Applied mineral exploration methods, hydrothermal fluids, baro-acoustic decrepitation, CO2 rich fluids
Viewpoints:

How CO2 inclusions form from aqueous fluids

Understanding heterogeneous fluids : why gold is not transported in CO2 fluids

Gold-quartz deposits form from aqueous heterogeneous fluids: NOT from CO2 fluids

Inclusion shapes can prove heterogeneous FI trapping

Disproportional FI trapping from heterogeneous fluids explains gas-dominant systems

A discussion of H2 analysis by mass spectrometry

A mechanism to form H2 in the MS ioniser during analyses


News:

Sangan skarn Fe deposits, Iran

New model 205 decreptiometer

Studies of 6 Pegmatite deposits

A study of the Gejiu tin mine, China


Exploration using palaeo-hydrothermal fluids

Using opaque minerals to understand ore fluids


Understanding baro-acoustic decrepitation.

An introduction to fluid inclusions and mineral exploration applications.



 Interesting Conferences:


AGCC expo, Adelaide, Aust. Oct. 14-18 2018

-----2019-----

ECROFI, June 24-26, Budapest, Hungary

AOGS, Singapore, 28 Jul-2 Aug 2019

SGA, Glasgow Scotland, Aug. 27-30 2019


Comprehensive Geology Conference Calendar


Nevada deposits, including jasperoids

CO2 in Nevada


The Au deposits in Nevada are young and in contrast with typical archaen deposits they lack any significant  CO2 in their fluid inclusions. The samples from these 3 deposits, as well as jasperoid style deposits in Nevada, all lack any significant low temperature CO2 decrepitation peak.

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Jasperoids - Nevada  1


There are numerous jasperoid outcrops in eastern Nevada, most of which are simply surficial silicification, but some of them are gold mineralized and formed from hydrothermal fluids. Decrepitation can be used as a screening procedure to discriminate between these two types of jasperoid.

The Cranovitch and Jaydee pits are small gold deposits in the Robinson district. The Purple vein deposit, in the Carlin district, was an exploration prospect when this drillcore was sampled in 1990. See the adjacent figure for some surface results at Purple Vein. An example of typical background jasperoid from near the Easy Junior mine shows the contrast between the mineralized and barren jasperoids.

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Jasperoids - Nevada  2


Within known deposits, most but not all samples decrepitate. Two samples from the Purple Vein deposit show the range of decrepitation which can occur, sometimes over quite small distances. Some 50 samples of background jasperoids were collected in eastern Nevada and almost all of these had no decrepitation. The North Easy ridge sample is one of the few from outside of a known mine which did decrepitate. Samples from close to but not actually within mines also show no decrepitation activity indicating that there is almost no detectable anomalous aureole outside of the mineralized zone itself. Although decrepitation does seem capable of discriminating between potentially mineralized and barren jasperoids, a high sampling density is required to compensate for the lack of aureoles around the mineralized zones.
 

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