ANAMAR News

Stay up to date with our latest news.
Sep
01

What can fossils tell us about the rock surrounding them? Fossil scallops in the Coquille River as a case study

During a benthic survey off the Coquille River, Oregon, in September 2013, ANAMAR was collecting samples of epifauna using a 12-foot otter trawl when suddenly the gear encountered unidentified rock.  The trawl net snagged and the cable instantly snapped, losing the gear on the seafloor in about 45 feet of water.  Although many attempts were made to recover the trawl using a grapple hook off the deck of the survey vessel (R/V Pacific Storm), the gear was too entangled on the seafloor to be brought up with that method.  Directly following completion of the benthic survey, an ANAMAR subcontractor returned to the site and recovered the trawl gear using SCUBA divers.  The trawl was still in good shape and the remaining trawl tows were completed for the survey.  In addition to finding the trawl gear, the divers also observed several fossil scallop shells embedded in the rock on the seafloor.  The fossil scallops were in excellent condition (see images below).  The divers were able to pry a few of the fossil shells loose for closer inspection and photography.

Fossil Scallops Coquille Pic1

Because the area where the survey took place is an ocean dredged material disposal site (ODMDS), information on the naturally occurring rocks found there is of interest to agencies tasked with managing the site (U.S. Army Corps of Engineers and the U.S. Environmental Protection Agency).  For this reason, and also out of personal interest, I began collaborating with paleontologists to determine the identity of the fossil scallops in the hopes of learning more about the rock they were found in.  I soon found my answer after contacting specialists at the Burke Museum of Natural History in Seattle, Washington.  Dr. Elizabeth Nesbitt, Curator of Paleontology, graciously identified the fossil scallops as either Patinopecten coosensis or P. oregonensis based on photos I sent her.  The flared portions of the shell adjacent to the hinge (called auricles) serve as key characteristics differentiating these two species.  These fossils lacked auricles so they could not be identified beyond these two species.  However, based on the fossils and the associated matrix, Dr. Nesbitt was able to identify the rock formation the fossils were found in!

The rocks and fossils are part of the Empire Formation which is better known from exposures about 20 miles south of the Coquille River, at Cape Blanco, Oregon.  The Empire Formation, composed mostly of sandstone, along with the fossils it contains, are as old as 12 million years (Miocene) but it is theorized to be closer to 8 to 5 million years (Miocene-Pliocene epoch boundary).  Since we know the identity of the rock as being part of the Empire Formation, we therefore know something about its composition.  In this case, the rocks that snagged the trawl gear must have been composed of sandstone and some siltstone.  This formation represents sands deposited in what was then a small marine basin, which now is only represented by Coos Bay.  It is probable that other rocks within the ODMDS are also fossiliferous sandstone/siltstone from the Empire Formation.

The above is an example of how fossils can help us infer the identity of the surrounding substrate.  In this case, the identity of the fossil scallops, along with the matrix attached to the fossils, were used to pinpoint the exact formation they represent.  Knowing the formation, we then were able to learn more about the composition and approximate geological age of surrounding rocks that represent the same formation.  All this information came from observing and collecting a handful of fossils incidental to recovering of some equipment from the seafloor!

Interestingly, the French word for scallop is Coquille.  Thus, the Coquille River, where the fossils were collected, was actually named after a scallop!

Sources:

Ehlen, J.  1967.  Geology of state parks near Cape Arago, Coos County, Oregon.  The Ore Bin 29(4):61–82. 

Nesbitt, E.  Department of Paleontology, Burke Museum of Natural History, University of Washington, Seattle, WA.  Pers. comm. 12/06/13.

Portell, R.W.  Department of Invertebrate Paleontology, Florida Museum of Natural History, University of Florida, Gainesville, FL.  Pers. comm. 11/18/13.

Continue reading
  171 Hits
0 Comments
171 Hits
  0 Comments
Jan
30

Military Ocean Terminal Sunny Point: Army's Primary East Coast Deepwater Port

Many of us probably don’t think about the importance of dredging in relation to national security and maintaining access to our military bases and terminals.  Maintaining access to navigation basins, access channels, and berthing areas is a critical component in our nation’s ability to accomplish its military and national security mission.  When these waterways and berthing areas become shoaled, the immediate capacity of a facility or base to transport materials and personnel is reduced or delays are incurred until full project capabilities are restored through dredging. 

ANAMAR recently sampled and tested dredge material at the Military Ocean Terminal Sunny Point (MOTSU), which is one of the largest military terminals in the world.  It is a high-security facility that is constantly patrolled by boats with armed soldiers.  And for good reason—MOTSU is the key ammunition shipping point on the Atlantic coast for the Department of Defense and is the Army's primary east coast deepwater port.  As the world's largest military terminal, Sunny Point ships more explosive cargo and equipment to the nation's armed forces and allies than any other facility.  The mission of the facility is to be prepared to quickly and effectively support the U.S. military and allies through the shipment of munitions, ordnance, or other military materials in response to any global situation or military requirement.  The maintenance of navigation depth at MOTSU is a prerequisite to maintaining a high state of operational preparedness at the facility.

Built in 1951, the terminal serves as a transfer point between rail cars, trucks, and ships during the import or export of weapons, ammunition, explosives, tanks, and military equipment for the U.S. Army.  MOTSU sprawls across 8,600 acres on the west side of the Cape Fear River, near the towns of Boiling Spring Lakes and Southport.  A vast majority of MOTSU’s real estate is longleaf and loblolly pine forest, which provides a barrier between shipping operations and the general public.  To prevent harm to the surrounding community, there is a 2,100-acre buffer zone on Pleasure Island (Carolina, Kure, Wilmington, and Fort Fisher beaches) and a 4,300-acre buffer in Brunswick County.  Despite its isolation, Sunny Point is an impressive facility.  Its three huge docks can handle several ships simultaneously.  Large cranes and 62 miles of tracks within the terminal move military supplies and explosive cargo.  The two most controversial cargoes shipped through the terminal were World War II nerve gas in 1970 and European spent nuclear fuel rods in 1994.

Sources:

Mims, Bryan.  2015.  Secrets of Sunny Point.  Our State Magazine.  May 26, 2015.  https://www.ourstate.com/military-ocean-terminal-sunny-point/.  Accessed 01/02/18.

Wikipedia.  https://en.wikipedia.org/wiki/Military_Ocean_Terminal_Sunny_Point  Accessed 01/29/18.

Continue reading
  2416 Hits
0 Comments
2416 Hits
  0 Comments

©2006-2016 ANAMAR Environmental Consulting, Inc. | Web design & hosting provided by Blu Dove Designs

Gainesville, FL (352) 377-5770
Portland, OR (503) 220-1641
Fax: (352) 378-7620 • This email address is being protected from spambots. You need JavaScript enabled to view it.