1. Pinaki Sar Department of Biotechnology
Exploring microbial diversity and function within the granitic-basaltic deep crustal system of Koyna-Warna (India) region
Pinaki Sar
Department of Biotechnology
Indian Institute of Technology Kharagpur
India
Collaborators
Sufia K Kazy, National Institute of Technology Durgapur, India
Sukanto Roy, National Geophysical Research Institute, Hyderabad, India

2. Deep biosphere within basaltic – granitic (igneous rocks) systems
Igneous rocks constitute ~95% of the Earth’s crust
Deep crustal system represents an Extreme Habitat for Life
Aphotic
Devoid of Org C
Subjected to high temperature/pressure at some point in their history
Oligotrophic
Basalt
Granite
Image source :

3. Biogeochemical importance;
Microbiology of deep, igneous crust seems more intriguing, though relatively less studied
Biogeochemical importance;
Limits of life ?
Newly generated (annually) and recycled (~ 60 M yrs)
Upper (500 m), subseafloor basalts are significantly porous and permeable, hydrologically active
Largest potential microbial habitat
Who are they ?
What are their function
Microbiology of basaltic/grantic deep subsurface (marine/terrestrial) are less studied and mostly unexplored
Some more reports for ocean crust than terrestrial habitats
Unlike deep oceanic subsurface which may be partially dependent on organic C and energy derived from photosynthetic process, life within terrestrial crystalline rocks are independent to photosynthesis

4. What remained largely unexplored and poorly understood :
Distribution and diversity of microbes in terrestrial igneous rocks
Knowledge on their metabolic functions and their impact on global C and nutrient cycles
Bacterial communities in different (sub-)sea floor habitats, demonstrating that subsurface crustal bacteria are distinct from the bacteria in other deep-sea environments; Wang et al 2013; Edward et al 2011

5. What powers deep microbiome
What powers deep microbiome ? Extent of microbial catabolic potential within deep igneous crust
Abiogenic H2 driven metabolic pathways ?
Role in C/N/nutrient cycling
Rock weathering and climate change

6. Acetogenic –Methanogenic metabolism with abiogenic H2X
In igneous rock systems ?
Acetogenic –Methanogenic metabolism with abiogenic H2
Geomicrobial processes at a subsurface shale-sandstone interface; Fredrickson and Balkwill, 2006

7. H2 driven system Abiotic diagenetic formation of low mw compounds
Anaerobic lithoautotrophic metabolism
SLiMEs (?)
Small Org comp
Methanogen
Abiotic processes
Temperature
Abiotic geogenic H2
Anaerobic heterotrophic metabolism H2
N2 fixation
Denitrification/NH4 oxidation
Radiolytic decomposition of water
Water-rock interaction
Diffusion from deeper levels

8. The Deccan Traps
The Deccan Traps are a large igneous province, on the Deccan Plateau (west-central India (between 17–24N, 73–74E)
One of the largest volcanic features on Earth
Consist of multiple layers of solidified flood basalt [together >2,000 m thick and cover an area of 500,000 km2 and a volume of 512,000 km3 (123,000 cu mi)]
formed between 60 and 68 million years ago [end of the Cretaceous period] linked to the Cretaceous–Paleogene extinction event

9. Seismic activity in deccan Trap at Koyna-Warna region
Reservoir triggered seismicity (RTS) record in past 38 years:
>10 earthquakes of Mz5;
>150 earthquakes of Mz4
>100,000 earthquakes of Mz0
soon after the impoundment of the Shivaji Sagar Lake created by
Koyna Dam in Western India in 1962

10. Drilling site at Koyna
Drilling is proposed up to nearly 7 KM, so far ~1.5KM drilling is done
Cores recovered so far revealed :
Flood basalt pile with numbers of lava flow
Each flow has vesicular / amygdaloidal layer unde lined by massive basalt
Microbial presence (successful extraction of DNA and amplification of 16 S rRNA gene regions) from samples of 1300 M depth
Low C environment
Core samples from borehole KBH-1 showing (a) massive basalt, (b) vesicular and amygdaloidal basalt with large vugs filled with quartz and/or calcite
JOUR.GEOL.SOC.INDIA, VOL.81, FEB. 2013

11. Major aim of the proposed work
Delineating the environmental limit of life within the terrestrial baslatic/granitic system
Understanding the processes that potentially define diversity /distribution of life in deep terrestrial crustal system
Possible modes of microbial interactions within such environment affecting C and nutrient cycle, rock weathering etc.

