GEOLEX

Summary of Citation: Beclabito

Publication:
Condon, S.M. and Huffman, A.C., Jr., 1988, Revisions in nomenclature
   of Middle Jurassic Wanakah Formation, northwest New Mexico
   and northeast Arizona, IN Revisions to stratigraphic nomenclature
   of Jurassic and Cretaceous rocks of the Colorado Plateau:
   U.S. Geological Survey Bulletin, 1633-A, p. A1-A12

Usage in Publication:
Beclabito Member*

Modifications:	Geologic Province:	Dominant Lithology:
Named	San Juan basin Black Mesa basin	Sandstone Siltstone Mudstone

Summary:
Named middle member, Wanakah Formation, San Rafael Group for Beclabito dome, San Juan Co, NM. Type section measured at Horse Mesa which extends from sec 17, T38N, R31E, Apache Co, AZ, Black Mesa basin to secs 26, 27, T29N, R21W, San Juan Co, NM, San Juan basin. Recognized throughout northwest NM and northeast AZ. Name applied to rocks that were formerly assigned to Summerville Formation, term restricted in this report to San Rafael Swell area, UT. Most outcrops examined are on west side of basin. Not identifiable with certainty south of Toadlena. Consists of reddish-orange to reddish-brown sandstone, siltstone, sandy siltstone, mudstone. Sandstone is very fine, fine, and medium grained, well to moderately sorted, subangular to subround. Sedimentary structures consist of ripple cross stratification, small scale trough cross-beds, and wavy, subparallel, horizontal laminations. A thick-bedded to massive, structureless sandstone (35 ft thick at type) at base occupies same stratigraphic position as Bilk Creek Sandstone Member of Wanakah in southwest CO. Siltstone and mudstone are red brown, wavy laminated. Is 108 ft thick at type. Ranges from 125 to 200 ft thick. Overlies Todilto Limestone Member (reduced rank); underlies Horse Mesa Member (new), both of Wanakah. Intertongues with Cow Springs Sandstone. Middle Jurassic age. Deposited on margin of Todilto-Pony Express basin as coastal sabkha-marginal marine unit. Rocks equivalent to Beclabito of se UT.

Summary of Citation: Beclabito

Publication:
Condon, S.M., 1989, Revisions of Middle Jurassic nomenclature
   in southeastern San Juan basin, New Mexico, IN Evolution of
   sedimentary basins, San Juan basin: U.S. Geological Survey
   Bulletin, 1808-E, p. E1-E21

Usage in Publication:
Beclabito Member*

Modifications:	Geologic Province:	Dominant Lithology:
Revised Overview	San Juan basin

Summary:
As the middle member of Middle Jurassic Wanakah Formation of San Rafael Group, Beclabito underlies, in the southeast San Juan basin and Acoma Sag area, the newly named Mesita Member, upper member of the Wanakah. Composed of interbedded reddish-brown to white, silty sandstone, sandy siltstone, and claystone. Forms steep slopes or series of ledges above Todilto Limestone Member of Wanakah. Ranges from 0 in south to 125 ft thick at Mesita. Individual beds have ripple cross-laminations, small-scale cross-bedding, and irregular, subhorizontal wavy laminations or flat-bedding. Is generally very fine to fine grained, but becomes coarser grained to south. Basal beds grade south into chert-pebble conglomerate. Is of marginal marine, sabkha, and fluvial origin. Cross section; nomenclature chart.

Summary of Citation: Beclabito

Publication:
Condon, S.M., 1989, Stratigraphic sections of the Middle Jurassic
   Wanakah Formation, Cow Springs Sandstone, and adjacent rocks,
   from Bluff, Utah, to Lupton, Arizona: U.S. Geological Survey
   Oil and Gas Investigations Chart, OC-131, 1 sheet

Usage in Publication:
Beclabito Member*

Modifications:	Geologic Province:	Dominant Lithology:
Areal limits	San Juan basin Paradox basin Black Mesa basin

Summary:
In the Todilto Park area, the Beclabito Member of Wanakah Formation and the Cow Springs Sandstone intertongue. The Chuska Mountains are used as an arbitrary dividing line between use of Beclabito to north in San Juan Co, NM, San Juan basin, Apache Co, AZ, Black Mesa basin, and San Juan Co, UT (as far north as Bluff), Paradox basin, and use of Cow Springs to south in McKinley Co, NM, San Juan basin.

Summary of Citation: Beclabito

Publication:
GNU Staff, 1989, GNU Staff remark by M.E. Mac Lachlan.  Relationship
   of Zuni Sandstone (Jz), Cow Springs Sandstone (Jcs), Entrada
   Sandstone (Je), and Wanakah Formation (Jw) in San Juan basin
   (adapted from Condon and Huffman, 1988; Condon, 198?).: U.S.
   Geological Survey, unpublished geologic names committee note

Usage in Publication:
Beclabito Member

Modifications:	Geologic Province:	Dominant Lithology:
Figure	San Juan basin

Summary:
Members of Wanakah: Jwt, Todilto Limestone Member; t, Todilto notch of Anderson (1983); Jwpe, Pony Express Limestone Member; Jwb, Beclabito Member; Jwbc, Bilk Creek Sandstone Member; Jwhm, Horse Mesa Member; Jwu, upper member. [We apologise. The figure for this synopsis is being reconstructed.]

Summary of Citation: Beclabito

Publication:
Condon, S.M., 1992, Geologic framework of pre-Cretaceous rocks
   in the Southern Ute Indian Reservation and adjacent areas,
   southwestern Colorado and northwestern New Mexico, IN Geology
   and mineral resources of the Southern Ute Indian Reservation:
   U.S. Geological Survey Professional Paper, 1505-A, p. A1-A56

Usage in Publication:
Beclabito Member*

Modifications:	Geologic Province:	Dominant Lithology:
Areal limits	San Juan basin Paradox basin Black Mesa basin

Summary:
Wanakah Formation unconformably overlies Entrada Sandstone. In AZ, it and NM is divided into (ascending): Todilto Limestone, Beclabito, and Horse Mesa Members. In adjacent southwest CO, it is divided into (ascending): Pony Express Limestone, Bilk Creek, and an upper member. Pony Express = Todilto, Bilk Creek and the upper member = Beclabito. The basal unit (of 3) of Junction Creek Sandstone = Horse Mesa. Isopach maps of the members and = rocks shows interval present throughout report area (NM, CO, UT, AZ; San Juan, Black Mesa, and Paradox basins. Todilto (and Pony Express) may be thick as 120 ft; was deposited in a large restricted marine basin. The Beclabito (and Bilk and upper member) also present throughout area described above (isopach map); may be 150+ ft thick; is a marginal marine and sabkha deposit. The Horse member (and lower unit of Junction Creek) are also present over area described above, may be as thick as 80 ft; is of lacustrine origin. Middle Jurassic age.