Pages authored by Henry H. Gray:

  1. Surficial Geology / Indiana Glacial Boundries
    There are two “glacial boundaries” of major significance in Indiana geology. The outer boundary, which marks the southernmost advance of the older ice sheets and is commonly known as “the glacial boundary,” transits an inverted U-shaped line across much of southern Indiana.
  2. Surficial Geology / Loess
    Simply put, loess is a deposit of wind-blown silt. A blanket of loess is widespread across the hills of southern Indiana and is an important component of many soils. The term is of German origin and in America is pronounced in many ways, the most common of which is “lus.”
  3. Fossils / Conostichus
    These loose specimens of Conostichus were among many found in the bed of an intermittent stream in southwestern Monroe County, Indiana, where they have weathered out of nearby coal-bearing rocks of Pennsylvanian age.
  4. Fossils / Nautiloids
    In the most recent ice age, which lasted from 2 million to 10,000 years ago, vast seas of ice called glaciers covered much of Indiana. As the glaciers advanced into southeastern Indiana, they scoured the land and exposed the sediments left by a much older shallow inland sea of the Ordovician Period (510 to 438 million years ago).
  5. Rock Unit Names / Maquoketa Group
    Type locality and use of name: The Maquoketa Shale was named by White (1870, p. 180-182) for exposures of blue and brown shale that aggregate 80 feet (25 m) in thickness along the Little Maquoketa River in Dubuque County, Iowa.
  6. Rock Unit Names / Stephensport Group
    Type locality and description: The name Stephensport, though having some earlier mention (see Swann, 1963, p. 83), was formally proposed in a group sense by Gray, Jenkins, and Weidman (1960, p. 37), who redefined it to consist in descending order of the Glen Dean Limestone, the Hardinsburg Formation, the Golconda (now Haney)...
  7. Rock Unit Names / West Baden Group
    Type locality and description: The name West Baden was originally proposed as a group name in 1920 by E. R. Cumings in a letter to Stuart Weller (Cumings, 1922, p. 514). The term received no subsequent use, however, until it was revived in a slightly modified sense by Gray, Jenkins, and Weidman (1960, p. 44-48).
  8. Blue River Group / Aux Vases Formation
    Type section and use of name in Indiana: The name Aux Vases Sandstone was given by Keyes (1892, p. 296) to sandstone exposed in the bluffs at the mouth of the Aux Vases River in eastern Ste. Genevieve County, Mo.
  9. Blue River Group / Renault Formation
    Type locality, characteristic section, and use of name in Illinois: The Renault Limestone was named by Stuart Weller (1913, p. 120, 122) for exposures in Renault Township, Monroe County, Ill., but he designated no type section.
  10. Blue River Group / Ste. Genevieve Limestone
    Type locality and history of name in Indiana: The Ste. Genevieve Limestone was named by Shumard (1860, p. 406; 1873, p. 293-294) for exposures in the bluff of the Mississippi River south of Ste. Genevieve, Mo.
  11. Paoli Limestone / Downeys Bluff Member
    Type section and use of name in Indiana: According to Atherton (1948, p. 129), the name Downeys Bluff was proposed in an unpublished manuscript by F. E. Tipple for a member of the Paint Creek Formation. The unit was later given formational status (Willman and others, 1975, p. 153).
  12. Paoli Limestone / Popcorn Member
    Type section and history of name: The Popcorn Sandstone Bed was named by Swann (1963, p. 32-33) for 7 feet (2.1 m) of fine-grained calcareous sandstone at the base of the Paoli Limestone in Malott's (1952, p. 80) Popcorn Spring section in the SE¼SE¼SW¼ sec.
  13. Paoli Limestone / Shetlerville Member
    Type section and use of name: The Shetlerville Formation was named by Stuart Weller (1920b, p. 123) for exposures of shale and limestone just east of Shetlerville, Hardin County, Ill.
  14. St. Louis Limestone / Sisson Member
    Type and reference sections: The Sisson Member was named by Keller and Becker (1980) for a crossroads community in southern Knox County, Ind. The type section is in the T & H No. 1 Lane well, in sec. 21, T. 1 N., R. 10 W., about 3 miles (5 km) east of Sisson.
  15. Ste. Genevieve Limestone / Levias Member
    Type locality and use of name: The name Levias Limestone Member was given by Sutton and Weller (1932, p. 430, 439) to the part of the Ste. Genevieve Limestone that is above what was then considered the Rosiclare Sandstone Member in the area just east of Levias, Crittenden County, Ky.
  16. Buffalo Wallow Group / Branchville Formation
    Type and reference sections and description: The Branchville Formation was named by Gray (1978, p. 8) for a small settlement in Perry County, Ind.
  17. Buffalo Wallow Group / Degonia Sandstone
    Type locality and description: The Degonia Sandstone was named by Stuart Weller (1920a, p. 403-405 1920b, p. 216) for exposures of massive cliff-forming crossbedded sandstone and thin-bedded ripple-marked sandstone in Degonia Township, Jackson County, Ill. Total thickness of this unit in its type area is as much as 100 feet (30 m).
  18. Buffalo Wallow Group / Kinkaid Limestone
    Type locality and use of name in Indiana: The Kinkaid Limestone was named by Stuart Weller (1920b, p. 218) for exposures of gray and yellow-gray cherry limestone, varicolored shale, and a few thin beds of sandstone along Kinkaid Creek, Jackson County, Ill.
  19. Buffalo Wallow Group / Palestine Sandstone
    Type locality and use of name in Illinois: The Palestine Formation was named by Stuart Weller (1913, p. 128-129) for exposures of thick-bedded sandstone, thin-bedded ripple-marked sandstone, and sandy shale, 75 feet (23 m) in total thickness, in Palestine Township, Randolph County, Ill.
