Planetary science and exploration in the deep subsurface: results from the MINAR Program, Boulby Mine, UK

The subsurface exploration of other planetary bodies can be used to unravel their geological history and assess their habitability. On Mars in particular, present-day habitable conditions may be restricted to the subsurface. Using a deep subsurface mine, we carried out a program of extraterrestrial analog research – MINe Analog Research (MINAR). MINAR aims to carry out the scientific study of the deep subsurface and test instrumentation designed for planetary surface exploration by investigating deep subsurface geology, whilst establishing the potential this technology has to be transferred into the mining industry. An integrated multi-instrument suite was used to investigate samples of representative evaporite minerals from a subsurface Permian evaporite sequence, in particular to assess mineral and elemental variations which provide small-scale regions of enhanced habitability. The instruments used were the Panoramic Camera emulator, Close-Up Imager, Raman spectrometer, Small Planetary Linear Impulse Tool, Ultrasonic drill and handheld X-ray diffraction (XRD). We present science results from the analog research and show that these instruments can be used to investigate in situ the geological context and mineralogical variations of a deep subsurface environment, and thus habitability, from millimetre to metre scales. We also show that these instruments are complementary. For example, the identification of primary evaporite minerals such as NaCl and KCl, which are difficult to detect by portable Raman spectrometers, can be accomplished with XRD. By contrast, Raman is highly effective at locating and detecting mineral inclusions in primary evaporite minerals. MINAR demonstrates the effective use of a deep subsurface environment for planetary instrument development, understanding the habitability of extreme deep subsurface environments on Earth and other planetary bodies, and advancing the use of space technology in economic mining

The sedimentology and depositional environment of the Beatrix Reef: Witwatersrand supergroup.

A Dissertation Submitted to the Faculty of Science University of the Witwatersrand, Johannesburg for the Degree of Master of Science.Beatrix Mine is located 35 km south of the city of Welkom in the Welkom Goldfield and as such forms the most southerly of the Witwatersrand-type gold mines. The Beatrix Reef overlies an angular unconformity at the base of the Turffontein Subgroup, Central Rand Group Significant, southerly truncation of over 600m of the Johannesburg Subgroup, and the lower formations of the Turffontein Subgroup, occur at this unconformity in the Beatrix area.. characteristics of the Beatrix Reef conglomerates such as the morphology, sorting and packing of clasts, and the arrangement. of the sediments in various sedimentary structures and facies/ sequences, suggest deposition within a braided fluvial environment on a coarse-grained braid-delta. Sedimentation occurred after the fluvial degradation of previously deposited units, and culminated in a marine/ lacustrine transgression. Low aggradation rates led to significant reworking and concentration of placer materials in a depositional model probably typical of ventral Rand Group placer formation. Heavy minerals (and gold) are concentrated in response to hydraulic conditions and show a close association with large and small scale sedimentary features. Transport directions deduced from the sedimentary structures suggest a north to south dispersal of sediment down the braid plain. Sedimentary structures in the finer rained units at the base of the Eldorado Formation are indicative of tidal influences and document the marine transgression as the culmination of the degradational events. The lithologys sedimentary structures and facies sequences of the coarser grained units of the Eldorado Formation well as the overall coarsening upward of these lithologies indicate sedimentation in a braided , fluvial system, on an alluvial fan prograding across the preyiously deposited units" Sedimentary ~tructures and lithologic variations confirm a continued north to south dispersal pattern. In the area south of the Sand over the period of fluvial degradation and transgression after the formation of the Beatrix: Reef was followed by more rapidly aggreding fluvial progradation due to a major change in base level in response to compressional tectonics and uplift along the Western Margin Structure. Only in post-Central Rand Group times did relaxation and extensional tectonics result in the outpourings of the Ventersdorp .supergroup lavas and the cessation of active Witwatersrand Supergroup sedimentation.Andrew Chakane 201

Planetary science and exploration in the deep subsurface:results from the MINAR Program, Boulby Mine, UK

The subsurface exploration of other planetary bodies can be used to unravel their geological history and assess their habitability. On Mars in particular, present-day habitable conditions may be restricted to the subsurface. Using a deep subsurface mine, we carried out a program of extraterrestrial analog research – MINe Analog Research (MINAR). MINAR aims to carry out the scientific study of the deep subsurface and test instrumentation designed for planetary surface exploration by investigating deep subsurface geology, whilst establishing the potential this technology has to be transferred into the mining industry. An integrated multi-instrument suite was used to investigate samples of representative evaporite minerals from a subsurface Permian evaporite sequence, in particular to assess mineral and elemental variations which provide small-scale regions of enhanced habitability. The instruments used were the Panoramic Camera emulator, Close-Up Imager, Raman spectrometer, Small Planetary Linear Impulse Tool, Ultrasonic drill and handheld X-ray diffraction (XRD). We present science results from the analog research and show that these instruments can be used to investigate in situ the geological context and mineralogical variations of a deep subsurface environment, and thus habitability, from millimetre to metre scales. We also show that these instruments are complementary. For example, the identification of primary evaporite minerals such as NaCl and KCl, which are difficult to detect by portable Raman spectrometers, can be accomplished with XRD. By contrast, Raman is highly effective at locating and detecting mineral inclusions in primary evaporite minerals. MINAR demonstrates the effective use of a deep subsurface environment for planetary instrument development, understanding the habitability of extreme deep subsurface environments on Earth and other planetary bodies, and advancing the use of space technology in economic mining.</p