Hydrocarbon seeps and their associated chemosymbiosis-based communities have been documented throughout modern oceans, as well as in Neoproterozoic through Pleistocene aged rocks in the stratigraphic record. A particularly good record of ancient hydrocarbon seeps occurs in Mesozoic strata (Tithonian-Maastrichtian) along the western North American continental margin, cropping out throughout the Great Valley Group forearc strata and the Franciscan Complex. This extensive record allows for the comparison of the paleoecological signatures of stratigraphically and spatially related hydrocarbon seeps, which are geotectonically, petrographically, and isotopically consistent with each other.

This volume details the function of hydrocarbon seeps, their evolution over time, the most important seep occurrences and the fauna present in ancient hydrocarbon seeps. While several publications exist that cover modern seeps and vents, fossil seeps only constitute a small component of the literature. As such, many geologists, stratigraphers and paleontologists, as well as undergraduates and graduate students, are not very familiar with ancient hydrocarbon seep deposits and their associated fauna. This text is the first to comprehensively discuss the nature of such animal groups and how to recognize them. In addition to summarizing available knowledge on these topics for specialists in the field, this book offers the background needed to be of use to students as well as the wider community of geologists and paleontologists.

Onshore fold-thrust belts are commonly perceived as 'difficult' places to explore for hydrocarbons and are therefore often avoided. However, these belts host large oil and gas fields and so these barriers to effective exploration mean that substantial unexploited resources may remain. Over time, evaluation techniques have improved. It is possible in certain circumstances to achieve good 3D seismic data. Structural restoration techniques have moved into the 3D domain and increasingly sophisticated palaeo-thermal indicators allow better modelling of burial and uplift evolution of source and reservoirs. Awareness of the influence of pre-thrust structure and stratigraphy and of hybrid thick and thin-skinned deformation styles is augmenting the simplistic geometric models employed in earlier exploration. But progress is a slow, expensive and iterative process. Industry and academia need to collaborate.