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SUPERFÍCIE ESTRIADA POR GELEIRA NEOPALEOZOICA NO PARAGUAI ORIENTAL

1999; Sociedade Brasileira de Geologia; Volume: 29; Issue: 2 Linguagem: Inglês

10.25249/0375-7536.199929233236

2177-4382

Cláudio Riccomini, Victor F. Velázquez,

Fish biology, ecology, and behavior

A subhorizontal, completely striated surface, developed upon sedimentary glacial deposite of the Late Paleozoic Aquidabán Formation, has been found in the village of Escobar, Eastern Paraguay. The striae are shallow, parallel grooves a few millimeters apart, rarely deeper than l mm, orientated N35E. Locally the surface is covered by diamictite with flat-iron-shaped and striated clasts. The characteristics of the pavement and its association with the diamictite support its origin by glacial abrasion. Transverso fractures associated with the surface indicate ice movement from southwest to northeast. This sense of movement is not consistem with a glacier source centered upon the Asunción Arch, as postulated in previous works. Rather, the data favour a source area located to the south-southeast of the Paraná Basin.