DOCSLIB.ORG

Reflectance Spectral Characteristics of Minerals in the Mboukoumassi

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

minerals Article Reflectance Spectral Characteristics of Minerals in the Mboukoumassi Sylvite Deposit, Kouilou Province, Congo Xian-Fu Zhao 1,2, Zong-Qi Wang 1,*, Jun-Ting Qiu 3,* and Yang Song 2 1 Ministry of Land and Resources Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China; [email protected] 2 School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China; [email protected] 3 National Key Laboratory of Science and Technology on Remote Sensing Information and Image Analysis, Beijing Research Institute of Uranium Geology, Beijing 100029, China * Correspondence: [email protected] (Z.-Q.W.); [email protected] (J.-T.Q.); Tel.: +86-10-82251207 (Z.-Q.W.); +86-10-64962683 (J.-T.Q.) Academic Editor: Dimitrina Dimitrova Received: 20 March 2016; Accepted: 23 May 2016; Published: 14 June 2016 Abstract: This study presents reflectance spectra, determined with an ASD Inc. TerraSpec® spectrometer, of five types of ore and gangue minerals from the Mboukoumassi sylvite deposit, Democratic Republic of the Congo. The spectral absorption features, with peaks at 999, 1077, 1206, 1237, 1524, and 1765 nm, of the ore mineral carnallite were found to be different from those of gangue minerals. Spectral comparison among carnallite samples from different sylvite deposits suggests that, in contrast to spectral shapes, the absorption features of carnallite are highly reproducible. Heating of carnallite to 400 and 750˝C, and comparing the spectra of heated and non-heated samples, indicates that spectral absorption is related to lattice hydration or addition of hydroxyl. Since carnallite undergoes deliquescence easily, the absorption features of carnallite in the 350–2500 nm spectrum could serve as a robust tool for carnallite identification and separation. Keywords: reflectance spectrum; mineral classification and separation; sylvite deposit; Mboukoumassi; Congo 1. Introduction Potassium, a common soil fertilizer, is important for modern agriculture as it improves water retention, nutrient value, and disease resistance of food crops. Often referred to as potash, most industrial potassium is derived from sylvite deposits, including those in Canada, Russia, China, Belarus, Israel, Germany, Chile, the United States, Jordan, Spain, the United Kingdom, and Brazil. Potash ores are typically rich in potassium chloride (KCl) and sodium chloride (NaCl), and are often buried deep below the Earth's surface. Extraction of potash ore is typically by conventional shaft mining with the extracted ore ground into grains. Carnallite (KCl¨ MgCl2¨ 6H2O), a key potassium-bearing mineral used for potassium production, is usually spatially associated with halite, a common gangue mineral in carnallite ore. The occurrence of halite may reduce the economic benefit of sylvite and increase difficulties during potassium purification. Therefore, to improve processing efficiency, it is necessary to determine halite content and distinguish carnallite from gangue minerals. Traditional geochemical methods for halite content estimation are limited because analyzed samples are typically collected discontinuously from drill cores, and the dissolution method for separating carnallite from halite is time-consuming and uneconomic. Minerals 2016, 6, 55; doi:10.3390/min6020055 www.mdpi.com/journal/minerals Minerals 2016, 6, 55 2 of 9 Minerals 2016, 6, 55 2 of 9 discontinuously from drill cores, and the dissolution method for separating carnallite from halite is time-consuming and uneconomic. Hyperspectral remote sensing,sensing, whichwhich hashas beenbeen successfullysuccessfully usedused inin lithologicallithological classificationclassification [1[1–5]–5] and alteration mineral identificationidentification [6–8], [6–8], provides a potentialpotential alternativealternative for halitehalite estimationestimation andand carnallite separation in the solid state. Materials thatthat interact with the electromagnetic waves emitted from the sunsun cancan bebe recordedrecorded byby hyperspectralhyperspectral sensorssensors inin thethe formform ofof aa spectrum.spectrum. A spectrum can essentially fingerprintfingerprint aa material;material; itit cancan be be used used to to search search for for material material with with a similara similar spectrum spectrum and and to investigateto investigate the the composition composition of theof the material material [9]. [9]. In this study, thethe reflectancereflectance spectraspectra (350–2500(350–2500 nm) of several mineral samples (anhydrite, glauberite, halite, carnallite, and tachydrite) were recorded from the Mboukoumassi sylvite deposit, Kouilou Province,Province, DemocraticDemocratic Republic Republic of of the the Congo. Congo. This This was was done done using using an ASDan ASD Inc. Inc. (Boulder, (Boulder, CO, USA)CO, USA) TerraSpec TerraSpec® spectrometer® spectrometer in an attempt in an toattempt understand to under the spectralstand the features spectral of thesefeatures minerals of these and evaluateminerals theand capability evaluate ofthe hyperspectral capability of remote hyperspe sensingctral technologyremote sensing in identification technology andin identification classification ofand minerals classification in the of sylvite minerals deposit. in the sylvite deposit. 