Class Specifications - G.40
Senior Petrological Technologist - 8662
Petrological Technologist - 8663

May, 1980

Series Concept

Petrological Technologists perform, or supervise the performance, or procedures required to produce workable thin-section, probe section, or other polished section samples of petrologic specimens; and perform other related duties as required.

Incumbents typically perpare samples in accordance with the type of investigation to be performed, determine whether special impregnating materials and procedures are required and what cutting, grinding, polishing and mounting techniques are to be used; utilize special techniques for preparation of unconsolidated and fragile samples for impregnation by the removal of salt water and other inhibiting substances without disturbing the physical structure of the sample; identify the need for and deve1op new techniques for the preparation of samples and electromicroprobe samples, depending on the nature of the sample and purpose for which the section is intended; prepare slide samples for microscopic examination by adopting preparation techniques depending upon investigator's interest in petrofabrics, mineralogy, micropaleontology or mineral alteration processes; select mounting material of proper optical properties; determine approprate thickness of a section for the nature of the investigation, grind and polish the section to the required thickness; and determine the finished sample thickness by optical interferometry.

Class Concepts

Senior Petrological Technologist

Under general supervision, incumbents are assigned responsibility for the operation of a petrological preparation laboratory.

Incumbents at this level typically maintain and select all laboratory equipment; design and fabricate equipment not available commerically; instruct graduate students and visitors in laboratory procedures; and supervise at least one Petrological Technologtst.

Petrological Technologist

Under supervision incumbents perform the full range of duties described in the series concept in the preparation of samples for examination.

Minimum Qualifications

Incumbents for positions included in the Petrological Technologist series are expected to have (1) the ability to prepare thin and polished sections of soft and hard rocks, (2) familiarity with impregnation, photomicrography, and microscope techniques, and (3) proficiency in general geologic laboratory techniques; and skills, knowledges and abilities essential to the successful performance of the duties assigned to the position.