Citation:

j.chemgeo.2016.02.001

Name: Trace element chemistry of pyrobitumen from the Tau-Tona mine in South Africa
Published: 2017-08-07
License: https://creativecommons.org/licenses/by/3.0/

Always quote citation above when using data! You can download the citation in several formats below.

Published: 2017-08-07 • DOI registered: 2017-09-05

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Abstract:

High-grade gold and uranium mineralization in the Witwatersrand basin is intimately associated with pyrobitumen, implying that hydrocarbons may have played a role in the genesis of these ores. The nature of the pyrobitumen in the Carbon Leader Reef was therefore investigated to determine if hydrocarbons were essential to the ore-forming process. The relative proportions of trace elements in pyrobitumen seams and nodules are, in large part, similar to those of organic-rich shales located within the sedimentary succession. This indicates a strong genetic relationship between the pyrobitumen and the shales. A network of veins and veinlets filled with pyrobitumen, and the occurrence of oil inclusions in detrital and authigenic quartz grains, provide compelling evidence that the pyrobitumen was derived from a mobile (liquid hydrocarbon) precursor that circulated in the Carbon Leader Reef. Uranium, Au, Sb, Pb, Ag, Te, Th, Bi, Se and W are enriched relative to their concentrations in the shales. This is particularly the case for U and Au. The pervasive and relatively homogeneous distribution of the uranium is consistent with the presence of ubiquitous, submicroscopic uraninite in the pyrobitumen documented in an earlier study. In contrast, the distribution of the gold is heterogeneous, indicating the presence of irregularly distributed gold micrograins. These grains are concentrated mainly in the interstices between pyrobitumen nodules. Secondary minerals, such as brannerite, monazite-(Ce) and galena, are also concentrated in these interstices.

On the basis of this study, we propose that intrabasinal shale units of the Witwatersrand Supergroup were the source for the pyrobitumen in the Carbon Leader Reef. These shales produced and released liquid hydrocarbons during the burial of the sedimentary succession. Phyllosilicates enriched in trace metals were transferred from the shales into the newly produced liquid hydrocarbons and were transported stratigraphically upward by the latter into the Carbon Leader Reef. During migration, the liquid hydrocarbons dissolved detrital uraninite present in the basin, adding to the uranium budget. The liquid hydrocarbons were converted into pyrobitumen in response to further burial, and precipitated uraninite nanocrystals. Post-depositional, hydrothermal fluids interacted with the hydrocarbons and deposited gold by reduction on hydrocarbon surfaces. The interaction of these fluids with the hydrocarbons may have released U, Th, REE, Pb and Ti from the hydrocarbons and triggered the formation of secondary brannerite, monazite-(Ce) and galena. The results of this study provide convincing evidence that the hydrocarbon liquids that formed the pyrobitumen seams in the Carbon Leader Reef played an essential role in the remobilization and redeposition of uranium and gold, respectively, in the Witwatersrand Supergroup.

Coverage:

Latitude: -26.500000 * Longitude: 27.250000

Event(s):

Tau-Tona_Mine * Latitude: -26.500000 * Longitude: 27.250000 * Location: South Africa * Comment: Position is estimated from map.

Parameter(s):

