Magnetic fabric and rock-magnetic character of the Mesozoic ¯ood basalts of the Parana Basin, Brazil Endale Tamrat*, Marcia Ernesto Instituto Astono Ãmico e GeofõÂsico, Universidade de Sa Äo Paulo, Rua do Mata Äo 1226, CEP 05508-900, Sa Äo Paulo, SP, Brazil Received 13 September 1998; received in revised form 23 January 1999; accepted 18 February 1999 Abstract We have studied the magnetic fabric of Mesozoic basaltic ¯ows from ®ve sequences of the Parana Magmatic Province (PMP), southern Brazil, to infer paleo¯ow direction and to locate possible magma feeders. A well de®ned orientation pattern, indicative of the ¯ow direction has been evidenced by the low ®eld anisotropy of magnetic susceptibility (AMS). One sequence from the southern part of the basin, JS (27 ¯ows, 513 specimens), shows maximum AMS ellipsoid trending approximately NW±SE. Two sequences from the west±central part of the basin, IC (13 ¯ows, 173 specimens), and PA (17 ¯ows, 324 specimens), trend E±W. Two sequences from the south-eastern part of the basin, CV (24 ¯ows, 436 specimens) and BV (20 ¯ows, 103 specimens) show maximum AMS ellipsoid trends approximately NE± SW. In all cases the minimum axes of the AMS ellipsoids are tightly grouped vertically or sub-vertically to the bedding with a relatively weak degree of anisotropy, indicative of the primary origin of the magnetic fabric. Rock-magnetic parameters of some representative samples, such as isothermal remanent magnetization (IRM), high ®eld hysteresis loops and thermomagnetic curves suggests that the dominant magnetic mineral is a pseudo-single to small multi-domain grain size of magnetite. These and other observations are consistent with the conclusions that ¯ows emanating from dierent sources may align their maximum susceptibility directions parallel to drainage that channel the ¯ow or they will re¯ect regional pre¯ow topographic structure and magma-source distributions. # 1999 Elsevier Science Ltd. All rights reserved. Journal of Geodynamics 28 (1999) 419±437 0264-3707/99/$ - see front matter # 1999 Elsevier Science Ltd. All rights reserved. PII: S0264-3707(99)00019-8 * Corresponding author. Fax: +55-11-818-5034. E-mail address: tamrat@iag.usp.br (E. Tamrat)