[en] The state of Minas Gérais, Brazil, contains numerous karsts booth inside carbonated and non carbonated rocks. Différent caves are found in quartzite and Itaberite formations (Banded Iron formation). The term karst is used in the meaning of "any features of the classical karst morphology (caves, sink-holes, lapies...) where dissolution plays the main genetically action and this in any kind of rocks".
In some areas, lapiaz and kamenitza affect wide landscapes (area of Diamantina, Natural Parc of Rio Preto). Several caves are found and some of these are several kilomeetres long (grutta do Bromelias, Natural Parc of Ibitipoca). Inside caves, we found numerous forms like dissolution alveoli, spelothems, .... Many times, the cave sides and solutional forms are covered by crust which solidify a very crumbly quartzite. Différent morphologies show an primary solutional stage of the rocks before a physical erosional stage which destroy the earliest forms (piping, river érosion, collapsing).
Disciplines :
Earth sciences & physical geography
Author, co-author :
Willems, Luc ; Université de Liège - ULiège > Département de géologie > Pétrologie sédimentaire
Rodet, Joël; Université de Rouen & CNRS > géologie
Auler, Augusto; Universidade Federal de Minas Gerais > Geografia, Instituto de Geoscièncias
Pilo, Luiz; Universidade de Sào Paulo > Biologia, Instituto de Biociências,
Pouclet, André; Université d'Orléans > géologie > ISTO
Language :
French
Title :
Karsts en roches non carbonatées - l'exemple des quartzites et des itabérites de Minas Gerais, Brésil
Alternative titles :
[en] Karsts in non carbonated rocks - examples in quartzite and itabirite rocks from Minas Gérais, Brazil