2. Geological Geological Backgrounds Backgrounds The Mboukoumassi dep depositosit in in the the southwest southwest of of Kouilou Kouilou Province Province in inthe the Democratic Democratic Republic Republic of ofthe the Congo Congo is an is animportant important potash potash and and halite halite depos depositit in inthe the Congo Congo Basin Basin (Figure (Figure 1).1 ).The The deposit deposit is ishosted hosted in inCretaceous Cretaceous strata strata and and covered covered by by Quat Quaternaryernary sediments. sediments. The The Cretaceous sedimentary strata consist of basalbasal continentalcontinental sedimentary rocks,rocks, a middle stratum of rock salt, and a capping of marine sedimentary rocks. The continental sediment sedimentaryary rocks were formed before or coeval with the formation ofof the the African-American African-American continent continent rift. The rift. rock The salt layerrock bearssalt lightlayer pink, bears salmon-colored light pink, andsalmon-colored dark salmon and colored dark salmon carnallite, colored bluish carnallite, white to steelbluish gray white or lightto steel brown gray halite,or light bischofite, brown halite, and tachydrite.bischofite, and This tachydrite. unit is composed This unit of fouris composed sedimentary of four cyclothems, sedimentary with cyclothems, bischofite and with tachydrite bischofite in theand toptachydrite layer, and in the bituminous top layer, shaleand bituminous (or asphaltenes-halite) shale (or asphaltenes-halite) in the bottom layer. in the The bottom rock layer. salt layer The thickensrock salt fromlayer the thickens edges to from the centerthe edges of the to basin, the cent wither thickness of the basin, in the with range thickness of 170–600 in m. the The range marine of sedimentary170–600 m. The rocks marine were sedimentary deposited at rocks the edge were of depos the thenited African at the edge continental of the then margin African and continental differ from mostmargin other and marine differ from deposits most because other marine it lacks depos sulfatesits because and carbonates. it lacks sulfates and carbonates. Figure 1. Geological map for Mboukoumassi deposit (Mod (Modifiedified after Martiniand Bowles (1994) [[10]).10]). Minerals 2016, 6, 55 3 of 9 During the Cretaceous Period, the Mboukoumassi deposit was located in a rift basin where tectonicDuring movements the Cretaceous were lacking, Period, resulting the Mboukoumassi in negligible deposit deformation. was located This inis aevident rift basin from where the tectonichorizontal movements and highly were continuous lacking, deposit, resulting and in its negligible uniform deformation.thickness. Only This minor is evident small faults from and the horizontalsome caverns and can highly be found continuous in the strata. deposit, and its uniform thickness. Only minor small faults and someThe caverns dominant can be ore found minerals in the in strata. the Mboukoumassi deposit are carnallite and potassium-halite. The potassium-haliteThe dominant ore ore minerals bodies inare the discontinuous Mboukoumassi and deposit are lenticular are carnallite in shape, and as potassium-halite. opposed to the Thestratiform potassium-halite and continuous ore bodies carnallite are discontinuousore bodies. The and gangue are lenticular minerals in include shape, ashalite, opposed anhydrite, to the stratiformbischofite, tachydrite, and continuous plus minor carnallite amounts ore bodies. of dolomite, The ganguecalcite, and minerals clay. The include ore-bearing halite, anhydrite,stratum is bischofite,mainly composed tachydrite, of carnallite plus minor and amounts halite ofinterb dolomite,eds, where calcite, bituminous and clay. Theshale ore-bearing and bischofite stratum are isdeveloped. mainly composed The total average of carnallite thickness and haliteof strata interbeds, that hosts where ore bodies bituminous is 259.61 shale m. and bischofite are developed. The total average thickness of strata that hosts ore bodies is 259.61 m. 3. Samples and Analytical Methods 3. Samples and Analytical Methods The mineral samples analyzed in this study were collected from drill cores BS-3 and ZK143. The photographsThe mineral
Recommended publications
  • 1469 Vol 43#5 Art 03.Indd

