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Pseudovitrinite Working Group

February 27, 2020

Filled under Com II

Status active

established

Conveners

Dr. Lila W. Gurba

Previous convener: Lila Gurba and Colin R. Ward (1996-2008)

Members

Background

Pseudovitrinite in high-volatile bituminous coal of the Gunnedah Basin, New South Wales, Australia (Photo L.W. Gurba). Width of field 22 um, reflected light, oil immersion. Note small grains of pyrite in some slit openings. (From Gurba and Ward, 1998).

The Pseudovitrinite Working Group is concerned with investigating the precise nature and properties of the material referred to as pseudovitrinite, and with the need for its recognition in rank studies and coal utilization. The term pseudovitrinite was introduced by Benedict, Thompson, Shigo & Aikman (1968) to describe vitrinite-like material in Appalachian coals which displays higher than collotelinite (former telocollinite) reflectance, slitted structure, remnant cellular structure and an absence of pyrite inclusions. During the coking process pseudovitrinite was regarded as poorly reactive.

According to the ICCP System (1994), related terms for collotelinite include:

‘Vitrinite A’ (Brown et al., 1964), and

Pseudovitrinite (Benedict et al., 1968).

According to ICCP System 1994, the so-called pseudovitrinite is derived from similar plant material as collotelinite. Its reflectance is somewhat higher than that of telinite and collotelinite in the same coal. It may show some cell structure and typically has small slits (‘comma-slits’) and serrated fragment margins.

The reflectance of collotelinite (ICCP System 1994) is used widely as an index of the rank of coal, and also of organic matter in sediments. This implies that “so-called pseudovitrinite” (if present) should be included in routine vitrinite reflectance determinations. Work on the high-volatile coals in the Gunnedah Basin, Australia (Gurba and Ward, 1996, 1998, 1999) suggests for example that, if followed, this will result in abnormally high reflectance values in coals where the pseudovitrinite material is abundant.

However, it should be noted that Pseudovitrinite is not classified as a maceral in accordance to the nomenclature enclosed in the ICCP System 1994 and published by ICCP (1998). It is not enclosed in the ISO 7404-1:2016.

Objectives of the Pseudovitrinite Working Group 1996-2004

The objectives of the Pseudovitrinite Working Group, established in 1996 [with input from Marlies Teichmuller, Harold Smith, Neely Bostick, Alan Davis, Wolfgang Kalkreuth, and others] and reconfirmed at the ICCP’s Wellington meeting in 1997 are to:

Confirm existing and to further develop an acceptable series of defining criteria for this material, so that it can be distinguished in some way from other forms of vitrinite;
Evaluate the significance of the material in coal rank studies.
Determine of the in situ chemistry of this and other macerals of the vitrinite group;
Further study of the origin of pseudovitrinite.
Evaluate the properties and behaviour of the material in industrial applications.
Determination of its technological properties (optional).
A critical re-appraisal of the use of the name “pseudovitrinite” in general, and in publications in particular.

Complementary research suggested included:

Round Robin Exercise: identification of pseudovitrinite and the measurement of the reflectance of different vitrinite macerals;
In-situ chemistry of vitrinite and other macerals using electron microprobe);
Etching techniques;
Micro hardness.

A letter from L. Benedict, strongly supporting the working groups program for the study of pseudovitrinite was received in February 1997.

Identification Criteria of Pseudovitrinite

The original definition of pseudovitrinite by Benedict et al. (1968) set out the following criteria for its distinguishing from other vitrinites:

Primary importance

Greater reflectance from polished surfaces in oil
Slitted structures
Remnant cellular structures

Secondary importance:

Uncommon fracture patterns, dendritic or brecciated fractures, serrated fractures on particles edges, wedge-shaped fractures, relief fractures,
Higher relief in polished section
Paucity or absence of pyritic inclusions

Deliverables

A bibliography of published papers, unpublished open file reports, abstracts from symposia, and unpublished data:

Status: 1^st Draft completed (August 2019). It will be available from the ICCP website.

Atlas of pseudovitrinite microphotographs:

Status: completed; it will be uploaded to the ICCP website.

Scientific Publications:

(a) ICCP Pseudovitrinite Handbook –

Status: 1^st draft finalized (L. Gurba, J. Kus and M. Misz-Kennan); it will be circulated to the PSV WkGr members for further input and review. It is planned to submit for publication in the International Journal of Coal Geology by the end of 2019.

(b) Pseudovitrinite – An appraisal of the work carried-out by the International Committee for Coal and Organic Petrology (ICCP). Lila W. Gurba, A. Harold V. Smith, Barbara Kwiecinska and others.

Status: the 1^st draft completed. It will be presented at the ICCP meeting in September 2019. It is planned to submit for publication in the International Journal of Coal Geology by the end of 2019.

References

Benedict, L.G., Thompson, R.R., Shigo, J.J. and Aikman, R.P., 1968. Pseudovitrinite in Appalachian coking coals. Fuel, 47, 125-143.

Gurba, L. W. & Ward, 1966. Proposal for a Pseudovitrinite Working Group. Presented at ICCP meeting in Heerlen, Holland, 1996. This report includes extensive background notes on the subject.

Gurba, L. W., & Ward, C. R. (1998). Vitrinite reflectance anomalies in the high-volatile bituminous coals of the Gunnedah Basin, New South Wales, Australia. International Journal of Coal Geology, 36(1-2), 111-140. doi:10.1016/S0166-5162(97)00033-5

Gurba, L. W., & Ward, C. R. (1999). The nature of pseudovitrinite in Gunnedah Basin coals, NSW, Australia. Romanian Journal of Mineralogy, 79(1), 7-8.

International Committee for Coal Petrology (ICCP), 1998. The new vitrinite classification (ICCP System 1994). Fuel 77 (5), 349–358.

Smith, A.H.V, 1980. An appraisal of the work carried out on pseudovitrinite by the ICCP and the direction of future work, unpublished.

Activities

1966-1980 Activities:

Investigation of pseudovitrinite by ICCP was begun in 1966, but due to a certain amount of controversy and international disagreement about defining criteria, activity ceased around 1971. A historical account of the work carried out by the ICCP during this period was reported by A.H.V. Smith (1980) in a report entitled An appraisal of the work carried out on pseudovitrinite by the ICCP and the direction of future work. No further work was conducted on the material by ICCP, however, for 15 years after that time.

1996-2008 Activities:

Interest in pseudovitrinite was rekindled in 1996 at the ICCP meeting in Heerlen, Holland

[https://www.iccop.org/documents/iccp-news-14.pdf/], following a report presented by Gurba and Ward (1996). A new Pseudovitrinite Working Group was formed at that meeting, with responsibility to investigate the nature and properties of the material and develop appropriate recognition criteria. A total of twenty two members were involved between 1996-2003 in the activities of the group.

2012-2020

The Pseudovitrinite Working Group was reactivated in 2012 with the main goal to deliver a White Paper on Pseudovitrinite, headed by Lila Gurba, Jolanta Kus, Magdalena Misz-Kennan and other members of the Working Group [https://www.iccop.org/documents/iccp-news-no-63-2.pdf/].

2012 Activities: