Share

First State Geology Newsletter Signup

First State Geology has been the newsletter of DGS for over 25 years.

Click here to signup!

Site content related to keyword: "Shellpot Creek"

Stream Station: Shellpot Creek at Wilmington

USGS 01477800 SHELLPOT CREEK AT WILMINGTON, DE

Station Type: 
Stream
Period of Record: 
1945 to Present
Frequency: 
Monthly
Map County: 
New Castle County
Map Location: 
39.760972,-75.5186944

Outcrop Bd44-b: Bringhurst Gabbro boulders in Shellpot Creek

Rock Outcrop Bd44-b: Bringhurst Gabbro boulders in Shellpot Creek

Found in the creek bed and flood plain, the large boulders in Shellpot Creek are excellent examples of Bringhurst Gabbro. The gabbro is very coarse-grained with crystals up to 2" long; however, variations in the grain size exist over a scale of a few inches. While observing this rock closely, one can occasionally find grains of orthopyroxene (possibly bronzite) up to 4" long. Some of the boulders have grains of olivine surrounded by double coronas of orthopyroxene, spinel, and hornblende.