sections
The onset of the vegetation collapse
occurred before the end-Permian extinction
(EPE) in both

19. 5 minute

20. Non-marine
Marine
Age; Based on Zircon U-Pb
(Burgess et al., 2014 PNAS).
C-D, 50 kyr

21. Introducti
Geological
setting
Method
s
Results
Conclusio
n
terrestrial ecosystem
collapse was
accompanied by a soil
erosion event, and was
followed by the end-
Permian marine
extinction.
6. Conclusion
Two separate events
devastated the
terrestrial ecosystem
prior to the marine
extinction event, over
a timespan of dozens
of kyr.
Bacteria flourished in
the non-marine
section coeval with a
decline in terrestrial
plants and in the
marine section
during the end-
Permian marine
extinction
A proto-recovery of
herbaceous plants (not
woody plants) occurred
dozens of kyr after the
EPME coincide with Global
warming

22. Introducti
Method
s
Geological
Setting
Result
Discussi
on
Conclusio
n
Thanks you very much
for the patience hearing