#	Name	Short Name	Unit	Principal Investigator
1	Comment	Comment		Fuchs, Sebastian
2	Comment 2 (continued)	Comm 2		Fuchs, Sebastian
3	Calcium	Ca	mg/kg	Fuchs, Sebastian
4	Scandium	Sc	mg/kg	Fuchs, Sebastian
5	Titanium	Ti	mg/kg	Fuchs, Sebastian
6	Vanadium	V	mg/kg	Fuchs, Sebastian
7	Chromium	Cr	mg/kg	Fuchs, Sebastian
8	Manganese	Mn	mg/kg	Fuchs, Sebastian
9	Iron	Fe	mg/kg	Fuchs, Sebastian
10	Cobalt	Co	mg/kg	Fuchs, Sebastian
11	Nickel	Ni	mg/kg	Fuchs, Sebastian
12	Copper	Cu	mg/kg	Fuchs, Sebastian
13	Zinc	Zn	mg/kg	Fuchs, Sebastian
14	Arsenic	As	mg/kg	Fuchs, Sebastian
15	Selenium	Se	mg/kg	Fuchs, Sebastian
16	Strontium	Sr	mg/kg	Fuchs, Sebastian
17	Yttrium	Y	mg/kg	Fuchs, Sebastian
18	Zirconium	Zr	mg/kg	Fuchs, Sebastian
19	Niobium	Nb	mg/kg	Fuchs, Sebastian
20	Molybdenum	Mo	mg/kg	Fuchs, Sebastian
21	Ruthenium	Ru	mg/kg	Fuchs, Sebastian
22	Palladium	Pd	mg/kg	Fuchs, Sebastian
23	Silver	Ag	mg/kg	Fuchs, Sebastian
24	Cadmium	Cd	mg/kg	Fuchs, Sebastian
25	Tin	Sn	mg/kg	Fuchs, Sebastian
26	Antimony	Sb	mg/kg	Fuchs, Sebastian
27	Tellurium	Te	mg/kg	Fuchs, Sebastian
28	Lanthanum	La	mg/kg	Fuchs, Sebastian
29	Cerium	Ce	mg/kg	Fuchs, Sebastian
30	Praseodymium	Pr	mg/kg	Fuchs, Sebastian
31	Neodymium	Nd	mg/kg	Fuchs, Sebastian
32	Samarium	Sm	mg/kg	Fuchs, Sebastian
33	Europium	Eu	mg/kg	Fuchs, Sebastian
34	Gadolinium	Gd	mg/kg	Fuchs, Sebastian
35	Terbium	Tb	mg/kg	Fuchs, Sebastian
36	Dysprosium	Dy	mg/kg	Fuchs, Sebastian
37	Holmium	Ho	mg/kg	Fuchs, Sebastian
38	Erbium	Er	mg/kg	Fuchs, Sebastian
39	Thulium	Tm	mg/kg	Fuchs, Sebastian
40	Ytterbium	Yb	mg/kg	Fuchs, Sebastian
41	Lutetium	Lu	mg/kg	Fuchs, Sebastian
42	Hafnium	Hf	mg/kg	Fuchs, Sebastian
43	Tantalum	Ta	mg/kg	Fuchs, Sebastian
44	Tungsten	W	mg/kg	Fuchs, Sebastian
45	Platinum	Pt	mg/kg	Fuchs, Sebastian
46	Gold	Au	mg/kg	Fuchs, Sebastian
47	Thallium	Tl	mg/kg	Fuchs, Sebastian
48	Lead	Pb	mg/kg	Fuchs, Sebastian
49	Bismuth	Bi	mg/kg	Fuchs, Sebastian
50	Thorium	Th	mg/kg	Fuchs, Sebastian
51	Uranium	U	mg/kg	Fuchs, Sebastian

License:

Creative Commons Attribution 3.0 Unported (CC-BY-3.0)

Size:

1220 data points

Data

Download dataset as tab-delimited text — use the following character encoding:

