Bed 2b - Perilla Mbr, Lowell Fm, Ninety One Hills (Cretaceous of the United States)

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

• Paleocoordinates: 38.9° N, 62.8° W (Wright 2013)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Perilla Member (Lowell Formation), Albian (113.0 - 100.5 Ma)

• STRATIGRAPHIC RELATIONS: Overlying the Quajote Mbr (Aptian) and underlying the Pedregosa Mbr (Albian) of the Lowell Fm (Aptian-Albian) . THICKNESS: 85 ft thick unit. AGE: Albian, based on ammonite and trigoniid biostratigraphy. STRATIGRAPHIC POSITION: Immediately above Bed 2c and below Bed 2a of the Perilla Mbr.

• group of beds-level stratigraphic resolution

Environment/lithology: coastal; poorly lithified, yellow shale and poorly lithified, argillaceous limestone

• ENVIRONMENT: Environmental data not reported, presumably shallow water siliciclastic. PROVINCE: Pedregosa basin
• SPECIFIC LITHOLOGY: Friable, light-yellow shale and distintergrated argillaceous limestone. LITHIFICATION: Poorly 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 64987: authorized by Austin Hendy, entered by Austin Hendy on 18.09.2006

Creative Commons license: CC0 (CC0)

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 ex gr. aliformis, Trigonia mearnsi, Trigonia stolleyi
Trigonia mearnsi Stoyanow 1949 clam
Trigonia stolleyi Hill 1893 clam
 Carditida - Astartidae
Astarte adkinsi
Astarte adkinsi Stoyanow 1949 clam
 Pectinida - Neitheoidae
Neithea vicinalis
Neithea vicinalis Stoyanow 1949 scallop
 Pectinida - Pectinoidae
Pecten peregrina