Bisbee Group | |
---|---|
Stratigraphic range: | |
Type | Group |
Sub-units | Glance Conglomerate, Morita Formation, Mural Limestone, Cintura Formation |
Underlies | Bronco Volcanics |
Overlies | Naco Formation |
Thickness | Over 1,770 meters (5,810 ft) |
Lithology | |
Primary | Sandstone, claystone, limestone |
Other | Conglomerate |
Location | |
Coordinates | 31°25′N109°57′W / 31.42°N 109.95°W |
Region | Arizona New Mexico Chihuahua |
Country | United States Mexico |
Type section | |
Named by | E.T. Dumble |
Year defined | 1902 |
The Bisbee Group is a geologic group in Arizona, [1] Mexico, and New Mexico. [2] It preserves fossils dating back to the early Cretaceous period. [3]
The group consists of sandstone, claystone, limestone, and conglomerate, [1] with a maximum thickness of 1,770 meters (5,810 ft) in the Chiricahua Mountains. [4] In the Tombstone, Arizona, area, it overlies the Naco Formation. [5] In the Bisbee area, the group is divided into four formations, which in ascending stratigraphic order are the Glance Conglomerate, the Morita Formation, the Mural Limestone, and the Cintura Formation. [3] These extend into northern Sonora. [6] The group is overlain by the Bronco Volcanics, [7] the Nipper Formation, or the Faraway Ranch Formation. [8] [2]
In the Chiricahua Mountains, where the thickest section is found, the Crystal Cave Formation and Onion Saddle Formation are found between the Glance Conglomerate and the Morita Formation. A thrust fault has placed the lower Jurassic beds over the Cretaceous beds. [4]
In southwestern New Mexico, the group thickens to 21,000 feet (6,400 m) and is divided into the Glance Conglomerate, the Hell-to-Finish Formation, the U-Bar Formation, and the Mojado Formation. [9] [10] [11] [2]
In northwestern Sonora, in addition to the Glance Conglomerate, the Morita Formation, the Mural Limestone, and the Cintura Formation, the group includes the Cerro de Oro Formation and Arroyo Sásabe Formation. [12]
The group was deposited in the Bisbee basin, which was the central basin of the Jurassic-Cretaceous border rift belt. This rift belt was located between the Mogollon Highlands of central Arizona and New Mexico, which formed the northern shoulder of the belt, and Cordilleran (or Alisitos) volcanic arc along what is now the western side of the Gulf of California. [13] Deposition began in the late Jurassic with the Glance Conglomerate. This was followed by at least three additional marine transgressions. The second of these was restricted to western Sonora and deposited the Cerro de Oro Formation. This was followed by deposition of typical fluvial, tidal flat, and delta deposits of the Morita Formation to the west and marine beds to the east. The third and largest incursion formed the lagoon belt of the Arroyo Sásabe Formation and the marine Mural Limestone. This was followed by delta deposits of the Cintura Formation. A final small fourth incursion affected only northeastern Sonora. [12]
The group contains fossils such as the mollusc Exogyra and the clam Trigonia characteristic of the Cretaceous. [1] The limestone formations contain fossils of scleractinian corals from a diversity of genera, including several species not found elsewhere. [14]
The Bisbee beds were first named by E.T. Dumble in 1902 for exposures around Bisbee, Arizona. [1] In 1904, Frederick Leslie Ransome divided the Bisbee Group into formations in the Bisbee area. [3] By 1938, the group had been mapped into the Tombstone, Arizona area [5] and into southwestern New Mexico. [9] Samuel G. Lasky defined several new formations within the group, but some of these were synonyms for each other due to fault doubling. [10]
The Entrada Sandstone is a formation in the San Rafael Group found in the U.S. states of Wyoming, Colorado, northwest New Mexico, northeast Arizona, and southeast Utah. Part of the Colorado Plateau, this formation was deposited during the Jurassic Period sometime between 180 and 140 million years ago in various environments, including tidal mudflats, beaches, and sand dunes. The Middle Jurassic San Rafael Group was dominantly deposited as ergs in a desert environment around the shallow Sundance Sea.
The Morrison Formation is a distinctive sequence of Upper Jurassic sedimentary rock found in the western United States which has been the most fertile source of dinosaur fossils in North America. It is composed of mudstone, sandstone, siltstone, and limestone and is light gray, greenish gray, or red. Most of the fossils occur in the green siltstone beds and lower sandstones, relics of the rivers and floodplains of the Jurassic period.
The Cutler Formation or Cutler Group is a rock unit that is exposed across the U.S. states of Arizona, northwest New Mexico, southeast Utah and southwest Colorado. It was laid down in the Early Permian during the Wolfcampian epoch.
The San Rafael Group is a geologic group or collection of related rock formations that is spread across the U.S. states of New Mexico, Arizona, Utah and Colorado. As part of the Colorado Plateau, this group of formations was laid down in the Middle Jurassic during the Bajocian, Bathonian and Callovian Stages.
