Transcript Slide 1
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
http://woodshole.er.usgs.gov/epubs/b olide/ancient_cataclysm.html
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://ijolite.geology.uiuc.edu/02SprgClass/geo117/Ocea n%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
Results: Genera and Species Classification
Distinguishing features of a genus:
•
Planktic vs. Benthic
•
Agglutinated test vs. secreted test agglutinated secreted
Results: Genera and Species Classification
Distinguishing features of a genus: Limbate
•
Planktic vs. Benthic
•
Agglutinated test vs. secreted test
•
Limbate/Costate structures Costate
Results: Genera and Species Classification
Distinguishing features of a species:
•
Morphology of Aperture
(Echols and Armentrout, 1980)
Results: Genera and Species Classification
Distinguishing features of a species:
•
Morphology of Aperture
•
Coiling of test:
•
Planispiral
•
Involute
•
Trochospiral
http://www.andreaperl.de/14_69_ammonia html.html
Results: Genera and Species Classification
Distinguishing features of a species:
•
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
8.
Bulimina sp. A, 200x
9.
Fissurina sp. A, 1000x 10. Fissurina sp. A, 700x 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
8.
Bulimina 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 14. Fissurina sp. A, 51x
Conclusions:
Goals included:
•
Gaining experience in SEM techniques and theory
Conclusions:
Goals included:
•
Gaining experience in SEM techniques and theory
•
Foram picking techniques
Conclusions:
Goals included:
•
Gaining experience in SEM techniques and theory
•
Foram picking techniques
•
Start gathering images of representative genera for catalog
Conclusions:
Goals included:
•
Gaining experience in SEM techniques and theory
•
Foram picking techniques
•
Start gathering images of representative genera for catalogue
•
All goals were accomplished during semester
Conclusions:
Goals included:
•
Gaining experience in SEM techniques and theory
•
Foram picking techniques
•
Start gathering images of representative genera for catalogue
•
All goals were accomplished during semester Questions:
•
Genera/species change from distal to proximal?
Conclusions:
Goals included:
•
Gaining experience in SEM techniques and theory
•
Foram picking techniques
•
Start gathering images of representative genera for catalogue
•
All goals were accomplished during semester Questions:
•
Genera/species change from distal to proximal?
•
Environmental changes shown by distribution within sediment?
Conclusions:
Goals included:
•
Gaining experience in SEM techniques and theory
•
Foram picking techniques
•
Start gathering images of representative genera for catalogue
•
All goals were accomplished during semester Questions:
•
Genera/species change from distal to proximal?
•
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