1 Comment	2 Comm 2	3 Ca [mg/kg]	4 Sc [mg/kg]	5 Ti [mg/kg]	6 V [mg/kg]	7 Cr [mg/kg]	8 Mn [mg/kg]	9 Fe [mg/kg]	10 Co [mg/kg]	11 Ni [mg/kg]	12 Cu [mg/kg]	13 Zn [mg/kg]	14 As [mg/kg]	15 Se [mg/kg]	16 Sr [mg/kg]	17 Y [mg/kg]	18 Zr [mg/kg]	19 Nb [mg/kg]	20 Mo [mg/kg]	21 Ru [mg/kg]	22 Pd [mg/kg]	23 Ag [mg/kg]	24 Cd [mg/kg]	25 Sn [mg/kg]	26 Sb [mg/kg]	27 Te [mg/kg]	28 La [mg/kg]	29 Ce [mg/kg]	30 Pr [mg/kg]	31 Nd [mg/kg]	32 Sm [mg/kg]	33 Eu [mg/kg]	34 Gd [mg/kg]	35 Tb [mg/kg]	36 Dy [mg/kg]	37 Ho [mg/kg]	38 Er [mg/kg]	39 Tm [mg/kg]	40 Yb [mg/kg]	41 Lu [mg/kg]	42 Hf [mg/kg]	43 Ta [mg/kg]	44 W [mg/kg]	45 Pt [mg/kg]	46 Au [mg/kg]	47 Tl [mg/kg]	48 Pb [mg/kg]	49 Bi [mg/kg]	50 Th [mg/kg]	51 U [mg/kg]
Median, Bitumen #1	massive pyrobitumen seam, (n=14)	315.0	6.4000	281.000	0.4800	25.400	85.000	623.00	0.2290	5.900	1.000	0.350	9.00	2.840	3.80000	409.0000	23.60000	5.30000	0.0155	0.0082	0.0910	41.0000	0.0201	0.3700	39.0000	0.266	7.20000	58.00000	13.80000	102.0000	68.0000	22.30000	16.90000	87.0000	118.000	21.30000	60.0000	7.50000	46.0000	5.00000	0.5100	7.90000	1.2900	0.00145	296.0000	0.03100	5240.0000	1.55000	1798.00000	18870.00000
Mean, Bitumen #1	massive pyrobitumen seam, (n=14)	346.0	6.0000	382.000	0.7000	28.700	91.000	739.00	31.0000	23.100	1.560	0.440	75.00	3.100	3.80000	526.0000	21.60000	5.70000	0.0203	0.0082	0.1060	69.0000	0.0216	0.5100	42.0000	0.490	9.60000	79.00000	16.90000	112.0000	79.0000	21.30000	23.10000	117.0000	159.000	27.70000	75.0000	9.60000	59.0000	6.10000	0.4700	9.10000	1.6800	0.00330	429.0000	0.03200	5300.0000	1.69000	1853.00000	18810.00000
Minimum, Bitumen #1	massive pyrobitumen seam, (n=14)	246.0	2.3100	111.000	0.2910	7.600	58.000	197.00	0.1040	2.050	0.330	0.073	6.20	1.230	2.11000	110.0000	7.30000	2.65000	0.0091	0.0082	0.0176	0.0530	0.0122	0.2800	27.0000	0.168	3.10000	29.10000	6.80000	44.0000	25.3000	8.60000	4.50000	26.9000	28.900	5.00000	14.1000	1.94000	13.9000	1.65000	0.1750	3.70000	0.7000	0.00080	0.0910	0.01490	2894.0000	0.79000	873.00000	12920.00000
Maximum, Bitumen #1	massive pyrobitumen seam, (n=14)	528.0	9.2000	1251.000	1.2600	70.000	125.000	1288.00	249.0000	146.000	5.200	0.750	535.00	5.400	6.10000	1101.0000	35.00000	8.70000	0.0450	0.0082	0.2550	209.0000	0.0370	1.3100	68.0000	1.680	19.00000	163.00000	34.00000	215.0000	171.0000	33.00000	52.00000	270.0000	354.000	61.00000	163.0000	21.00000	127.0000	12.60000	0.8500	17.00000	4.7000	0.00940	1423.0000	0.06000	8920.0000	3.30000	2947.00000	26580.00000
Median, Bitumen #2	massive pyrobitumen seam, (n=14)	191.0	11.0000	128.000	0.4400	20.100	14.700	462.00	5.6000	118.000	58.000	0.310	37.00	2.110	9.30000	502.0000	87.00000	2.49000	0.3000	0.0097	0.0830	45.0000	0.0510	0.4100	13.7000	0.275	1.51000	11.80000	3.60000	31.0000	53.0000	24.40000	18.30000	105.0000	125.000	19.90000	51.0000	6.10000	38.0000	4.00000	1.2700	0.71000	4.5000	0.00244	389.0000	0.41000	3220.0000	0.14800	980.00000	14570.00000
