Hell-to-Finish Formation
Geologic formation in New Mexico
From Wikipedia, the free encyclopedia
The Hell-to-Finish Formation is a geologic formation in southwestern New Mexico. It preserves fossils dating back to the early Cretaceous period.[1][2][3]
| Hell-to-Finish Formation | |
|---|---|
| Stratigraphic range: | |
| Type | Formation |
| Unit of | Bisbee Group |
| Underlies | U-Bar Formation |
| Overlies | Various Paleozoic units, Broken Jug Formation |
| Thickness | 1,700–3,500 feet (520–1,070 m) |
| Lithology | |
| Primary | Shale, mudstone, siltstone |
| Location | |
| Coordinates | 31.5433°N 108.3411°W |
| Region | New Mexico |
| Country | United States |
| Type section | |
| Named for | Hell-to-Finish tank |
| Named by | R.A. Zeller Jr. |
| Year defined | 1965 |
  Hell-to-Finish Formation (the United States)  Hell-to-Finish Formation (New Mexico) | |
Description
The formation consists mostly of red to red-brown to gray or green shale, mudstone, and arkosic siltstone. The base of the formation is a well indurated conglomerate derived from the underlying Paleozoic beds. Minor arkose and limestone are present in the uppermost beds.[1] The total thickness is up to 1,700–3,500 feet (520–1,070 m) but varies considerably over the region. The formation rests on a profound unconformity with underlying Paleozoic formations in most locations, but overlies the Broken Jug Formation in the Little Hatchet Mountains.[4] The Hell-to-Finish Formation is transitional to the overlying U-Bar Formation.[3] The transitional contact with the Aptian U-Bar Formation suggests that the Hell-to-Finish Formation cannot be much older than Aptian.[5]
The formation is interpreted as being deposited in an arid client, based on the nature of paleosols within the formation.[6] Deposition took place in a west-northwest-trending rift basin.[7]
Fossils
The upper beds of the formation contain abundant pelecypods.[1] However, no age-diagnostic fossils have been found in the formation.[5]
History of investigation
The formation was first defined by Zeller in 1965 for exposures near the Hell-to-Finish tank in the southern Big Hatchet Mountains of New Mexico.[1]
