caa a22 4500 477064353 CHVBK 20180405111408.0 cr unu---uuuuu 170330e19961201xx s 000 0 eng 10.1007/BF02440100 doi (NATIONALLICENCE)springer-10.1007/BF02440100 Inception and demise of a Neoproterozoic ocean basin: evidence from the Ougda complex, western Hoggar (Algeria) [Elektronische Daten] [J. Dostal, R. Caby, C. Dupuy, C. Mevel, J. Owen] The Neoproterozoic Ougda magmatic complex occurs within platformal carbonate rocks in the western part of the Pan-African fold belt of the Tuareg shield (NW Africa). It is composed of - 800 Ma old, relatively high P-T (i.e., Grt + Cpx-bearing: P > 5 kbar; T≈900'Q, tholeiitic mafic/ultramafic cumulates and related rocks intruded by intermediate to mafic calcalkali plutons (e.g., Cpx+Hbl-bearing gabbro) and dikes. Apparent contrasts in structural level of crystallization indicate that the calc-alkali rocks are significantly younger than the tholeiites, which temporally correlate with a period of regional extension in this part of Africa. Intrusion of the calc-alkali rocks may have occurred during the formation of an arc after the tholeiitic rocks had been (diapirically?) emplaced within the shelf carbonates, and prior to (> 630 Ma) the Pan-African orogeny. Data reported herein indicate that the Ougda complex records the inception and demise of a Neoproterozoic ocean basin. Similar crustal sections have been described from collisional (e.g., Aleutian islands) and extensional (e.g., Ivreä-Verbano zone) settings, indicating that processes operating in both environments can generate nearly indistinguishable igneous suites; the prevalence of shallow-level calc-alkali rocks in both settings may mask the presence of more mafic, tholeiitic rocks at depth. Springer-Verlag, 1996 Pan-African nationallicence tectonics nationallicence geochemistry crustal extension nationallicence island arc tholeIIte nationallicence calc-alkali gabbro nationallicence Dostal J. Department of Geology, Saint Mary's University, Halifax, Nova Scotia B3H3C3, Canada aut Caby R. Laboratoire de Tectonophysique, Universite de Montpellier II, Sciences et Techniques, F-34095, Montpellier, Cedex 05, France aut Dupuy C. Centre Geologique et Geophysique, Universite de Montpellier II, Sciences et Techniques, F-34095, Montpellier, Cedex 05, France aut Mevel C. Laboratoire de Petrologie, Universite P. et M. Curie, 4 place Jussieu, F-75252, Paris, Cedex 05 aut Owen J. Department of Geology, Saint Mary's University, Halifax, Nova Scotia B3H3C3, Canada aut Geologische Rundschau Springer-Verlag 85/4(1996-12-01), 619-631 0016-7835 85:4<619 1996 85 531 https://doi.org/10.1007/BF02440100 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02440100 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Dostal J. Department of Geology, Saint Mary's University, Halifax, Nova Scotia B3H3C3, Canada aut NATIONALLICENCE 700 1- Caby R. Laboratoire de Tectonophysique, Universite de Montpellier II, Sciences et Techniques, F-34095, Montpellier, Cedex 05, France aut NATIONALLICENCE 700 1- Dupuy C. Centre Geologique et Geophysique, Universite de Montpellier II, Sciences et Techniques, F-34095, Montpellier, Cedex 05, France aut NATIONALLICENCE 700 1- Mevel C. Laboratoire de Petrologie, Universite P. et M. Curie, 4 place Jussieu, F-75252, Paris, Cedex 05 aut NATIONALLICENCE 700 1- Owen J. Department of Geology, Saint Mary's University, Halifax, Nova Scotia B3H3C3, Canada aut NATIONALLICENCE 773 0- Geologische Rundschau Springer-Verlag 85/4(1996-12-01), 619-631 0016-7835 85:4<619 1996 85 531 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer