Paleozoic formations in Trans-Pecos Texas
نویسندگان
چکیده
منابع مشابه
Chromosome numbers in Chihuahuan Desert Cactaceae. III. Trans-Pecos Texas.
Chromosome numbers are reported for 112 collections of Cactaceae, including 102 collections of Opuntia. Reports are presented for 33 species in five genera and a total of 36 taxa. Two specimens were sterile. Emphasis was given to the documentation of intraspecific ploidy-level consistencies and differences, because of the current poor state of knowledge about the populational integrity of chrom...
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Predation of livestock and big game remains a matter of concern for ranch managers and operators in the Trans-Pecos. Current evidence indicates that mountain lions (Felis concolor), bobcats {Lynx rufus), and coyotes (Canis latrans) are the primary predators involved, although little information is available on bobcats. A gradual shift from sheep to cattle management has resulted in a correspond...
متن کاملRegional groundwater flow paths in Trans-Pecos, Texas inferred from oxygen, hydrogen, and strontium isotopes
r a 200 .015 : +1 570 qu.edu Summary Stable isotopes, radiogenic isotopes, and major ion chemistry are used to constrain flow paths in a fracture-controlled regional groundwater flow system in far west Texas. The flow system occurs in Permian and Cretaceous sedimentary rocks and Cenozoic alluvial basin fill. Samples from springs and wells in the study area were analyzed for major ions and hydro...
متن کاملEarly Basin and Range Development in Trans-pecos Texas and Ad3acent Chihuahua: Magmatism and Orientation, Timing, and Style of Extension
Magmatism during early Basin and Range extension in Trans-Pecos Texas consisted of widespread but volumetrically minor alkali basalts (24-17 Ma), an alkalic mafic to intermediate composition stratovolcano (28-27 Ma), and a dominantly rhyolitic, possibly bimodal, caldera complex in adjacent Chihuahua (3128 Ma). This magmatism contrasted sharply with the much more voluminous and compositionally m...
متن کاملGeochronological and Taxonomic Revisions of the Middle Eocene Whistler Squat Quarry (Devil’s Graveyard Formation, Texas) and Implications for the Early Uintan in Trans-Pecos Texas
The Whistler Squat Quarry (TMM 41372) of the lower Devil's Graveyard Formation in Trans-Pecos Texas is a middle Eocene fossil locality attributed to Uintan biochronological zone Ui1b. Specimens from the Whistler Squat Quarry were collected immediately above a volcanic tuff with prior K/Ar ages ranging from ∼47-50 Ma and below a tuff previously dated to ∼44 Ma. New 40Ar/39Ar analyses of both of ...
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ژورنال
عنوان ژورنال: American Journal of Science
سال: 1908
ISSN: 0002-9599
DOI: 10.2475/ajs.s4-25.150.474