Signs of ancient development and ultrahigh pressure conditions in the passive continental margin region (on example of Israel)

Abstract

Latest discoveries of diamonds (over 400 micro-diamonds and three macro-diamonds) and an enormous number of indicator minerals (such as Cr-diopside, orange garnet, pyrope, picroilmenite, moissanite, carbonado, corundum, black spinel, olivine, perovskite, aegirine, Ti-augite, etc.) in southern Israel indicate the existence of ultrahigh-pressure conditions in the lithosphere in ancient times and the presence in the lithosphere rocks typical for the Archean – Early Proterozoic periods. Integrated analysis and reinterpretation of some geophysical and geological data for Israel and surrounding regions shows that:

Full text

Trans. of Annual Conf. on Geology and Mineralogy, St. Catharines,
Canada, GS-15, p. 424, 2004
Signs of ancient development and ultrahigh pressure conditions in the
passive continental margin region (on example of Israel)
Eppelbaum, L.V.1 and Pilchin, A.N.2
1Dept. of Geophysics and Planetary Sciences, Raymond and Beverly Sackler Faculty of Exact
Sciences, Tel Aviv University, Ramat Aviv 69978, Tel Aviv, Israel; E-mail: lev@frodo.tau.ac.il
2Universal Geoscience and Environment Consulting Company, 205 Hilda Ave., Willowdale,
Ontario, M2M 4B1, Canada; E-mail: apilchin1521@rogers.com
Latest discoveries of diamonds (over 400 micro-diamonds and three macro-diamonds)
and an enormous number of indicator minerals (such as Cr-diopside, orange garnet,
pyrope, picroilmenite, moissanite, carbonado, corundum, black spinel, olivine,
perovskite, aegirine, Ti-augite, etc.) in southern Israel indicate the existence of ultrahigh-
pressure conditions in the lithosphere in ancient times and the presence in the lithosphere
rocks typical for the Archean – Early Proterozoic periods. Integrated analysis and
reinterpretation of some geophysical and geological data for Israel and surrounding
regions shows that: (1) mean heat flow in the Dead Sea basin and surrounding areas of
Israel and Eastern Mediterranean ranges in interval of 35-40 mW/m2 and its minimal
value was registered in southern Israel, (2) in the igneous complexes of southern Israel a
considerable amount of olivine phenocrysts was found, (3) eclogite-like rocks and garnet
granulites were found in the vicinity of Mt. Carmel of northern Israel, and eclogite rocks
and diamonds were found in NW Syria, (4) the Archean - Early Proterozoic rocks were
described in Saudi Arabia, Egypt and Menderes massif (Turkey), (5) conditions of
extensional tectonics exist in Israel since the Late Proterozoic, (6) in this region
involvement of both continental and oceanic lithosphere sources is proved, (7) there are
strong proofs of existence paleo-oceans of at least the Middle Proterozoic age, (8) some
seismic data allow to supposing that peridotite plate(s), which was under-thrust the
continental lithosphere, occurs in the upper mantle of southern Israel, (9) a lot of
signatures showing evidence of reworking ancient continental crust in Israel and
surrounding regions was recognized, (10) a tremendous amount of potassium-rich
granitoids and A-type granites in Israel and surrounding regions was identified, (11)
Middle Proterozoic and Late Proterozoic metamorphic and magmatic rocks are known in
southern Israel, Sinai, Jordan and Syria, (13) Israeli lithosphere is characterized by a
cooling regime. These facts suggest that the region underwent significant tectonic activity
before the Late Proterozoic.