Bed 7l (Arkill Limestone) - Saavedra Mbr, Lowell Fm, Ninety One Hills (Cretaceous of the United States)

Where: Cochise County, Arizona (31.4° N, 109.9° W: paleocoordinates 32.0° N, 63.5° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Saavedra Member (Lowell Formation), Aptian (125.0 - 113.0 Ma)

• STRATIGRAPHIC RELATIONS: Overlying the Joserita Mbr (Aptian) and underlying the Cholla Mbr (Aptian) of the Lowell Fm (Aptian-Albian). THICKNESS: 2 ft thick unit. AGE: Aptian, based on ammonite and trigoniid biostratigraphy. STRATIGRAPHIC POSITION: Immediately above Bed 7m and below Bed 7k of the Saavedra Mbr.

• bed-level stratigraphic resolution

Environment/lithology: lithified, shelly/skeletal, brown, gray, sandy limestone

• ENVIRONMENT: Environmental data not reported, presumably shallow water carbonate. PROVINCE: Pedregosa basin
• SPECIFIC LITHOLOGY: Grayish brown and buff arenaceous limestone replete with skeletal material. LITHIFICATION: Lithified, based on facies description, figures and age.

Size class: macrofossils

Reposited in the USNM

• COLLECTOR: A. Stoyanow, assisted by G. Scott, J.B. Reeside, and R.W. Imlay. REPOSITORY: USNM, Washington and U. Texas and Bureau of Economic Geology, Texas.

Primary reference: A. Stoyanow. 1949. Lower Cretaceous stratigraphy in southeastern Arizona. Geological Society of America Memoir 38:1-156 [A. Hendy/A. Hendy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 65002: authorized by Austin Hendy, entered by Austin Hendy on 18.09.2006

Creative Commons license: CC BY (attribution)

Taxonomic list

• COMPLETENESS: Not exhaustive, but representative of common and biostratigraphically significant forms. NOMENCLATURE: Authoritative publication for ammonites and bivalvia, and hence these carry species-level names; other taxa often not designated with species-level names.
Show authors, comments, and common names
Bivalvia
 Trigoniida - Trigoniidae
Trigonia reesidei
Trigonia reesidei Stoyanow 1949 clam