Validation of Sediment Accumulation Regions in Kansas,
USA
W. 1. Watney, J. Kruger, J. c. Davis, J. Harff, R. A. Olea, and G. C. Bohling
1
Introduction
Recognition of recurrent structural deformation and sedimentation in cratonic
shelves is not new and these processes affect these areas worldwide (Merriam
and Forster, submitted b). "Plains-type folds" have been described in the literature since the turn of the century. Structural reactivation continues to be documented in the northern Midcontinent, USA and refined in timing, spatial distribution, and causal relationships (Gerhard et al. 1982; Baars and Watney 1991;
Berendson 1997; Watney et al. 1997; Merriam and Forster; submitted b). This
chapter further documents km-scale reactivation features.
Regionalized classification based on thicknesses of genetic stratigraphic units
was used to differentiate sediment accumulation regions (SARs) on the Kansas
shelf, bordering the Arkoma and Anadarko basins (Fig.la,b); Watney et al. 1995;
1997). Regionalized classification is a statistical procedure previously described
by Harff and Davis (I 990), that divides an area into regions that are as homogeneous as possible while as distinct as possible from other regions. Each of the 15
different km-sized regions is defined by a similar thickness of six genetic stratigraphic intervals, including four successive Late Pennsylvanian (late Carboniferous) high-frequency, genetic stratigraphic units (GSUs) (Fig. 2) that are part
of the Nuyaka Creek genetic set (GS) (Fig. 2). Two other genetic units included
in the regionalized classification are divisions of the Muncie Creek genetic set
that overlies the Nuyaka Creek GS. The divisions consist of a lower carbonatedominated interval and an upper clastic-dominated section. These divisions reflect significant changes in internal lithofacies of GSUs included in the Munice
CreekGS.
The GSUs range in thickness from 10 to 150 ft (3 to 50 m). They are bounded
by thin flooding units, commonly overlain by a thin, radioactive condensed section (black shale). The succeeding lithofacies depends on shelflocation and vary
from clastics to carbonates indicating an upward shallowing trend culminating
in subaerial exposure and often paleosol development. Subaerial exposure affects most of the shelf except along its lowest reaches (Watney et al.1989). GSUs
are also associated with pronounced shifts of lithofacies across the shelf and result in non -Waltherian facies successions. Spatial variations in the lithofacies
USA
W. 1. Watney, J. Kruger, J. c. Davis, J. Harff, R. A. Olea, and G. C. Bohling
1
Introduction
Recognition of recurrent structural deformation and sedimentation in cratonic
shelves is not new and these processes affect these areas worldwide (Merriam
and Forster, submitted b). "Plains-type folds" have been described in the literature since the turn of the century. Structural reactivation continues to be documented in the northern Midcontinent, USA and refined in timing, spatial distribution, and causal relationships (Gerhard et al. 1982; Baars and Watney 1991;
Berendson 1997; Watney et al. 1997; Merriam and Forster; submitted b). This
chapter further documents km-scale reactivation features.
Regionalized classification based on thicknesses of genetic stratigraphic units
was used to differentiate sediment accumulation regions (SARs) on the Kansas
shelf, bordering the Arkoma and Anadarko basins (Fig.la,b); Watney et al. 1995;
1997). Regionalized classification is a statistical procedure previously described
by Harff and Davis (I 990), that divides an area into regions that are as homogeneous as possible while as distinct as possible from other regions. Each of the 15
different km-sized regions is defined by a similar thickness of six genetic stratigraphic intervals, including four successive Late Pennsylvanian (late Carboniferous) high-frequency, genetic stratigraphic units (GSUs) (Fig. 2) that are part
of the Nuyaka Creek genetic set (GS) (Fig. 2). Two other genetic units included
in the regionalized classification are divisions of the Muncie Creek genetic set
that overlies the Nuyaka Creek GS. The divisions consist of a lower carbonatedominated interval and an upper clastic-dominated section. These divisions reflect significant changes in internal lithofacies of GSUs included in the Munice
CreekGS.
The GSUs range in thickness from 10 to 150 ft (3 to 50 m). They are bounded
by thin flooding units, commonly overlain by a thin, radioactive condensed section (black shale). The succeeding lithofacies depends on shelflocation and vary
from clastics to carbonates indicating an upward shallowing trend culminating
in subaerial exposure and often paleosol development. Subaerial exposure affects most of the shelf except along its lowest reaches (Watney et al.1989). GSUs
are also associated with pronounced shifts of lithofacies across the shelf and result in non -Waltherian facies successions. Spatial variations in the lithofacies