Rheology of fine-grained siliciclastic rocks in the middle crust—evidence from structural and numerical analysis

Plate Rheology and Mechanics

“…It was shown, however, that lower amounts of weak phases such as micas or albites may result in significantly smaller strength than that of quartz or quartzite (see discussion in Burov, 2002). It was also noted that polyphase aggregates are weaker than their constituents and that different mineral species may take a lead in the experiments and nature (e.g., Kenis et al, 2005;Kohlstedt et al, 1995). 4.…”

Guidebook for Field Trips in Western Maine and Northern New Hampshire

“…Subsequently, the maximum stress rotated to cause bedding-parallel shortening (mullions). Microstructural observations suggest a dislocation mechanism of deformation in the quartz veinlets, and pressure solution mechanisms in very weak sediment (Kenis et al 2005). …”

“…The mullions record a two-step history (Kenis et al 2005) beginning with hydrofracturing of the sandstone bed, resulting in the quartz veinlets, under a vertical maximum compressive stress due to either sedimentary or tectonic loading. Subsequently, the maximum stress rotated to cause bedding-parallel shortening (mullions).…”

Multiphase Boudinage: a case study of Amphibolites in Marble in the Naxos Migmatite core

“…This complexity can be apparent when boudins are the result of more than one deformation event. Some multiphase structures such as mullions or bone boudins are indicative for a certain sequence of 25 deformation (Kenis et al, 2005;Maeder et al, 2009). Similarly, Chocolate Tablet Boudins form by two phases of extension of layers in different directions (Abe and Urai, 2012;Zulauf et al, 2011aZulauf et al, , 2011b, and have been used in some studies for the reconstruction of the deformation history of rocks (Casey et al, 1983;Reber et al, 2010).…”

“…Since their earliest description (Harker, 1889;Lohest, 1909;Ramsay, 1881) and initial confusion in 20 nomenclature of mullions and boudins, (c.f. Kenis et al, 2005;Kenis and Sintubin 2007) our understanding of these structures has greatly improved, and a taxonomy was established to describe the diversity of observed boudin structures (Goscombe et al, 2004). Although boudins are often depicted in 2-dimensions it has been recognized that in 3D boudins can be complex (Zulauf et al, 2011b).…”