John D. Dwyer
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B. Sc. Honours Thesis
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A section of the lower Meguma (Lower Paleozoic) near Ship Harbour, Nova Scotia, was examined in detail in terms of bed thickness, sedimentary structures and grain size.
Interpretation of depositional processes and environment was attempted in view of models of sediment gravity flow and deep sea fan deposition.
The deposition of beds is the product of sediment gravity flows in the mid fan area of a deep sea fan. The thick sands showing delayed and complex grading and thin lutite layers may be the product of a combination of fludizied flow and grain flow transitional with immature turbidity current deposition. Sediment flows appear to have been confined in channels and on open areas. A reverse trend in this environment indicates retrograde development of the fan.
The variation in bed thickness is believed to reflect the changing distribution of sediment gravity flows in channelled and unchannellled areas of the fan. Trends in sand thicknesses similar to those found in other deposits were observed. Power spectrum analysis was used to determine if there were cyclic variations in sand thickness. Evidence of periodic tendencies of several scales was found, up to a vertical thickness of 25 m. These cycles are attributed to channel switching and depositional lobe movement.
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Pages: 132
Supervisor: D. B. Clarke