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Document Type |
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Article In Journal |
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Document Title |
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The Al Ays Batholith: A Late Proterozoic Granitoid Batholith Associated with the Al Ays Volcanic Arc Complex, Hijaz Terrane, Arabian Shield باثوليت العيس : باثوليت جرانيتي قبل كمبري متأخر مصاحب لمعقد صخور العيسى البركانية ، منطقة الحجاز ـ المملكة العربية السعودية |
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Subject |
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Earth Sciences |
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Document Language |
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English |
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Abstract |
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The Al Ays batholith is located in the Hijaz microplate of the
Arabian Shield. It intrudes the volcanic facies (andesitic and basaltic lavas
and pyroclastic material) of the mature arc-derived Al Ays volcanosedimentary
sequence. The batholith is composite, 3-30 km wide by about
50 km long, and ranges from diorite to granite. A 5-point Rb/Sr isochron
gave an ageo f706:t 2 Maand an initial 87SrJ86rSarti oofO. 70319:t 0.00002.
The granitoid rocks of the batholith are calc-alkaline, metaluminous to
subaluminous, with moderate LREE enrichment and a negative Eu anomaly,
and show a wide compositional range (SiO254.40-72.30%, Cao 1.16-
6.29%, K20 1.8-3.94%, Rb 7-85 ppm. Sr 89-397 ppm, Y 7-40 ppm, Zr 40-
337 ppm, Rb/Sr ratios 0.06-0.95).
The young age, calc-alkaline association, compositionally expanded nature
with a spectrum of rock types from dioritic to granitic, short crustal residence
time, and the syn- to late-collisional tectonic 'environment all
suggest a model that the Al Aysvolcano-plutonic complex (743 :t 12.to 725
:t 12 Ma) formed as a result of subduction and melting of oceanic lithosphere
beneath the pre-existing arc-basement of volcano-plutonic rocks and
their sedimentary derivatives. |
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ISSN |
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1012-8832 |
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Journal Name |
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Earth Sciences Journal |
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Volume |
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7 |
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Issue Number |
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1 |
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Publishing Year |
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1414 AH
1994 AD |
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Number Of Pages |
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18 |
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Article Type |
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Article |
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Added Date |
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Sunday, October 11, 2009 |
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Researchers
| محمد عمر نصيف | M. O. NASSIEF | Researcher | | |
| عبدالعزيز عبدالملك رادين | A. A. RADAIN | Researcher | | |
| سيد علي | S. ALl | Researcher | | |
|