Diagenetic Alteration of the Wingate Formation: Possible Indications of Hydrocarbon Microseepage, Lisbon Valley, Utah

Meteorological Controls on Reversible Resonance Changes in Natural Rock Arches

“…Notably, however, samples with the highest porosity and lowest clay content displayed the opposite effect, with swelling pressure decreasing over the same increase in the relative humidity. While representative samples were not tested from the upper Wingate Sandstone interval that hosts Aqueduct Arch, a general description of the formation points to the likelihood of similar behavior to these outlier sandstones, as it is moderately to well‐sorted with low clay content (Merin & Segal, 1989), leading to a high porosity (15%–20%) and large pore size that may prevent swelling pressures from building internally. It is challenging to disentangle the effects of relative humidity from temperature in an arid environment, where the two often exhibit a highly correlated, inverse relationship.…”

Reflectance spectroscopic mapping of diagenetic heterogeneities and fluid-flow pathways in the Jurassic Navajo Sandstone

“…Figure 7 shows the clay absorption spectral range for several unaltered red, bleached, and otherwise altered (secondarily stained reddish-brown and yellowish-orange) samples of Navajo Sandstone from a variety of localities. The variation in clay content within these samples is analyzed by normalizing the data to the absorption at 2.07 mm because iron oxides, carbonates, and clays have no absorption features at this wavelength (Merin and Segal, 1989). The variability and maximum amount of clay increases in the more altered reddish-brown and yellowish-orange sandstone samples ( Figure 7C).…”

“…Much of the published geosciences-related reflectance spectroscopy applications involve spectra-lithologic mapping and exploration for economic minerals, commonly within volcanic or metamorphic rocks (Hunt, 1979;Kruse et al, 1999;Cudahy and Okada, 2000;Ellis and Scott, 2004), mapping differences between geologic formations (Clark et al, 1992;Rowan et al, 2004), alteration related to hydrothermal systems (White et al, 2001;Gupta, 2003;Hubbard et al, 2003;Martini, 2003a, b;Van Ruitenbeek et al, 2005), and modern hydrocarbon seeps (Yang et al, 2000;van der Meer et al, 2002). Studies of intraformational low-temperature diagenesis using reflectance and imaging spectroscopy are less common (Merin and Segal, 1989;Beitler et al, 2003), but can provide an important framework for understanding reservoir heterogeneity and evaluating fluid flow related to the prediction of natural resource distribution.…”