The Kayenta Formation is a geological formation in the Glen Canyon Group that is spread across the Colorado Plateau province of the United States, including northern Arizona, northwest Colorado, Nevada, and Utah. Traditionally has been suggested as Sinemurian-Pliensbachian, but more recent dating of detrital zircons has yielded a depositional age of 183.7 ± 2.7 Ma, thus a Pliensbachian-Toarcian age is more likely. A previous depth work recovered a solid "Carixian" age from measurements done in the Tenney Canyon. More recent works have provided varied datations for the layers, with samples from Colorado and Arizona suggesting 197.0±1.5-195.2±5.5 Ma, while the topmost section is likely Toarcian or close in age, maybe even recovering terrestrial deposits coeval with the Toarcian Oceanic Anoxic Event. This last age asignation also correlated the Toarcian Vulcanism on the west Cordilleran Magmatic Arc, as the number of grains from this event correlate with the silt content in the sandstones of the upper layers.
The San Juan Basin is a geologic structural basin located near the Four Corners region of the Southwestern United States. The basin covers 7,500 square miles and resides in northwestern New Mexico, southwestern Colorado, and parts of Utah and Arizona. Specifically, the basin occupies space in the San Juan, Rio Arriba, Sandoval, and McKinley counties in New Mexico, and La Plata and Archuleta counties in Colorado. The basin extends roughly 100 miles (160 km) N-S and 90 miles (140 km) E-W.
The Summerville Formation is a geological formation in New Mexico, Colorado, and Utah of the Southwestern United States. It dates back to the Oxfordian stage of the Late Jurassic.
The Ringbone Formation is a Campanian geologic formation in southwestern New Mexico.
Fujian is a south eastern coastal province of China. The eastern half of the province is largely covered by Jurassic Period acid volcanic rocks and Cretaceous tuffaceous sandstone. However, there are rocks of a variety of ages including the oldest around 1800 Ma. The deposits from the Triassic are predominantly on land, whereas the older ones are marine sediments.
The Mojado Formation is a geologic formation in southwestern New Mexico. It preserves fossils dating back to the early Cretaceous period.
The Curtis Formation is a geologic formation in Utah. It preserves fossils dating back to the Callovian age of the Jurassic period.
The Mural Limestone is a geologic formation of the Bisbee Group in Arizona and Mexico. It preserves fossils dating back to the Cretaceous period.
The Cintura Formation is a geologic formation in the northeastern Sonora of Arizona and Mexico. It preserves fossils dating back to the Cretaceous period.
The geology of Arizona began to form in the Precambrian. Igneous and metamorphic crystalline basement rock may have been much older, but was overwritten during the Yavapai and Mazatzal orogenies in the Proterozoic. The Grenville orogeny to the east caused Arizona to fill with sediments, shedding into a shallow sea. Limestone formed in the sea was metamorphosed by mafic intrusions. The Great Unconformity is a famous gap in the stratigraphic record, as Arizona experienced 900 million years of terrestrial conditions, except in isolated basins. The region oscillated between terrestrial and shallow ocean conditions during the Paleozoic as multi-cellular life became common and three major orogenies to the east shed sediments before North America became part of the supercontinent Pangaea. The breakup of Pangaea was accompanied by the subduction of the Farallon Plate, which drove volcanism during the Nevadan orogeny and the Sevier orogeny in the Mesozoic, which covered much of Arizona in volcanic debris and sediments. The Mid-Tertiary ignimbrite flare-up created smaller mountain ranges with extensive ash and lava in the Cenozoic, followed by the sinking of the Farallon slab in the mantle throughout the past 14 million years, which has created the Basin and Range Province. Arizona has extensive mineralization in veins, due to hydrothermal fluids and is notable for copper-gold porphyry, lead, zinc, rare minerals formed from copper enrichment and evaporites among other resources.
The geology of Yukon includes sections of ancient Precambrian Proterozoic rock from the western edge of the proto-North American continent Laurentia, with several different island arc terranes added through the Paleozoic, Mesozoic and Cenozoic, driving volcanism, pluton formation and sedimentation.
The Toyonishi Group is a group of Mesozoic rock strata in Japan, and was originally named by Tatsuro Matsumoto in 1949. It distributes in the southern half of Shimonoseki City, Yamaguchi Prefecture, southwest Japan, and deposited during the Uppermost Jurassic-Lower Cretaceous along the East Asian continental margin.
The Hell-to-Finish Formation is a geologic formation in southwestern New Mexico. It preserves fossils dating back to the early Cretaceous period.
The Horquilla Formation is a geologic formation exposed in southern Arizona and New Mexico. It preserves fossils dating back to the Pennsylvanian.
The Broken Jug Formation is a geologic formation in southwestern New Mexico. It was likely deposited in the late Jurassic period.
The Hidalgo Formation is a geologic formation of Maastrichtian age in southwestern New Mexico. It is of interest to geologists for the clues it preserves of the nature of Laramide deformation in the latest Cretaceous.