Middle-Late Ordovician magmatism and Late Cretaceous collision in the southern Maya block, Rabinal-Salama area, central Guatemala: Implications for North America-Caribbean plate tectonics

Kinematic reconstruction of the Caribbean region since the Early Jurassic

“…The Chuacús complex has been interpreted as a part of the Yucatan block (Dengo, 1969;Donnelly et al, 1990;Ratschbacher et al, 2009), or as the separate Jacalteco terrane accreted to the Yucatan block by shearing along the Baja Verapaz shear zone (Ortega-Gutiérrez et al, 2007;Ortega-Obregón et al, 2008;Solari et al, 2011). (Ultra-)high pressure metamorphism in the Chuacús complex has been dated at 76-62 Ma (U-Pb, Rb-Sr and 40 Ar-39 Ar cooling ages of white mica and amphibole; Ratschbacher et al, 2009;and references therein;Martens et al, 2012).…”

“…The Baja Verapaz shear zone is a 5-10 km wide, south dipping shear zone, thrusting (with a minor sinistral strikeslip component) the Chuacús complex onto pre-Silurian low-grade metasedimentary rocks of the Yucatan block (Ratschbacher et al, 2009). Shearing in the Baja Verapaz shear zone is simultaneous with metamorphism in the Chuacús complex, dated by 74-66 Ma white micas from sheared shales (K-Ar dating, Ortega-Obregón et al, 2008) and~70 Ma white micas in mylonite gneiss (Ratschbacher et al, 2009).…”

“…6). The four main features in the fault zone are, from north to south, the Polochic fault, the Baja Verapaz shear zone (a 5-10 km wide greenschist facies mylonite zone), the Motagua fault and the Jocotán fault (Ortega-Obregón et al, 2008;Ratschbacher et al, 2009).…”

Ultrahigh-pressure minerals and metamorphic terranes – The view from China

“…Which of these was the collider that triggered Chuacús subduction and eclogite-facies metamorphism remains a matter of debate. It may have been thickened proto-Caribbean oceanic crust (e.g., Rosenfeld, 1993), the Cretaceous Antillean arc (Pindell et al, 2005;García-Casco et al, 2008), or the continental Chortís block (Ortega-Obregón et al, 2008).…”

An Evaluation of Proposed Mechanisms of Slab Flattening in Central Mexico

“…The truncation of structural trends in addition to the juxtaposition of the modern trench and the Paleogene batholith suggests subsequent forearc removal (KARIG, 1978;MORAN-ZENTENO et al, 2007SCHAAF et al, 1995). The Chortis block is often assumed to be the missing forearc, though this correlation is just as often called into question (KEPPIE and MORAN-ZENTENO, 2005;MORAN-ZENTENO et al, 2009;ORTEGA-GUTIERREZ et al, 2007;ORTEGA-OBREGON et al, 2008). Recent studies evaluating the multiple reconstructions proposed for the Chortis block do not find much evidence to support the hypothesis that it represents the missing forearc and prefer a model of wholesale subduction erosion (KEPPIE, 2009).…”