    1469 Vol 43#5 Art 03.Indd

    1469 The Canadian Mineralogist Vol. 43, pp. 1469-1487 (2005) BORATE MINERALS OF THE PENOBSQUIS AND MILLSTREAM DEPOSITS, SOUTHERN NEW BRUNSWICK, CANADA JOEL D. GRICE§, ROBERT A. GAULT AND JERRY VAN VELTHUIZEN† Research Division, Canadian Museum of Nature, P.O. Box 3443, Station D, Ottawa, Ontario K1P 6P4, Canada ABSTRACT The borate minerals found in two potash deposits, at Penobsquis and Millstream, Kings County, New Brunswick, are described in detail. These deposits are located in the Moncton Subbasin, which forms the eastern portion of the extensive Maritimes Basin. These marine evaporites consist of an early carbonate unit, followed by a sulfate, and fi nally, a salt unit. The borate assemblages occur in specifi c beds of halite and sylvite that were the last units to form in the evaporite sequence. Species identifi ed from drill-core sections include: boracite, brianroulstonite, chambersite, colemanite, congolite, danburite, hilgardite, howlite, hydroboracite, kurgantaite, penobsquisite, pringleite, ruitenbergite, strontioginorite, szaibélyite, trembathite, veatchite, volkovskite and walkerite. In addition, 41 non-borate species have been identifi ed, including magnesite, monohydrocalcite, sellaite, kieserite and fl uorite. The borate assemblages in the two deposits differ, and in each deposit, they vary stratigraphically. At Millstream, boracite is the most common borate in the sylvite + carnallite beds, with hilgardite in the lower halite strata. At Penobsquis, there is an upper unit of hilgardite + volkovskite + trembathite in halite and a lower unit of hydroboracite + volkov- skite + trembathite–congolite in halite–sylvite. At both deposits, values of the ratio of B isotopes [␦11B] range from 21.5 to 37.8‰ [21 analyses] and are consistent with a seawater source, without any need for a more exotic interpretation.
  • United States Patent (11) 3,615,174

