Формация Кармель в штате Юта: Геологическое описание и история изучения.

Geological formation in Utah, U. S.

The Carmel Formation is a geologic formation in the San Rafael Group that is spread across the U. S. states of Wyoming, Utah, Colorado, north east Arizona and New Mexico. Part of the Colorado Plateau, this formation was laid down in the Middle Jurassic during the late Bajocian, through the Bathonian and into the early Callovian stages.

In 1928 Gilluly and Reeside stated an intent to name the formation after the village of Mount Carmel, Utah but did not give a type locality. They noted it as a basal formation in the San Rafael Group in San Rafael Swell, in Emery County, Utah. An overview along with a type locality and source of name was stated by Gregory and Moore in 1931. Mackin revised the formation's description and assigned the Homestake Limestone Member to it in 1954. Harshbarger and others created an overview in 1957. Its eastern areal limits were described by Wright and others in 1962. In 1963, western areal limits along with an overview were completed by Schultz and Wright. Another revision was done by Phoenix in 1963 who also added a Judd Hollow Tongue member. Isotopic dating was conducted by Marvin and others in 1965. The Kolob, Crystal Creek, Paria River, Winsor, and Wiggler Wash members were assigned by Thompson and Stokes in 1970. Areal limits were adjusted by O'Sullivan and Craig in 1973 and again in 1983 by Blakey and others. An overview was completed by Chapman in 1989. Hintze and others conducted isotopic dating and created an overview in 1994.

There have been a number of paleontological finds within the Carmel Formation. Among these have been bryozoans, and dinosaur footprints.

The formation preserves a rare Jurassic hardground interpreted as a carbonate lagoon between oolitic shoals and a subtidal zone. The hardground community was dominated by bivalves such as Liostrea, Plicatula, and Modiolus. The ichnofossil Gastro‐chaenolites is present, often with fossils of Lithophaga preserved inside. The rare bryozoan Arachnidium is found in attachment scars of Liostrea. Though bivalves were abundant, the community is lacking in the diversity seen in other Jurassic hardgrounds, suggesting a restricted shelf environment.