Abstract The West Bernard area is in northern Wharton County, Texas, 60 mi west of Houston. It encompasses approximately 120 sq mi and includes eight gas fields. Total gas reserve (502 billion cu ft) is mostly in two fields—West Bernard, in which the structure is a large, low-relief Yegua anticline, and Spanish Camp, in which the structure is a prominent Miocene anticline. The most important and outstanding structural element is a Frio-Vicksburg isopachal anticline which covers the entire area. Stratigraphy is a major factor in effecting accumulation, particularly in the formation of many small pools. The most interesting and important stratigraphic feature is the West Bernard field Clodine (Yegua) sandstone bar, which contains approximately one-tenth of the area's gas reserves. Gas first was discovered in December 1936 in Miocene sandstone at Spanish Camp field. East Bernard field, which first produced from the Yegua, was discovered in May 1940. West Bernard field, which contains most of the Yegua reserves, was found in 1947. The small South Lissie field is the most recent discovery (May 1958). Total daily production from the area is 37 million cu ft of gas and 110 bbls of condensate. The condensate and half of the gas are derived from the Yegua, and the remaining (dry) gas is obtained from Miocene sandstone and from the Frio. Oil has not been found in commercial quantities, but a few wells did penetrate very thin oil columns.

ABSTRACT Seventy-seven species of smaller calcareous foraminifers belonging to thirty-two genera and fourteen families, and two groups of uncertain affinity are distinguished in Mississippian and Lower Pennsylvanian strata from four localities in southern and eastern Nevada. Most belong to the Superfamily Endothyraceae, a group characterized by skew, planispiral, or erect growth, a simple or cribrate aperture, and a layered wall of secreted calcite. Five new species are named. The Mississippian foraminifers permit recognition of assemblage zones based on the global zonation scheme of Bernard Mamet. The Pennsylvanian strata are not zoned. Formations studied in the Arrow Canyon Range, north-central Clark County, include the Crystal Pass Limestone, Dawn Limestone, Anchor Limestone, Bullion Limestone, Yellowpine Limestone, Battleship Wash Formation, Indian Springs Formation, and the lower part of the Bird Spring Formation. The Joana Limestone was studied southwest of Ely, Nevada, at Ward Mountain in the Egan Range, and the lower part of the exposed Ely Limestone was studied northwest of Ely in the vicinity of the Moorman Ranch and in the Butte Mountains. The upper part of the Crystal Pass Limestone in the Arrow Canyon Range contains foraminifers that appear to be late Kinderhook in age, but the lower beds lack stratigraphically useful foraminifers. The entire formation has been previously assigned to the Late Devonian on the basis of conodont assemblages. The Dawn Limestone which disconformably overlies the Crystal Pass Limestone is early and middle, and, possibly, late Osage in age. The successively overlying Anchor and Bullion Limestones contain only sparse, nondiagnostic foraminifers, but, based on their stratigraphic position, they are late Osage to middle Meramec. The overlying Yellowpine Limestone and the lower beds of the Battleship Wash Formation contain a well developed middle and late Meramec fauna; however, the upper part of the Battleship Wash is middle to late Chester with no evidence of an intervening early Chester fauna. The Indiana Springs Formation and the lowest part of the overlying Bird Spring Formation are late Chester. The remainder of the Bird Spring that was measured was deposited in Morrow time. At Ward Mountain the lower member of the Joana Limestone has a late Kinderhook fauna. The upper member is Osage in age. Foraminifers are scarce in the lower part of the exposed Ely Limestone at the Moorman Ranch and Butte Mountains sections. The microfaunal associations suggest a Morrow age for these rocks.