Bathurst Area Research Articles

A multi‐disciplinary characterisation of Heath Steele belt deposits, Bathurst Mining Camp: a basis for identifying new targets for the exploration

ABSTRACTAlthough the Bathurst Mining Camp has been explored for more than 40 years, high‐resolution airborne geophysical survey has led to the detection of several new volcanogenic massive sulphide occurrences in the region. The discovery of these concealed exploration targets depended directly on the knowledge of the multi‐parameter signature of the major deposits and the search for the repeatability of these signatures in other regions. The Heath Steele B deposit, within the southern part of the Bathurst Mining Camp, together with an associated magnetite‐rich iron formation and adjacent tuffaceous sedimentary rocks, produced strong, co‐extensive magnetic and conductivity anomalies. However, the strong anomalies observed in the geophysical data can be related to non‐mineralised lithology such as mafic dykes or graphite. So a direct identification of exploration targets using geophysical data only can be difficult. For this reason, the joint interpretation of geophysical and geochemical signature can considerably improve the identification of new deposits. Using these techniques, we identify three new possible targets, characterised by local magnetic and apparent conductive highs. Two of these areas are located in the Heath Steele belt, and their geochemistry has been studied in detail. The proximity of these targets (less than 1.5 km) from known occurrences of hydrothermal sediments (magnetite, siderite, and stilpnomelane) confirms their exploration potential. The fourth identified area is most likely associated with a regional anomaly related to an unmapped ferromagnetic structure and was earlier disregarded as a possible target. The joint interpretation of geophysical and geochemical data allowed us to identify two new targets for exploration and to exclude one area interpreted as associated with a regional anomaly. Therefore, the search parameters (physical proprieties and hydrothermal sediment geochemical pattern distribution) are established with a success index of 75%. The index was limited by the absence of geochemistry data over the third target. The procedure presented in this paper can be used to search for new targets elsewhere in the Bathurst area and even in other base metal regions.

Apatite (U – Th)/He age constraints on the Mesozoic and Cenozoic evolution of the Bathurst region, New South Wales: evidence for antiquity of the continental drainage divide along a passive margin

The apatite (U – Th)/He and fission track thermochronometers are combined to constrain the Mesozoic and Cenozoic denudational history of the Bathurst region in New South Wales. New apatite (U – Th)/He ages across the continental drainage divide range from 83 ± 14 to 114 ± 18 Ma (±2σ), supporting the evidence from previously published apatite fission track (AFT) data that the region underwent a period of rapid denudation during the mid-Cretaceous. The apatite He-derived thermal histories constrain the amount of erosion in the area and suggest that spatial variations in denudation of the Bathurst Batholith correspond to three broad regions with different histories. The area of the continental drainage divide separates the eastern flank where denudation was rapid at 120 – 90 Ma, and >3 km of crust was removed in about 30 million years, from the western flank, where denudation was less rapid and less prominent. The coincidence of some of the AFT and He ages with the timing of continental extension and Tasman Sea opening suggests that the rapid denudation east of the continental drainage divide was associated with the rifting processes. Such an interpretation means that the escarpment that bounds the Blue Mountains on the east was not formed at the time of rifting and may be a later topographic feature, connected with exhumation of an earlier structural feature and/or related to post-Mesozoic tectonic activity. The evolution of the area west of the continental drainage divide is characterised by rates of denudation higher than on the rest of the plateau but lower than on the eastern flank in the Bathurst area. The reason for this pattern is still unclear. It is possible that faults of the Lachlan Fold Belt were reactivated during the Cretaceous extension and later, but no faults are mapped across the batholith. Overall, the data imply that the continental margin in the Bathurst region evolved by plateau downwearing pinned to the continental drainage divide. This means in turn that the continental drainage divide is a longstanding topographic feature, dating from before Tasman Sea breakup.

Potential for cassava production in the Bathurst region of the Eastern Cape Province of South Africa

Cassava (Manihot esculenta) is a minor crop in South Africa that has had periodic rises in interest since it was first cultivated in the country. Interest in the crop has waned over the years, but the crop is now being used as a source of high quality starch, which has again stimulated interest in its use as a commercial crop. No cassava is cultivated in the Bathurst area despite the apparently suitable climatic conditions. This study was conducted in order to evaluate the potential of this area for dryland cassava production. Eight varieties (I92/0326, I90/00330, I93/0170, TMS60444, TMS90853, ThaiI, Aunty Alice and Tokunbo) were planted at a density of 8 300 plants ha-1 using tissue cultured plants. Harvesting took place at 6, 15 and 21 months after planting (MAP), with each harvest date being established as a separate block. Tuber yields 6 MAP ranged from 8 to 22 t ha-1, with I93/0170 producing the highest yield. After 15 months, the highest yield was around 34 t ha-1 produced by TMS90853, although no significant (P>0.05) differences were noted between varieties at this stage. TMS60444 produced a yield of 76 t ha-1 21 MAP. Only three varieties showed significant (P

