sign in sign up
<<
Home , Ulexite

Canadian Mineralogist Vol. 13, pp. 370-376 (1975)

HOWLITE AND ULEXITE FROM THE CARBONIFEROUS AND ANHYDRITE BEDS IN WESTERN NEWFOUNDLAND

V. S. PAPEZIK Department of Geology, Memorial University of Newfoundland, St. John's, Newfoundland

AND

C. C. K. FONG* Development Division, Newfoundland Department of Mines and Energy, St. John's, Newfoundland

Abstract forme de nodules composes en forme de fram- boises de 0.5 a 2 cm de diametre; elle est com The Carboniferous anhydrite and gypsum beds posed de minces cristaux en plaquettes d'une in southwestern Newfoundland contain small longueur de moins de 0.1 mm avec des plans (100) quantities of ulexite (NaCaBsCV8H20) and how- proeminents. Ces deux mineraux ont aussi ete trou- lite (Ca2SiB509(OH)5). The ulexite occurs as ir ves dans deux regions non-localisees auparavant de regular patches 1-3 cm in diameter, consisting of la Nouvelle-Ecosse — le gisement Pb-Zn de Gays white fibrous crystals; the forms composite River et une carriere de gypse pres de Milford. La framboidal nodules about 0.5 to 2 cm in diameter, howlite semble avoir ete formee d'un gel; la forma consisting of thin platy crystals less than 0.1 mm tion des borates 6tait contemporaine avec la preci long with prominent (100) planes. The two min pitation de sulfate de calcium. erals were also found at two localities in Nova Sco La presence des mineraux de borate (en petites tia not previously reported — the Gays River quantites) semble etre courante dans l'anhydrite et Pb-Zn deposit and a gypsum quarry near Milford. le gypse du Bassin Carbonifere des provinces de The howlite is believed to have been formed from l'Atlantique; par contre on ne rapporte aucune a gel; the formation of the borates was contempo autre presence similaire ailleurs pour l'instant. Les raneous with the precipitation of calcium sulphate. quantites normales de bore dans Peau de mer sont Borate , in small quantities, seem to be suffisantes pour expliquer la quantite de borates common in the anhydrite and gypsum of the Car observee. 11 est fort possible que de semblables pe boniferous Basin of the Atlantic Provinces, but no tites quantities de borates soient presentes dans reports of similar occurrences elsewhere are known d'autres gisements d'anhydrite-gypse mais elles au- at this tims. The normal amounts of in sea- raient ete negligees. Si elles sont vraiment absentes water are sufficient to account for the observed de d'autres lits marins evapores, la difference peut quantity of borates. It is possible that similar small etre causee par les variances dans le pH, la solubi- quantities of borates are present in other anhydrite- lite, le taux d'evaporation, etc. piutot que par la gypsum deposits but have been overlooked. If they presence ou Pabsence des sources exterieures de are truly absent from marine beds else bore. where, the difference may be caused by differences (Traduit par le journal) in pH, , rate of evaporation etc. rather than by the presence or absence of external sources of boron. Introduction

The occurrence of borate minerals in the Resume gypsum deposits of Lower Carboniferous (Wind Les lits de gypse et d'anhydrite de la periode Car- sor) age in the Atlantic Provinces of Canada bonifere du sud-ouest de Terre-Neuve contiennent was first discovered more than 100 years ago de petites quantites d'ulexite (NaCaB509»8H20) et de by Henry How, then Professor of Chemistry howlite, Ca2SiB509(OH)s. L'ulexite se presente and Natural History at King's College in Wind sous forme de taches irregulieres de 1 a 3 cm de sor, Nova Scotia. How described "natro-boro- diametre; celles-ci sont composees de cristaux " (now ulexite, NaCaBs09*8H20) from blancs fibreux; la howlite, elle, se presente sous "a bed of a very extensive formation of gypsum at Windsor, on the Clifton estate, lately the property of Judge Haliburton" (How 1857), ♦Publication authorized by the Director of Min and "cryptomorphite" (now ginorite, CaiBuOn* eral Development Division, Department of Mines 8H20; Hey & Bannister 1952) from "the same and Energy, St. John's. quarry, at a distance of about 100 yards and

