Calgary, AB Tel: +1 403.290.1320

Deformable Plate Reconstructions

Palaeogeography

Palaeoenvironment

 

 

 



"As petroleum exploration becomes increasingly focused on deep-water continental margins, there is a corresponding increased awareness of the importance of surface plate kinematic analyses and deformable plate tectonic reconstructions as exploration tools."

The motion of rigid lithospheric plates on the Earth’s surface is described by means of a pole of rotation (Euler pole) and an angular velocity about the pole. However, continental lithosphere does not behave rigidly and the application of rigid-body plate reconstruction methods results in plate overlap or underfit in areas that have undergone continental extension and compression respectively. The amount of overlap is useful in estimating the total extension that has occurred across the margin, but the accurate restoration of the palaeo-geometry of adjacent basins required a new approach to plate kinematics and a new generation of plate reconstruction software.

GeoArctic Pioneers Deformable Plate Technology

In 1999 GeoArctic significantly advanced deformable plate modelling with the development of the first deformable plate reconstruction software that accurately removed the effects of pre-breakup extension across conjugate margins, thereby providing a means to better evaluate basin formation and evolution. For the first time accurately restored structure maps, palaeogeography maps, sediment source area maps, source rock and reservoir facies maps could be reconstructed to their relative palaeo-position allowing us to evaluate the structural development of a basin, the depositional setting and provenance of reservoir rocks, source rock distribution, basin connectivity, palaeo-climate and ocean currents.

The deformable plate model comprising calculations of vertical movement and lateral, depth-dependent,
and time-dependent variations in the amount and direction of stretching are stored as TINs
(Triangulated Irregular Networks), a vector data structure that partitions geographic space into
contiguous, non-overlapping Delaunay triangles. The information stored in the TINs can be applied to any gridded or vector datasets such as structure maps,
palaeogeographic maps, wells, licence blocks, and seismic lines, etc. to restore their geometry through geologic time.

Since 1999 GeoArctic’s technology has been used successfully in proprietary industry studies in the North Atlantic and Arctic. In 2007 Fugro-Robertson adopted GeoArctic’s deformable plate technology for their Plate Wizard™ global plate reconstruction initiative. GeoArctic continues to use the software and other proprietary tools and techniques for regional studies, proprietary industry studies, including the ongoing North Atlantic-Arctic deformable-plate model research project.

Selected References...

A New Approach to Plate Kinematics

GeoArctic’s proprietary plate tectonic modeling workflow allows all available regional geological and geophysical data to be used to build a detailed structural and palaeogeographic history of a margin. We create maps of continental lithospheric extension (ß factors) for each tectonic event around a margin (ßeta-STACK™). The ßeta-STACK™ is the primary input to the deformable plate reconstruction software.

GeoArctic's deformable plate reconstruction method advances earlier ideas first put forward by Srivastava and Verhoef (1992) for the removal of extension at plate margins. Their approach, however, used a gross estimation of ß factors from the measurement of plate overlap, which cannot account for lateral, depth-dependent, and time-dependent variations in the amount and direction of extension or movement in the vertical plane due to tectonic subsidence. The workflow and methods designed by GeoArctic to create the ßeta-STACK™ are key to the development of deformable plate models and reconstructions and represent a new approach to defining pre-breakup plate kinematics. Whittaker et al (2000) first describe a 4D deformable plate reconstruction using ß factors calculated from 3D tectonic subsidence maps as input. This method has since evolved to include the wide range of geological processes responsible for basin development as input into a deformable plate model.

References:

Whittaker, R. C. Karpuz. R., Wheeler. W, & Ady, B. 2000: 4D regional tectonic modeling [of the North Atlantic]: plate reconstructions using a geographic information system. PETEX Convention, London, Abstract

Srivastava S. P., & Verhoef, J., 1992: Evolution of Mesozoic sedimentary basins around the North Central Atlantic: a preliminary plate kinematic solution. In J. Parnell (Ed.), Basins on the Atlantic Seaboard: petroleum geology, sedimentology and basin evolution, Geological Society, Special Publication, 62, 397-420.

 
 
Copyright 2012 GeoArctic Ltd. - Deformable Plate Reconstructions