And I Will Dwell in Their Midst (review)

Reviewed by: And I Will Dwell in Their Midst Leo Davids And I Will Dwell in Their Midst, by Etan Diamond. Chapel Hill: University of North Carolina Press, 2000. 215 pp. $39.95 (c); $18.95 (p). This book is a thorough picture of the Orthodox Jewish community in suburban Toronto. In seven well-documented chapters, Diamond deals with the history, geog raphy, and culture of a major North American Jewish community, focusing on its paradoxical combination of modernity/consumerism with tradition/religiosity, as this has developed during the past 60 years or so. Its title is from Sh’mos/Exodus Chap. 25, verse 8. The author has included a number of interesting demographic tables and maps, making sure that the historical material is not merely impressionistic or anecdotal, but includes concrete data. One additional asset in the book is a four-page glossary, which defines for the less-informed reader many terms originating in Yiddish, Hebrew, or the Talmud’s Aramaic (pp. 161–164). Diamond shows a very good knowledge of the Toronto Jewish community, having resided here for a number of years during the 1990s. He is quite a cosmopolitan Jew, having lived in many communities across the continent. He points out the commonal ities, the essential similarity of Orthodox neighborhoods throughout Canada and the United States (p. xv). When he considered the available literature on modern Jewish life, Diamond found the term “Orthodox” used in reference to the highly visible East European sort of Ortho dox community, but little attention was being paid to the more modern, English- speaking Orthodox sector. This book, therefore, focuses on this much less visible modern or centrist Orthodox community, which has blossomed especially over the past 30 to 40 years. If one were to identify the book’s central theoretical issue, it is that the survival of a committed religious community in the modern world is paradoxical. After all, modernization theorists have long believed that high levels of affluence and schooling tend to be associated with secularism and the abandonment of strict religious practice. Thus, scholarly observers of the Jewish scene had long predicted the triumph of the Reform movement and the fading away of Jewish Orthodoxy (pp. 5–7). Most people who were not themselves associated with the Orthodox community saw it as rigid, demanding, and unlikely to survive in a society that emphasizes individual freedom and lifestyle choice. So the discovery by social scientists of a flourishing and growing North American Orthodox Jewish community posed a difficult question to be answered in this context of what we usually expect, regarding social and cultural change, under conditions of freedom and prosperity. In short, in this study Diamond sets out to explain not only what “Orthodox” Jewish means today, but why it is not just surviving but growing and prospering! [End Page 169] In regard to what sector of the Jewish community he is describing, Diamond presents a clear and valuable overview of the differences between centrist or modern Orthodoxy and the right wing, highly traditional sector (pp. 11–14). Unlike the ultra- Orthodox Hassidic or “Yeshivish” elements in the Jewish community, the population which Diamond studied is pro-Zionist, favors higher education and professional occupations, and dresses in normal, modern clothes. Thus, many would overlook people belonging to this part of the Orthodox community because they are not especially visible but blend in with the general cultural landscape of the larger society. Diamond argues that this ignores the important dynamic of the suburban Orthodox Jewish community, which has built a viable, even impressive, way of life despite all the predictions of Orthodoxy’s inevitable disappearance. He notes that even the right-wing Orthodox families, who apparently reject modern society and what it offers, have long ago decided to make their peace with the suburbs, their nice single-family homes, and an automobile-centered community. However, the focus of this book is not on those elements, whose Toronto location for the past several decades has remained in the Lawrence and Bathurst area. The book describes the northward growth of Toronto Jewry from the old Kensington Market ghetto—which was the center of the Jewish community before World War II—up Bathurst...

