Measurements of the Suitability of Large Rock Salt Formations for Radio Detection of High Energy Neutrinos

We have investigated the possibility that large rock salt formations might be suitable as target masses for detection of neutrinos of energies about 10 PeV and above. In neutrino interactions at these energies, the secondary electromagnetic cascade produces a coherent radio pulse well above ambient thermal noise via the Askaryan effect. We describe measurements of radio-frequency attenuation lengths and ambient thermal noise in two salt formations. Measurements in the Waste Isolation Pilot Plant (WIPP), located in an evaporite salt bed in Carlsbad, NM yielded short attenuation lengths, 3-7 m over 150-300 MHz. However, measurements at United Salt's Hockley mine, located in a salt dome near Houston, Texas yielded attenuation lengths in excess of 250 m at similar frequencies. We have also analyzed early ground-penetrating radar data at Hockley mine and have found additional evidence for attenuation lengths in excess of several hundred meters at 440 MHz. We conclude that salt domes, which may individually contain several hundred cubic kilometer water-equivalent mass, provide attractive sites for next-generation high-energy neutrino detectors.Comment: 21 pages, 8 figures, to be submitted to Nuclear Instruments and Method

Measurements of radio propagation in rock salt for the detection of high-energy neutrinos

We present measurements of the transmission of radio/microwave pulses through salt in the Cote Blanche salt mine operated by the North American Salt Company in St. Mary Parish, Louisiana. These results are from data taken in the southwestern region of the 1500 ft. (457 m) deep level of the mine on our third and most recent visit to the mine. We transmitted and received a fast, high-power, broadband pulse from within three vertical boreholes that were drilled to depths of 100 ft. (30 m) and 200 ft. below the 1500 ft. level using three different pairs of dipole antennas whose bandwidths span 125 to 900 MHz. By measuring the relative strength of the received pulses between boreholes with separations of 50 m and 169 m, we deduce the attenuation of the signal attributed to the salt medium. We fit the frequency dependence of the attenuation to a power law and find the best fit field attenuation lengths to be 93 \pm 7 m at 150 MHz, 63 \pm 3 m at 300 MHz, and 36 \pm 2 m at 800 MHz. This is the most precise measurement of radio attenuation in a natural salt formation to date. We assess the implications of this measurement for a future neutrino detector in salt.Comment: 33 pages, 10 figures. Submitted to Nuclear Inst. and Methods in Physics Research,

An integrated model of clastic injectites and basin floor lobe complexes: implications for stratigraphic trap plays

Injectites sourced from base-of-slope and basin-floor parent sandbodies are rarely reported in comparison to submarine slope channel systems. This study utilises the well-constrained palaeogeographic and stratigraphic context of three outcrop examples exposed in the Karoo Basin, South Africa, to examine the relationship between abrupt stratigraphic pinchouts in basin-floor lobe complexes, and the presence, controls, and character of injectite architecture. Injectites in this palaeogeographic setting occur where there is: (i) sealing mudstone both above and below the parent sand to create initial overpressure; (ii) an abrupt pinchout of a basin-floor lobe complex through steep confinement to promote compaction drive; (iii) clean, proximal sand beds aiding fluidisation; and (iv) a sharp contact between parent sand and host lithology generating a source point for hydraulic fracture and resultant injection of sand. In all outcrop cases, dykes are orientated perpendicular to palaeoslope, and the injected sand propagated laterally beneath the parent sand, paralleling the base to extend beyond its pinchout. Understanding the mechanisms that determine and drive injection is important in improving the prediction of the location and character of clastic injectites in the subsurface. Here, we highlight the close association of basin-floor stratigraphic traps and sub-seismic clastic injectites, and present a model to explain the presence and morphology of injectites in these locations

Studies in petroleum geology; reprints, 1935-1955

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Not availabl

Exploration into the New Millenium 1

I am entering my 71st year as a member of our profession and as an explorer for petroleum. During those 71 years I have devoted much of my time and resources to activities pertinent to our profession and our association. As I venture forth in the last few golden years of my life, I find that our geoscience professions have undergone many changes, particularly in the last 20 years — some good, some very bad — but the professions have always looked to the future, and that is the reason this conference was convened at the beginning of this millenium. I am indeed honored ñ yes, very pleased – to have been asked to present the keynote address to this second Pratt Conference. The first was held in Phoenix, Arizona, December 2-5, 1984, and was called the Wallace E. Pratt Memorial Conference on “Future Petroleum Provinces of the World. ” I had the pleasure of presenting the opening address at that meeting on December 2, 1984. That was the best conference of its kind ever held by our auspicious Association. I am honored to have had the privilege of chairing it and participating as a speaker. Fred Dix, who was Executive Director of AAPG, and Bill St. John who was program chairman, contributed much to the success of the Conference. Their contributions enhanced the Conference in every way