370 Downloaded from http://pubs.geoscienceworld.org/canmin/article-pdf/13/4/370/3445609/370.pdf by guest on 24 September 2021 HOWLITE AND ULEXITE FROM CARBONIFEROUS GYPSUM AND ANHYDRITE BEDS 371

at about 20 feet lower level" (How 1861). Both rence of ulexite and from the gypsum minerals were associated with , Na2Ca- quarry at Hillsborough, south of Moncton, New (SO^j. Later, How reported a new mineral Brunswick (Walker 1921). More recently, Sa- which he named "silicoborocalcite" (now how bina (1965) found crystals of howlite up to lite, Ca2SiB5Os(OH)5) from a locality at Noel, 1.3 cm long, associated with fine-grained how Hants Co., Nova Scotia, "in nodules sometimes lite and danburite, in gypsum near Iona, Cape as large as a man's head" (How 1868, 1877). Breton Island (see Fig. 1 for all localities). How's original localities were later re-exam In this paper, we report for the first time the ined and his discoveries confirmed by N. R. occurrence of howlite and ulexite in the Lower Goodman, who also found howlite as nodules Carboniferous evaponte deposits in western up to 5 cm in diameter at Wentworth, Hants Newfoundland. In addition, during a recent field County, as "small nodules" at Cheverie (Hants trip organized by the Nova Scotia Department Co.) and Bevis Point (Victoria Co., Cape Bre of Mines, we found howlite and ulexite in anhy ton Island), and as nodules more than 15 cm in drite in drill-cores from the newly explored diameter "in a clay horizon in the National Gays River Pb-Zn deposit about 8 km southeast Gypsum Co. quarries at Dingwall (Cape Breton of Shubenacadie, and ulexite nodules in the Island)". Goodman further reported ulexite at large gypsum quarry near Milford, both in Wentworth, Dingwall, Bevis Point, and at White Halifax Co., Nova Scotia. We further obtained Head near Cheverie, and in addition described from Mr. W. Lewis, Senior Geologist of the the occurrence of danburite (CaSUB*08) at Fundy Gypsum Co., a specimen of gypsum White Head and "in the shore outcrop 2 miles from Hillsborough, New Brunswick, contain SW of Iona, Victoria Co. (Cape Breton Island)", ing several ulexite nodules, thus confirming and inyoite, CajBeOn'lSHsO, as "beautiful Walker's earlier report. It is clear therefore that colourless crystals" from the Wentworth area, borate minerals, in small quantities, are wide Hants Co., all in Nova Scotia (Goodman 1957). spread in the Lower Carboniferous evaporite Earlier, T. L. Walker had reported the occur basin of the Atlantic Provinces.

1 FLAT BAY 2 FISCHELL"S BROOK

3 DINGWALL

4 BEVIS POINT

5 IONA

6 GAYS RIVER 7 MILFORD

6 NOEL 4*" 9 WENTWORTH

K) WINDSOR

11 CHEVERIE

12 HILLSBOROUGH

CARBONIFEROUS (UNDIVIDED)

• BORATE LOCALITIES

no o wo too

KiLOHcrun

a** »L Fig. 1. Borate localities in the Carboniferous basin of the Atlantic region.