Mean, Bitumen #2	massive pyrobitumen seam, (n=14)	217.0	10.8000	233.000	0.4800	27.300	15.700	1658.00	10.1000	110.000	72.000	0.580	62.00	2.050	8.70000	533.0000	109.00000	2.42000	0.4500	0.0097	0.0880	112.0000	0.0510	1.3500	19.2000	0.380	1.47000	11.90000	3.50000	31.0000	52.0000	24.90000	18.50000	104.0000	123.000	20.80000	54.0000	6.50000	40.0000	4.30000	1.4900	0.63000	5.0000	0.00244	959.0000	0.34000	2962.0000	0.20200	1036.00000	14140.00000
Minimum, Bitumen #2	massive pyrobitumen seam, (n=14)	145.0	6.1000	99.000	0.2280	12.300	10.900	160.00	1.3500	17.700	12.800	0.135	10.70	1.480	5.40000	163.0000	52.00000	1.45000	0.0710	0.0080	0.0288	0.3300	0.0510	0.2100	8.6000	0.145	0.78000	6.90000	2.39000	20.3000	33.0000	15.30000	10.70000	58.0000	68.000	10.50000	24.9000	3.10000	19.7000	1.68000	0.7500	0.27400	2.9600	0.00244	1.0100	0.08300	2335.0000	0.05400	630.00000	9490.00000
Maximum, Bitumen #2	massive pyrobitumen seam, (n=14)	325.0	15.2000	856.000	0.9900	88.000	26.900	8590.00	48.0000	217.000	205.000	2.500	239.00	2.580	11.20000	888.0000	235.00000	3.50000	1.3200	0.0113	0.1490	616.0000	0.0510	7.8000	62.0000	1.140	1.84000	15.20000	5.00000	44.0000	62.0000	31.00000	25.30000	139.0000	174.000	32.00000	87.0000	10.50000	64.0000	7.00000	2.7300	0.88000	9.3000	0.00244	4810.0000	0.66000	3420.0000	0.46000	1351.00000	17390.00000
Median, Bitumen #3	massive/nodular pyrobitumen seam, (n=14)	215.0	12.8000	855.000	1.2000	11.600	61.000	253.00	0.1430	3.200	0.420	0.044	7.10	1.490	3.40000	189.0000	24.00000	2.32000	0.0193	0.0076	0.0490	0.0450	0.0360	1.1600	20.6000	0.200	0.44000	7.90000	2.00000	14.8000	16.8000	3.80000	9.40000	37.0000	67.000	9.90000	24.8000	3.40000	22.3000	1.93000	0.5400	0.23000	3.2000	0.00208	0.1950	0.03800	4210.0000	0.17900	954.00000	18720.00000
Mean, Bitumen #3	massive/nodular pyrobitumen seam, (n=14)	213.0	14.6000	1448.000	1.7900	17.000	54.000	324.00	1.5100	73.000	0.550	0.139	7.30	1.520	8.00000	227.0000	35.00000	3.10000	0.0400	0.0071	0.0570	46.0000	0.0430	14.8000	21.0000	0.206	0.56000	7.90000	2.04000	15.5000	19.1000	3.70000	9.60000	39.0000	72.000	11.90000	31.0000	3.90000	25.5000	2.23000	0.7600	0.36000	3.2000	0.00208	287.0000	0.07300	4200.0000	0.19600	1016.00000	18670.00000
Minimum, Bitumen #3	massive/nodular pyrobitumen seam, (n=14)	104.0	5.9000	113.000	0.2490	2.480	27.700	127.00	0.0080	0.155	0.067	0.028	5.00	0.880	2.28000	99.0000	13.60000	1.25000	0.0182	0.0047	0.0330	0.0044	0.0085	0.5000	11.4000	0.117	0.21100	3.90000	0.89000	7.3000	11.7000	1.88000	4.70000	21.3000	32.000	5.90000	14.8000	1.86000	10.9000	0.89000	0.3300	0.09200	1.3700	0.00095	0.0940	0.01330	2467.0000	0.06500	651.00000	10070.00000
