000			02157nab a2200229 4500
005			20260520000315.0
008			260224s2012 xxu
245	0	0	_aAn integrated model of the structural evolution of the central Brooks Range foothills, Alaska, using structural geometry, fracture distribution, geochronology, and microthermometry
260			_a _b _cdic. 2012
270			_a21/01/2013 ; 21/01/2013
300			_a29 p. ; 2245-2274
520			_aTranscripción del resumen del autor: 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 deformational 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.
581			_a12
773	0		_tAAPG Bulletin _g96
942			_cARTICULO
100	1		_aDuncan, Alec _952910
100	1		_aHanks, Catherine _952911
100	1		_aWallace, Wesley K. _952912
100			_aO'Sullivan, Paul B _952913
100	1		_aParris, Thomas M. _952914
999			_c187532 _d187532