Where: California (35.0° N, 116.8° W: paleocoordinates 34.1° N, 111.2° W)

When: Calico Member (Barstow Formation), Hemingfordian (20.4 - 16.0 Ma)

• Overlying fine-grained lacustrine beds (here referred to as the Calico Member of the Barstow Formation) are bracketed between ca. 19 and 16.9 Ma, and are thus older than the type section of the Barstow Formation in the Mud Hills. Several 17.1–16.8 Ma calc-alkaline dacite domes intrude the Calico Member.

Environment/lithology: lacustrine - large; lithified, nodular, brown shale

Size class: macrofossils

Preservation: replaced with calcite, replaced with silica, replaced with other

Collection methods: Repository: private collection of Ruth Kirkby, Riverside, California

Primary reference: W. D. Pierce. 1960. Fossil arthropods of California no 23. Silicified insects in Miocene nodules from the Calico Mountains. Bulletin of the Southern California Academy of Sciences 59:40-49 [M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 152198: authorized by Matthew Clapham, entered by Matthew Clapham on 11.11.2013

Creative Commons license: CC BY (attribution)