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The Santa Cruz - Tarija Province of Central South America: Los Monos - Machareti(!) Petroleum System

September 1, 1999

The Los Monos - Machareti(!) total petroleum system is in the Santa Cruz - Tarija Province of Bolivia, Argentina and Paraguay. Province history is that of a Paleozoic, intracratonic, siliciclastic rift basin that evolved into a Miocene (Andean) foreland fold and thrust belt. Existing fields are typified by alternating reservoir and seal rocks in post-Ordovician sandstones and shales on anticlines. Thick Devonian and Silurian shale source rocks, depositionally and erosionally confined to this province, at a minimum have generated 4.1 BBOE known ultimate recoverable reserves (as of 1995, 77% gas, 15% condensate, 8% oil) into dominantly Carboniferous reservoirs with average 20% porosity and 156 md permeability. Major detachment surfaces within the source rocks contributed to the thin-skinned and laterally continuous nature of the deformation. Tertiary foreland burial adequate for significant source maturation coincided with the formation of compressional traps. Further hydrocarbon discovery in the fold and thrust belt is expected. In the foreland basin, higher thermal gradients and variable burial history - combined with the presence of unconformity and onlap wedges - create potential there for stratigraphic traps and pre-Andean, block-fault and forced-fold traps.

Publication Year 1999
Title The Santa Cruz - Tarija Province of Central South America: Los Monos - Machareti(!) Petroleum System
DOI 10.3133/ofr9950C
Authors Sandra J. Lindquist
Publication Type Report
Publication Subtype USGS Numbered Series
Series Title Open-File Report
Series Number 99-50
Index ID ofr9950C
Record Source USGS Publications Warehouse
USGS Organization U.S. Geological Survey