    United States Patent (11) 3,615,174

    United States Patent (11) 3,615,174 72 Inventor William J. Lewis 3,342,548 9/1967 Macey....... A. 2319 X South Ogden, Utah 3,432,031 3/1969 Ferris........................... 209/166 X 21 Appl. No. 740,886 FOREIGN PATENTS 22, Filed June 28, 1968 45 Patented Oct. 26, 1971 1,075,166 4f1954 France ......................... 209/66 (73) Assignee NL Industries, Inc. OTHER REFERENCES New York, N.Y. Chem. Abst., Vol. 53, 1959, 9587e I & EC, Vol. 56, 7, Jy '64, 61 & 62. Primary Examiner-Frank W. Lutter 54 PROCESSFOR THE SELECTIVE RECOVERY OF Assistant Examiner-Robert Halper POTASSUMAND MAGNESUMWALUES FROM Attorney-Ward, McElhannon, Brooks & Fitzpatrick AQUEOUSSALT SOLUTIONS CONTAINING THE SAME 11 Claims, 4 Drawing Figs. ABSTRACT: Kainite immersed in brine in equilibrium con 52) U.S. Cl........................................................ 23138, verted to carnalite by cooling to about 10 C. or under. Car 209/11, 209/166,23191, 22/121 nallite so obtained purified by cold flotation. Purified carnal (5) Int. Cl......................................................... B03b 1100, lite water leached to yield magnesium chloride brine and B03d 1102, C01f 5126 potassium chloride salt. Latter optionally converted to potas 50 Field of Search............................................ 209/166,3, sium sulfate by reaction with kainite, or by reacting the carnal 10, 11; 23.19, 38, 121 lite with kainite. Naturally occurring brine concentrated to precipitate principally sodium chloride, mother liquor warm 56 References Cited concentrated to precipitate kainite, cooled under mother UNITED STATES PATENTS liquor for conversion to carnallite. A crude kainite fraction 2,479,001 8/1949 Burke........................... 23.191 purified by warm flotation and a crude carnallite fraction pu 2,689,649 9, 1954 Atwood....
  • Ancient Potash Ores

    Ancient Potash Ores

    www.saltworkconsultants.com John Warren - Friday, Dec 31, 2018 BrineSalty evolution Matters & origins of pot- ash: primary or secondary? Ancient potash ores: Part 3 of 3 Introduction Crossow of In the previous two articles in this undersaturated water series on potash exploitation, we Congruent dissolution looked at the production of either Halite Mouldic MOP or SOP from anthropo- or Porosity genic brine pans in modern saline sylvite lake settings. Crystals of interest formed in solar evaporation pans Dissolved solute shows stoichiometric match to precursor, and dropped out of solution as: dissolving salt goes 1) Rafts at the air-brine interface, A. completely into solution 2) Bottom nucleates or, 3) Syn- depositional cements precipitated MgCl in solution B. 2 within a few centimetres of the Crossow of depositional surface. In most cases, undersaturated water periods of more intense precipita- Incongruent dissolution tion tended to occur during times of brine cooling, either diurnally Carnallite Sylvite or seasonally (sylvite, carnallite and halite are prograde salts). All Dissolved solute does not anthropogenic saline pan deposits stoichiometrically match its precursor, examples can be considered as pri- while the dissolving salt goes partially into solution and a mary precipitates with chemistries new daughter mineral remains tied to surface or very nearsurface Figure 1. Congruent (A) versus incongruent (B) dissolution. brine chemistry. In contrast, this article discusses the Dead Sea and the Qaidam sump most closely resemble ancient potash deposits where the post-deposition chem- those of ancient MgSO4-depleted oceans, while SOP fac- istries and ore textures are responding to ongoing alter- tories in Great Salt Lake and Lop Nur have chemistries ation processes in the diagenetic realm.
  • OCCURRENCE of BROMINE in CARNALLITE and SYLVITE from UTAH and NEW MEXICO* Manrr Loursp Lrnosonc

    OCCURRENCE of BROMINE in CARNALLITE and SYLVITE from UTAH and NEW MEXICO* Manrr Loursp Lrnosonc