12. Objectives
Analysis of microbial diversity and composition within the basaltic-, granitic- and transition zones from deep subsurface environment of Koyna region: Combination of metagenome based sequencing techniques and enrichment/isolation of bacteria (include virus and fungi as well after this meeting )
Metabolic function and microbial role in biogeochemical cycling of carbon, rock microbiome interaction (weathering); effect –response of seismic activities: Metagenome and metatranscriptome analysis, WGS analysis of predominant isolates, metabolic modeling, getting ideas of novel metabolic routes running the biogeochemical reactions
Integration of geochemical/environmental data and comparative metagenomic analysis of deep basaltic-granitic biosphere with and without seismic activities: Assessment of the extent of microbial distribution and diversity, potential involvement in C cycle

13. Work flow: implementaion
Elucidation of effect of seismic activity and crustal properties on microbial diversity and activity
Analysis of microbial function
Analysis of microbial diversity, community structure, abundance
Obj . I
Obj . II
Obj . III
Time scale (year) 5
Drilling, sample collection and analysis
Molecular genomic analysis
Data integration and modeling

14. Deliverables Deep carbon observatory goals :
Elucidation of microbial diversity/distribution within carbon limited, dark, deep terrestrial crust
Better insight in understanding on survival strategies and role under deep subsurface igneous rocks
Delineation of limits for microbial deep life and their interaction with critical nutrient cycling
Global significance : Global primer site of RTS within basaltic/granitic crust
Microbial role in rock weathering
Nutrient cycling, CO2 sequestration and other aspects of climate change
Biomineralization; Bioremediation, Bioprospecting (Access of novel microbes and enzymes for industrial application)

15. Budget Details (five years)
Particulars
Cost in USD (approx)
Equipment (NG Sequencer)
3,20,000
Accessory equipment
65,000
Drilling
1,50,000
Chemicals/Consumables, contingency
2,00,000
Staff (01 PDF, 02 RF, 01 RA)
1,20,000
International/domestic travel, material transport
45,000
Total
11,00,000
PDF: post doc fellow; RF: Research fellew /Ph D, RA: Research assistant

16. Thank You

17. Deep subsurface : the hidden and unexplored habitat for microbes
Edwards et al., Annu. Rev. Earth Planet. Sci. 2012
The largest potential ecosystem on Earth, estimated to harbour half of all the biomass; and 2/3 of all microbial biomass on Earth ( X 1030)
Depth of distribution: Functionally and taxonomically diverse populations extending several kilometres underground
Adaptation : temperature limit 121oC, pressures of up to 1.6 Gpa
Function: fundamental role in global biogeochemical cycles over short and long time scale
With the discovery of deep microbial ecosystems in sedimentary basins−as well as microbial life in granites, deep gold mines, and oil reservoirs—the view of the scientific community was opened to a hidden and largely unexplored inhabited realm on our planet.
(Itavaara et al., FEMS Microbiol Ecol )

18. The deep biosphere : an extreme habitat for microbes
With increasing depth there are several constrains that affect composition, extent, life habitats, and the living conditions in deep subsurface
Increasing temperature and pressure
Nutrient limitation, limited porosity and permeability
Decreasing available carbon and energy sources
Rates of microbial activity in deep subsurface is slow (orders of magnitude over that in surface environments)
With average generation times of hundreds to thousands of years
…and therefore defies our current understanding of the limits of life

19. The deep biosphere The huge size
Largely unexplored biogeochemcial process driving the deep biosphere
“Investigation of the extent and dynamics of subsurface microbial ecosystems an intriguing and relatively new topic in today’s geoscience research” ICDP, 2010

20. Widely disseminated deep biosphere pose fundamental questions :
IODP Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE)
Natural Earthquake Laboratory at Focal Depth (DAFSAM-NELSAM)
Taiwan Chelungpu Drilling Project (TCDP)
Lomonosov Ridge in the Central Arctic Basin
Outokumpu deep borehole, Fennoscandian Shield
kind of microorganisms ? populate the deep subsurface?
their extension and limits?
metabolic processes ? carbon and energy sources ?
survival strategies? link to early life on Earth?
biological alteration of rock
impact on the global -biogeochemical cycle and -climate?
Nature of microbial communities and their function in active seismogenic zone
Effect of fracturing (during earthquake) on microbial communities
Interrelation between geochemistry, microbiology and nature/location of fracture zones
ICDP 2010

