Editor’s desk This 200th issue of Preview features an article by James Grove and his colleagues on the widespread impact that historical gold mining has had on Victoria’s riverine landscapes. It is no exaggeration to say that some of these landscapes have been completely reworked. The Victorian population reacted in horror in the late 19th century as fertile floodplains were destroyed over what is estimated to be a quarter of the length of Victorian rivers. In upstream reaches the stratigraphic column was inverted, in downstream reaches flooding dumped overwhelming volumes of sludge. The physical changes wrought in these landscapes have significant ramifications for the movement of water through the landscape. It is obvious that rivers are still adjusting, but the impact on groundwater systems is unknown. Needless to say, the design and interpretation of near surface geophysical surveys in these regions would be a challenge, and the design and interpretation of near surface geochemical surveys an absolute nightmare! It is interesting to note, however, that collective memories are short and many tree-changers would be completely unaware of the history of their prized bush blocks. I have found such blissful ignorance to be the norm amongst tree-changers living in former tin mining regions in far north Queensland. This 200th issue of Preview also brings us a kaleidoscope of news and commentary from around Australia and around the world. Ken Witherly summaries the latest report on Exploration Trends and Developments, and Dick Irvine reviews Norm Paterson’s book on Canadian mining geophysics. We have reports on a new national geophysical survey in Sierra Leone, and on new surveys, geophysical data and products from the Geological Surveys of Western Australia, South Australia and Tasmania. David Denham (Canberra observed) looks back at the Federal election that was. Michael Asten (Education matters) reminds students about the Frank Arnott Award, reports on the mentoring of early-career professionals in Victoria, and brings us news about the SEG Honorary Lecturer and the recently announced SEG Distinguished Instructor Short Course. Terry Harvey (Minerals geophysics) returns to the “real”world of potential field modelling. Nobody bit after his last column on a world without mining, but I note that the piece is a popular download! Mick Micenko (Seismic window) revisits pitfalls in seismic processing. Tim Keeping (Data trends) takes a look at open data formats for a post DOS world. And, our new webmaster, Ian James, reviews the performance of the ASEG’s website (Webwaves). He lists the countries in which the ASEG doesn’t have a digital presence – it is surprising to discover that there are only thirteen – so, if you are visiting Bhutan or Burundi, Svalbard or Turkmenistan, Ian would like to have a word with you!! Enjoy! Lisa Worrall Preview Editor previeweditor@aseg.org.au  Editor’s desk 1 PREVIEW JUNE 2019