The Western Canada Sedimentary Basin is remarkable in two essential regards. First, there is superb natural exposure of practically all of the basin strata in the Rocky Mountain Fold and Thrust Belt. Pre-orogenic Proterozoic to Jurassic strata of the ancient continental margin crop out extensively in the imbricate thrust slices that dominate the various ranges of the Canadian Rockies. Syn-orogenic Jurassic to Tertiary rocks of the foreland basin, deposited cratonward of the easterly advancing thrust belt, are extensively exposed in the front ranges and foothills. The availability of two- and three-dimensional surface exposure in the deformed belt allows for otherwise unachievable insights not only into the facies and stratigraphic architecture of the rocks themselves but also into the close tectono-stratigraphic relationships between the Rockies and the associated sedimentary strata of the undeformed craton. Second, the cratonic subsurface realm of the Western Canada Sedimentary Basin is amongst the most comprehensively documented in the world, although the control density is not particularly exceptional. What is exceptional is that geological and petrophysical data from virtually all of the 193,000 wells in Western Canada are publicly available, most now in digital form, through the provincial conservation boards. There can be no doubt that this subsurface database is truly unparalleled in the world, both in nature and in scope. Thus, given the exceptional character of both the surface and subsurface control, and the opportunity to integrate data and interpretations from both the Cordilleran and cratonic realms, it is clear that the Western Canada Sedimentary Basin is an ideal candidate for comprehensive tectono-stratigraphic synthesis and basin analysis.
This synthesis opportunity was first recognized in the early 1960s when a group of far-sighted industry, government and academic geologists in the Alberta Society of Petroleum Geologists (now the Canadian Society of Petroleum Geologists) banded together to undertake a comprehensive regional analysis of the entire Phanerozoic succession in the basin. The result was the production of the first atlas of Western Canada - Geological History of Western Canada, compiled by McCrossan and Glaister (1964). By any standards, it was a landmark publication, later emulated in many other parts of the world.
In the years since publication of the first atlas, the database of wells in Western Canada has increased many fold. Technical improvements in the resolution and reliability of subsurface measurements have resulted in quantum advancements. Geological ideas on the stratigraphic and structural evolution of the basin have been revolutionized, most centrally by the concepts of plate tectonics, which were not widely accepted at the time of compilation of the first atlas. In addition, there has been very considerable evolvement in basin analysis techniques, embracing previously uncharted concepts of facies analysis, sequence stratigraphy, basin architecture, thermal-organic maturity, and resource localization. The time is clearly ripe for a fresh regional synthesis. There is also growing realization that, although one of the primary benefits of a modern atlas compilation is the fostering of enlightened exploration for earth resources, there are crucial additional benefits with respect to sustainable development - environmentally sensible interaction between society and the solid earth upon which it is founded.
The goal of the Atlas project has always been stated thus - "as a community of geologists in Western Canada, to compile and produce a new atlas of the subsurface geology of the Western Canada Sedimentary Basin". The two output objectives - "1) to establish and release an electronic database of consistently interpreted subsurface information; and 2) to produce a printed volume ..." - are jointly realized with the publication of this book and its attached voucher for the Atlas database. Readers are referred to Chapter 1 for information on the geological tenets around which the Atlas is structured and on the book's through-going standards, protocols, assumptions and constraints. Data processing and map production are dealt with in Chapter 35.
Notwithstanding the project's complexity, and in full appreciation of the vast human resources that were deployed to create this book, it is nonetheless true that the proof of the Atlas is in its utilization. Not only must the maps and cross sections and related illustrations prove their integrity, they must ultimately prove their worth - by bringing to light previously undetected trends and by allowing all of us previously undiscerned insights.
Grant Mossop
Irina Shetsen
Co-compilers
March, 1994
We are eager to learn of errors that readers may spot in the text and figures, in order to apply corrections should there be a second printing. Please send errata to: Grant Mossop, ISPG/GSC, 3303 - 33 Street N.W., Calgary, Alberta, T2L 2A7.
