PT Journal
AU El Safty, BAZM
   El-Wahed, MA
   Pour, AB
   Abdelnasser, A
TI Orogenic Gold in Transpression and Transtension Zones: Field and Remote Sensing Studies of the Barramiya–Mueilha Sector, Egypt
SO Remote Sensing
JI Remote Sensing
PY 2019
BP 2122
VL 11
IS 18
PU MDPI AG
DI 10.3390/rs11182122
WP https://macau.uni-kiel.de/receive/macau_mods_00000392
LA en
DE Advanced Space borne Thermal Emission and Reflection Radiometer (ASTER); Sentinel 2; Synthetic Aperture Radar (SAR) data; Egyptian Eastern Desert; gold mineralization; structural control; transpression and transtension zones
SN 2072-4292
AB Multi-sensor satellite imagery data promote fast, cost-efficient regional geological mapping
that constantly forms a criterion for successful gold exploration programs in harsh and inaccessible
regions. The Barramiya–Mueilha sector in the Central Eastern Desert of Egypt contains several
occurrences of shear/fault-associated gold-bearing quartz veins with consistently simple mineralogy
and narrow hydrothermal alteration haloes. Gold-quartz veins and zones of carbonate alteration and
listvenitization are widespread along the ENE–WSW Barramiya–Um Salatit and Dungash–Mueilha
shear belts. These belts are characterized by heterogeneous shear fabrics and asymmetrical or
overturned folds. Sentinel-1, Phased Array type L-band Synthetic Aperture Radar (PALSAR),
Advanced Space borne Thermal Emission and Reflection Radiometer (ASTER), and Sentinel-2 are
used herein to explicate the regional structural control of gold mineralization in the Barramiya–Mueilha
sector. Feature-oriented Principal Components Selection (FPCS) applied to polarized backscatter ratio
images of Sentinel-1 and PALSAR datasets show appreciable capability in tracing along the strike of
regional structures and identification of potential dilation loci. The principal component analysis
(PCA), band combination and band ratioing techniques are applied to the multispectral ASTER and
Sentinel-2 datasets for lithological and hydrothermal alteration mapping. Ophiolites, island arc
rocks, and Fe-oxides/hydroxides (ferrugination) and carbonate alteration zones are discriminated
by using the PCA technique. Results of the band ratioing technique showed gossan, carbonate, and
hydroxyl mineral assemblages in ductile shear zones, whereas irregular ferrugination zones are
locally identified in the brittle shear zones. Gold occurrences are confined to major zones of fold
superimposition and transpression along flexural planes in the foliated ophiolite-island arc belts.
In the granitoid-gabbroid terranes, gold-quartz veins are rather controlled by fault and brittle shear
zones. The uneven distribution of gold occurrences coupled with the variable recrystallization of
the auriferous quartz veins suggests multistage gold mineralization in the area. Analysis of the host
structures assessed by the remote sensing results denotes vein formation spanning the time–space
from early transpression to late orogen collapse during the protracted tectonic evolution of the belt.
PI Basel
ER