Applied Mineral Exploration
Discussion and research relevant to mineral
exploration. NT DME Tanami decrepitation tests
2/3/02
36 samples from the Tanami region were analysed by decrepitation to compare the results with previous heating stage results from the same samples carried out by the N.T. Geological Survey.
The samples were analysed without knowledge of their locations or geology or fluid inclusion data and this report is a summary of the raw data. Partial geological and location information was later provided by the geologist and a subsequent interpretation compares the decrepitation data with microthermometric and location information.
A geological summary of the tanami area incorporating the decrepitation and fluid inclusion data was published by the N.T. geological survey.
The decrepitation intensity of the samples varied widely and so these results have been grouped by decrepitation magnitude in the following plots. The presence of CO2 is indicated by decrepitation up to 300 C (BURLINSON, K. (1988) - An instrument for fluid inclusion decrepitometry and examples of its application. Bull. Mineral. 111, 3-4, 267-278. ; MAVROGENES, J.A., BODNAR, R.J., GRANEY, J.R., McQUEEN, K.G. and BURLINSON, Kingsley (1995) - Comparison of decrepitation, microthermometric and compositional characteristics of fluid inclusions in barren and auriferous mesothermal quartz veins of the Cowra Creek gold district, New South Wales, Australia. J. Geochem. Explor. 54, 167-176. ). In each plot the CO2 containing samples are listed first. To convert the analytical run numbers in the plots to geological sample numbers refer to the cross-tabulations.
7 samples were analysed in duplicate for quality control - see the DUPLICATES information.
Most samples used were 0.5 grams, but 3
samples
were re-analysed using 1.5 gram samples. In these plots the larger
sample
results are presented in these cases. Many samples contained traces of
carbonate, which interferes with the results. All samples were tested
during
preparation and washed with HCl to dissolve carbonates where
necessary.
Samples which were acid washed are labeled as such in the raw data
file
titles. Where uncleaned and cleaned results from the same sample were
obtained,
these plots only show the cleaned sample results.
Run Sample
H1558 11487
H1559 11490
H1560 11053
H1562 11117
H1584 11872
H1589 11132
H1592 11112
Run Sample
H1550 11160
H1593 11358
H1594 11847
Run Sample
H1554 11161
H1572 11656
H1578 11762
H1580 11858
Run Sample
H1568 11498
H1581 11859
H1582 11862
H1583 11869
H1588 11079
Run Sample
H1556 11355
H1563 11357
H1573 11740
H1586 11756
H1591 11514
Run Sample
H1551 11426
H1565 11359
H1567 11363
H1570 11524 ***
Possibly misnumbered sample - location details uncertain**
H1575 11418
H1576 11448
H1587 11757
Run Sample
H1555 11221
H1557 11425 ***
Possibly misnumbered sample - location details uncertain**
H1571 11526
H1574 11417
H1577 11451
Sample numbering error
When the geologist concerned provided sample location information, it became clear there had been a numbering problem. He claims a sample numbered 11424 was analysed, but no such sample was received at the laboratory. The geologist claims that sample 11424 is actually sample 11524 mis-numbered. But his sample descriptions of 11524 and 11424 differ, so this cannot be correct. Because the geologist declined to provide any sample information for 13 of the samples the data set is not closed and it is impossible to deduce which sample is the one he claims as 11424 with certainty. It is likely that the undescribed sample 11425 may actually be 11424, but the geologist refuses to resolve this discrepancy.Consequently I consider that the results for
samples
11524 and 11425 and 11424 in this report and in the geological
information
the geologist concerned has published elsewhere must be
considered
as unreliable and incorrect.
Complete run-sample cross reference in RUN order
Complete run-sample cross reference in SAMPLE order
Field sample descriptions and sample locations