Insights into crust formation and recycling in North Africa from combined U–Pb, Lu–Hf and O isotope data of detrital zircons from Devonian sandstone of southern Libya
Published:January 01, 2014
Guido Meinhold, Andrew C. Morton, C. Mark Fanning, James P. Howard, Richard J. Phillips, Dominic Strogen, Andrew G. Whitham, 2014. "Insights into crust formation and recycling in North Africa from combined U–Pb, Lu–Hf and O isotope data of detrital zircons from Devonian sandstone of southern Libya", Sediment Provenance Studies in Hydrocarbon Exploration and Production, R. A. Scott, H. R. Smyth, A. C. Morton, N. Richardson
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Combined U–Pb, Lu–Hf and O isotope data of detrital zircons from the Devonian sandstone of southern Libya provide important new boundary parameters for reconstruction of palaeosource areas and sediment transport and may lead to novel approaches to test current plate tectonic models, with important implications for our understanding of the evolution of northern Gondwana (in present-day coordinates) during the Palaeozoic. Detrital zircon U–Pb ages from Devonian sandstone of the eastern margin of the Murzuq Basin show four main age populations: 2.7–2.5 Ga (13%), 2.1–1.9 Ga (10%), 1.1–0.9 Ga (25%) and 0.7–0.5 Ga (46%). The ubiquitous occurrence of c. 1.0 Ga detrital zircons is characteristic of the Saharan Metacraton sedimentary cover sequence and provides new insights into palaeogeographic reconstructions of Gondwana-derived terranes in the Eastern Mediterranean and SW Europe. The Lu–Hf isotope data suggest that zircons crystallized within a narrow time interval from magmas with heterogeneous Hf isotope compositions. These magmas were derived by melting of pre-existing rocks, rather than being juvenile. The calculated Hf model ages range from 3.7 Ga to 1.3 Ga, with a major population between 2.8 Ga and 1.9 Ga, indicating prominent recycling of Archaean and Palaeoproterozoic crust.
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Sediment Provenance Studies in Hydrocarbon Exploration and Production
Sediment provenance studies concern the origin, composition, transportation and deposition of detritus and therefore are an important part of understanding the links between basinal sedimentation, and hinterland tectonics and unroofing. Such studies can add value at many stages of hydrocarbon exploitation, from identifying regional-scale crustal affinities and sediment dispersal patterns during the earliest stages of exploration, to detailed correlation in producing reservoirs and understanding the impact of mineralogy on reservoir diagenesis.
The volume showcases the wide variety of techniques available, using examples and applications from all aspects of sediment provenance research. The papers are organized into four sets around the following themes:
Overview: applications of provenance information in hydrocarbon reservoir sandstones
Provenance, diagenesis and reservoir quality
Provenance studies linking sediment to source
Looking forward: development of techniques and data handling
This book is dedicated to the memory of Maria Mange and Robert A. Scott.