    OCCURRENCE OF BROMINE IN CARNALLITE AND SYLVITE FROM UTAH AND NEW MEXICO* Manrr Loursp LrNosonc ABSTRACT Both carnallite and sylvite from Eddy County, New Mexico, contain 0.1 per cent of bromine. The bromine content of these minerals from Grand county, utah, is three times as great. No bromine was detected in halite, polyhalite, l5ngbeinite, or anhydrite from New Mexico. Iodine was not detected in any of these minerals. on the basis of the bromine content of the sylvite from New Mexico, it is calculated that 7,000 tons of bromine were present in potash salts mined from the permian basin during the period 1931 to 1945. INrnooucrroN The Geological Survey has previously made tests for bromine and iodine in core samples of potash salts from New Mexico.r Bromine was found to be present in very small amounts. No systematic quantitative determinations were made, nor was the presenceof bromine specificalry correlated with quantitative mineral composition. Sections of potash core from four recently drilled wells and selected pure saline minerals from Eddy County, New Mexico, together with two cores from Grand County, Utah, were therefore analyzed for their bromine and iodine content. The percentage mineral composition was then correlated with the bromine content. rt was found that bromine was restricted to carnall- ite and sylvite. fodine was not detected in any of the samples analyzed. If present, its quantity must be less than .00570. Brine and sea water are the present commercial sourcesof bromine in the United States, though both Germany and U.S.S.R. have utilized potash salts as a source of bromine.
  • Anomalously High Cretaceous Paleobrine Temperatures: Hothouse, Hydrothermal Or Solar Heating?

    Anomalously High Cretaceous Paleobrine Temperatures: Hothouse, Hydrothermal Or Solar Heating?

    minerals Article Anomalously High Cretaceous Paleobrine Temperatures: Hothouse, Hydrothermal or Solar Heating? Jiuyi Wang 1,2 ID and Tim K. Lowenstein 2,* 1 MLR Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China; [email protected] 2 Department of Geological Sciences and Environmental Studies, State University of New York, Binghamton, NY 13902, USA * Correspondence: [email protected]; Tel.: +1-607-777-4254 Received: 1 November 2017; Accepted: 9 December 2017; Published: 13 December 2017 Abstract: Elevated surface paleobrine temperatures (average 85.6 ◦C) are reported here from Cretaceous marine halites in the Maha Sarakham Formation, Khorat Plateau, Thailand. Fluid inclusions in primary subaqueous “chevron” and “cumulate” halites associated with potash salts contain daughter crystals of sylvite (KCl) and carnallite (MgCl2·KCl·6H2O). Petrographic textures demonstrate that these fluid inclusions were trapped from the warm brines in which the halite crystallized. Later cooling produced supersaturated conditions leading to the precipitation of sylvite and carnallite daughter crystals within fluid inclusions. Dissolution temperatures of daughter crystals in fluid inclusions from the same halite bed vary over a large range (57.9 ◦C to 117.2 ◦C), suggesting that halite grew at different temperatures within and at the bottom of the water column. Consistency of daughter crystal dissolution temperatures within fluid inclusion bands and the absence of vapor bubbles at room temperature demonstrate that fluid inclusions have not stretched or leaked. Daughter crystal dissolution temperatures are reproducible to within 0.1 ◦C to 10.2 ◦C (average of 1.8 ◦C), and thus faithfully document paleobrine conditions.
  • Potash Deposits in the Devonian Prairie Evaporite, Southwestern Manitoba Lo Eo Gic G a a L B S O U

    Potash Deposits in the Devonian Prairie Evaporite, Southwestern Manitoba Lo Eo Gic G a a L B S O U

