Bulk sampling of coarse clastic sediments for particle-size analysis

A guide is provided to the minimum sample masses required to obtain reproducible measures of the particle-size distributions of coarse sediments. This is based on studies of the actual particle-size distributions of a range of clastic deposits. Procedures are given to enable representative bulk samples of tills, fluvial gravels and beach gravels to be taken.     

The Romanian earthquake of August 30, 1986: A study based on GEOSCOPE very long-period and broadband data

The Romanian earthquake of August 30, 1986 is the second largest intermediate depth event in this area since the worldwide deployment of digital instrumentation, and the first one since the installation of GEOSCOPE network. It offers the unique opportunity to document this well-known but poorly understood zone of deep continental seismicity using high quality teleseismic data in different frequency bands. The source is well constrained both from very-long period surface wave data observed on GEOSCOPE stations and, independently, from body wave modelling at various worldwide stations. The depth obtained is approximately 140 kilometers, the seismic moment, 0.8 10²⁷ dyne-cm and the mechanism from both data sets is very similar to that of the previous 1940 and 1977 Vancrea events, indicating that these events, although having occurred at noticeably different depths, are expressions of the same tectonic process. However, from the detailed study of the source using broadband data, it can be inferred that the source presents much less complexity than the 1977 event.     

Malham Cove: splendour and enigma

A dry waterfall that recently came to life, a landform that is not karstic in the middle of a great karst terrain, underground drainage that is not as simple as it seems, and on‐going debate about how it was formed: Malham Cove is more than just a spectacular sight.     

Lötschberg–geology for tunnellers

Switzerland's Lötschberg tunnels present a long story of both failure and success. Tunnelling that began 100 years ago ended in a massive disaster–which is a classic of engineering geology–but subsequent works were very much more successful.