  20. Buffalo Wallow Group / Vienna Limestone Member
    Type locailty and description in Illinois: The Vienna Limestone was named by Stuart Weller (1920a, p. 396-398) for exposures near Vienna, Johnson County, Ill. As originally described, the lower part of the formation was cherty limestone, and the upper part was black fissile shale.
  21. Buffalo Wallow Group / Waltersburg Sandstone
    Type locality and description in Illinois: The Waltersburg Sandstone was named by Stuart Weller (1920a, p. 398) for exposures of a massive cliff-forming sandstone near Waltersburg, Pope County, Ill. The unit is as much as 70 feet (21 m) thick, but it is absent or unrecognizable in many places.
  22. Branchville Formation / Leopold Limestone Member
    Type section and description: The Leopold Limestone Member was named by Gray (1978, p. 10) for exposures near Leopold in central Perry County. The type section is in a road cut on former State Route 37 and was initially described by Malott, Esarey, and Bieberman (1948, p. 13).
  23. Tar Springs Formation / Tick Ridge Sandstone Member
    Type section and description: The Tick Ridge Sandstone Member was named by Gray (1978, p. 8) for Tick Ridge, a physiographic feature 3 miles (4 km) south of Taswell in Crawford County, Ind. A section about 2 miles (3 km) north of Taswell, first described by Malott (1925, p. 129), was designated as the type section.
  24. Tobinsport Formation / Bristow Sandstone Member
    Type section and history of name: The Bristow Sandstone Member was named for Bristow in west-central Perry County, Ind. The name was originally applied in a formational sense (Malott, 1925, p. 111-112) but was later suppressed in favor of the term Palestine Sandstone from the standard Chesterian section (Malott, 1931, p. 222).
  25. Tobinsport Formation / Siberia Limestone Member
    Type section and history of name: In Malott's (1925) seminal paper on outcropping upper Chesterian rocks of southernmost Indiana, he identified and traced a thin limestone bed that had earlier been named, but not described, as the Siberia Limestone (Malott and Thompson, 1920).
  26. Maquoketa Group / Dillsboro Formation
    Type area, representative sections, and former names: The name Dillsboro Formation was proposed by Brown and Lineback (1966, p. 1020-1021) for "the sequence of highly fossiliferous argillaceous limestones and cat careens shales that lie between the shale of the Kope Formation and the dolomitic limestone of the Saluda Formation [now a...
  27. Maquoketa Group / Kope Formation
    Type area, former names, and use of name in Indiana: Weiss and Sweet (1964) proposed the name Kope Formation for 240 feet (75 m) of shale and minor interbedded limestone that “lies between the Point Pleasant formation and shaly limestones equivalent to the Fairmount and MacMillan formations” m the Maysville area of Kentucky and Ohio.
  28. Maquoketa Group / Scales Shale
    Type locality and use of name in Illinois: The Scales Shale was initially named the Scales Formation by Templeton and Willman (1963, p. 135) for the village of Scales Mound, Jo Daviess County, Ill., near which the formation is exposed in railroad cuts.
  29. Maquoketa Group / Whitewater Formation
    Type Locality, description, and correlation: The Whitewater Formation was named by Nickles (1903, p. 208) for exposures of bluish-gray rubbly limestone and interbedded calcareous shale along the Whitewater River at Richmond, Wayne County, Ind.
  30. Whitewater Formation / Saluda Member
    Type locality and use of name: The name Saluda Bed was first used by Foerste (1902, p. 369) in describing a cliff-forming gray silty dolomitic limestone exposed along Saluda Creek 6 miles (10 km) south of Hanover, Jefferson County, Ind. The name replaced the term Madison Beds (of Borden, 1874, and others), which was preoccupied.
  31. Stephensport Group / Beech Creek Limestone
    Type section and description: The Beech Creek Limestone was named by Malott (1919, p. 11-15) for exposures along Beech Creek in Greene County, Ind. Malott later (19b2, p. 73-78) designated a type section at Rays Cave in sec.
  32. Stephensport Group / Big Clifty Formation
    Type locality and history of name in Indiana: The name Big Clifty Sandstone is generally credited to Norwood (1876), who, however, did not specifically indicate the source of the name. Presumably it derives from Big Clifty Creek in Grayson County, Ky. (Butts, 1917, p. 87; Willman and others, 1975, p. 157).
  33. West Baden Group / Bethel Formation
    Type locality and history of name in Indiana: The name Bethel Sandstone was first used by Butts (1917, p. 63-64) in describing exposures of thick-bedded coarse-grained sandstone and slabby sandstone 10 to 40 feet (3 to 12 m) thick in the vicinity of Bethel School, near Marion, Crittenden County, Ky.
  34. West Baden Group / Elwren Formation
    Type locality, reference section, and description: The Elwren Sandstone was named by Malott (1919, p. 11) for a series of exposures “in the cuts of the Illinois Central Railway” near Elwren, Monroe County, lnd.
  35. West Baden Group / Reelsville Limestone
    Type section and description: The Reelsville Limestone was named by Malott (1919, p. 10-11) for exposures of gray, biomicritic, somewhat ferruginous, and locally sandy limestone about 3 feet (1 m) thick near Reelsville, Putnam County, Ind.
  36. West Baden Group / Sample Formation
    Type locality and use of name in Indiana: The Sample Formation was originally named the Sample Sandstone Member of the Gasper Oolite by Butts (1917, p. 70-73), who designated a type locality at Sample Station, Breckinridge County, Ky.