Downloaded from http://pubs.geoscienceworld.org/canmin/article-pdf/13/4/370/3445609/370.pdf by guest on 24 September 2021 372 THE CANADIAN MINERALOGIST

Borates in Newfoundland Brook and in the Flat Bay gypsum quarry. The Geological setting rocks of the Anguille and Codroy Groups are folded here into an elongate anticline, the axis The Carboniferous rocks of Newfoundland of which runs NE-SW, almost parallel to the form the northeasterly part of a large Carboni coastline. A nearly continuous section of these ferous basin extending across the Gulf of St beds is exposed in Fischell's Brook. The An Lawrence through Prince Edward Island to guille Group is here represented by about 200 New Brunswick and Nova Scotia. In New ft. (61 m) of sandy conglomerate that grades foundland, Carboniferous rocks are found in towards the top of the group into a 10-foot two separate basins within a relatively narrow, (3 m) quartzitic sandstone. This is conformably elongate, northeasterly-trending belt in the overlain by a 60-foot (18 m) thick formation western part of the island, extending from Cape consisting of alternating limestone and shale, Anguille in the southwest to White Bay in the the Ship Cove Formation, which marks the base northeast. Rocks of the southwesterly Carboni of the Codroy Group. The Ship Cove Forma ferous basin are exposed along the shore of St. tion is followed by an approximately 3000-foot George's Bay and in the adjacent Anguille (915 m) thick sequence of red, finely cross- Mountains, forming a belt 20-25 km wide and bedded siltstone, sandstone, green shale and about 100 km long; they are separated by a ma , overlain by a 1200-foot (366 m) se jor fault of regional extent from the igneous quence of alternating dark grey shale and car and metamorphic rocks of the Long Range bonate; the carbonates consist of marine fossili- Complex to the southeast. ferous limestone, algal limestone, small alga! The Carboniferous sediments of this basin reefs and red, dense, non-fossiliferous dolomite. have been subdivided into three stratigraphic The evaporite horizons in the Fischell's Brook units. The lowest, the Anguille Group, consists section attain a thickness of 150 ft. (46 m) and of a thick sequence of terrestrial clastic sedi 200 ft. (61 m) respectively..Howlite was found ments, mainly sandstone, shale and conglo in the higher of the two horizons, which crops merate; it is of Mississippian age, and is be out by the railway bridge on the southern bank lieved to be equivalent to the Upper Horton of the stream (48°18'30"N, 58°40'30"W) in a Group of Nova Scotia. The middle unit, the vertical cliff. The outcrop consists of blue anhy Codroy Group, comprises limestone, siltstone drite at the cliff base and white gypsum on top; and thick Ca sulphate beds, followed by silt- the anhydrite is bedded, with grey mud stringers stone, sandstone and minor limestone of non- marking the bedding. marine origin. The Codroy Group, of Upper The howlite appears as white nodules in the Mississippian age, has been correlated with the anhydrite; being somewhat more resistant to Windsor Group of Nova Scotia. The upper erosion than the anhydrite, the nodules are unit, mainly Pennsylvanian but including locally most conspicuous on weathered surfaces. Most rocks of Late Mississippian age, is the Bara- of the nodules are from 0.5 cm to 1.5 cm in chois Group, consisting of sandstone, siltstone diameter and have a characteristic crenulated and conglomerate with minor limestone and surface resembling a cauliflower; when clean, some coal beds. It is equivalent in part to the the surface has a vitreous to pearly luster (Fig. Can?o Group and partly to the Pictou Group of 2, 3). Although the nodules are small, they are Nova Scotia (Riley 1962). fairly abundant at this locality — about one Evaporite sequences, comprising mainly an nodule per square foot of exposed surface (10- hydrite and gypsum with a few salt beds, are 11 nodules per square meter). The white gypsum confined to the Codroy Group. The occurrences in the upper part of the cliff is inaccessible, and of gypsum at numerous localities within the thus the total thickness of the howlite-bearing area have been described by several authors horizon is not known. So far, howlite is the (e.g. Hayes & Johnson 1938; Baird 1957). A only boron-containing mineral found at this large gypsum quarry south of Flat Bay, owned locality. by the Flintkote Co. of Canada, is now in oper The most abundant in the Flat ation; in 1973, it produced about 735,000. tons Bay gypsum quarry is ulexite, which forms ir of gypsum (Stonehouse 1973). regular to oval masses 1-3 cm across, consisting of very fine felted fibers. The ulexite masses Borate localities are somewhat crumbly and less resistant to weathering than the howlite nodules described Small quantities of borate minerals have been above, but are conspicuous on light grey found so far at two localities within the gyp weathered surfaces by their pure white colour sum deposits in Newfoundland — at Fischell's (Fig. .4); their main host rock is gypsum, but