21. Requirements of microbes in deep biosphere
‘Living space’
Liquid water
Energy and nutrients
Porosity
Permeability
Tectonostratigraphic setting
Electron donor
Electron acceptor
Carbon source
thermodynamic potential of chemical reactions

22. Microbial metabolism within deep subsurface
Little org C
Lithoautotrophic metabolism
Small org molecules are microbially synthesized from H2 and CO2
Independent of surface photosynthetically derived mater
Igneous rocks
Buried org C is the main C and e source
Heterotrohic metabolism
Depends on surface photosynthetically derived mater
Sedimentary rocks

23. Abiotic diagenetic formation of low mw compounds
Scheme visualizing potential carbon and energy sources of deep microbial ecosystems OM = organic matter, mw = molecular weight
CH4
Acetate, CO2 and H2
Organic acids and alcohols
Soluble monomers (sugar and amino acids)
Complex polymers (CH2 O, proteins)
Fermentation
Syntrophic fermentation
Methanogen
Organic matter deposition
Biotic processes
Preserved OM (Kerogen, Bitumen, Humics
Thermal activation
Abiotic diagenetic formation of low mw compounds
Anaerobic microbial metabolism
Abiotic processes
Temperature
e acceptor limited
Independent from primary microbial degradation processes

24. What have we learned? All Observations are consistent with the laws of physics
Extended known biosphere to 3 km, not limited by energy
Revealed biomass, biodiversity, unusual traits & microbes with indications of autotrophic ecosystems
Slow rates of deep subsurface microbial activity but linked with geological interfaces
Deep subsurface biosphere not linked to the surface (?)
Deep anaerobic communities fueled by subsurface abiotic energy sources (?)(Likely)

25. Objectives
Analysis of microbial abundance, diversity and composition within the deep subsurface environment of the seismic zone of Koyna-Warna region
Elucidation of functional role of indigenous microorganisms within the seismic zone
The effect of seismic activity on microbial community and function

26. Work flow
Elucidation of effect of seismic activity and crustal properties on microbial diversity and activity
Analysis of microbial function
Analysis of microbial diversity, community structure, abundance
Obj . I
Obj . II
Obj . III
Time scale (year) 3
Sample collection and analysis
Molecular analysis
Data integration and modeling

27. Work Plan
Objective 1.:
Analysis of microbial abundance, diversity and composition
Metagenome extraction
Amplification of 16S rRNA gene
Library preparation
Sequencing [NGS]
Sequence analysis
DGGE analysis
Sanger sequencing
Community diversity and composition
Sample collection from cores
Direct microscopic count
MPN count (Tot, Sox / red & Feox / red , methanogenic and hydrogen utilizing bacteria)
Plate count
Geochemical analysis
Enumeration of cell counts
Analysis of community composition
Elemental analysis (XRF, ICP)
TOC, TC, TS, TP analysis
Anion analysis
EPMA analysis

28. Objective 2 Analysis of microbial communities’ function
Total community
Analysis of metabolic diversity
PM - Biolog system
Analysis of genes related to S, Fe, C, N cycles
S cycle: dsr
Fe cycle: Fur
C cycle: mcrA, RuBisCO
N cycle: nif, nirK, amoR
NG sequencing of complete metagenome

29. Effect of seismic activity on microbial community and function
Objective 3
Effect of seismic activity on microbial community and function
Comparison of community structure across depth
Comparison of community function across depth
Integration of microbiological data with geochemical and other relevant data on seismic activity within the samples from various depths

30. Expected out come
Understanding the deep terrestrial biosphere with seismogenic activity
Distribution, extent and composition of deep microbial communities within the basaltic-granitic subsurface
Impact of seismic activity and subsurface CO2, N2, and H2 production on microbial community structure and function, existence of SLiMEs?
Correlation of microbial activity, geochemistry/rock systems and seismic activity within the zone of RTS

31. Recurring Particulars 1st Year (Rs) 2nd Year (Rs) 3rd Year (Rs)
Total (Rs)
Manpower
Senior Research Fellow (01)
216000
648000
Technical Assistant (01)
144000
432000
Sub-Total
360000
Consumables
600000
800000
Travel
200000
100000
500000
Contingency
300000
Overhead
752000
292000
232000
Sub-Total of Recurring
Grand Total
(Non-Recurring + Recurring)

32. Thank You

33. Justification of Equipment
Fluorescence Microscope
The fluorescent microscope is required for all microscopic enumeration of bacteria, cell counts, FISHT etc. This equipment is the major requirement for microbiological analysis related to the project.
Incubator shaker
The temperature controlled shaker will be used for molecular biology work.
Gel electrophoresis system
with accessories
The gel electrophoresis apparatus will be used for all routine DNA work.
Work station for bioinformatics with accessories
The computer will be required for all bioinformatics data analysis
Ultra deep fridge
Ultra deep fridge will be used to store the samples from cores and other microbiological samples. Ion selective electrodes will be required for the Orion multiparameter meter to be used in the field.

