TY - JOUR
T1 - A new look on Imperial Porphyry
T2 - a famous ancient dimension stone from the Eastern Desert of Egypt—petrogenesis and cultural relevance
AU - Abu El-Enen, Mahrous M.
AU - Lorenz, Joachim
AU - Ali, Kamal A.
AU - von Seckendorff, Volker
AU - Okrusch, Martin
AU - Schüssler, Ulrich
AU - Brätz, Helene
AU - Schmitt, Ralf Thomas
N1 - Funding Information:
Acknowledgements The authors thank Hesham Sallam and Hassan Eliwa for their field assistance. Sample DKK from Mons Porphyrites was collected and kindly provided to this study by Rosemarie and Dietrich D. Klemm (Dießen, Germany). Thanks to Martin Whitehouse, Kerstin Lindén and Lev Ilyinsky, Swedish Museum of Natural History Stockholm, for their help with CL-images and zircon isotope analyses. Field work was partially supported by the Mansoura University, Egypt, which is gratefully acknowledged. We highly appreciate the
Funding Information:
The authors thank Hesham Sallam and Hassan Eliwa for their field assistance. Sample DKK from Mons Porphyrites was collected and kindly provided to this study by Rosemarie and Dietrich D. Klemm (Die?en, Germany). Thanks to Martin Whitehouse, Kerstin Lind?n and Lev Ilyinsky, Swedish Museum of Natural History Stockholm, for their help with CL-images and zircon isotope analyses. Field work was partially supported by the Mansoura University, Egypt, which is gratefully acknowledged. We highly appreciate the useful suggestions of the editor and two reviewers Peter Johnson and Ghaleb Jarrar.
Publisher Copyright:
© 2018, Springer-Verlag GmbH Germany, part of Springer Nature.
PY - 2018/10/1
Y1 - 2018/10/1
N2 - Imperial Porphyry, a famous dimension stone of spectacular purple color, was quarried in the Mons Porphyrites area north of Jabal Dokhan in the Eastern Desert of Egypt, from the beginning of the first until the middle of the fifth century AD. During this period, the valuable material was processed as decorative stone and was used for objects of art, reserved exclusively for the Imperial court of the Roman Empire. Later on, only antique spoils of smaller or bigger size have been re-used for these purposes. The Imperial Porphyry is a porphyritic rock of trachyandesitic to dacitic composition that occurs in the uppermost levels of shallow subvolcanic sill-like intrusions, forming a member of the Dokhan Volcanic Suite. Its purple color is mainly due to dispersed flakes of hematite, resulting from hydrothermal alteration of a dark green Common Porphyry of similar composition, underlying the Imperial Porphyry. Both, the Common Porphyry and the purple Imperial Porphyry’, are extensively exposed in the Roman quarries. Contacts between Common and Imperial Porphyry are irregular and gradational. In both rock types, intrusive breccias are frequent, indicating a complex intrusion history. U–Th–Pb zircon geochronology on two samples of Imperial Porphyry and one sample of the Common Porphyry yielded an age range of 609–600 Ma, thus confirming earlier results of radiometric dating. Geochemical evidence indicates that both the Imperial and the Common Porphyry are of medium- to high-K calc-alkaline affinity. The magmas have formed by partial melting of a subduction-modified upper mantle. The subsequent intrusion took place within a highly extended terrane (HET).
AB - Imperial Porphyry, a famous dimension stone of spectacular purple color, was quarried in the Mons Porphyrites area north of Jabal Dokhan in the Eastern Desert of Egypt, from the beginning of the first until the middle of the fifth century AD. During this period, the valuable material was processed as decorative stone and was used for objects of art, reserved exclusively for the Imperial court of the Roman Empire. Later on, only antique spoils of smaller or bigger size have been re-used for these purposes. The Imperial Porphyry is a porphyritic rock of trachyandesitic to dacitic composition that occurs in the uppermost levels of shallow subvolcanic sill-like intrusions, forming a member of the Dokhan Volcanic Suite. Its purple color is mainly due to dispersed flakes of hematite, resulting from hydrothermal alteration of a dark green Common Porphyry of similar composition, underlying the Imperial Porphyry. Both, the Common Porphyry and the purple Imperial Porphyry’, are extensively exposed in the Roman quarries. Contacts between Common and Imperial Porphyry are irregular and gradational. In both rock types, intrusive breccias are frequent, indicating a complex intrusion history. U–Th–Pb zircon geochronology on two samples of Imperial Porphyry and one sample of the Common Porphyry yielded an age range of 609–600 Ma, thus confirming earlier results of radiometric dating. Geochemical evidence indicates that both the Imperial and the Common Porphyry are of medium- to high-K calc-alkaline affinity. The magmas have formed by partial melting of a subduction-modified upper mantle. The subsequent intrusion took place within a highly extended terrane (HET).
KW - Cultural relevance
KW - Dokhan Volcanics
KW - Eastern Desert
KW - Imperial Porphyry
KW - Petrogenesis
KW - U–Pb zircon age dating
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U2 - 10.1007/s00531-018-1604-z
DO - 10.1007/s00531-018-1604-z
M3 - Article
AN - SCOPUS:85046034071
SN - 1437-3254
VL - 107
SP - 2393
EP - 2408
JO - International Journal of Earth Sciences
JF - International Journal of Earth Sciences
IS - 7
ER -