Acknowledgements
The overriding purpose of all these foreleaf pages (i-x) is to cite and acknowledge and thank the hundreds of individuals and scores of institutions and corporations that contributed to the success of the Atlas project. No typeset account of roles and responsibilities, nor any merely verbal acknowledgement, can truly express our collective gratitude to all of the parties involved in the project. Nonetheless, we commend these foreleaf pages to your attention, particularly the two succeeding pages (iv-v). In addition, there are acknowledgements in each Atlas chapter and these too we commend to your attention. Thought should be given also to the families of the cited individuals, for theirs was in many instances both an enormous sacrifice and an invaluable support.
In the formative years of the project (1985-86), when the feasibility of the concept and the availability of resources were being extensively probed, there were many visionary and optimistic supporters and proponents. They have our heartfelt thanks. Even the naysayers perhaps deserve acknowledgement, for their arguments served to stiffen our resolve.
In the compilation years (1987-92), most of the scientific work was carried by the authors and the contributors, who not only worked up their data and interpretations but also supplied crucial input to the Atlas database. During the manuscript preparation stage, the authors were tested and tried and even harassed (sometimes unjustly), but they all came through in the end and they all deserve our profound thanks. At project headquarters, where the data processing and mapping were manifest, a number of workers provided invaluable support. In this regard special thanks are extended to Kelly Roberts, project technician for data entry and plotting, not only for her tireless good work, cheerfully rendered, but also for her buoying moral support. In the data compilation area as well, we wish to express special thanks to our colleagues in Saskatchewan and Manitoba - Fran Haidl, Ruth Bezys, and particularly Jim Christopher - who provided reams of carefully judged stratigraphic data for large parts of the Phanerozoic, well beyond their chapter/division responsibilities.
In the publication production years (1992-94), the project became increasingly dependent upon contracted parties and a few key staff members and volunteers. Jim Dixon and Jo Munro deserve great credit for their splendid editorial work. Dale Hite designed the volume, implemented advanced computer processing for layout and colour separation, and coordinated all aspects of final publishing, including sitting on the presses at all hours. The handsomeness of the volume is largely to his credit. Our most heartfelt thanks are reserved for Mika Madunicky, the project coordinator. Without her efficient handling of myriad communication and organizational tasks, discharged with unfailing attention to detail and consummate inventiveness, the project would surely have foundered beyond redemption.
We would like to close with some personal expressions of gratitude.
Irina Shetsen - "I would like to thank my son, Alex Shetsen, for clarifying in my mind many mathematical concepts that I had to struggle with, and for his support and encouragement throughout the long, arduous, and often stressful task of Atlas compilation."
Grant Mossop - "I am grateful to all of the parties to the project, but there are three areas of personal acknowledgement that warrant highlighting. First, I am endlessly grateful to those individuals who, through unwavering scientific conviction or simply faith in my ideas and abilities, supported my Atlas endeavours through thick and thin. Some of these people are directly connected with the project, others are not; they know who they are. Second, I wish to express my appreciation to the management of the Geological Survey of Canada and particularly to the staff of the Institute of Sedimentary and Petroleum Geology for their forbearance in accommodating the huge amount of time that I was absent from my GSC director's job (1991-94) in order to travel to project headquarters in Edmonton to finish the Atlas work. Theirs is a tacit and inherent belief that sacrifices must be made and accommodated in order to complete a large scientific project. Finally, and most profoundly, I wish to acknowledge the boundless strength and support afforded me by my family. Our three children - Jenny, Jonathan and David - have grown up without any knowledge of what it must be like to have dad free in the evenings or home on the weekends. And Ruth, heaven sent, the embodiment of all that is most noble in human endeavour, deserves more credit than anyone can possibly know. She is a saint. Bless her."
Grant Mossop
Irina Shetsen
Co-compilers
March, 1994