Downloaded from http://pubs.geoscienceworld.org/canmin/article-pdf/13/4/370/3445609/370.pdf by guest on 24 September 2021 howlite and ulexite from carboniferous gypsum and anhydrite beds 373

Figs. 2-7. (2) Howlite nodules from Fischell's Brook, southwestern Newfoundland; (3) howlite nodule from Dingwall, Nova Scotia (don. by E. R. W. Neale); (4) ulexite patches in weathered gypsum, Flat Bay quarry, S. W. Newfoundland; (5) scanning electron microscope image of ulexite, Flat Bay; (6) scanning electron microscope image of howlite, Fischell's Brook; (7) scanning electron micro scope image of single crystal of howlite, Fischell's Brook.

Downloaded from http://pubs.geoscienceworld.org/canmin/article-pdf/13/4/370/3445609/370.pdf by guest on 24 September 2021 374 THE CANADIAN MINERALOGIST

some have been found also in the underlying overlapping bundles. This simple habit of ulex anhydrite. The occurrence of ulexite is re ite, with its characteristic square to rectangular stricted to some parts of the quarry, suggesting cross-sections formed apparently by equal or that the mineral is concentrated within a rela almost equal development of two pinacoids in tively narrow stratigraphic horizon; but as the the vertical zone, differs somewhat from the structure of the evaporite beds in this area, highly modified crystals reported by Murdoch which may be very complex in detail, has not (1940, Figs. 3 to 5). The crystals appear to be yet been worked out, no more precise statement terminated by simple pinacoidal planes, but can be made at this time. these may be planes or sur No howlite has been observed by either faces rather than true crystal terminations. Con author in the surface exposures of the Flat Bay siderable difficulties were encountered in ob gypsum quarry, but a short piece of a drill- serving ulexite crystals at high magnifications, core from the quarry, collected by C. Fong, probably due to their transparency combined contains a typical howlite nodule 1.5 cm in with a relatively loose packing. diameter, enclosed in anhydrite. The presence of the silicoborate in the Flat Bay area is thus established, but a more systematic search of A"-Ray Diffraction Study both surface exposures and drill-core will be The borate minerals from the Newfoundland needed before the distribution of the borate localities were studied by standard methods on minerals can be determined. a Philips jc-ray diffractometer, together with a specimen of howlite from Dingwall, Nova Sco of Howlite and Ulexite tia, and a specimen of porcelaneous howlite from California, both kindly provided by G. R. Several typical nodules of howlite and ulexite Grantham, Curator of Geology of the Nova from various localities were examined by scan Scotia Museum in Halifax. Cell dimensions for ning electron microscope (Cambridge Scientific the two minerals were calculated by R. G. Instruments "Stereoscan" Mark 2A, operated Cawthorn of Memorial University from the by Dr. V. C. Barber, Department of Biology, diffractometer data, using a computer program Memorial University of Newfoundland). of Appleman et al. (1972). The howlite nodules were found to consist of The Ar-ray study shows a close similarity be tightly-packed thin platy crystals. The size of tween specimens of howlite from Fischell's the crystals ranges from 10 to about 50 microns. Brook, Dingwall and California, and an equally In the nodules from Fischell's Brook and Ding good correspondence between the investigated wall, the average size is about 30-40 microns howlite and ulexite and published x-ray data on and the largest crystal observed was 110 mi both minerals (Murdoch 1940, 1957; Clark & crons long; in dense porcelain-like nodules from Christ 1959; Finney et al. 1970; Stojanovic California the crystals are smaller, about 10-20 1967; Traill 1969). The narrow range of varia microns on the average, but their habit and tion can probably be ascribed to the purity of parallel packing are very similar to the Cana chemical composition of the borate minerals, dian specimens. The thickness of the plates with only a small range of substitution in the ranges from 2 to about 6 microns (Fig. 6). One lattice. of the nodules from Fischell's Brook disaggre A much greater discrepancy was noted in gated in water to a fine white powder. Scanning the relative intensities of the diffraction peaks electron microscope showed that this powder of howlite from different localities (Table 1). consisted of single crystals and small crystal This is particularly evident when our results aggregates of howlite (Fig. 7), closely resembling and those given in several previous publica an illustration of a "typical crystal habit of tions are compared to intensities calculated from howlite" presented by Murdoch (1957, p. 521); structural factors (Smith et al. 1973). The ano the platy habit of the mineral is the result of a maly consists mainly of the enhancement of shortening along the crystallographic a-axis and the /i00 peaks and a relative suppression of the corresponding development of a prominent others. This appears to be related to the mor (100) face (Murdoch 1957). phology of the crystallites with the prominent The "cottonballs" of ulexite consist of thin (100) face (Figs. 6, 7) and possibly to (100) needle-like crystals, some with almost square cleavage. Although the anomalous variation in cross-sections, others somewhat flattened. The peak intensities may thus be caused simply by crystals are about 1-3 microns thick and from preferred orientation produced during the pack 50 to 80 microns long (Fig. 5); they are ar ing of diffractometer holders, it persisted in our ranged in loosely-packed, randomly-oriented patterns even after its cause had been identified