    Potash deposits in the Devonian Prairie Evaporite, southwestern Manitoba lo eo gic g a a l b s o u t r i v n e a MGS y m M.P.B. Nicolas 1928 Manitoba Geological Survey, Winnipeg, Manitoba, Canada Potash Geology 3. Esterhazy Member The Esterhazy Member is the most economic Potash Exploration potash beds. It consists of euhedral to subhedal halite 2. Regional and Local Geology crystals with large anhedral sylvite crystals and minor 1. Introduction interstitial carnolite and clays (Figure 7 and 8). In Manitoba, the Paleozoic-, Mesozoic- and Cenozoic-age strata form a basinward-thickening, southwesterly- 6. Potash Resource 7. Exploration History The Prairie Evaporite is a thick Denonian-aged evaporitic sloping wedge, with the strata reaching a total thickness of 2.3 km in the extreme southestern corner of Manitoba The Esterhazy Member is intermittently present in R29W1 R28 R27 R26 R25 R24 R23 sequence dominantly consisting of halite and anhydrite. It Legend (Figure 4). The potash-bearing Devonian-age Prairie Evaporite was deposited within the Elk Point Basin (Figure Formal mineral resource estimates have been prepared for The discovery of potash in Manitoba was in an oil well T30 a narrow, elongate strip in southwestern Manitoba, includes four potash-bearing members, from oldest to youngest N 5). The Prairie Evaporite consists mainly of thick halite beds, with minor anhydrite and four localized potash beds. the Russell deposit, most recently in 2009. A historical resource drilled in 1951 at 15-18-10-27W1. This discovery led to salt distribution WA T29 from Township 5 to 21, Ranges 27 to 29 W1 (Figure E A H B C Within the basin, the formation can exceed 210 m in thickness, and lies at depths of 200 to 2,700 m below surface.
  • Assessment of the Molecular Structure of the Borate Mineral Boracite

    Assessment of the Molecular Structure of the Borate Mineral Boracite

    Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 96 (2012) 946–951 Contents lists available at SciVerse ScienceDirect Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy journal homepage: www.elsevier.com/locate/saa Assessment of the molecular structure of the borate mineral boracite Mg3B7O13Cl using vibrational spectroscopy ⇑ Ray L. Frost a, , Yunfei Xi a, Ricardo Scholz b a School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, G.P.O. Box 2434, Brisbane, Queensland 4001, Australia b Geology Department, School of Mines, Federal University of Ouro Preto, Campus Morro do Cruzeiro, Ouro Preto, MG 35400-00, Brazil highlights graphical abstract " Boracite is a magnesium borate mineral with formula: Mg3B7O13Cl. " The crystals belong to the orthorhombic – pyramidal crystal system. " The molecular structure of the mineral has been assessed. " Raman spectrum shows that some Cl anions have been replaced with OH units. article info abstract Article history: Boracite is a magnesium borate mineral with formula: Mg3B7O13Cl and occurs as blue green, colorless, Received 23 May 2012 gray, yellow to white crystals in the orthorhombic – pyramidal crystal system. An intense Raman band Received in revised form 2 July 2012 À1 at 1009 cm was assigned to the BO stretching vibration of the B7O13 units. Raman bands at 1121, Accepted 9 July 2012 1136, 1143 cmÀ1 are attributed to the in-plane bending vibrations of trigonal boron. Four sharp Raman Available online 13 August 2012 bands observed at 415, 494, 621 and 671 cmÀ1 are simply defined as trigonal and tetrahedral borate bending modes. The Raman spectrum clearly shows intense Raman bands at 3405 and 3494 cmÀ1, thus Keywords: indicating that some Cl anions have been replaced with OH units.
  • Seepage Chemistry Manual

    Seepage Chemistry Manual

    RECLAMManagAingTWateIr iOn theNWest Report DSO-05-03 Seepage Chemistry Manual Dam Safety Technology Development Program U.S. Department of the Interior Bureau of Reclamation Technical Service Center Denver, Colorado December 2005 Form Approved REPORT DOCUMENTATION PAGE OMB No. 0704-0188 The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 2. REPORT TYPE 3. DATES COVERED (From - To) 12-2005 Technical 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Seepage Chemistry Manual 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Craft, Doug 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT Bureau of Reclamation, Technical Service Center, D-8290, PO Box 25007, NUMBER Denver CO 80225 DSO-05-03 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10.
  • Chlorine and Bromine Isotope Evolution Within a Fully Developed Upper Permian Natural Salt Sequence

    Chlorine and Bromine Isotope Evolution Within a Fully Developed Upper Permian Natural Salt Sequence

