An integrated model of the structural evolution of the central Brooks Range foothiUs, Alaska, using structural geometry, fracture distribution, geochronology, and microthermometry
MetadataShow full item record
Episodic deformation, triangle zone development, and related back thrusting in the central Brooks Range foothills are major factors in the distribution of fractures and the thermal history of rocks involved in the deformation. Structural reconstructions suggest that the rocks forming the Endicott Mountains allochthon, the youngest and northernmost part of the orogen during its first phase, were emplaced during the Early Cretaceous (Valanginian) at temperatures approximately 150°C. Fractures associated with that deformation are filled with synkinematic calcite cement, indicating that they formed in the presence of fluids. After a period of quiescence during the Late Cretaceous, renewed deformation involved the shortening of the existing orogenic wedge and the development of a triangle zone and overlying back thrust in adjacent mid- to Late Cretaceous rocks of the foreland basin. This later de-formational event and subsequent uplift resulted in two sets of uncemented barren fractures that formed in all parts of the fold and thrust belt. Restriction of cement-filled fractures to the older and structurally deeper parts of the orogen implies that the youngest and most obvious fractures visible at the surface developed at shallow depths and temperatures and thus may not have been an important factor in petroleum migration. © 2012. The American Association of Petroleum Geologists. All rights reserved.
Showing items related by title, author, creator and subject.
Structural geology and gold mineralisation of the Ora Banda and Zuleika districts, Eastern Goldfields, Western Australia.Tripp, Gerard I. (2000)Late-Archaean deformation at Ora Banda 69km northwest of Kalgoorlie, Western Australia, resulted in upright folds (D2), ductile shear zones (D3), and a regional-scale brittle-ductile fault network (D4). Early low-angle ...
40Ar/39Ar ages in deformed potassium feldspar: evidence of microstructural control on Ar Isotope systematicsReddy, Steven; Potts, G.; Kelley, S. (2001)Detailed field and microstructural studies have been combined with high spatial resolution ultra-violet laser 40Ar/39Ar dating of naturally deformed K-feldspar to investigate the direct relationship between deformation-related ...
Microstructural design and properties of high performance recycled cellulose fibre reinforced polymer eco-nanocompositesAlamri, Hatem Rashed (2012)In recent years, cellulose fibre-reinforced polymer composites have been gaining a great attention in several engineering applications due to their desirable properties, which include low density, low cost, renewability ...