Fluid Inclusion Microscope

What are fluid inclusions?

Fluid Inclusions are microscopic vacuoles in minerals that contain geo-fluids (solids, gases, brines, petroleum and mixtures there of). They are a microscopic record of the Pressure, Volume, Temperature and Composition of the fluids that were present when the inclusions were formed. By carefully studying fluid inclusions on specially designed microscopes and heating and freezing them, invaluable geochemical and geological information can be obtained. This data is often otherwise unobtainable. Image courtesy of Dr Gordon Macleod (http://www.gmac-geochem.com/)

Microthermometry Facilities

The school has two state of the art fluid inclusion microscope systems.

Fluid Inc System

The first system has been specially adapted to allow work to be conducted on micron scale inclusions hosted in digenetic cements. The microscope used is a Nikon BX51, with x10 oculars, x5, x10, x40 and x50 long working distance lenses. The microscope also has an inbuilt magnification system of up to x2, giving a maximum magnification of x1000. The scope is fully equipped with transmitted white light and incidental UV light facilities. Attached to the system is a SPOT INSIGHT digital camera, which transmits live video to a PC attached to the system. Images can be saved to the PC and manipulated for reports and presentations. Attached to this microscope is a modified USGS heating and freezing stage, designed by Fluid Inc. USA. This allows microthermometry to be performed on inclusions, by passing heated air, or heated nitrogen over the sample, inclusions can be heated to 700 °C. By passing nitrogen gas passed through liquid nitrogen over the sample, inclusions can be cooled to -190 °C.

Linkam system

The second system is a Leitz Metallux 3 microscope, with x10 oculars, x5, x10 , x20 x40 and x60 long working distance lenses. The microscope also has an inbuilt magnification system of up to x3, giving a maximum magnification of x1800. The scope is fully equipped with transmitted white light and incidental UV light facilities, UV light allowing petroleum inclusions to be identified. Attached to this microscope is a LINKAM heating and freezing stage. This allows microthermometry to be performed on inclusions, by passing heating the sample on a conductive block, inclusions can be heated to 600 °C. By passing liquid nitrogen over the sample, inclusions can be cooled to -190 °C. The LINKAM system is microprocessor controlled and heating and freezing rates can be controlled very accurately.