E. Cristallini et al., DEEP-STRUCTURE OF THE METAN-GUACHIPAS REGION - TECTONIC INVERSION IN NORTHWESTERN ARGENTINA, Journal of South American earth sciences, 10(5-6), 1997, pp. 403-421
New deep seismic-reflection data obtained by reprocessing an industria
l line from the eastern sector of the Salta rift system, Northwestern
Argentina, are examined. An oil well located along the line provides s
tratigraphic control for the seismic interpretation. The corresponding
synthetic seismogram extends this interpretation through the Met;in t
rough. The data show the deep structure of the rift, consisting of a s
eries of half-grabens, filled with Cretaceous red beds of the Pirgua S
ubgroup. The sag phase deposits consist of limestones, marls, shales a
nd evaporites of the Balbuena and Santa Barbara Subgroups, deposited i
n a transitional marine to lacustrine environment. Several oblique eas
t-dipping reflectors at 10 to 20-24 km depth, are interpreted as maste
r shears that control the extensional mechanics of the rift system, pa
rtially reactivated during Andean compression. The structure of this e
astern sector of the rift is integrated through a regional cross-secti
on through the entire rift system. The section clearly shows that trou
ghs and highs may be related to flats and ramps of a regional master s
hear dipping to the east. (C) 1998 Elsevier Science Ltd. All rights re
served.