Sediment yields and soil loss rates from native forest, pasture and cultivated land in the Bathurst area, New South Wales

Summary Sedimentation surveys of small dams in granite catchments in the Bathurst area of New South Wales (NSW) demonstrate that land use is the dominant factor determining soil loss rates and sediment yields. We found that cultivated catchments produced, on average, 3.1 t ha−1y−1 whereas grazed pasture and forest/woodland catchments exported only 2.2 and 0.8 t ha−1y−1, respectively. The yields for cultivated and grazed catchments are high by Australian standards. Dam sediments were enriched in clay and organic matter in comparison to catchment topsoils. The dams were deliberately selected so that gully and bank erosion were not active geomorphic processes in the catchments and so the measured sediment yields could be validly compared to soil loss rates predicted by various versions of the Universal Soil Loss Equation. The Modified Universal Soil Loss Equation, Soiloss and Revised Universal Soil Loss Equation did not closely predict the measured sediment yields, as we have found ensewhere in NSW. Although Soiloss is the only empirical equation to use Australian data, it is not as accurate in the Bathurst area as for areas near Sydney. Further research is needed to test and develop soil loss prediction equations under Australian conditions.

A history of mining in the Bathurst area, northern New Brunswick, Canada : W. M. Luff, CIM Bulletin, 88(994), 1995, pp 63–68

A history of mining in the Bathurst area, northern New Brunswick, Canada : W. M. Luff, CIM Bulletin, 88(994), 1995, pp 63–68

Zoned sodic amphibole: Petrologic indicator of changing pressure and temperature during tectonism in the Bathurst Area, New Brunswick, Canada

Amphibole, zoned from an actinolite core through a barroisite layer to a crossite or ferroglaucophane rim, coexists with epidote, chlorite, albite, quartz, phengite, sphene, magnetite, and calcite in metabasites of the Tetagouche Group near Bathurst, New Brunswick. Stratigraphic, structural and regional-metamorphic evidence suggests that these rocks were situated in the hangingwall of a SE-dipping subduction zone during the Taconian Orogeny. Using microprobe analyses of the coexisting minerals, a dehydration reaction and a subsequent hydration reaction have been balanced in the system SiO2-Al2O3-TiO2-Fe2O3-(Fe, Mg, Mn)O-CaO-Na2O-K2O-H2O, so as to describe the development of the zoned amphiboles. Relatively large coefficients for magnetite in these reactions accord with the absence of sodic amphibole in associated magnetite-free metabasites, indicating that ferric iron has a significant effect on the transition from greenschist to epidote-blueschist fades. Relatively small residuals of FeO, MgO and MnO show that these components are only weakly partitioned between the reactant and product assemblages. The procedure of Holland and Richardson (1979) has been used to calculate apparentP-T paths that trace the growth histories of the zoned amphiboles from a low-P environment to a high-P environment. Although the apparent pressure-change is implausibly large and the final temperature implausibly low, it is clear that the Bathurst metabasites followed a very differentP-T path than those of the Austrian Alps, despite their identical mineral assemblage.

Methods of exploration for strata-bound mineral deposits in the Appalachian-Caledonian Orogen

In response to a questionnaire on the topic of strata-bound mineral deposits in the Caledonian-Appalachian orogen circulated in 1980-1981, 82 contributions were received: United States (20), Canada (17), Denmark--for Greenland (3), Ireland (3), United Kingdom (10), Norway (6), and Sweden (23).On the basis of 68 strata-bound mineral deposits found in the past, the most successful methods of exploration have been geologic mapping and ground electromagnetic surveys, followed by geologic interpretation and prospecting. Boulder tracing found Laisvall and many other deposits in Sweden. The Brunswick 12 deposit in Canada was discovered by airborne magnetic and ground electromagnetic methods.Reports from 58 districts illustrate that a wider range of methods is currently being used for strata-bound mineral exploration in the Appalachian-Caledonian orogen than in the past. Geologic interpretation and ground electromagnetic techniques are proving to be most effective, followed by mapping and soil and till sampling. Photogeology, general prospecting, boulder tracing, drainage geochemistry, and airborne techniques are also achieving considerable success. Outstanding results are being obtained from magnetic and gravity surveys in the Bathurst area of Canada.

Petrographic and geochemical characteristics of iron-rich rocks and their significance in exploration for massive sulfide deposits, Bathurst, New Brunswick, Canada

