Geology and the Civil War in Southwestern Virginia: Union Raiders in the New River Valley, May 1864Joseph M. DuracinskyCloyd’sMountain -9 May 1864New River Bridge -10 May 1864Purpose- To tell the story of relatively unknown battles in southwestern Virginia during the American Civil War at Cloyd’s Mountain and New River Bridge.- To gain an understanding of why southwestern Virginia was an important area during the Civil War, especially to the Confederates, which leads to an understanding of the reasons for fighting at Cloyd’s Mountain and New River Bridge.- To discover how the geology of the area impacted the fighting at Cloyd’s Mountain and New River Bridge.2References- “Geology and the Civil War in Southwestern Virginia: Union Raiders in the New River Valley, May 1864,” Virginia Minerals, November 1997, Virginia Department of Mines, Minerals, and Energy.- Warfare in the Western World, Military Operations from 1600 - 1871, Doughty and Gruber, 1996.- http://www.wm.edu/geology/virginia- http://www.mme.state.va.us/DMR/3Outline- What’s Happening in the Civil War in Spring, 1864?- A Look At Virginia’s Physiographic Provinces- The Significance of Southwestern Virginia to the Confederates- Virginia’s Railroad Network- Why Fight at Cloyd’s Mountain and New River Bridge?- The Geology of Southwestern Virginia’s Valley and Ridge- Geologic Map at Cloyd’s Mountain and New River Bridge- General Crook’s 1864 New River Valley Campaign- The Fight at Cloyd’s Mountain- The Fight at New River Bridge - Concluding Comments45What’s Happening in the Civil War in Spring, 1864?- Post Gettysburg: Grant’s Approach in May 1864- Destroy Armies and Resources- “Grant’s Army” - Army of the Potomac - In Virginia- “Sherman’s Army” - Army in the West - In TennesseeA Look at Virginia’s Physiographic ProvincesAP - App. Plateau RV - Ridge & ValleyGV - Great ValleyM - Massanutten Mtn.CU - Coastal UplandsCL - Coastal LowlandsBM - Barrier Islands & Salt MarshnBR - North Blue RidgesBR - South Blue RidgeF - FoothillsML - Mesozoic LowlandsOP - Outer Piedmont6Significance of Southwestern Virginia to the Confederates Lead -Wythe CountySalt -SmythCounty- Mined Materials: Salt, Iron, Lead, Saltpeter, Coal.- Virginia was top producer of salt, lead, saltpeter, and coal in the Confederacy.- Virginia was second to Alabama in iron production in the Confederacy.- Nearly all of Virginia’s salt, iron, lead, and saltpeter came from the Valley and Ridge. 7Virginia’s Railroad Network Virginia & Tennessee RailroadLead -Wythe CountySalt -SmythCounty8- Virginia had most extensive railroad network in the Confederacy. - Salt mining in Smyth County and lead mining in Wythe County depended on the Virginia & Tennessee Railroad which connected Richmond to the west.- Virginia & Tennessee Railroad ran completely through southwestern Virginia along the length of the Great Valley (part of the Valley and Ridge).9Why Fight at Cloyd’s Mountain and New River Bridge? - Part of Grant’s Approach: Starve the Confederacy of their resources by disabling the railroad in the Valley and Ridge Province (i.e. destroy the New River Bridge).Pulaski CountyMontgomery CountyGiles CountyWest VirginiaNew River- Note: Wythe County (lead) borders Pulaski County to the west; Smyth County (salt) borders Wythe County to the west.- Note: Up to this point in the Civil War, there wasn’t much fighting in the Valley and Ridge because virtually no one wanted to deal with crossing the complex terrain.Geology of Southwestern Virginia’s Valley and Ridge 10- Precambrian to Middle Ordovician - carbonates and some shales deposited (was a continental shelf and under ocean water); Elbrook and Rome Formations form today’s valleys. - Middle Ordovician to Late Silurian- Taconic Orogeny(mountain building) followed by erosion, deposition, and lithification of siliciclastic sedimentary rock; Tuscaroraand Rose Hill Formations form today’s ridges. - Middle Silurian to Early Mississippian- Acadian Orogeny (mountain building) followed by erosion, deposition, and lithification of siliciclastic sedimentary rock; Keifer and Cloyd Formations also form today’s ridges. - Late Mississippian to Late Paleozoic- Terminal Alleghanian Orogeny caused by continental collision produced folded/faulted region we see today; erosion-resistant siliciclastic sedimentary rocks dominate ridges while erosion-prone carbonates underlie valleys (southwest-northeast trend of linear ridges and valleys). Stratigraphic Column of Valley and Ridge Province in southwestern VirginiaGeo. Map at Cloyd’s Mountain and New River Bridge 11Cloyd’sMountain -9 May New River Bridge -10 MayDevonian, Mississippian Ridge(i.e. Cloyd’s Mountain)Cambrian Valley(i.e. carbonates, Karst Features)Note: Pulaski overthrust fault at base of Cloyd’s MountainGeneral Crook’s 1864 New River Valley Campaign 12- GEN Crook led the Army of the Kanawha from Charleston, WV. This was another leg of Grant’s strategy in Virginia. Crook’s objective was to sever the Virginia and Tennessee Railroad by destroying the New River Bridge at Central Depot. If successful, Crook would continue eastward to link up with Sigel from the Shenandoah. - Chronology:- 29 April - Departed WV- 7 May - Entered Valley and Ridge- 9 May - Cloyd’s Mountain- 10 May - New River Bridge - 11 May - Return to WV- 19 May - Reached HQs in WVThe Fight at Cloyd’s Mountain 13Cloyd’sMountainUnion -CrookConfederate -JenkinsBack Creek, a New River tributary, flows between positions and coincides with Pulaski overthrustfault. - Geology Factors:- Confederates entrenched on small knolls developed on erosion-resistant portions of Elbrook and Rome Formations. - Opening Numbers:- Union Forces - 6500 men- Confederate Forces - 2400 men- Events:- Artillery dual at 1100 hours- Union assault and CQC- Confederate right collapses- Confederates retreat around 1200- Confederates move to NRB- Results:- Union lost 10% of their force- Confederates lost 23%14The Fight at New River Bridge - The New River Bridge at Central Depot (today Radford) had a 700ft long wooden superstructure and was supported by metal piers anchored in the river bottom.- Events:- Artillery dual at 1000 hours- Confederates expend ammunition- Bridge burned around 1300 hours- Confederates withdraw- Union begins return to WV- Geology Factors:- Cambrian carbonates and Karstfeatures are dominant.- Elbrook Dolomite bluffs (200ft high) exist on north and south ends of