34. Real time PCR machine
For all quantitative determination of rRNA and other genes; monitoring of expression levels of various functional genes this instrument is absolutely essential. In the present work transcriptional analysis of selected biogeochemical cycle relevant genes, abundance of specific microbial groups, -dynamics will be studied using this equipment. The proposed model is versatile and highly efficient. For this project this equipment is extremely essential

35. Justification of Manpower
Senior Research Fellow
One dedicated senior research fellow will be essential to assist the PI and co PI for carrying out the research work
Technical Assistant
One TA will be essential or field work, sample collection, sample processing and other relevant activities of the project.

36. Justification of Consumables
Consumables will be essential for carrying out culture independent RNA dependent and metagenomic analysis of microbial communities. Cost for RNA/DNA extraction kits, cDNA preparation, real time PCR reagents, primers, vectors and restriction enzymes, plasmid isolation kits, gel extraction and sequencing kits are all included. For real time based transcriptomic studies, cDNA kits and other reagents related to real time PCR (TaqMan probes, Syber green dye, etc.), nucleic acid quantification kits (pico green), etc. will be needed. For fluorescent microscopy and FISH analysis dedicated kite are required. Sequencing reagents, kits and other charges are included under this head. For all routine works general chemicals, glass and plastic ware are necessary. Bacterial type strains will be procured from National or international culture collection.

37. Justification of travel
Field sampling and analysis; Project meeting
Several visits to fields and analytical labs for analysis; Project meeting, if any
Field work and project presentation; Seminar participation
Field work and project presentation at DBT, if any; Seminar participation
Travel to fields
Several visits to fields for survey and sample collection
Travel to other laboratories
Sample analysis

38. Justification of Contingency
DNA sequencing, fatty acid analysis, GC content determination, Conference and meetings
Field expenditures, photocopy, computational works, cost of gas for AAS, anaerobic station
Expenditures related to sample collections and other field work, cost of field labors, porters, gases for anaerobic workstation (N2 and mix gas), computational work, photocopying; charges for PLFA analysis, type strains and genomic DNA samples (from DSMZ or ATCC or MTCC), sequencing etc. and any unforeseen expenditures
Sample collection related costs, Conference and meeting related expenditures; DNA sequencing
Sample collection related costs, Conference and meeting related expenditures; Visit to other labs for analysis and data verification; Cost of DNA sequencing

39. Extra slides

40. Expedition to deep biosphere

41. Map of DSDP, ODP, and IODP Legs (indicated by their numbers) considering microbial or deep microbial scientific objectives. b. Map showing completed and planned ICDP projects containing biogeochemical objectives. Black dots indicate ICDP projects where no biogeochemical objectives were included.

43. Microbial cells : the main biogeochemical engines of Earth
Microbes: the janitors of Earth
The most ubiquitous, abundant, most diverse live form on this planet
Occupy even most inhospitable niches
Vast metabolic and genetic repertoire
Responsible for many geobiochemical processes that take place deep in the Earth’s crust

44. Global prokaryotic biomass distribution, given in cell numbers (after Whitman et al. 1998).

45. Environmental parameters defining the dimensions of living space
Tectonostratigraphic setting
Distribution patterns, degree of sorting, lithology, etc.
Porosity and permeability
Subsidence, uplift and deformation of the basin fill control pressure (lithostatic, hydrostatic),
Modification in porosity and permeability of lithotypes.
Basin style and evolution control temperature gradient

46. Living space
Pore space; pore types and degree of interconnection are important factor controlling deep biosphere
microorganisms occupy only about one millionth of available porosity
An adequate flux of liquids or gases through rock pores is required to sustain life and this is governed by pore throat dimensions.
Permeability that regulates the pressure-driven transport of electron donors, electron acceptors, and nutrients to sustain living cells [Quartz arenites retain permeability to great depths and offer perhaps the most stable living accommodation for microorganisms while high reactivity of unstable volcanogenic sandstones and their mechanical weakness make them susceptible to rapid porosity and permeability loss, in some cases at relatively low temperatures]
Fractures are orders of magnitude more permeable than pore systems and often allow microbial growth and activity

47. Supply of food
Provision of food (electron donors) and oxidants (electron acceptor, e.g., O2) is controlled by the thermodynamic potential of chemical reactions, both organic and inorganic
The rate of microbially catalysed reactions can be up to 106 times higher compared to abiological rates
Depends on the rate of supply and removal of substrates and products, the concentration (above minimum thresholds and below toxic levels) and bioavailability of reactants and environmental conditions.