    Published in “Geochimica et Cosmochimica Acta” volume 245, pages 316-326. DOI: https://doi.org/10.1016/j.gca.2018.11.010. Use the above information when citing this article. Chlorine and bromine isotope evolution within a fully developed Upper Permian natural salt sequence HGM Eggenkampa,*, P Louvatb, J Griffioenc,d, P Agriniera aÉquipe de Géochimie des Isotopes Stables, Institut de Physique du Globe de Paris, Sorbonne Paris Cité, UMR 7154, CNRS, 1 rue Jussieu, 75238 Paris Cedex 05, France bÉquipe de Géochimie des Enveloppes Externes, Institut de Physique du Globe de Paris, Sorbonne Paris Cité, UMR 7154, CNRS, 1 rue Jussieu, 75238 Paris Cedex 05, France cTNO Geological Survey of the Netherlands, P.O. Box 80015, Utrecht, The Netherlands dCopernicus Institute of Sustainable Development, Utrecht University, P.O. Box 80115, Utrecht, The Netherlands *Corresponding author, email [email protected] Abstract The behaviour of chlorine and bromine isotopes in evaporite deposits differs significantly. We studied the isotope variations of both elements in a fully developed natural salt sequence from Zechstein evaporite deposits (Wuchiapingian, Upper Permian) in the Northern Netherlands. We observed that the Cl isotope variations follow previously predicted characteristics, showing slightly positive δ37Cl (relative to seawater) in halite (NaCl) dominated layers (up to +0.05 ‰), decreasing to moderately negative values in carnallite (KMgCl3•6H2O) and bischofite (MgCl2•6H2O) dominated layers (down to -0.55 ‰). Bromine isotope variations, the first ever measured in marine evaporite samples, show a different characteristic. δ81Br values 1 of 27 decrease quickly in layers dominated by halite (from +0.2 to -0.5 ‰) and increase again in layers dominated by carnallite and bischofite (up to - 0.1±0.2‰).
  • Minerals Found in Michigan Listed by County

    Minerals Found in Michigan Listed by County

    Michigan Minerals Listed by Mineral Name Based on MI DEQ GSD Bulletin 6 “Mineralogy of Michigan” Actinolite, Dickinson, Gogebic, Gratiot, and Anthonyite, Houghton County Marquette counties Anthophyllite, Dickinson, and Marquette counties Aegirinaugite, Marquette County Antigorite, Dickinson, and Marquette counties Aegirine, Marquette County Apatite, Baraga, Dickinson, Houghton, Iron, Albite, Dickinson, Gratiot, Houghton, Keweenaw, Kalkaska, Keweenaw, Marquette, and Monroe and Marquette counties counties Algodonite, Baraga, Houghton, Keweenaw, and Aphrosiderite, Gogebic, Iron, and Marquette Ontonagon counties counties Allanite, Gogebic, Iron, and Marquette counties Apophyllite, Houghton, and Keweenaw counties Almandite, Dickinson, Keweenaw, and Marquette Aragonite, Gogebic, Iron, Jackson, Marquette, and counties Monroe counties Alunite, Iron County Arsenopyrite, Marquette, and Menominee counties Analcite, Houghton, Keweenaw, and Ontonagon counties Atacamite, Houghton, Keweenaw, and Ontonagon counties Anatase, Gratiot, Houghton, Keweenaw, Marquette, and Ontonagon counties Augite, Dickinson, Genesee, Gratiot, Houghton, Iron, Keweenaw, Marquette, and Ontonagon counties Andalusite, Iron, and Marquette counties Awarurite, Marquette County Andesine, Keweenaw County Axinite, Gogebic, and Marquette counties Andradite, Dickinson County Azurite, Dickinson, Keweenaw, Marquette, and Anglesite, Marquette County Ontonagon counties Anhydrite, Bay, Berrien, Gratiot, Houghton, Babingtonite, Keweenaw County Isabella, Kalamazoo, Kent, Keweenaw, Macomb, Manistee,
  • Potash – Recent Exploration Developments in North Yorkshire

