Demand Analysis of Recreation Visits to Chitral Valley: A Natural Resource Management Perspective

Recreational visits are primarily about human activity which involves travel from an originating area to a destination for cultural, economic, and social exchange processes. People travel to exotic locations for sight seeing, picnicking, bird watching, and for cultural and religious settings. However, accessibility to such areas is often free, which not only results in environmental hazards but also deprives the cash destitute government from revenue that such these sites offer. Valuing the recreational benefits associated with a destination based on tourists’ preferences can help formulate an appropriate policy for Natural Resource Management (NRM). Environmental and natural resource management studies often try to measure the welfare change associated with a policy change. Welfare is generally defined as area under the demand curve; accordingly, by estimating the demand curve, consumer surplus is obtained which shows the welfare changes associated with an environmental policy change [Gunatilake (2003)]. The recreational values thus obtained can be utilised for a cost benefit analysis of a policy option, thereby, managing a park or a natural resource on a sustainable basis

Paleomagnetism of Late Jurassic Rocks in the Northern Canelo Hills, Southeastern Arizona

The Canelo Hills volcanics are exposed in the Canelo Hills, a northwest trending range in Santa Cruz County, southeast Arizona. The formation is composed of silicic tuffs and flows as well as volcaniclastic conglomerates and sandstones. Strikes of the rocks are generally to the northwest with moderate dips to the southwest and northeast. Apparent age results from the sequence studied paleomagnetically include two published isotopic dates of 147 ± 6 Ma (K-Ar, biotite) and 149 ± 11 Ma (whole rock, Rb-Sr) and a Rb/Sr isochron age, reported here, which indicates an age of 151 ± 2 Ma. Paleomagnetic samples were collected from 17 cooling units in the northern Canelo Hills. Samples from most of these units responded to alternating field (af) demagnetization, and secondary components were generally erased by peak af between 10 and 50 mT. Samples from five sites showed no response to af demagnetization. Thermal demagnetization of samples from these units produced no significant changes in direction of natural remanent magnetization (NRM), although within-site clustering of NRM directions was improved. Data from two sites were rejected because of failure to isolate a well-determined characteristic NRM. Of the remaining 15 sites, 10 sites were of normal polarity, while five sites showed reversed polarity. Intensities of the characteristic NRM ranged from 4 × 10−3 to 3 × 10−1 A/m. The data from these 15 cooling units yield a formation mean direction of I = 29.9°, D = 334.9° with k = 33.4 and α95 = 6.7°. The resulting paleomagnetic pole is at 62.2°N, 130.3° (dp = 4.1°, dm = 7.4°). This pole is between poles obtained from the Summerville and lower Morrison formations. The Canelo Hills pole is thus consistent both in position and age with the Late Jurassic episode of rapid apparent polar wander originally defined by paleomagnetic data from the Summerville and Morrison formations

K-Ar dating of young volcanic rocks

Potassium-Argon (K-Ar) age dates were determined for forty-two young geologic samples by the Laboratory of Isotope Geochemistry, Department of Geosciences, in the period February 1, 1986 to June 30, 1989. Under the terms of Department of Energy Grant No. FG07-86ID12622, The University of Arizona was to provide state-of-the-art K-Ar age dating services, including sample preparation, analytical procedures, and computations, for forty-two young geologic samples submitted by DOE geothermal researchers. We billed only for forty samples. Age dates were determined for geologic samples from five regions with geothermal potential: the Cascade Mountains (Oregon); the Cascade Mountains (Washington); Ascension Island, South Atlantic Ocean; Cerro Prieto, Mexico; and Las Azufres, Mexico. The ages determined varied from 5.92 m.a. to 0.62 m.a. The integration of K-Ar dates with geologic data and the interpretation in terms of geologic and geothermal significance has been reported separately by the various DOE geothermal researchers. Table 1 presents a detailed listing of all samples dated, general sample location, researcher, researcher's organization, rock type, age, and probable error (1 standard deviation). Additional details regarding the geologic samples may be obtained from the respective geothermal researcher. 1 tab

Geochronologic contributions to the tertiary sedimentary-volcanic sequences ("baucarit formation") in sonora, México

Fechamientos radiométricos por el método K-Ar, en flujos de rocas volcánicas intercaladas y suprayacientes a conglomerados volcanogénicos y areniscas de origen continental en Sonora, México, arrojan edades comprendidas entre 33 y 5 m.a. Entre éstas, las rocas volcánicas asociadas con conglomerados y areniscas conocidos como "Formación Baucarit" varían en edad desde los 23 a los 10 m.a. Los estratos del Oligoceno-Mioceno medio contienen flujos de rocas volcánicas de composición basáltica, andesítica y andesítico-riolítica. Un pulso de magmatissmo silísico a nivel regional ocurrió entre 14 y 10 m.a. Las secuencias del Mioceno superior hasta el Pleistoceno se asocian fundamentalmente con vulcanismo basáltico. El proceso de extensión de la corteza es posterior a la deformación Larámide y posiblemente se inició en Sonora en el Eoceno tardío (?), seguido por la acumulación de conglomerados sintectónicos y flujos volcánicos del Oligoceno (33 a 24 m.a.). Este proceso fue puramente continuo a través del Terciario; no obstante, un período corto de deformación estructural distensiva ocurrió entre los 10 y 9 m.a. Este evento tectónico puede ser el responsable de la fisiografía actual de la Sierra Madre Occidental ('Provincia de Sierras y Valles Paralelos") en Sonora, México