Outcrop 9. Clastic Injectites in the Cerro Toro Formation, Lago Sofia
Published:January 01, 2009
S.M. Hubbard, B.W. Romans, S.A. Graham, 2009. "Outcrop 9. Clastic Injectites in the Cerro Toro Formation, Lago Sofia", Stratigraphic Evolution of Deep-Water Architecture: Examples of controls and depositional styles from the Magallanes Basin, southern Chile, Andrea Fildani, Stephen M. Hubbard, Brian W. Romans, J.A. Covault, W.H. Crane, A. Bernhardt, Z.R. Jobe, D.A. Armitage, J.C. Fosdick, M.R. Shultz, J. Clark, D.R. Lowe, S.A. Graham
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Outcrop accessibility: easy Outcrop Coordinates: 51.5394°S; 72.6291°W Refer to outcrop 9 on location map
The injectites at Lago Sofia were first reported by Scott (1966) and Winn and Dott (1979). The first comprehensive evaluation of the features was done by Schmitt (1991), with a more recent summary published by Hubbard et al. (2007), who noted the geometrically analogous nature of the injectites to similar features in the North Sea.
The injectites at Lago Sofia are exposed in 3-D, characterized by a near vertical outcrop of channel deposits in the lowest part of the succession. The middle part of the succession where the injectites are most prevalent is exposed on an ancient terrace, allowing for plan-view mapping of the injectite complex. The upper part of the stratigraphic succession is exposed sub-vertically, permitting visualization of the cross-cutting relationships between injectites and host strata (Fig. 9.1).
A series of three channel bodies (C1–C3) are laterally offset and progressively younger eastward. Each channel body is associated with injected bodies at its margins. Both margins of C1 experienced sediment remobilization and injection. Channel C2 experienced injection solely on its western margin; the associated injectite, I3, bifurcates and is observed to cross-cut >125 m of overlying stratigraphy. Channel C3 is the smallest, as is its accompanying injectite (I4).
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Stratigraphic Evolution of Deep-Water Architecture: Examples of controls and depositional styles from the Magallanes Basin, southern Chile
This large format (11 × 17 inch) all color outcrop atlas and field guide was produced for the SEPM Research Conference held in Chile in February, 2009. It contains a wealth of information on the world class deep water outcrops of the Cretaceous of the Magallanes Basin in the Ultima Esperanza District, Chilean Patagonia. This book covers the significant outcrops in the region the Punta Barrosa Formation, CerroToro Fm., and the Tres Pasos Fm.