    Potash – Recent Exploration Developments in North Yorkshire

    F.W. Smith, J.P.L. Dearlove, S.J. Kemp, C.P. Bell, C.J. Milne and T.L. Pottas POTASH – RECENT EXPLORATION DEVELOPMENTS IN NORTH YORKSHIRE 1 1 2 1 2 3 F.W. SMITH , J.P.L. DEARLOVE , S.J. KEMP , C.P. BELL , C.J. MILNE AND T.L. POTTAS 1 FWS Consultants Ltd, Merrington House, Merrington Lane Trading Estate, Spennymoor DL16 7UT. 2 British Geological Survey, Nicker Hill, Keyworth, Nottingham. NG12 5GG. 3 York Potash Ltd, 7-10 Manor Court, Scarborough. YO11 3TU. ABSTRACT Polyhalite is not a rare mineral worldwide, but it rarely forms more than a minor component of evaporite sequences. York Potash Ltd is exploring an area of interest between Whitby and Scarborough, North Yorkshire, UK, in which an Exploration Target of 6.8 to 9.5 billion tonnes has been identified. Polyhalite exploration by York Potash has primarily been by drilling boreholes from surface, that are then cored through the Zechstein evaporite sequence. Assay samples have been analysed initially by quantitative X-ray diffraction, with subsequent analyses by Inductively Coupled Plasma Atomic Emission Spectroscopy. The assay results reported in this paper for the weighted average ore zone sections range from 78 to 97% polyhalite, with high grade sections in places exceeding 99% polyhalite. The exploration results have lead to a revised conceptual model for the Fordon Evaporites in North Yorkshire, in particular defining the differences between the three depositional environments of the Shelf, Basinal and intervening Transitional or Ramp facies and the occurrence of additional potash horizons in the region. Of particular significance was the discovery of accessory or exotic minerals associated with the polyhalite.
  • Experimental Drill Hole Logging in Potash Deposits Op the Cablsbad District, Hew Mexico

    Experimental Drill Hole Logging in Potash Deposits Op the Cablsbad District, Hew Mexico

    EXPERIMENTAL DRILL HOLE LOGGING IN POTASH DEPOSITS OP THE CABLSBAD DISTRICT, HEW MEXICO By C. L. Jones, C. G. Bovles, and K. G. Bell U. S. GEOLOGICAL SURVEY This report is preliminary and has not been edited or Released to open, files reviewed for conformity to Geological Survey standards or nomenclature. COHTEUTS Page Abstract i Introduction y 2 Geology . .. .. .....-*. k Equipment 7 Drill hole data . - ...... .... ..-. - 8 Supplementary tests 10 Gamma-ray logs -T 11 Grade and thidmess estimates from gamma-ray logs Ik Neutron logs 15 Electrical resistivity logs 18 Literature cited . ........... ........ 21 ILLUSTRATIONS Figure 1. Generalized columnar section and radioactivity log of potassium-bearing rocks 2. Abridged gamma-ray logs recorded by commercial All companies and the U. S. Geological Survey figures 3« Lithologic, gamma-ray, neutron, and electrical resistivity logs ................. are in k. Abridged gamma-ray and graphic logs of a potash envelope deposit at end of 5« Lithologic interpretations derived from gamma-ray and electrical resistivity logs - ...... report. TABLE Table 1. Summary of drill hole data 9 EXPERIMENTAL DRILL HOLE LOGGING Iff POTASH DEPOSITS OP THE CARISBAD DISTRICT, HEW MEXICO By C. L. Jones, C. G. Bowles, and K. G>. Bell ABSTRACT Experimental logging of holes drilled through potash deposits in the Carlsbad district, southeastern Hew Mexico, demonstrate the consider­ able utility of gamma-ray, neutron, and electrical resistivity logging in the search for and identification of mineable deposits of sylvite and langbeinite. Such deposits are strongly radioactive with both gamma-ray and neutron well logging. Their radioactivity serves to distinguish them from clay stone, sandstone, and polyhalite beds and from potash deposits containing carnallite, leonite, and kainite.