geoscience.net logo
+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Mapping Precambrian basement structure beneath the Williston Basin in Canada; insights from horizontal-gradient vector processing of regional gravity and magnetic data


, : Mapping Precambrian basement structure beneath the Williston Basin in Canada; insights from horizontal-gradient vector processing of regional gravity and magnetic data. Canadian Journal of Exploration Geophysics 34(1-2): 40-48

Horizontal-gradient vector (HGV) processing of regional gravity and aeromagnetic data from southeastern Saskatchewan and southwestern Manitoba is undertaken as part of a study of Precambrian basement geology beneath the Williston Basin in Canada. The HGV method resolves potential-field anomalies in more detail than do many other data enhancement techniques. In HGV maps, the horizontal gradient of the gravity or magnetic field is treated as a vector, having both a direction and magnitude. The gradient is represented on a map as an arrow with an origin at a grid node. Varying the arrow polarity (uphill or downhill--towards or away from local maxima in the potential field) provides HGV displays with differing images of potential-field anomaly fabric. HGV patterns within the study area are highly variable and include linear and curvilinear anomalies of varying orientations, and circular and ovoid anomalies occurring singly and in curvilinear belts. These patterns indicate crystalline basement beneath this part of the Williston Basin is composed of a complex mosaic of crustal belts, faults, and plutons. The analysis of HGV-processed potential-field data provides new insights into the crustal structure and tectonic fabric of the Archean Superior Province, Proterozoic Trans-Hudson Orogen, and intervening Churchill-Superior boundary zone beneath the northern Williston basin. East-west and north-south aligned potential-field anomalies outline the main Kenoran (2.8-2.4 Ga) and Hudsonian (1.9-1.8 Ga) age crustal fabrics, respectively. In magnetic HGV maps, the transition from E-W-trending (Superior Province) to N-S-trending (Churchill Province) crustal fabrics commonly appears gradational or irregular, suggesting the Churchill-Superior "boundary zone" within the study area is broad and structurally segmented. In gravity HGV maps, a prominent N-S aligned belt of ovoid-shaped anomalies appears to provide a regionally consistent potential-field signature for part of the boundary zone. The Tabbernor fault zone in the central Trans-Hudson Orogen can be identified in magnetic HGV maps, but is not readily apparent in gravity maps. Interpretation of Precambrian basement domains and trends provides a regional framework for detailed investigations of basement sedimentary cover interaction in this economically important part of the Williston Basin.

US$29.90


Other references

Malavolta V.A.Jr; Carvalho M.L.; Rodrigues Neto J.; Pompeu J.Jr, 1984: Variability of resistance to xanthomonas campestris pathovar citri in citrus sinensis cultivars. Fitopatologia Brasileira 9(2): 388

Jeong, H.S.; Funari, T.; Gordon, K.; Richard, G.; Agim, N.G., 2017: Concurrent Chondrodysplasia Punctata Type 2 (Conradi-Hunermann-Happle Syndrome) and Ichthyosis Vulgaris in Teenaged Twin Girls. We present concurrent X-linked chondrodysplasia punctata and ichthyosis vulgaris in adolescent fraternal twin girls, notable for initial presentation with dry skin in adolescence, characterized by dark-brown scale typical of ichthyosis vulgaris an...

Nanashima, A.; Tobinaga, S.; Abo, T.; Nonaka, T.; Hidaka, S.; Takeshita, H.; Sawai, T.; Nagayasu, T., 2012: Extended right hepatectomy for hilar bile duct carcinoma using the modified liver hanging maneuver. To achieve complete extended right hepatectomy or trisectionectomy for a bismuth type IV hilar bile duct carcinoma, we propose the application of Belghiti's liver hanging maneuver (LHM) using a small nasogastric tube. This small nasogastric t...

Yegnanarayan, R.; Balwani, J.H., 1994: Circadian variations in high blood pressure lowering effects of clonidine and alpha methyl dopa. Two antihypertensive agents - clonidine and alpha methyl dopa were administered to hypertensive patients as a single dose at four fixed time points: 08:00, 12:00, 16:00, 20:00, The magnitude of fall in blood pressure, the peak and duration of effe...

Wang, E.L.; Kanda, N.; Umezawa, H., 1969: A new antibiotic, gougeroxymycin. Gougeroxymycin, produced by a str. resembling Streptomyces gougerotii, was active against various fungi including Trichophyton mentagrophytes (3.12 jug/ml) and Candida albicans (6.25 mu g/ml) but not C. tropicalis or Cryptococcus neoformans.

Clulow, J.; Clulow, S.; Guo, J.; French, A.J.; Mahony, M.J.; Archer, M., 2013: Optimisation of an oviposition protocol employing human chorionic and pregnant mare serum gonadotropins in the barred frog Mixophyes fasciolatus (Myobatrachidae). Protocols for the hormonal induction of ovulation and oviposition are essential tools for managing threatened amphibians with assisted reproduction, but responses vary greatly between species and even broad taxon groups. Consequently, it is necess...

Schachter, E.N.; Doyle, C.A.; Beck, G.J., 1984: A prospective study of asthma in a rural community. Changes in symptoms and pulmonary function among asthmatic subjects in the general population remain poorly characterized. We studied 1,303 white residents aged seven years and older in Lebanon, Conn, a rural community largely unaffected by air po...

Lewis, M.M., 1951: The promotion and maintenance of mental health in the military community. Journal of the Royal Army Medical Corps 96(1): 17-40

Meng Liangyi, 1999: Silicification and mineralization in hydrothermal deposits. In hydrothermal deposits there are many types of alteration, including potassic alteration (altered minerals are potassic feldspar and biotite), sericitization, silicification, argillization, chloritization, carbonification and propylitization, bu...

Gardner, M.C., 1947: The type locality of Sigmodon minimus goldmani. Journal of Mammalogy, 28: 190