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"Origin of the Sinai-Negev erg, Egypt and Israel: mineralogical and geochemical evidence for the importance of the Nile and sea level history" (2013 Overall, the mineralogical data suggest that the dunes are derived dominantly from the Nile Delta, with Sinai wadi sands being a minor contributor. Geochemical data that proxy for both the light mineral fraction (SiO 2 /10eAl 2 O 3 þ Na 2 O þ K 2 OeCaO) and heavy mineral fraction (Fe 2 O 3 eMgOeTiO 2 ) also indicate a dominant Nile Delta source for the dunes. Thus, we report here the first empirical evidence that the SinaieNegev dunes are derived dominantly from the Nile Delta. Linkage of the SinaieNegev erg to the Nile Delta as a source is consistent with the distribution of OSL ages of Negev dunes in recent studies. Stratigraphic studies show that during the Last Glacial period, when dune incursions in the SinaieNegev erg began, what is now the Nile Delta area was characterized by a broad, sandy, minimally vegetated plain, with seasonally dry anastomosing channels. Such conditions were ideal for providing a ready source of sand for aeolian transport under what were probably much stronger glacial-age winds.With the post-glacial rise in sea level, the Nile River began to aggrade. Post-glacial sedimentation has been dominated by fine-grained silts and clays. Thus, sea level, along with favorable climatic conditions, emerges as a major influence on the timing of dune activity in the SinaieNegev erg, through its control on the supply of sand from the Nile Delta. The mineralogy of the SinaieNegev dunes is also consistent with a proposed hypothesis that these sediments are an important source of loess in Israel.Published by Elsevier Ltd.

This study records that Pompeii, long before its final devastation by the 79 A.D. Vesuvius eruption in southern Italy, was damaged by several mass gravity flows. Composition of the deposits indicates that they were derived from volcaniclastic cover of carbonate highlands positioned 14 km NE of the city. Stratigraphic and petrologic analyses of sections in excavations and drill cores in and near Pompeii record the presence of three downslope‐directed debris flows dated between 8th and 2nd century B.C. Some of these deposits were channelized via a stream bed that once extended from high reliefs to Pompeii. It is proposed that one of these events may have been partially responsible for urban decline during the 4th century B.C. These mass flows are interpreted as having been triggered primarily by intense rains in a manner similar to those that have occurred and destroyed towns in this region during the past 50 years. Our investigation shows that Pompeii and adjacent areas in the past, much as in recent time, have likely been most frequently susceptible to episodic damage by avalanches and mass flows of volcaniclastic material resulting from hydrological effects rather than from volcanic events, earthquake tremors, and societal disruptions such as wars.