48. Microbial distribution in geospheres
Greatest biomass inhabits within the surface/near surface lithosphere and shallow hydrosphere: reliance on photosynthesis / derived food chain
Microorganism make the major component of biosphere because they can grow under diverse conditions and have different metabolic pathways
Anaerobic organisms are dominant inhabitants of lithosphere .. generally decrease with increasing depth
Because, organic matters are too recalcitrant to be degraded or water, nutrients and TEAs can not be supplied or temporaries are too high
Surprisingly large bacterial populations with considerable diversity are present at depths near and over 1000m
Given the remarkable
capacity of microorganisms to utilize a wide range of energy
sources, including light, organic matter and inorganic materials,
and their broad distribution across the surface of the planet, it
should come as no surprise that the deep terrestrial subsurface
harbors diverse microbial populations. Many such environments
contain all of the requirements for prokaryotic life including
water-filled space in pores and fractures, energy in the form of
buried organic matter (kerogen), gases such as methane or H2,
and reduced inorganic ions (multiple sulfur species and metals
such as Fe and Mn), and various essential inorganic elements
including carbon, nitrogen, phosphorous, and sulfur.
Extension of the biosphere on Earth

49. Out come of deep borehole studies by ICDP and/or IODP
To be added in end
The lower depth limit of the biosphere has not been reached in any borehole studies
and the factors that control the abundance and activities of microbes at depth and the lower depth limit of life are still poorly understood.
Given the remarkable capacity of microorganisms to utilize a wide range of energy sources, including light, organic matter and inorganic materials, and their broad distribution across the surface of the planet, it should come as no surprise that the deep terrestrial subsurface harbors diverse microbial populations. Many such environments contain all of the requirements for prokaryotic life including
water-filled space in pores and fractures, energy in the form of buried organic matter (kerogen), gases such as methane or H2,and reduced inorganic ions (multiple sulfur species and metals such as Fe and Mn), and various essential inorganic elements including carbon, nitrogen, phosphorous, and sulfur.
The largely unexplored deep biosphere must play fundamental role in global biogeochemical cycles over both short and longer time scales

50. Potential limiting factors for microbes in deep biosphere
The original chemical composition of the sediment
Response of microbes and its organic and inorganic components to increasing temperature
Availability of liquid water
Increasing pressure during burial may not be a major limitation as some microorganisms can cope well with high pressure (>100 Mpa) and there is some evidence for metabolic activity at GPa pressures.

52. Microbiology of seismic zones
Molecular hydrogen, H2, is the key component to link
the inorganic lithosphere with the subsurface biosphere.
Geochemical and microbiological characterizations of natural
hydrothermal fields strongly suggested that H2 is an important
energy source in subsurface microbial ecosystems because of
its metabolic versatility. One of the possible sources of H2
has been considered as earthquakes: mechanoradical reactions
on fault surfaces generate H2 during earthquake faulting.
However it is unclear whether faulting can generate
abundant H2 to sustain subsurface chemolithoautotrophic
microorganisms, such as methanogens.

53. Wanger et al 2007

55. Culture dependent analysis
Isolation of pure culture bacteria
(different enrichment cond., aerobic and anaerobic cond.)
Identification
(16S rRNA gene, FAME, API, etc.)
Metal resistance and transformation studies
Metabolic Characterization

56. * * What have we learned? Novel indigenous microbes and communities
Novel and unusual deeply branched sequences may be indicative of ancestral linkages, (early life?),
Novel products for biomed and biotech applications
1 mm
image courtesy of Gordon Southam
Novel Bacterial lineages unique to the SA deep-subsurface:
South Africa Subsurface Firmicutes Groups (SASFiG)
SASFiG-6
SASFiG-5 *
SASFiG-4
SASFiG-7
SASFiG-3
SASFiG-9 *
SASFiG-8
SASFiG-1
*SASFiG-9 (isolated)
Detected within a water-bearing dyke/fracture at 3.2 Km depth.
strictly anaerobic; iron-reducer
optimal growth temperature = 60 oC
virgin rock temp = ~ 45 oC
SASFiG-2

57. Key Experiments: Culture-Independent Evidence for Deep Life
Genomic advancements
Sequencing of a microbe required ~18 months in mid 90’s
Currently >150 microbes have been sequenced
In 2004 TIGR discovers 1.2 million new bacteria/archea genes in the Sargasso Sea
By 2005 JGI could sequence 400 microbes per year
Could early life in the subsurface have
survived the Hadean bombardment?

