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P. 194 (from p.192) "PEHUENCHE" ? Throughout the length of the baranca & generally forming the base of its steepest part is a white tuffaceous bed, characteristic in this series which contains little or no white elsewhere. It rests on the Banco Negro (& equivalents) and grades more or less into the overlying beds. The bulk of the supposed Pehuenche and of the nearly vertical face of the cliff is a series about 60' thick at FA and 90'thick at FB. This is fairly massive but with some separation into variable (broadly lenticular) beds, & with cross bedding. It consists of sands and tuffaceous sands, fine to coarse, usually with scattered pebbles of pumice and other volcanic debris. The color is generally greenish grey, sometimes with a vaguely violet tinge from a distance. No fossils were found. "ARGILES FISSILAIRES" ? Above this grey and green series are the beds which Feruglio homologizes with the argiles fissilaires. The maximum thickness assignable to these at FA is 50', at FB is about 25'. The details are sufficiently given in the profiles. P. 195 The upper surface of the grey-green series consists of hard tuff weathering brown & vesicular or nodular, introducing the arg. fis. Type of rock. In fact this appears to be merely a somewhat more thin-bedded, variable, and altered part of the underlying "Pehuenche "EOCENE" ? The "arg. fis." terminates above with a characteristic bed of very irregular, platy, silicified tuffs with limonite nodules, often interbedded with grey to black clays. Resting on the surface of these are clays, the basal part generally very black. [Feruglio, "Apuntes etc." , p.431, <
estan cubiertas por un banco de arena y ripio?.>> I did not observe this, which must be very local at least at Las Violetas.] Above this follows a series of clays and tuffs irregularly intercolated with soft and hard fine sand to gravel, grey or white in color. These contain mammals, but extremely rare wherever I saw them. The lowest in place were about 25' above the "arg. fis." These beds are not exposed in