Clay Minerals of the Argille Scagliose of the Modenese Apennines

Publisher Website
Google Scholar
Abstract
Samples of the argille sca.eliose from various localities in the Modenese Apennines have been studied by optical, X-ray and d.t.a, methods as part of an investigation into the composition and origin of this remark- able allochthonous formation. Illite, chlorite and a kaolinitic mineral of "fireclay" type are widespread. Samples from one locality contain also a conspicuous 22-28 .~ swelling chlorite, the origin of which is discus- sed. It is as yet mlcertain whether this mineral is confined *.o clays containing exotic blocks of ophiolite (grcenstone) or whether it is more widely distributed. INTRODUCTION A programme of work on the allochthonous clays of the Apennines, financed by the National Research Council of Italy, has been under- taken in order to investigate the composition and characteristics of these sediments; and if possible to determine their age and the con- ditions under which they were originally deposited. This work, started in 1942, has involved two separate lines of research. The palaeontological side has been largely developed by E. M. Gallitelli, the mineralogical-petrological aspects by the author and his co- workers (see Gallitelli and Gallitelli 1949). The allochthonous formation known as the argille scagliose con- sists of a shaly matrix in which are enveloped exotic blocks of basic igneous material ("ophiolites"), limestones, sandstone and other rocks. The whole sequence is regarded by Merla (1951) as material which has slid eastwards in gigantic "'orogenic landslips" during the elevation of the Apennines. Neither its original position in the geosyncline nor its age are known with certainty. The investigations described in this paper were made on samples of the argille scagliose from Varana, Sassomorello and Castelvecchio in the Modenese Apennines. They were collected close to enveloped blocks of ophiolite (gabbro, diabase or serpentine) and consist of red and grey clays both of which contain arenaceous foraminifera of Upper Cretaceous age (E. M. Gallitelli 1943 (a) and (b), 1947). These clays have been separated by suspension in water into fractions with a particle size of 30-12tz, 12-5/z, 5-1tz and 1-0.1t, for optical, X-ray and d.t.a, examination. RESULTS

This publication has 0 references indexed in Scilit: