Fire frequency during changing climatic conditions yields insights into the ecological responses and adaptations during times of

-

spanning the Younger Dryas (12,900 – 11,600 cal yr BP) for east -central Michigan.

Four lakes south of Flint, Michigan were sampled within a 10 mile radius range of each other. These lakes are situated in hummocky drift terrain near the Saginaw lobe moraines. Swift and Slack Lakes are on the northwest side of these moraines, so formed later and are therefore, younger than Big Fish and Lake Sixteen, which fall southeast of this geomorphological feature.

All four lakes indicate high charcoal levels following deglaciation. There appears to be a consistent pattern of elevated charcoal abun -dance amongst them. Stratigraphically, the bottom peak in Swift and Slack correlates chronologically to ~14,000 Cal BP. Big Fish and Lake Sixteen have older dates (15,160 Cal BP and 15,840 Cal BP re -spectively). The earliest major peak in Big Fish begins an estimated ~1100 years later than the 15,160 Cal BP date. In Lake Sixteen there is a lesser double peak at the 15,840 Cal BP date which precedes the pattern of spikes common to all lakes.

The charcoal peaks follow the rise in organic content, and the accu -mulating sediments vary from dark organic to lighter colored lami -

Our preliminary estimate of duration of these charcoal intervals in

12,200 14C (14,050 Cal BP) and continue for about 1,500 years (till 12,550 BP). If so, these appear to occur in the cooling prior to the start of the Younger Dryas and they continue until the middle of the Younger Dryas, suggesting that for these lakes the transition between climate states is a controlling factor.

3. STUDY LOCATION

The Data Joanne P. Ballard (ballarjn@email.uc.edu) & Professor Thomas V. Lowell

SUMMARY OF RESULTS

2. THE STUDY OBJECTIVES

After Marlon et al. 2009.

