Palaeogeography in exploration

Abstract

Palaeogeography is the representation of the past surface of the Earth. It provides the spatial context for investigating how the Earth evolves through time, how complex processes interact and the juxtaposition of spatial information. In hydrocarbon exploration, palaeogeographies have been used to map and investigate the juxtaposition, distribution and quality of play elements (source, reservoir, seal and trap), as boundary conditions for source-to-sink analysis, climate modelling and lithofacies retrodiction, but most commonly as the backdrop for presentations and montages. This paper demonstrates how palaeogeography has been and can be used within an exploration workflow to help mitigate exploration risk. A comprehensive workflow for building palaeogeographies is described which is designed to provide a standard approach that can be applied to a range of tasks in exploration and academia. This is drawn from an analysis of the history of palaeogeography and how it has been applied to exploration in the past and why. Map applications, resolution and content depend on where in the exploration and production (E&P) cycle the map is used. This is illustrated here through three case studies, from the strategic decisions of global new ventures exploration to the more detailed basin and petroleum analyses of regional asset teams evaluating basins and plays. Through this, the paper also addresses three commonly asked questions: (1) How can I use palaeogeography in my workflow? (2) How reliable are the maps? (3) How do I build a palaeogeography?

Predicting sediment discharges and erosion rates in deep time—examples from the late Cretaceous North American continent

“…Each palaeoDEM comprises a single elevation raster with a spatial resolution of 0.1° latitude × 0.1° longitude, which equates to a cell size of ~11 × 11 km (Figure 1). Getech constructs palaeoDEMs using the methodology of Markwick and Valdes (2004) and Markwick (2018), based on concepts developed by Ziegler et al (1985). Getech palaeoDEMs have been used in a number of studies on pre‐Quaternary palaeoclimate (e.g.…”

“…In this study, we evaluate high‐resolution palaeogeographies as a first‐order investigative tool in palaeo‐sediment routing system analysis. Palaeogeographic reconstructions offer a conceptual model of Earth's topography during time‐integrated ‘slices’ of the geologic past (Markwick, 2018; Markwick & Valdes, 2004) and improvements to reconstruction methods and data sets over recent decades (see review in Markwick, 2018) have significantly enhanced our understanding of palaeotopography. Digitisation of these models as palaeo‐digital elevation models (palaeoDEMs) is now employed by various research communities (e.g.…”

“…Palaeogeographic reconstructions are of increasing scientific importance across fields such as pre‐Quaternary palaeoclimate modelling and hydrocarbon exploration (evaluation of play element distributions, e.g. Markwick, 2018). Major advances to the resolution of palaeogeographies are attributed to growth of the extensive lithologic, tectonic and palaeontologic data sets that underpin them (see discussion in Markwick, 2018; Markwick & Valdes, 2004).…”

“…Markwick, 2018). Major advances to the resolution of palaeogeographies are attributed to growth of the extensive lithologic, tectonic and palaeontologic data sets that underpin them (see discussion in Markwick, 2018; Markwick & Valdes, 2004). Markwick and Valdes (2004) developed a method that uses geographic information systems (GIS) to digitise high‐resolution palaeogeographies as palaeoDEMs and facilitate their use in palaeoclimate modelling, lithofacies retrodiction and source‐to‐sink analysis.…”

The Eocene-Oligocene transition: a review of marine and terrestrial proxy data, models and model-data comparisons

“…The tectonic evolution of the southern continents, opening a pathway for the Antarctic Circumpolar Current, has long been linked with long-term Eocene cooling and the EOT (Kennett et al, 1975). However, there remain major challenges in reconstructing the paleogeography at or around the EOT, requiring a series of methodological steps (Baatsen et al, 2016;Kennett et al, 1975;Markwick, 2007Markwick, , 2019Markwick and Valdes, 2004;Müller et al, 2008). The first step is to use modern day geography and relocate the continental and ocean plates according to a plate tectonic evolution model, used in software such as GPlates (Boyden et al, 2011).…”