In this paper we present a model for the growth of a maar-diatreme complex in a shallow marine environment. The Miocene-age Costa Giardini diatreme near Sortino, in the region of the Iblei Mountains of southern Sicily, has an outer tuff ring formed by the accumulation of debris flows and surge deposits during hydromagmatic eruptions. Vesicular lava clasts, accretionary lapilli and bombs in the ...

Most practitioners measure investment performance based on the CAPM, determining portfolio"alphas" or Sharpe Ratios. But the validity of this analysis rests on the validity of the CAPM, whichassumes either normally distributed (and therefore symmetric) returns, or mean-variance preferences.Both assumptions are suspect: even if asset returns were normally distributed, the returns of ...