QemSCAN is a scanning electron microscope (SEM) system, initially designed to support the mining industry by providing rapid automated quantitative mineral analyses. The system is based upon Carl Zeiss SEMs fitted with up to four light-element energy dispersive X-ray spectrometers. Representative subsamples are mounted into either resin or wax blocks and polished prior to analysis, or can be mounted onto carbon tape. During analysis, X-ray spectra are collected at a user-defined pixel spacing and are acquired very rapidly ( c. 10 ms per pixel). The measured spectra are automatically compared against a database of known spectra and a mineral or phase name is assigned to each measurement point by the QemSCAN computer software programs. In this way the near-surface qualitative elemental composition of each particle is systematically mapped, assigned to a mineral name or chemical compound/species, and digital pixel maps of each particle are created. Depending upon a range of parameters, including the particle size and the user-defined pixel spacing (which can vary between 0.20 μm and 25 μm), approximately 1000 particles, each 1–10 μm in size, can be measured per hour using a 1 μm pixel spacing. In addition to providing a qualitative elemental analysis and mineralogical or phase assignment for each particle, data relating to particle size, shape and calculated specific density are also generated. In this study, the potential application of this automated SEM system in forensic geoscience was evaluated by the analysis of: (1) a series of soil samples, and (2) a series of dust samples from an industrial complex. In both case studies, the mine-ralogy/phase composition of each sample analysed was found to be distinctive. In addition, textural data for the soil samples and particle shape data for the dust samples show that they can be clearly distinguished. Automated SEM using QemSCAN has clear potential application in the analysis of soil or other trace evidence in forensic case work.

One of the most important outcrops of uppermost Cretaceous (Campanian–Maastrichtian) sedimentary rocks in the southern high latitudes occurs within the James Ross Island group, northeastern Antarctic Peninsula. These rocks comprise a 1500–2000 m thick sequence of predominantly shallow marine clastic sediments that were deposited within a retro-arc basin. They are virtually undeformed and have yielded prolific invertebrate and vertebrate faunas, and a wide range of plant taxa. Campanian–Maastrichtian strata are contained within two component formations of the Upper Cretaceous-lower Tertiary Marambio Group. The lower Santa Marta Formation is approximately 1100m thick and has three constituent members. Ammonites within the Santa Marta Formation indicate an early to late Campanian age assignment. Dinoflagellates suggest that the lower levels of the formation may range into the Santonian Stage. In the northern James Ross Island to Vega Island region there is a conformable transition into the overlying López de Bertodano Formation. Here the basal Cape Lamb Member is unconformably overlain by the Sandwich Bluff Member. Although there are some lithological and fauna1 discrepancies, which are attributed to marked lateral facies changes across the basin, it is believed that the Cape Lamb Member can be correlated with the lower to middle regions of the 1200 m thick sequence of undifferentiated López de Bertodano Formation lithologies exposed on Seymour Island. Molluscan data indicate a late Campanian–Palaeocene age range for this upper formation. Dinoflagellates again suggest that the lowest beds may be slightly older. The correlation presented provides the basis for a formal subdivision of the Campanian and Maastrichtian stages in the southern high latitudes. It has also revealed two major basin shallowing events (in the late Campanian–early Maastrichtian and latest Maastrichtian, respectively) and the existence of a major fault/fault zone across southeastern James Ross Island. The improved temporal framework will aid late Cretaceous palaeoclimatic and palaeobiological studies in Antarctica.