58. Earth’s subsurface microbial ecology
The biosphere extends deep into the subsurface
Limited by geothermal gradient and nutrient flux
Biomass generally low relative to the surface
Distribution is very patchy and hetergenous
Rates of community metabolism very low
Volumetrically largest part of the biosphere

59. Subsurface lithoautotrophic microbial ecosystems (SLiMEs)

60. Basalt:  - Forms on the surface of the earth  - Because it forms on the surface it cools quickly and has a fine texture (mineral grains are too fine to see with the naked eye).  - The source of this rock comes from partially melted material in the mantle.  - It usually leaves the mantle at mid-ocean ridges, where new seafloor is being formed. That's why most of the ocean crust consists of basalt or gabbro (the intrusive version of basalt).  - Because basalt comes from a mantle source, it's very mafic and consists of dark, dense minerals rich in iron and manganese (usually olivine and pyroxene).  Granite:  - Forms underneath the surface of the earth.  - Because it forms under the surface the magma cools slowly, grains have time to grow and therefore it has a coarse grained texture. Grains can be easily seen with the naked eye.  - Granite forms when a part of the continental crust melts to form magma and solidifies again. The heat needed for this to happen can come from different sources, for example magma from the mantle which causes the crust to melt.  - Because of the above granite will be found on the continental crust (mostly at least).  - The crust consists of lighter minerals than deeper parts of the earth, and that is why the minerals you will find in granite will be lighter, less dense and richer in SiO2 than those found in basalt (granite is therefore a much more felsic rock). Minerals you will typically find is quartz, orthoclase and plagioclase

61. Extent, Million Years Ago
Eon
Era
Period
Extent, Million Years Ago
Phanerozoic
Cenozoic
Quaternary (Pleistocene/Holocene)
Neogene (Miocene/Pliocene)
Paleogene (Paleocene/Eocene/Oligocene)
Mesozoic
Cretaceous
Jurassic
Triassic
Paleozoic
Permian
Carboniferous (Mississippian/Pennsylvanian)
Devonian
Silurian
Ordovician
Cambrian
Proterozoic
Neoproterozoic
Ediacaran
Cryogenian
Tonian
Mesoproterozoic
Stenian
Ectasian
Calymmian
Paleoproterozoic
Statherian
Orosirian
Rhyacian
Siderian

62. History[edit]
The Deccan Traps formed between 60 and 68 million years ago,[2] at the end of the Cretaceous period. The bulk of the volcanic eruption occurred at the Western Ghats (near Mumbai) some 66 million years ago. This series of eruptions may have lasted less than 30,000 years in total.[3]
The original area covered by the lava flows is estimated to have been as large as 1.5 million km², approximately half the size of modern India. The Deccan Traps region was reduced to its current size by erosion and plate tectonics; the present area of directly observable lava flows is around 512,000 km2 (197,684 sq mi).
Effect on climate and contemporary life[edit]
The release of volcanic gases, particularly sulfur dioxide, during the formation of the traps contributed to contemporaryclimate change. Data points to an average drop in temperature of 2 °C in this period.[4]
Because of its magnitude, scientists formerly speculated that the gases released during the formation of the Deccan Traps played a role in the Cretaceous–Paleogene extinction event (also known as the K–Pg extinction), which included theextinction of the non-avian dinosaurs. Sudden cooling due to sulfurous volcanic gases released by the formation of the traps and localised gas concentrations may have contributed significantly to mass extinctions. However, the current consensus among the scientific community is that the extinction was triggered by the Chicxulub impact event in Central America (which would have produced a sunlight-blocking dust cloud that killed much of the plant life and reduced global temperature, called an impact winter).[5]

64. Core samples from borehole KBH-1 showing (a) massive basalt, (b) vesicular and amygdaloidal basalt with large vugs filled with quartz and/or calcite, (c) flow-top breccia, (d) red bole bed and overlying massive basalt, (e) vugs filled with zeolite, and (f) basement granite at 951 m depth.