ABSTRACT Saif, S.-I., 1983. Petrographic and geochemical characteristics of iron-rich rocks and their significance in exploration for massive sulfide deposits, Bathurst, New Brunswick, Canada. In: G.R. Parslow (Editor), Geochemical Exploration 1982. J. Geochem. Explor., 19: 705–721. About 25 economically significant, Kuroko-type massive sulfide bodies lie in a metamorphosed volcano-sedimentary complex (probable Middle Ordovician) known as Tetagouche Group, in Bathurst area, New Brunswick. Despite unresolved structural complexities, it does appear that they were deposited during a particular phase of volcanic activity and are, therefore, contemporaneous. Most of the sulfide bodies are closely associated with iron-rich rocks representing various facies of iron formation, and together with sulfides it constitutes the “ore horizon” which, therefore, is highly magnetic. Aeromagnetic and ground-magnetic techniques are useful to locate the ore horizon but problems are created because of the occurrence of iron-rich rocks with no sulfide, along another horizon in the Tetagouche Group. Petrographic and geochemical characteristics of various types of iron-rich rocks have been studied to see if the iron-rich rocks of the ore horizon can be distinguished from the iron-rich rocks of the other horizon. The iron-rich rocks found in the Tetagouche Group can be classified into five types: (1) cherty magnetitic rocks; (2) iron-rich chloritic rocks; (3) sideritic rocks; (4) basic iron formation; and (5) maroon shale. The basic iron formation, which is quite magnetic, gives a false indication of the ore horizon wherein the presence of any of the first three types of rocks is expected. Moreover, the basic iron formation is generally similar in appearance and mineralogy to some of the cherty magnetitic and chloritic rocks. Regarding major element composition, TiO2, Na2O, Al2O3 and CaO are higher whereas Fe2O3, FeO and MnO are lower in the basic iron formation than in the other iron-rich rocks. These geochemical characteristics can help distinguish the barren rocks of the basic iron formation from those of the ore horizon during the exploration programs.

The formation of massive sulfide deposits on the sea floor

Salinity and temperature data from fluid inclusions in Cyprus and Kuroko massive sulfide deposits indicate that the ore solutions were buoyant on entering the sea water. They probably rose from the sea floor like axisymmetric conical plumes derived from a finite source or as line plumes from a linear source. The height to which they rose depended on the magnitude of the density gradients in the ambient sea water. However, in the region immediately above the outlet pipe, the effect of interference between the many vents making up the pipe and the effect of the anticipated very low flow rate probably caused necking of the plume and a drastic retardation of the normal loss of vertical velocity and buoyancy caused by entrainment of sea water.Solubility data for copper sulfides indicate that virtually all the copper was precipitated by quenching immediately above the vent. Precipitation of sphalerite (+ or - galena) took place higher in the plume and the very fine grained particles of these phases were probably entrained in the plume, carried to considerable heights, and in many cases dispersed. During the inevitable slowing of the flow rate and cooling of the hydrothermal system, sphalerite (+ or - galena) was precipitated immediately above the vent. This was probably the most important way of forming vertically zoned Cyprus and Kuroko deposits.Thin, sheetlike, well-banded deposits like Rosebery and many in the Bathurst area of Canada, may have a different form because they developed in relatively shallow water. In this situation the plume, stagnating at the water surface, spreads laterally for considerable distances, raining sphalerite and galena to the sea floor. This hypothesis predicts such deposits will have greater metal contents than other massive sulfides, higher Zn/Cu ratios, a lack of sulfur isotope equilibration between minerals, and wide geochemical halos.

Simulation of limestone diagenesis—a model based on strontium depletion: Discussion

preparation. Blueschist metamorphismin the Bathurst area of New Brunswick. HELMSTAEDT, H. 1973. Structural geology of the Bathurst-Newcastle district. In New England Intercollegiate Geological Conference (NEIGC) Geology of New Bmnswick Field Guide to Excursions. Edited by N. Rast. pp. 34-43. 1978. Geochemistry of volcanic rocks from the Tetagouche Group, Bathurst, New Brunswick, Canada: Discussion. Canadian Journal of Earth Sciences, 15, pp. 16801681. MCBRIDE, D. E. 1976. Tectonic setting of the Tetagouche Group, host to the New Bmnswick polymetallic massive sulphide deposits. Geological Association of Canada, Special Paper No. 14, pp. 473-485. PAJARI, G. E., RAST, N., and STRINGER, P. 1977. Paleozoic vulcanicity along the Bathurst-Dalhousie Geotraverse, New Brunswick, and its relation to structure. Geological Association of Canada, Special Paper No. 16, pp. 1 1 1-124. PEARCE, J. A., and CANN J . B. 1971. Ophlolite origin investigated by discriminant analysis using Ti, Zr and Y. Earth and Planetary Science Letters, 12, pp. 339-349. RAST, N., and STRINGER, P. 1974. Recent advances and the Interpretation of the geological structure of New Brunswick. Geoscience Canada, 1(4), pp. 15-25. SKINNER, R. 1974. Geology of the Tetagouche Lakes, Bathurst and Nepisiquit Falls map-areas, New Brunswick. Geological Survey of Canada, Memoir 37 1, 133 p. WHITEHEAD, R. E. S., and GOODFELLOW, W. D. 1978. Geochemistry of volcanic rocks from the Tetagouche Group, Bathurst, New Brunswick, Canada. Canadian Journal of Earth Sciences, 15, pp. 207-219. WILLIAMS, H., KENNEDY, M. J . , and NEALE, E. R. W. 1972. The Appalachian structural province. In Variations in tectonic styles in Canada. Edited by R. A. Price and R. J. W. Douglas. Geological Association of Canada, Special Paper No. 11,pp. 180-261.

