000			02851nab a2200217 4500
005			20260520000317.0
008			260224s2013 xxu ing
041			_aInglés
245	0	0	_aRecognition criteria for distinguishing between hemipelagic and pelagic mudrocks in the characterization of deep-water reservoir heterogeneity
260			_a _b _coct. 2013
270			_a11/12/2013 ; 11/12/2013
300			_a18 p. ; 1785-1803
520			_aTranscripción del resumen del autor: Determination of turbidite event magnitude and frequency remains subjective and difficult to define. This is because turbidite sedimentation events commonly include both sand and mud, with the mud component commonly excluded from bed thickness studies because of the inability to establish a genetic link to the turbidity current. Pelagic mudrock is defined as fine-grained marine sediment derived primarily from biogenic particles, whereas hemipelagic mudrock includes both biogenic and terrigenous particles. Unfortunately, these compositional definitions do not account for differences in depositional process. Scanning electron microscopy, field emission scanning electron microscopy, and x-ray diffraction analyses of 70 samples from El Rosario Formation outcrops (Baja California, Mexico) and core from the Woodford Shale (Oklahoma) illustrate this distinction. Furthermore, these laboratory measurements are calibrated to 192 outcrop samples to provide a robust method for field identification of clay fabric and mineralogy to define turbidite sedimentation units. Pelagites show organized layering of clay platelets, few flocculates, and a lower proportion of high-density minerals. Hemipelagites have disorganized and chaotic clay fabrics characterized by visible flocculates and contain a higher proportion of denser particles. There may also be a corresponding change in clay mineralogy, for example, smectite in pelagites versus kaolinite in hemipelagites. These results indicate a settling velocity greater than shear velocity in pelagites, whereas hemipelagites record the opposite condition. Turbidity currents support and suspend denser grains, generate disorganized and chaotic clay fabrics, and provide more time for flocculation. Discrimination between pelagites and hemipelagites has important implications in the determination of turbidite event frequency and magnitude, which affects vertical connectivity and continuity of sand, deposited from multipartite turbidity currents. In addition, distinction between pelagites and hemipelagites provides a better understanding of mudrock reservoir architecture.
581			_a10
773	0		_tAAPG Bulletin _g97
942			_cARTICULO
100	1		_aOchoa, Jesús _953679
100	1		_aWolak, Jeannette _953680
100	1		_aGardner, Michael H. _953681
999			_c188044 _d188044