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Significance of Landfills As Sources of Fossils
Physical Aspects:
Location:
- Landfills are distributed throughout California from Oregon to
Mexico.
- They are located from the Pacific coast to the eastern slopes of the
Sierra Nevada.
Numbers: There are over 188 landfills operating within California (CIWMB
Solid Waste Information System Database as of April 1999).
Physical Dimensions:
Landfills range from 1 acre to 2,290 acres in size.
Landfill Depths can attain over 100 feet, providing for a long,
continuous stratigraphic record to be exposed.
Volumes of material in soil moved or removed can range in millions of
cubic yards.
These volumes can be removed in relatively short periods of time.
Time Durations:
Landfills can operate for long periods of time 5 to 100 years or longer.
- Provides for long-term research plans.
- Massive volumes of material can be removed over the lifetime of the
landfill.
- Materials that would take a lifetime with manual labor can be
excavated within days.
- Repeated visits to a site can be carried out until closure, which
can be years away.
Variety of Locations:
The 188 landfills scattered across the state provide potential for species
geographic distribution data.
Temporal distributions can be researched as species occur in different
age deposits, providing insight into longevity of species.
Fossils from a broad geologic time span and paleoenvironments are
potentially accessible as landfills occupy every geologic province in
California.
Currently, 28 landfills have yielded significant assemblages of fossils.
Ten sites have yielded significant vertebrate assemblages:
- 7 Land vertebrate assemblages.
Megavertebrates: Camelidae, Oreodonts, Equus.
Microvertebrates: Squirrel, pocket mouse, shrew.
- 6 Marine vertebrate assemblages.
Smaller bony fishes; barracuda, surgeonfish.
Cartilaginous fishes; sharks, rays.
Whales, dolphins, sea lions, manatee-like, and walrus-like mammals.
In addition, 15 sites have yielded marine invertebrate assemblages.
- Molluscs: Gastropods, Pelecypods, Cephalopods.
- Echinoidea: Urchins, sand dollar.
- Corals, Annelid worms, Foraminifera.
- One very rare, diverse faunal association of marine vertebrate,
invertebrate, microinvertebrate, land and marine plant fossils found in
a single assemblage - Puente Hills LF
Significant Discoveries from landfill finds, including:
New Species:
- Iguanid lizards, mice, didelphid marsupial - Frank R. Bowerman
LF
- Paradjidaumo, Namatomys, Simimys, Simimeryx heliscomys,
Macrotarsius roederi (Primate) - Simi Valley LF
- Great White Shark (Carcharocles megalodon): (rarely found) -
Santiago LF
Extended species distributions:
- Eurhinodelphidae: Dolphin found at F.R. Bowerman LF extends its
living (geographic) range several hundred miles SW of its current
known range.
- Nautiloid cephalopod: first found in California F.R. Bowerman
LF. Expands from W. Pacific, to Eastern Pacific region.
- Smaller vertebrates: more common than once realized - Simi
Valley LF
Extended temporal distributions:
- Didelphid marsupial specimen extends N. American age range.
- Baleen whale skeleton - First reported in Sycamore Canyon fm.
- Crocodile - Oldest recorded for the Sespe Fm. - Simi Valley LF
- Discovery of youngest known record of genus Eohaplomys (beaver).
Better understanding of paleoenvironments:
- Santiago LF - Indicates floodplain environments.
- F.R. Bowerman LF - Marsh environments and accompanying shallow
bays, sandy beaches and rocky areas.
- Signs at Simi Valley LF - point to a tropical climate with
intermittent flooding and seasonal drought.
- Signs of cool climate Repetto Fm - Puente Hills LF
Better age-dating of formations:
- Microvertebrates’ rapid evolution provides finer dating of
formations.
- Irvington Antelope and Armbrusters Wolf found at Fairmead site
firmly date the sediments there.
Improved understanding of known species, paleoenvironments, etc:
- Pachycetus: whale skeleton provided new information on its
sketchy record.
- New finds of rare known species: Wolf Eel and Mantis Stabbing
Shrimp - Prima Deshecha LF.
- Rare, or once considered absent, species of lizard (Paleoxantusia)
and shrew-like insectivores; Centetodon, Batodonoides, Proterixoides,
and first bats - Simi Valley LF.
- Accurate representation of species population ratios - Fairmead
LF.
These programs and legislation provide protections for paleontological
resources:
- National Historic Preservation Act (16 USC 470 Et Seq.).
- The Antiquities Act of 1906.
- The National Landmark Program, 1962.
- Surface Mining and Reclamation Act, 1977 (when dealing with mining and
gravel extraction sites).
- Federal Land Management and Policy Act 1976.
- National Environmental Policy Act 1969.(42 USC 4321-4347).
- In California:
- California Environmental Quality Act (CEQA).
- California Public Resources Code, Sec. 5097.
Importance of a Prepared Plan for Retrieval of Fossils:
- Avoids delays to operator for preparation of disposal site—their
main goal.
- Improves operator’s confidence in the procedure the next time a
locality is discovered.
- Assures specimens will be retrieved.
- Assures compliance with state and federal regulations (CEQA, etc).
Plans for Future Statewide Contact Listing and Policy
- CIWMB Policy/ LEA Advisory for procedures of operator contact and
remediation based on current working models.
- Reference list of institutions, qualified individuals for contact by
operators and Local Enforcement Agencies. Available through CIWMB, for
future needs in Landfills inexperienced with the process.
- Study, resolve shortcomings still present in current process. Work with
experts in the process for future projects.
- Coordination with CEQA requirements.
- Informational database in SWIS and web page for research use.
To Participate in the CIWMB Policy and Database Project
Contact: Jacques Graber
Associate Engineering Geologist
Remediation, Closures and Technical Services Branch
California Integrated Waste Management Board
PO Box 4025
Sacramento, Ca 95812
E-mail:
jgraber@ciwmb.Ca.Gov
Acknowledgements
For providing information on the landfills:
- Diana Wier—RMW Paleo-Associates
- Mark A. Roeder—Paleoenvironmental Associates
- E. Bruce Lander—Paleoenvironmental Associates
- Robert G. Dundas—Museum of Paleontology, U.C. Berkeley
- Kathleen Springer—San Bernardino Co. Museum
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