Dunedin non-marine deposits.
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A suite of non-marine rocks associated with the Dunedin Volcano, herein informally defined as Dunedin non-marine deposits, are described and implications arising from their study are discussed.
The deposits comprise rocks of pyroclastic, epiclastic and organic origin. Pyroclastites dominate and a variety of primary and redeposited lithotypes are described. Epiclastites are largely of volcanic derivation with a secondary component, in places, of reworked East Otago marine sediment and Haast schist-derived material. Organic sediments consist of localised pockets of diatomite and oilshale grading into lignite. These latter sediments are often in close association.
A distinct distribution pattern for non-marine deposits lying within the Kaikorai, Leith and Waitati Valleys is recognised. This is related to paleogeography. A sediment trap along a major fault zone: the Leith Fault Zone, is envisaged during the development of the Dunedin Volcano. Subsequent movement along the Leith Fault Zone has tectonically uplifted, and in places deformed, non-marine strata. A secondary set of E- W faults is also apparent.
Stratigraphic subdivision of the Dunedin Volcano sequence based on the recognition of distinct lithostratigraphic units within the Dunedin non-marine deposits (Older and Younger flood plain conglomerates; Benson, 1942, 1968) is considered to be unjustified.
The deposits comprise rocks of pyroclastic, epiclastic and organic origin. Pyroclastites dominate and a variety of primary and redeposited lithotypes are described. Epiclastites are largely of volcanic derivation with a secondary component, in places, of reworked East Otago marine sediment and Haast schist-derived material. Organic sediments consist of localised pockets of diatomite and oilshale grading into lignite. These latter sediments are often in close association.
A distinct distribution pattern for non-marine deposits lying within the Kaikorai, Leith and Waitati Valleys is recognised. This is related to paleogeography. A sediment trap along a major fault zone: the Leith Fault Zone, is envisaged during the development of the Dunedin Volcano. Subsequent movement along the Leith Fault Zone has tectonically uplifted, and in places deformed, non-marine strata. A secondary set of E- W faults is also apparent.
Stratigraphic subdivision of the Dunedin Volcano sequence based on the recognition of distinct lithostratigraphic units within the Dunedin non-marine deposits (Older and Younger flood plain conglomerates; Benson, 1942, 1968) is considered to be unjustified.
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146 leaves : col. illus., map (in pocket) ; 30 cm.
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1978Harvey
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POLYGON ((170.655563949687661 -45.68032585810321,170.529906249030461 -45.798657325753318,170.459838728721934 -45.797120147890617,170.462528017642228 -45.752884028056876,170.572014136675165 -45.677686727755599,170.655563949687661 -45.68032585810321))
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Harvey, Bruce Erle., “Dunedin non-marine deposits.,” Otago Geology Theses, accessed December 7, 2024, https://theses.otagogeology.org.nz/items/show/110.