Downloaded from http://pubs.geoscienceworld.org/canmin/article-pdf/13/4/370/3445609/370.pdf by guest on 24 September 2021 HOWLITE AND ULEXITE FROM CARBONIFEROUS GYPSUM AND ANHYDRITE BEDS 375

TABLE I. VARIATION IN LINE INTENSITIES IN POWDER PATTERNS OF HOULITE the matrix of conglomerates, sandstones and

Downloaded from http://pubs.geoscienceworld.org/canmin/article-pdf/13/4/370/3445609/370.pdf by guest on 24 September 2021 376 THE CANADIAN MINERALOGIST

Acknowledgements nite deposits of California. Econ. Geol. 16, 199- 214. We wish to thank Mr. R. G. Grantham, Cura Goodman, N. R. (1957): Gypsum in Nova Scotia tor of Geology, Nova Scotia Museum in Hali and its associated minerals. In The Geology of fax, for the specimens of howlite from Ding Canadian Industrial Mineral Deposits (M. F. wall, Nova Scotia, and from California, which Goudge et al. editors), Can. Inst. Mining & Met., were included in our study. Mr. D. B. Jorgensen, Montreal, 110-114. Senior Staff Geologist, U.S. Gypsum Co., pro Hayes, A. O. & Johnson, H. (1938): Geology of vided valuable information on gypsum deposits the Bay St. George Carboniferous area. Nfld. in the U.S.A.; we are thankful to Mr. W. L. Geol. Surv. Bull. 12. Lewis, Senior Geologist, Fundy Gypsum Co., Hey, M. H. & Bannister, F. A. (1952): The iden tity of cryptomorphite and ginorite. Mineral. for interesting discussions and for a specimen of Mag. 29, 955-959. ulexite from Hillsborough, New Brunswick. How, H. H. (1857): On the occurrence of natro- Our thanks are also due to Dr. L. G. Berry, boro-calcite with Glauber salt in Gypsum of Queen's University, for unpublished data on Nova Scotia. Amer. J. Sci. 24, 230-235. howlite and a copy of the paper by Stojanovic, (1861): Natro-boro-calcite and another and to our colleagues, N. P. James of the De borate occurring in the gypsum of Nova Scotia. partment of Geology and W. D. Machin of the Amer. J. Sci. 32, 9-13. Department of Chemistry, for valuable discus (1868): Contributions to the mineralogy sions. The cooperation of Dr. V. C. Barber, Dr. of Nova Scotia, m. Borates and other minerals in anhydrite and gypsum. Phil. Mag. 35, 32-41. R. G. Cawthorn and Mr. J. Vahtra is grate (1877): Contributions to the mineralogy fully acknowledged. Mr. W. March prepared of Nova Scotia. Mineral. Mag. 1, 257-260. the phototgraphs and Ken Byrne the map. Mason, B. (1966): Principles of Geochemistry. We further wish to express our thanks to (3rd ed.). John Wiley & Sons, New York. Mr. F. S. Shea, Mr. P. S. Giles and their col Murdoch, J. (1940): Crystallography of ulexite. leagues for an excellent field trip to various Amer. Mineral. 