. Bulletin of the Geological Society of America. Geology. EXPOSURES ALONG ESTRADA CENTRAL OF PERNAMBUCO 83 originally deposited in water where clays alternated with the volcanic ejectamenta that form the feldspathic beds. A prominent feature of these bedded rocks is a felted appearance that is characteristic of the old Paleozoic rocks through the highlands of Brazil. In the felted silicious schists are occasional lenses or bands of flint or chalcedony closely re- sembling novaculites, some of them more than a meter in length and 20 centimeters wide; one was noted having a length of 3 meters an
. Bulletin of the Geological Society of America. Geology. EXPOSURES ALONG ESTRADA CENTRAL OF PERNAMBUCO 83 originally deposited in water where clays alternated with the volcanic ejectamenta that form the feldspathic beds. A prominent feature of these bedded rocks is a felted appearance that is characteristic of the old Paleozoic rocks through the highlands of Brazil. In the felted silicious schists are occasional lenses or bands of flint or chalcedony closely re- sembling novaculites, some of them more than a meter in length and 20 centimeters wide; one was noted having a length of 3 meters and a width of 2 centimeters. These flints are partly surrounded by and partly penetrated by pink feldspars. The schists vary in color from nearly black where they are unweathered to gray where they are. Figure 14.—Looking west from* Antonio Olyntho. weathered. The black ones are exceedingly hard. The pink feldspars are characteristic of all or nearly all of them, and many of them contain quartz lenses. All of these bedded rocks are much jointed, the clean, smooth joints cutting for the most part square across the beds. The joints are from 1 centimeter to 15 centimeters apart. The schistose rocks about Antonio Olyntho are slickensided. This fact, together with the faults exposed at Antonio Olyntho and the gen- eral structure, so far as it is visible between the Serra da Russa and the west end of the valley, lead to the conclusion that the region is much faulted, especially along the east-west belt crossed by the railway be- tween Caruaru and Antonio Olyntho. According to the observations of Dombre, the granitic rocks found about Bezerros continue to Sao Bento, about 40 kilometers south and a. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Geological Society of America. [New York : The Society]
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