Kinematics of the Greater Himalayan sequence, Dhaulagiri Himal ...

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Robinson et al. 2003; Bollinger et al. 2006; Kohn 2008).
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Recent research on kinematics in the Himalaya has focused on analysis near the top of
the Greater Himalayan sequence and within the STDS (Law et al. 2004, Jessup et al. 2006), near
the centre of the Greater Himalayan sequence (Grasemann et al. 1999 - see following discussion
on the position of the MCT; Martin et al. 2005; Carosi et al. 2006), and near its base (Jessup et
al. 2006; Carosi et al. 2007; Figure 1a). These studies provide critically important empirical data
that describe the kinematics of extrusive flow within the orogen and provide constraints within
which more refined models can be developed.
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One of the most fundamental challenges for the interpretation of kinematics within the
Greater Himalayan sequence is identifying and locating the bounding shear zones. Whether a
specimen is sampled from the base of the mid-crustal slab or the middle depends upon where
these shear zones are mapped. For example, the nature and location of the MCT is the subject of
considerable debate (e.g., Searle et al. 2008), one that has been complicated in central Nepal by
recent studies of the Ramgarh thrust (Figure 1b; Pearson & DeCelles 2005; Robinson et al.
2006). Locating and structurally documenting the position of the MCT and the Ramgarh thrust
is critical in providing constraints on lower boundary conditions and kinematics during the
extrusion and southward transport of the Greater Himalayan sequence. Consistency with respect
to how key tectonic boundaries, such as the MCT, are recognized is essential for comparing data
from different studies along the Himalaya.
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In this paper we present the results of geologic mapping transects that extend across the
Greater Himalayan sequence in the Kali Gandaki and Myadi valleys of central Nepal (Figure 1c).
Field observations are augmented by microstructural analyses of oriented specimens, which
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