Maximum, Bitumen #3	massive/nodular pyrobitumen seam, (n=14)	351.0	27.9000	4810.000	6.4000	58.000	71.000	904.00	13.8000	836.000	1.810	0.320	10.60	2.490	54.00000	445.0000	115.00000	8.70000	0.0810	0.0090	0.1150	400.0000	0.0980	163.0000	32.0000	0.350	1.65000	13.10000	3.30000	26.9000	31.0000	5.30000	15.90000	67.0000	135.000	24.60000	60.0000	7.20000	49.0000	4.40000	2.5900	0.88000	5.6000	0.00320	3090.0000	0.48000	5970.0000	0.52000	1880.00000	27900.00000
Median, Bitumen #4	nodular pyrobitumen seam, (n=12)	433.0	19.1000	371.000	3.7000	62.000	86.000	1055.00	0.5600	5.600	2.670	0.420	19.10	4.100	28.10000	762.0000	70.00000	5.30000	0.0460	0.0098	0.1830	29.2000	0.0480	2.7500	102.0000	2.020	3.30000	20.80000	5.10000	42.0000	66.0000	15.30000	34.00000	147.0000	271.000	42.00000	109.0000	13.90000	91.0000	8.20000	1.3600	1.33000	6.5000	0.00650	470.0000	0.11400	16500.0000	8.40000	3280.00000	44200.00000
Mean, Bitumen #4	nodular pyrobitumen seam, (n=12)	565.0	37.0000	665.000	4.0000	64.000	106.000	1202.00	1.3700	10.500	16.200	0.560	65.00	5.100	65.00000	990.0000	99.00000	8.90000	0.4600	0.0096	0.2440	530.0000	0.1150	3.2000	159.0000	3.600	10.90000	47.00000	9.70000	71.0000	101.0000	24.30000	47.00000	205.0000	339.000	54.00000	141.0000	17.80000	116.0000	10.30000	1.9800	2.87000	12.0000	0.00750	4700.0000	0.20600	25430.0000	10.50000	4940.00000	67800.00000
Minimum, Bitumen #4	nodular pyrobitumen seam, (n=12)	171.0	9.0000	150.000	1.6100	26.000	39.000	433.00	0.1100	1.100	0.570	0.142	12.50	1.040	5.80000	142.0000	10.10000	1.54000	0.0115	0.0049	0.0490	0.0610	0.0240	0.4900	52.0000	0.200	0.71000	8.70000	2.34000	16.6000	19.2000	5.60000	7.90000	28.7000	56.000	9.30000	26.8000	3.50000	26.2000	1.91000	0.2040	0.26700	3.0000	0.00520	0.5200	0.06800	9910.0000	2.38000	795.00000	19520.00000
Maximum, Bitumen #4	nodular pyrobitumen seam, (n=12)	1520.0	135.0000	2762.000	7.9000	129.000	223.000	2201.00	7.4000	48.000	91.000	1.370	441.00	14.700	383.00000	2730.0000	260.00000	26.20000	3.3000	0.0142	0.6500	3580.0000	0.4300	8.2000	600.0000	12.700	72.00000	255.00000	44.00000	282.0000	317.0000	69.00000	134.00000	548.0000	930.000	142.00000	348.0000	43.00000	280.0000	28.10000	5.2000	8.70000	44.0000	0.01070	29600.0000	0.79000	97200.0000	31.00000	13150.00000	200400.00000
Median, Bitumen #5	massive pyrobitumen seam, (n=12)	270.0	8.0000	78.000	0.3400	4.900	53.000	99.00	0.0450	3.700	0.490	0.167	7.50	2.370	2.80000	274.0000	40.00000	2.21000	0.0279	0.0155	0.0610	1.8700	0.0210	0.2720	11.5000	0.510	0.16900	5.20000	2.85000	32.0000	57.0000	10.00000	15.40000	86.0000	112.000	17.30000	44.0000	5.30000	35.0000	2.95000	0.9900	3.60000	2.4700	0.00290	4.4000	0.03800	6870.0000	0.93000	1124.00000	18430.00000
