Foreword
More than half the global population lives where there is fresh groundwater in fractured bedrock, either rock near the surface or rock aquifers beneath unconsolidated aquifers. This book, Fractures and Faults and Sandstone-Shale/Mudstone Sequences and Their Impact on Groundwater represents a geological perspective on this subject and is part of the larger topic of fractured rock hydrogeology. This book follows on from Structural Geology Applied Fractured Rock Characterization (Groundwater Project book, 2023) that is a broad introduction to the origins of the fractures significant in rock hydrogeology. To gain a full understanding of what is presented in these books, the reader will need prerequisite knowledge of structural geology as provided in an introductory course or introductory textbook. Subsequent books by the Groundwater Project will focus on flow and contaminant behavior in fractures and faults.
This book about fractures and faults in sandstone and shale/mudstone sequences is important because the literature about fractured rock hydrogeology is sparse relative to unconsolidated deposits and karst and because sandstone is an important type of aquifer in many regions. This book focus on the use of visual observations of bedrock in the field for developing conceptual models about the structural features and groundwater occurrence in these features. Fractured rock is complex and boreholes for subsurface investigation are expensive. Structural geology insights from land surface observations are important to combine with information from boreholes. There is the common intuitive perception that faults are features where bulk permeability is large relative to the host rock, but in sandstone sequences this may or not be the case depending on how shale strata have been incorporated into the deformed during formation of faults, which may or may not result in restricting flow across and/ or along the faults. The nature of the faulting governs the characteristics of the joints and bedding plane fractures away from the faults.
The research conducted by the authors of this book has included sandstone and sandstone sequences in many countries, with the common factor being guiding and connecting influence of Dr. Atilla Aydin (1944 to 2022); Dr. Aydin, formerly a professor at Stanford University (1991 to 2015), was a global leader of research on the topic. Of the book co-authors, Ramil Ahmadov, Marco Antonellini, Eric Flodin and Jian Zhong were graduate students supervised by Dr. Aydin and Antonino Cilona, Shang Deng and Ghislain de Joussineau were postdoctoral scientists on his Stanford team. Drs. Cherry and Parker were collaborators with Dr. Aydin who provided their hydrogeologic expertise on the last major project involving sandstone sequences led by Dr. Aydin. The combination of expertise and experience of these authors provides readers with a unique window into fractures and faults in the groundwater context within sandstone sequences.
John Cherry, The Groundwater Project Leader
Guelph, Ontario, Canada, November 2022