Spatial correlation of stratigraphic units quantified from geological maps

Abstract Patterns of stratigraphic units on geological maps can be considered as sets and subjected to Minkowski operations. The paper describes experiments performed on binary images to correlate with one another patterns for the occurrences of acidic volcanic rocks and massive sulphide deposits in the Tetagouche Group of Middle-Late Ordovician age in the Bathurst area, New Brunswick. A method is presented for deriving the frequency distribution of the amount of acidic volcanics per random cell of variable size. The amount of acidic volcanics in cells that contain one or more deposits is related to the moments of this frequency distribution.

Sulfur isotopes and the origin of the sulfide deposits of the Bathurst-Newcastle area of northern New Brunswick

The regional geology of the Bathurst-Newcastle area is briefly outlined. There are 2 types of sulfide deposits in the area: a) epigenetic fissure deposits, and b) massive sulfide deposits. Geological evidence can be variously interpreted to suggest a syngenetic, a source bed, or a magmatic hydrothermal origin for the massive sulfide deposits. S 32 /S 34 ratios are presented for more than 300 sulfide samples from the host rocks and sulfide deposits. Four granite bodies are dated by the K-Ar method. Model Pb ages are presented for 5 galena samples. Sulfides disseminated through the black shale and argillites of the host rocks are enriched in S 32 (mean value 22.31) relative to the meteoritic ratio, and broad range of values. S 32 /S 34 ratios for the sulfide deposits fall into 2 distinct groups. In general one group (21.88-22.05) represents the massive sulfide deposits, while the other group (22.18-22.21) represents the fissure deposits. This suggests 2 separate, but probably closely related sources for the S. Granites intrusive into the host rocks of the sulfide deposits have a mean age of 386 + or - 10 m.y. Pb minerals in the sulfide deposits have a mean model Pb age of 370 + or - 20 m.y. Thus the Pb minerals and the granite bodies were emplaced during the same major orogenic event. The sulfide deposits of the Bathurst area have a narrow range of S 32 /S 34 values. Sulfide deposits thought to have a magmatic hydrothermal origin all have a narrow range of S 32 /S 34 values. It therefore seems reasonable that well homogenized magmatic hydrothermal solutions are the most logical source for the sulfide deposits. The homogeneity of the Pb isotope abundance data gives strong independent evidence that the ores are of a magmatic hydrothermal origin. The problem of why the massive sulfide deposit are enriched in S 34 is open for further investigation.

A BHC-resistant Tick

An arsenic-resistant tick was first noticed in the East London district of South Africa in 1938–39. It was a strain of the one host blue tick, B. decoloratus. BHC was very toxic to the tick, as 50 p.p.m. of the gamma isomer killed adult females in in vitro experiments. Field results in 1946–47 were equally convincing. Weekly dippings in BHC washes containing 50 p.p.m. gamma isomer brought the arsenicresistant tick under control.In March 1948, BHC was found to be ineffective against blue ticks at “Burnside”, “Mistley” and “Gulu”, farms in the East London district. Later, ticks at “Tharfield” and “Elmhirst” in the Bathurst area survived regular weekly dippings in BHC preparations. In vitro experiments showed that adult female blue ticks taken from these localities could withstand high concentrations of gamma BHC, while females of the same species from other areas were readily killed. Not even 1,000 p.p.m. would give 100 per cent. control of ticks from resistant areas, and different sources of gamma BHC were equally ineffective. Laboratory experiments further indicated that the ticks were still arsenic-resistant. Indeed arsenic resistance appears to be associated with BHC resistance, as no BHC-resistant tick has been found that is not arsenic-resistant. The chlorinated cyclic hydrocarbons toxaphene and chlordane were ineffective against BHC-resistant ticks, but controlled BHC-sensitive ticks in the laboratory. DDT gave moderate in vitro results against both resistant and sensitive ticks.