25, 754-762. mineral localities in Nova Scotia, organized by (1957): Crystallography and jc-ray meas the Nova Scotia Department of Mines. Part of urements of howlite from California. Amer. the field expenses of the senior author were Mineral. 42, 521-524. covered by NRC Grant A-2131, which is grate Riley, G. C. (1962): Stephenville map-area, New foundland. Geol. Surv. Can. Mem. 323. fully acknowledged. Fong's work comprised Sabina, A. P. (1965): Rocks and minerals for the part of a geological mapping project conducted collector: northeastern Nova Scotia, Cape Bre on behalf of the Mineral Development Division, ton and Prince Edward Island. Geol. Surv. Can. Newfoundland Department of Mines and Paper 65-10. Energy. Schaller, W. T. (1930): Borate minerals from the Kramer District, Mojave Desert, California. References U.S. Geol. Surv. Prof. Paper 158-1, 137-173. Smith, D. K., Tamm, Lowenhaupt & Rasmussen Appleman, D. E., Evans, H. & Handwerker, D. (1973): Annual Report to the Joint Committee (1972): Indexing and least-squares refinement of on Powder Diffraction Standards, 1973. flJn- powder diffraction data. US. Geol. Surv. Com publ. Rept.). puter Contrib. No. 20. Stojanovic, D. (1957): Howlit iz Jarandolskog Baird, D. M. (1957): Gypsum deposits of south Terciarnog basena. OHowlite from the Tertiary western Newfoundland. In The Geology of Cana basin of Jarandol). Proc. 6th Congr. Un. Geol. dian Industrial Mineral Deposits, M. F. Goudge Soc. Jugoslavia, Skopje, vol. 3, 35-43. (In Ser et al. editors), Can. Inst. Mining & Met., Mont bian, German summary). real, 124-130. Stonehouse, D. H. (1973): Gypsum and anhy Clark, J. R. & Christ, C. L. (1959): Studies of drite. Can. Minerals Yearbook 1973, No. 19, Min. borate minerals (V): reinvestigation of the x- Res. Branch, Ottawa. ray crystallography of ulexite and probertite. Traill, R. J. (1969): A catalogue of Canadian Amer. Mineral. 44, 712-719. minerals. Geol. Surv. Can. Paper 69-45. Finney, J. J., Kumbasar, I., Konnert, J. A. & Walker, T. L. (1921): Ulexite from the Maritime Clark, J. R. (1970): of the provinces. Univ. Toronto Studies, Geol. Ser. 12. calcium silicoborate, howlite. Amer. Mineral. 54-57. 55, 716-728. Foshag, W. F. (1921): The origin of the colema- Manuscript received May 1975, emended June 1975.

Downloaded from http://pubs.geoscienceworld.org/canmin/article-pdf/13/4/370/3445609/370.pdf by guest on 24 September 2021