格陵蘭外海羅蒙諾索夫海脊上獨特灰色沉積層之來源探討

Heavy Mineral Provenance of a Distinct Gray Layer from the Lomonosov Ridge off Greenland

周穎詩(Weng-Si Chao)

指導教授 ： 施路易

國立臺灣大學/理學院/地質科學研究所/碩士(2017年)

https://doi.org/10.6342/NTU201700098

摘要

無資料

關鍵字

北極海 ； 重礦物 ； 來源 ； 灰色沉積層 ； 生物擾動 ； 錳 ； 沉積學

並列摘要

The sediment deposited in the Arctic Ocean is transported by sea ice and icebergs, which are controlled by the Arctic surface circulations. Several cores from the central
Arctic, the Lomonosov Ridge north of Greenland and the Morris Jesup Rise contain a distinct grayish, ice rafted debris (IRD)-rich, layer with some specific features: a sharp lower boundary, relatively low content of manganese, and a lack of bioturbation.
Heavy minerals from these layers were analyzed primarily by Electron Probe X-Ray Microanalyzer (EPMA) and Scanning Electron Microscope-Energy Dispersive Spectrometer (SEM-EDS) to establish the prominent provenance areas. The provenance variations can show the paleo-distribution and transport pathways of sea ice and icebergs and even indicate the origin of some abrupt glacial events. Initial results suggest that the majority of the grains in the gray layer originated from a limited area near the Putorana Basalt Plateau. We therefore hypothesize that this gray layer is related to an abrupt ice dammed lake drainage from northern Siberia, tentatively dated to around the boundary between MIS 4 and 3 based on all available chronostratigraphic data points and the correlation of distinct geochemical and sedimentological features: variation in Mn, bulk density, bioturbation and abundance of planktonic and benthic foraminifera; including
published data and measured data in this study.

並列關鍵字

Arctic Ocean ； Heavy mineral ； Provenance ； Gray layer ； Bioturbation ； Manganese ； Sedimentology

參考文獻

Kristoffersen, Y., 1990. Eurasia basin. The Geology of North America, 50: 365-378.

Adler, R.E., Polyak, L., Ortiz, J.D., Kaufman, D.S., Channell, J.E.T., Xuan, C., Grottoli, A.G., Sellén, E. and Crawford, K.A., 2009. Sediment record from the western Arctic Ocean with an improved Late Quaternary age resolution: HOTRAX core HLY0503-8JPC, Mendeleev Ridge. Global and Planetary Change, 68(1–2): 18-29.

Axelsson, V., 1983. The use of X-ray radiographic methods in studying sedimentary properties and rates of sediment accumulation. Hydrobiologia, 103(1): 65-69.

Forcing of the cold event of 8,200 years ago by catastrophic drainage of Laurentide lakes. Nature, 400(6742): 344-348.

Behrends, M., Hoops, E. and Peregovich, B., 1999. Distribution Patterns of Heavy Minerals in Siberian Rivers, the Laptev Sea and the Eastern Arctic Ocean: An Approach to Identify Sources, Transport and Pathways of Terrigenous Matter. In: H. Kassens, H.A. Bauch, I.A. Dmitrenko, H. Eicken, H.-W. Hubberten, M. Melles, J. Thiede and L.A. Timokhov (Editors), Land-Ocean Systems in the Siberian