Graduate Research Projects

This listing includes both current and potential future research projects dealing with deformed sedimentary rocks in Canadian orogens. For further details contact John Waldron (email: john.waldron "at" ualberta.ca)

Development of the Late Paleozoic Maritimes Sedimentary Basin, Atlantic Canada

The Maritimes sedimentary basin is a huge sedimentary basin (more than 400 km in diameter and at least 12 km deep) that developed late in the history of the Appalachian orogen in Atlantic Canada, during Devonian to Permian time. An extensive database of seismic reflection profiles and a relatively small number of wells give information about the subsurface. On-land portions of the basin show evidence of deformation due to both transpression and transtension. In addition, the structural geometry in parts of the basin has been strongly modified by evaporite flow. This program of research incorporates several sub-projects using diverse datasets (seismic profiles, wells, field mapping) to produce a viable model for the subsidence mechanism and history of the basin. Projects include:

syncline in Horton Bluff Formation

Terrane evolution in the Early Paleozoic Appalachian-Caledonide orogen

Detrital zircon grains occur in many sandstones from which they can be extracted and rapidly dated using the laser-ablation multicollector inductively coupled plasma mass-spectrometer (LA-ICP-MS) at the University of Alberta. In contrast to most dating projects in igneous rocks, the object is not to determine the age of the rocks in which the zircons are found. Instead, we sample sandstones of known age from sedimentary basins, and use the detrital zircons to determine the ages of crustal units that were undergoing erosion and contributing detritus to the basin at that time. In this program, we will examine detrital zircon populations from Early Paleozoic sandstones in terranes of poorly known affinities in the Appalachians, such as Ganderia and Meguma, with the aim of locating those terranes in relation to the Iapetus and Rheic oceans.

In addition, the foreland basin of the Appalachians in Atlantic Canada though largely concealed beneath the Gulf of St. Lawrence, is extensively imaged in offshore and onshore seismic data. We will correlate the offshore and onshore data and investigate the history of the orogen as recorded in this basin, using a combination of seismic and provenance data.

Deformation processes in the Canadian Cordillera

The Canadian Cordillera provides superb opportunities to study processes of deformation in sedimentary rocks. In the foothills belt, folds and faults are intimately related. Significant controversies have surrounded the timing and relationships of faults and folds. In the Blairmore area a tight fold fits models of fault propagation folding, but the structure is modified by at least one lateral ramp, that produces changes in the plunge of the fold. The structure is an exceptionally well exposed example of a fold associated with loss of displacement on a thrust, and, from a practical point of view, it is an exposed analogue of petroleum-producing structures in the subsurface. Farther west, the McConnel thrust brings to surface exposure structures closely similar to those present in the subsurface of the foothills where they form important reservoirs for oil and natural gas. These projects examine structures exposed at the thrust front and compare them with those found in the subsurface, using a combination of outcrop and seismic data. In addition, the front ranges provide opportunities to study the flow of fluids and their role in dolomitization of carbonate rocks. Farther into the Cordillera, rocks from the early history of the Laurentian continental margin are exposed in the Cariboo Mountains, where they provide a natural laboratory for the study of ancient slope processes; work in this area is focussed upon distinguishing the various effects of soft-sediment and hard-rock deformation.