Cataloging Microfossils of Yakutat Bay, Alaska Alexander D. Ullrich Dept. of Geology Appalachian St. University Boone, NC

Cataloging Microfossils of Yakutat Bay, Alaska

Alexander D. Ullrich

Dept. of Geology

Appalachian St. University

Boone, NC

Field Setting:•Yakutat Bay, Alaska

•Hubbard Glacier-

•Tidewater glacier emptying into Disenchantment Bay, AK.

•High turbidity: high sed. discharge

•Low salinity

•Summer discharge causes thick mud layers

•Iceberg calving causes winter diamicton layers

Study Area

http://northlandsvs.com/

Multicore 8

Catalog of foraminifera•Distal Multicore chosen

•High-density, high diversity

•Picked 300 individual population

Multicorer on R/V Alpha Helix tailfan

Microfossils:•Tiny remains of bacteria, fungi, animals, plants, and protists

•Extremely useful as environmental indicators

•Foraminifera in particular:

•Species indicate salinity, high/low energy, bathymetry, DO content, temperature

•Seasonal variation

http://woodshole.er.usgs.gov/epubs/bolide/ancient_cataclysm.html

http://ijolite.geology.uiuc.edu/02SprgClass/geo117/Ocean%20images/Microfoss.html

Foraminifera:•Single-celled protists with shells (tests), called “forams” or “bugs” (Phylum: Protozoa)

•Consume algae, diatoms, other protists by extending protoplasm through aperture in test (psuedopodia)

•Protoplasm is inside test chamber (chambers added as foram grows)

•Often used in age-dating and correlation of rock

•Extant species used to interpret environments and climates

http://www.soton.ac.uk/~bam2/col-index/fossi-lindex/Forams/Eelco/med-agean2/pages/pl-02.htm

Pseudopodia

Protoplasm

Results: Genera and Species Classification

Distinguishing features of a genus:

•Planktic vs. Benthic




•Agglutinated test vs. secreted test

agglutinated

secreted




•Agglutinated test vs. secreted test

•Limbate/Costate structures

Limbate

Costate


Distinguishing features of a species:

•Morphology of Aperture (Echols and Armentrout, 1980)



•Morphology of Aperture

•Coiling of test:

•Planispiral

•Involute

•Trochospiral

http://www.andreaperl.de/14_69_ammoniahtml.html



•Morphology of Aperture

•Coiling of test:

•Evolute

•Involute

•Trochospiral

•Streptospiral

•Other morphological features (costate protrusion, limbate thickness, papillate presence, etc.)

Plate 1: Abundant Genera

1,2,3. Elphidium sp.A, 1000x

4,8. Buccella sp. A, 1000x

5,6. Epistominella sp. A, dextral, 1000x

7. Epistominella sp. A, sinistral, 1000x

9,10. Cassidulina minuta, 1000x

11, 12. Neogloboquadrina pachyderma, 1200x, 1100x

13, 14. Nonionella stella, 400x

15, 16. Nonionella labridorica, 400x

Plate 2: Limited Genera

1,2. Cribrostomoides sp. A, 1000x

3. Spiroplectammina sp. A, 1300x

4. Lagena sp. A, 500x

5. Triloculina sp. A, 700x

6. Triloculina sp. B, 400x

7. Bulimina sp. A, 400x


9. Fissurina sp. A, 1000x


11. Uvigerina sp. A, 250x

12. Fissurina sp. B, 1000x

Plate 3: Forams under a light microscope

1,2. Nonionella labridorica, 40x

3,4. Nonionella stella, 40x

5,6. Buccella sp. A, 51x

7. Epistominella sp. A, 51x


9. Cribrostomoides sp. A, 32x

10. Cassidulina limbata, 40x

11. Cassidulina norcrossi, 40x

12. Cassidulina sp. A, 40x

13. Cassidulina minuta, 64x


Conclusions:

Goals included:

•Gaining experience in SEM techniques and theory

Conclusions:

Goals included:


•Foram picking techniques

Conclusions:

Goals included:



•Start gathering images of representative genera for catalog

Conclusions:

Goals included:



•Start gathering images of representative genera for catalogue

•All goals were accomplished during semester

Conclusions:

Goals included:





Questions:

•Genera/species change from distal to proximal?

Conclusions:

Goals included:





Questions:


•Environmental changes shown by distribution within sediment?

Conclusions:

Goals included:





Questions:


•Environmental changes shown by distribution within sediment?

•Seasonal variation?

Future Research: Senior Thesis•Targeting specific foraminifera species as environmental indicators

•Specifically:

Elphidium excavatum forma clavatum

Elphidium frigidum

References:•Lipps, J.H., 1981, What,if anything, is micropaleontology?: Paleobiology, v. 7, no. 2, pp. 167-191.

•Echols, R.J., and Armentrout, J.M., 1980, Holocene foraminiferal distribution patterns on the shelf and slope, Yakataga- Yakutat area northern Gulf of Alaska: Proceedings of the Quaternary depositional environments of the Pacific Coast Pacific Coast Paleogeography Symposium, no. 4, pp. 281- 303.

•Bergen, F.W., and O’Neil, P., 1979, Distribution of Holocene foraminifera in the Gulf of Alaska: Journal of Paleontology, v. 53, no. 6, p. 1267-1292.

•Quinterno, P., Carlson, P., and Bruce F. Molnia, 1980, Benthic foraminifers from the eastern Gulf of Alaska: Quaternary depositional Environments of the Pacific Coast: Pacific Coast Paleogeographic Symposium 4,

Special Thanks to:

•Dr. Ruth Dewel, Dept. of Biology, ASU

•Dr. Ellen Cowan, Dept. of Geology, ASU

•Dr. Steven Hageman, Dept. of Geology, ASU

•Dr. Sarah Zellers, Dept. of Geology, MSU

•FEI Systems Technicians

•The 2005 SEM Lab class

Documents

Cataloging Microfossils of Yakutat Bay, Alaska Alexander D. Ullrich Dept. of Geology Appalachian St. University Boone, NC