TY  - JOUR
T1  - Petrology and Geochemistry of Volcanic Rocks in North Khur,
Northwestern Birjand
AU - Fotoohi Rad, Gholamreza AU - Abbasi niazabadi, Hossein 
JO  - Online Journal of Earth Sciences
VL  - 11
IS  - 1
SP  - 10
EP  - 20
PY  - 2017
DA  - 2001/08/19
SN  - 1991-7708
DO  - ojesci.2017.10.20
UR  - https://makhillpublications.co/view-article.php?doi=ojesci.2017.10.20
KW  - Volcanic rocks
KW  -North of Khur
KW  -calc alkaline
KW  -oceanic crust
KW  -subduction
KW  -Lut block
AB  - The study volcanic complex is located in southern khorasan province, in 90 km of northwest of
Birjand and in North of Khour. The study volcanic rocks are including Basaltic andesite andesite and
trachyandesite, Latite, Dacite to Rhyodacite and pyroclastic rocks are including Tuff and breccia. The essential
and common minerals of these rocks are plagioclase, clinopyroxene, hornblende, biotote and quartz and minor
and alteration minerals of these rocks are clay minerals, sericite, calcite, chlorite, epidote and secondary quartz.
The majority texture of these rocks is porphyry. Magmatic series of most samples are calc alkaline but some
samles have inclination to tholleitic serie. Positive abnormality of Pb is showing alteration of mantle wedge by
fluids which have originated from sinking oceanic crust and or from magma contamination with continental
crust. Enrichment of samples from Ba and Sr also are related to fluids which are derivated from water bearing
sediments and also separation and moving of these fluids from oceanic crust to mantle wedge. Negative
abnormality of P, Nb and Ti elements which has caused multiplication pattern in rare elements changing trend
in samples, can show formation of rocks in subduction area. Tectonic definition diagrams are showing that
andesitic basalts of area are situating in field of calc alkaline basalts of volcanic arc. Furthermore in diagram of
magmatic arc definition, the study rocks are situating in field of continental arc and seems which magmatism
of area has been result of subduction of a oceanic crust under the continental crust (Lut block).
ER  -