Flint

SwiftSlack

Lake Sixteen

Big Fish

Gainey site

Gainey Paleo-Indian Tool KitImage courtesy of Don Simons

1. ABSTRACT

References

6. THE DATA

Joanne P Ballard 3-25-2009

12,200 14C yr ~14,050 Cal BP yr A7, 57 cm

8,050 14C yr ~9,000 Cal BP yrA5, 67-71 cm

sediment-water interface732 cm

~3050 years

Swift Lake, Genesee County, Michigan

Magnetic susceptibility

MS A1

MS A2

MS A3

MS A4

MS A5

MS A6

MS A7

MS A8

0 100 200 3000 25 50 75 100

Organics

CarbonateA7

0 200 400 600 800 1000

Charcoal count -coarse resolution

A7

A6A4

A3

A2

A1

0 200 400 600 800 1000

A1

A2

A3

A4

Gamma Log Resistivity gm/cc

1400

1450

1500

1550

1600

1650

1700

1750

1800

1850

1900

1950

Dep

thin

cm

2000

Loss on ignition

0 1 2 3

A1

A5

A2

A3

A4

A6

A7

A8

A5A3

A4

A2

A1

A7

A6

A8

Joanne P Ballard 3-25-2009

12,050 14C

~13,900 Cal BP A4 51 cm

9,360 14C yrs

~10,580 Cal BP yrs A3 58-60 cm

Loss on IgnitionMagnetic susceptibility SI units Charcoal count

Slack Lake, Genesee County, Michigan

OrganicsCarbonate

0 25 50 75 1000 100 200 300

MS A1

MS A2

MS A3

MS A4

MS B1

MS B2

MS B3

MS B4

A2

A1

B4

B2

B1

B3

A4

A3

B4

1400

1450

1500

1550

1600

1650

1700

1750

1800

1850

Dep

th in

cm

0 200 400 600 800 1000-1

Gamma Log Density gm/cc

0 1 2 3

A1

B1

A2

A3

A4

B2

B3

B4

sediment-water interface945 cm

~1800 Cal years

13,350 14C

15,840 Cal BPA1 21 cm

A3 55 cm

Joanne P Ballard 3-25-09

0 200 400 600 800 10000 100 200 300

MS A1MS A2MS A3

Magnetic Susceptibility

Lake Sixteen, Oakland County, Michigansediment-water interface 488 cm

Loss on Ignition

0 25 50 75 100

Organics

Carbonate

A1 Organics

A1 carbonate

850

900

950

1000

1050

1100

A3

A1

A2

Charcoal coarse methodology

Charcoal Fine Methodology Dr. Cathy Whitlock’s Lab

11,150 14C years13,080 Cal BP years

0 200 400 600 800 1000-1 0 1 2 3

A1

A2, A3

Gamma Log - Density

12,850 +/-55 14C yrs15,160 Cal BP A2, 34-37 cm

10,300 14C yrs12,075 Cal BP yrsB1 - 85 cm

Big Fish Lake, Lapeer County, Michigan

0 200 400 600 800 10000 50 100 150 200 250 300

MS A1

MS A2

MS A3

MS A4

MS A5

MS B1

MS B2

MS B3

MS B4

A1

A3

A2

0 25 50 75 100

Org anics

Carbonates

A3 Org anics

A3 Carbonate

Loss on ignition Gamma Log Density gm/cc

- 1 0 1 2 3

A1, A2

A3

A4

A5

B1,B2, B3, B4

B1

A5

A2

A3

A4

B4

Magnetic susceptibility

B3

B2

B1

0 200 400 600 800 1000

Charcoal count - Fine resolutionCharcoal count - Coarse resolution

900

950

1000

1050

1100

1150

1200

1250

1300

1350

Dep

th in

cm

sediment-water interface945 cm

Joanne P Ballard 3-25-2009

A5

B3

B2

Comet Lulin February 2009 Could a comet like this one have struck North America at the start of the Younger Dryas?

8. CONCLUSIONS

5. WORKING HYPOTHESES

Extruding the lake sediment

in Michigan for 12,900 years ago? Analyzing lake sediments for

and later.Fire at 12,900 years ago does not manifest as more intense or larger

to early Holocene.While it can be ar

evidence to demonstrate an extraterrestrial source of ignition.

Future work

Pollen studies - vegetation yields insight into paleoenvironmental/paleoclimate change

Collect histo data collected in this study.

Expand study to a larger geographic region to determine if there is charcoal evidence of a contemporaneous

Firestone, R.B., A. West, J.P. Kennett, L. Becker, T.E. Bunch, Z.S. Revay, P.H. Schultz, T. Belgya, D.J. Kennett, J.M. Erland-son, O.J. Dickenson, A.C. Goodyear, R.S. Harris, G.A. Howard, J. B. Kloosterman, P. Lechler, P.A. Mayewski, J. Mont-gomery, R. Poreda, T. Darrah, S.S. Que Hee, A.R. Smith, A Stich, W. Topping, J.H. Wittke, and W.S. Wolbach. 2007. Evi-dence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling. PNAS, October 9, 2007. Vol. 104, No. 41, pp. 16016-16021.

Marlon, J. R., P. J. Bartlein, M. K. Walsh, S. P. Harrison, K. J. Brown, M. E. Edwards, P. E. Higuera, M. J. Power, R. S. Anderson, C. Briles, A. Brunelle, C. Carcaillet, M. Daniels, F. S. Hu, M. Lavoie, C. Long, T. Minckley, P. J. H. Richard, A. C. Scott, D. S. Shafer, W. Tinner, C. E. Umbanhowar, Jr., and C. Whitlock

Proceedings of the National Academy of the Sciences, January 2009 Early Edition. pp 1-6www.pnas.org_cgi_doi_10.1073_pnas.0808212106

Whitlock, Cathy & Larsen, Chris “Charcoal as a Fire Proxy,” Chapter 5 in: Smol, John P., Birks, H. John B., Last, William M., Editors,Tracking Environmental Change Using Lake Sediments, pp. 75 - 97Volume 3, Terrestrial, Algal and Siliceous Indicators. Springer Publisher: Kluwer Academic Publishers, 2001.

GISP2 Ice Core Datahttp://www.ncdc.noaa.gov/paleo/icecore/greenland/greenland.htmlhttp://www.ncdc.noaa.gov/paleo/icecore/greenland/gisp/gisp.htmlGrootes, P,M,, and M, Stuiver, 1997, Oxygen 18/16 variability in Greenland snow and ice with 10^3 to 10^5-year time resolution, Journal of Geophysical Research 102:26455-26470, NCDC NOAA World Data Center for Paleoclimatology

Google Earth aerial images of lakes

4. ON ICE FEBRUARY 2008

aspect of Firestone hypothesis Target Gainey archaeological site (Firestone, et al, 2007) Add 4 datasets for lateglacial paleo re recordin the Midwest

Coring crew at Slack Lake Justin Stroup & Don Simons drilling depth-check hole at Swift Lake

diatoms

sapropel

clay rich laminations clay, black laminae

diamict sand

iron - limonite

silt

Najas seeds

ostracode

Big Fish

500 m

Slack

400 m

Sixteen

400 m

Swift100 m

Implications – We can predict some outcomes for the charcoal data.Hypothesis 1. Bolide strikes North AmericaHypothesis 2. Younger Dryas is arid

Fire depends on at least 3 things to burn:*oxygen

Graphs - Data is organized by depth in centimeters in all four lakesMagnetic susceptibility data is an indication of the presence of magnetite particles or a change in density. This can be seen downcore where the glacial gravel is present in all cores, and when a

.

