Text and photos by Hutch Brown. On August 30, 2025, several ARMN members joined local residents for a geology walk in Holmes Run Gorge hosted by the Northern Virginia Mineral Club and Friends of Holmes Run. Holmes Run, part of Alexandria’s Cameron Run watershed, cuts a gorge through the Piedmont bedrock (the foundational rock underlyingContinueContinue reading “Geology Walk in Holmes Run Gorge”
Category Archives: Geology
Fossils Along Our Local Creeks
Text and photos by Hutch Brown. Skolithos linearis fossils found along Four Mile Run (top) andHolmes Run (bottom). I was walking along Four Mile Run in Arlington’s Barcroft Park when I found the rock at the right (5” X 5”, with loupe for scale) on a gravel bar. I’ve seen others like it near otherContinueContinue reading “Fossils Along Our Local Creeks “
Digging into the History and Mystery of an Arlington Streambank
Text and photos by Hutch Brown. As county volunteers, my son Alex and I routinely monitor Arlington’s streams for water-polluting bacteria (E. coli). Our current site is upper Lubber Run in Woodlawn Park, a small urban park in a relatively flat part of Arlington. While taking water samples in spring 2024, Alex noticed an anomalyContinueContinue reading “Digging into the History and Mystery of an Arlington Streambank”
Reading the Rocks: A Look at the Geology of Long Branch
Text and photos by Hutch Brown. The Long Branch Nature Center is a popular destination for exhibits, classes, and events. It is also the kickoff point for nature walks of all kinds along Long Branch creek in Glencarlyn Park. As you follow the paved road down to the creek’s confluence with Four Mile Run, youContinueContinue reading “Reading the Rocks: A Look at the Geology of Long Branch”