Abstract Strata of the Valmeyer Anticline are exposed in road anstream cuts along Illinois 156 (Fig. 1), which passes throughDennis Hollow from the east edge of Valmeyer to 1.5 mi (2.4km) east of Valmeyer, Monroe County (Sec.2, SE¼SE¼Sc.3, and N½Sec.10, T.3S., R.11W.; Valmeyer 7.5-minute Quadrangle);they are also exposed in the bluff face at Columbia QuarryPlant No. 3, which is 0.9 mi (1.5 km) north of Valmeyer(SE¼NW¼Sec.3, T.3S., R.11W.). The outcrops along Illinois 156are easily accessible with no more than a 300 ft (100 m) walkfrom the highway. Automobile parking is limited to a few widegrassy pullouts adjacent to the south side of the highway andalong driveways of property owners. The area north of Illinois156 has several owners; therefore permission to enter should beobtained from residents nearest a particular outcrop.

Abstract The Deerfield oil field, representing the only commercial production from the Trenton formation in Michigan, is centrally located near the western boundary of Monroe County, 35 miles southwest of Detroit. Activity in this field which started during 1920 was renewed in the spring of 1927 and has continued intermittently to the present time. This field, the northward extension of the "Bowling Green fault" or "drop-off," is on the northern and western edges of a north-plungingstructural nose on the northwestern flank of the Cincinnati arch. The Trenton formation is encountered at depths ranging from 2,050 to 2,110 feet. The producing zones are of secondarily crystallized dolomite and occur at various depths in the upper 125 feet of the Trenton. A non-productive area on top of the anticline is caused by a greater westward dip of the oil zones than of the Trenton formation. The productive closure is a 40- to 50-foot "halo" on the north and west flanks of the fold. The productive area is, therefore, approximately 220 acres with a total estimated recovery of 2,500 barrels per acre. This reservoir is of the gas-expansion type with no apparent water drive. The oil is dark green and has a gravity of 42.7º and a sulphur content of 0.17 per cent. Forty producing wells have been drilled into the field and seventeen of these are now on production. Two tests have been drilled below the Trenton. The deepest test, the Consolidated Development Company’s Lamont Bragg B-2, reached the total depth of 3,250 feet. It was estimated that the granite would have been encountered at approximately 3,800 feet.

Abstract The Monroe gas field, located in northeastern Louisiana, is about 425 square miles in area. It ranks third in area and initial reserves among the known gas fields, and has accounted for a large part of the natural gas production in Louisiana. Gas is produced from two separate reservoir zones known as the “Gas rock” and the “Second sand.” The Gas rock, or upper zone, occurs at depths ranging from 2,050 to 2,300 feet. In the western part of the field it lies within the Navarro (Upper Cretaceous) and consists of chalk and chalky sands of primary porosity. Because of erosion or non-deposition, the Navarro is absent over the central and eastern parts of the field where the Gas rock passes laterally into the eroded and leached part of older chalk beds, the Monroe gas rock formation (Upper Cretaceous). The Second sand, or lower reservoir zone, occurs 100–250 feet below the Gas rock horizon. It is in part Woodbine (Upper Cretaceous) in age, and in part Comanche. As of December, 1932, 876 gas wells have been completed in the field. Of approximately 70 wells testing the Second sand only 23 commercial wells have been obtained. The initial well-head pressure of each of the reservoirs was 1,020 pounds per square inch. The initial open-flow volumes from both the Gas rock and Second sand have ranged as high as approximately 50 million cubic feet. Approximately 1,592 billion cubic feet (metered and wasted) of gas have been taken from the reservoirs to the end of 1032.