Loss on Ignition is a test performed to assess what percentage or organics and carbonate are present in the lake sediment. Sometimes these are in lock-step as seen in Lake Sixteen. Organics

-

there are other minerals present, such as silica or clays.

Gamma log data are an indication of density

High resolution photographs of the lake cores were taken at the world class Limnological Re -search Center at University of Minnesota’s campus. These show sedimentological changes which can often be tracked in the LOI or MS graphs.

Stylized stratigraphic column. This shows the type of lithology and presence of organics such as Najas seeds, gastropods, diatoms, and ostracodes.

Charcoal. Sediment samples were collected at depth intervals continuously along the length of the core, treated to disaggregate, and sieved. The sieved samples were exam -ined under a light microsocope at ~23X and all charcoal particles were counted on a grid system. Vegetation and organic materials were noted and included on the stylized strati -graphic column.

Radiocarbon dates. Two dates were obtained on each lake for a total of 8 dates. 3 of these were obtained on bulk sediment (lower Lake Sixteen, Upper Lake Sixteen, Upper Big Fish) as no organic material was found at the desired stratigraphic level. The lower Big Fish date is on Najas seeds, abundant in sections of Big Fish. The Upper Swift Lake date is primarily on Daphnia egg cases. The bulk samples, Najas seeds and Daphnia are consid -ered to be subject to the possibility of contamination with carbonate if it is a hard water lake, which will skew the dates older by perhaps 800 years.

7. TIMELINE

UNCERTAINTIES in this timeline

so three are fairly robust. The older Swift and Slack dates are robust. Aquatic samples may be problematic if they are in a hard water lake and contami nated with “dead” carbon from inorganic carbonates. Bulk sediments may, but not necessarily, be erroneous due to carbonates or coal in the environment.

Calibration. Some dates have less uncertainty that others (bell shaped curve). Calib has been used to analyze and calibrate the radiocarbon dates.

Sedimentation. The estimate for the Younger Dryas horizon in these four lakes is interpolated from 2 radiocarbon dates in each lake, assuming constant sedimentation rate.

Swift Lake Lake Sixteen

100 200 300 400 500

charcoal counts

Timeline with charcoal levels, Michigan USA

0 100 200 300 400 500 0 100 200 300 400 500 0 100 200 300 400 500

Big Fish LakeSlack Lake

Joanne P Ballard 3-27-2009

- 44- 42- 40-38- 36-34

parts per mil

d18O GISP2 ice core

0

8000

9000

10000

11000

12000

13000

14000

15000

16000

17000

18000

Cal

ibra

ted

age,

yea

rs

more snow less snow

12,900 yr

~14,500 yr

~13,400 yr

warmer/wetter? cooler/drier?

Hypothesis 1Bolide strikesNorth America

100 200 300 400 500

predicted cha rcoal patterns

Timeline with hypotheses modeled

0 100 200 300 400 500 0 100 200 300 400 500

Hypothesis 3Hypothesis 2YoungerDryas is arid

Joanne P Ballard 3-31-2009

- 44

- 42- 40-38- 36-34

parts per mil

d18O GISP2 ice core

0

8000

9000

10000

11000

12000

13000

14000

15000

16000

17000

18000

Cal

ibra

ted

age,

yea

rs

more snow less snow

12,900 yr

~14,500 yr

~13,400 yr

warmer/wetter? cooler/drier?

simulated charcoal counts

Clovis 12,200 - ~13,000 or earlier

Later Paleo-Indian stone toolsRedstoneCumberland PointPlainview GoshenSuwanee-SimpsonFolsomGainey

REFERENCES

Joanne Ballard would like to thank:The Limnological Research CenterDepartment of Geology and Geophysics - University of Minnesota, Minneapolis

Donald B. Simons, Gainey site investigatorJohn Siler, Slack Lake ownerWilliam Swift, Swift Lake ownerAllen West, coauthor of Firestone et al.Cathy Whitlock, Montana State UniversityEric Grimm, Chair Botany, Illinois State MuseumThomas V. Lowell *Justin S. Stroup * Mike Oestreich

The Department of Geology at the University of Cincinnati