Sedimentology of the Swift Formation (Jurassic) in the Little Rocky Mountains of Montana
| dc.contributor.advisor | Hendry, M. Jim | en_US |
| dc.contributor.committeeMember | Sarjeant, William | en_US |
| dc.contributor.committeeMember | Renaut, Robin W. | en_US |
| dc.creator | Khalid, Mohamed Elamin Abdelhamid | en_US |
| dc.date.accessioned | 2010-02-04T07:36:07Z | en_US |
| dc.date.accessioned | 2013-01-04T04:25:20Z | |
| dc.date.available | 2011-02-04T08:00:00Z | en_US |
| dc.date.available | 2013-01-04T04:25:20Z | |
| dc.date.created | 1990 | en_US |
| dc.date.issued | 1990 | en_US |
| dc.date.submitted | 1990 | en_US |
| dc.description.abstract | The marine strata of the Swift Formation (Upper Callovian-Oxfordian) are widely distributed and well exposed in the Little Rocky Mountains of north-central Montana. The contact between the Swift and the underlying marine Rierdon Formation is sharp, whereas the upper contact with the non-marine Morrison Formation is gradational. The Swift Formation is about 30 m to 50 m thick and is divided into two members: a lower shale and an upper sandstone. Detailed sedimentological analysis defined six facies; three in each member. The shale member contains a conglomerate facies (Facies A), a shale-siltstone facies (Facies B), and a bioclastic limestone facies (Facies C). The facies of the sandstone member comprise a sandstone-siltstone-shale facies (Facies D), a cross-bedded sandstone facies (Facies E), and a limestone facies (Facies F). The Swift Formation forms a coarsening-upward sequence from mud to sand-silt-mud intercalations to sand, which has been interpreted by other people as a progradational sequence across a shelf. The Rierdon-Swift contact is a disconformity spanning three ammonite zones. The whole section of the Swift Formation is considered to be a shallow marine shelf deposit that formed in the course of a transgressive-regressive episode during Late Callovian-Oxfordian time. Facies A was produced by the reworking of sediment by waves in a nearshore setting during the early stage of the transgressive sea. Facies B was deposited from suspension in relatively deep, open, marine waters during the maximum expansion of the Oxfordian sea. Facies C was formed by the winnowing effect of frequent storm-generated waves, reworking the muddy platform deposits of Facies B. Facies D and E form a continuous regressive sequence that was deposited in a storm-dominated, lower shoreface environment. Facies F was deposited in a shallow, relatively protected setting. The depositional model proposed for the Swift Formation in the study area is one of a shifting pattern of sedimentation in a shallow marine setting, where inner shelf deposits passed transitionally into lower shoreface deposits; these, in turn, gave way to middle-to-upper shoreface sediments. The sea-level changes during the deposition of the Swift Formation were as a result of mainly local and regional tectonism; eustatic factors, if any, were minor. | en_US |
| dc.identifier.uri | http://hdl.handle.net/10388/etd-02042010-073607 | en_US |
| dc.language.iso | en_US | en_US |
| dc.title | Sedimentology of the Swift Formation (Jurassic) in the Little Rocky Mountains of Montana | en_US |
| dc.type.genre | Thesis | en_US |
| dc.type.material | text | en_US |
| thesis.degree.department | Geological Sciences | en_US |
| thesis.degree.discipline | Geological Sciences | en_US |
| thesis.degree.grantor | University of Saskatchewan | en_US |
| thesis.degree.level | Masters | en_US |
| thesis.degree.name | Master of Science (M.Sc.) | en_US |