Mean, Bitumen #5	massive pyrobitumen seam, (n=12)	287.0	8.7000	121.000	0.4800	8.000	52.000	299.00	0.0610	4.100	3.500	0.390	9.10	2.510	7.80000	755.0000	57.00000	2.84000	0.0380	0.0155	0.1290	25.6000	0.0198	0.2820	13.1000	0.770	1.12000	10.20000	3.60000	38.0000	65.0000	11.20000	23.30000	129.0000	168.000	29.80000	82.0000	9.90000	60.0000	6.10000	1.2300	4.40000	3.2000	0.00290	224.0000	0.06800	8210.0000	1.52000	1222.00000	18430.00000
Minimum, Bitumen #5	massive pyrobitumen seam, (n=12)	126.0	4.2000	23.000	0.0720	2.090	26.700	50.00	0.0086	0.245	0.052	0.063	6.70	1.190	0.81000	133.0000	20.80000	0.52000	0.0093	0.0155	0.0197	0.0330	0.0071	0.1480	4.7000	0.154	0.06700	2.68000	1.69000	20.7000	34.0000	5.50000	9.20000	52.0000	55.000	8.10000	20.6000	2.45000	16.4000	1.21000	0.6300	0.91000	1.4700	0.00170	0.6300	0.01840	1577.0000	0.51000	444.00000	6980.00000
Maximum, Bitumen #5	massive pyrobitumen seam, (n=12)	740.0	15.4000	572.000	1.5300	25.200	89.000	1880.00	0.2120	13.600	34.000	1.860	14.80	5.100	51.00000	5260.0000	194.00000	6.20000	0.0990	0.0155	0.7800	204.0000	0.0310	0.4100	25.0000	2.830	7.40000	50.00000	11.70000	90.0000	144.0000	24.00000	110.00000	595.0000	881.000	178.00000	500.0000	60.00000	353.0000	40.00000	3.1000	10.50000	6.0000	0.00410	1686.0000	0.21100	25610.0000	4.30000	2289.00000	30200.00000
Median, Average		270.0	9.7000	230.000	0.6900	18.600	61.000	416.00	0.2270	5.200	1.010	0.320	10.60	2.210	5.00000	372.0000	40.00000	3.00000	0.0450	0.0086	0.0640	9.6000	0.0260	0.6100	21.9000	0.330	1.30000	10.90000	3.20000	32.0000	51.0000	10.80000	15.90000	83.0000	116.000	17.80000	48.0000	6.20000	39.0000	3.40000	0.9100	1.23000	3.7000	0.00282	15.6000	0.05700	4390.0000	0.85000	1179.00000	19390.00000
Mean, Average		324.0	15.7000	618.000	1.5500	28.100	64.000	783.00	7.9000	43.000	16.600	0.450	39.00	2.810	19.10000	600.0000	63.00000	4.50000	0.2490	0.0093	0.1240	159.0000	0.0530	4.6000	51.0000	0.990	4.40000	28.80000	6.60000	50.0000	62.0000	15.90000	24.00000	117.0000	171.000	28.60000	76.0000	9.40000	60.0000	5.70000	1.1900	3.20000	5.1000	0.00400	1306.0000	0.13600	9410.0000	2.85000	2002.00000	27930.00000
Mean, 1 sigma error		34.0	1.1400	47.000	0.1100	2.240	6.100	70.00	0.0140	0.670	0.130	0.030	3.10	0.480	0.32000	42.0000	4.30000	0.25500	0.0115	0.0035	0.0023	0.5500	0.0120	0.2800	1.9900	0.079	0.18500	0.98000	0.35000	3.5000	4.9000	1.33000	1.81000	8.9000	12.700	1.97000	5.8000	0.71000	4.3000	0.44000	0.0950	0.20000	0.3200	0.00190	0.5500	0.00680	280.0000	0.06600	157.00000	1108.00000
Mean, Limits of detection		4.7	0.0172	0.089	0.0135	0.206	0.038	1.05	0.0074	0.067	0.045	0.037	0.78	0.105	0.00142	0.0016	0.00285	0.00153	0.0054	0.0077	0.0042	0.0039	0.0206	0.0107	0.0075	0.039	0.00106	0.00094	0.00085	0.0107	0.0064	0.00205	0.00089	0.0042	0.003	0.00095	0.0037	0.00111	0.0073	0.00086	0.0046	0.00106	0.0037	0.00520	0.0084	0.00139	0.0139	0.00128	0.00139	0.00124