{{Short description|Triassic lava bed in the United States}} {{Infobox rockunit | name = Sander Basalt | period = early Jurassic | age = 201.5 ± 1.3 Ma <ref>{{cite journal |last1=Gregory Shellnutt |first1=J. |last2=Dostal |first2=Jaroslav |last3=Yeh |first3=Meng-Wan |title=Mantle source heterogeneity of the Early Jurassic basalt of eastern North America |journal=International Journal of Earth Sciences |date=April 2018 |volume=107 |issue=3 |pages=1033–1058 |doi=10.1007/s00531-017-1519-0 |url=https://link.springer.com/article/10.1007/s00531-017-1519-0#:~:text=Radiometric%20dating%20(U%E2%80%93Pb%2C%2040%20Ar/%2039%20Ar),on%20the%20basis%20of%20stratigraphy%20and%20paleontology. |access-date=30 December 2025|url-access=subscription }}</ref> | image = | imagesize = | caption = | type = Rift basin | prilithology = Tholeiitic Basalt | otherlithology = | unitof = Culpeper Basin | subunits = Sandstone, Siltstone | underlies = Turkey Run Formation | overlies = Waterfall Formation | thickness = up to {{Convert|545|m|ft|-1}}<ref>{{cite web |last1=Lee |first1=K.Y. |title=Triassic-Jurassic geology of the southern part of the Culpeper Basin and the Barboursville Basin, Virginia |url=https://pubs.usgs.gov/publication/ofr80468 |website=Pubs USGS |publisher=United States Geological Survey |access-date=30 December 2025 |language=en |doi=10.3133/ofr80468 |date=1980}}</ref> <!----Location----> | location = Northwestern Virginia | coordinates = {{Coord|38.7605|N|77.68|W|display=inline}} | region = Eastern United States | country = United States | extent = {{Convert|30|mi|km}} }} {{Location map | Virginia | relief = yes | float = right | width = 400 | caption = Sander Basalt | label = Sander Basalt | lat = 38.7605 | long = -77.68 | position = right }}
'''Sander Basalt''' is the third and final basalt flow in the Culpeper Basin. Located just east of the Appalachian Mountains in northern Virginia, it is part of the larger Central Atlantic Magmatic Province (CAMP) large igneous province, and its associated rift valleys, Newark Supergroup, which was one of the largest volcanic eruptions in Earth's history.<ref>{{cite journal |last1=Marzoli |first1=Andrea |last2=Callegaro |first2=Sara |last3=Dal Corso |first3=Jacopo |last4=Davies |first4=Joshua H. F. L. |last5=Chiaradia |first5=Massimo |last6=Youbi |first6=Nassrrdine |last7=Bertrand |first7=Hervé |last8=Reisberg |first8=Laurie |last9=Merle |first9=Renaud |last10=Jourdan |first10=Fred |title=The Central Atlantic Magmatic Province (CAMP): A Review |journal=The Late Triassic World |date=2018 |volume=46 |pages=91–125 |doi=10.1007/978-3-319-68009-5_4 |url=https://www.researchgate.net/publication/321135576_The_Central_Atlantic_Magmatic_Province_CAMP_A_Review |access-date=30 December 2025 |language=en}}</ref> It is associated with the initial break up of the ancient supercontinent of Pangea and just before the opening of the Atlantic Ocean.<ref>{{cite web |last1=Davies |first1=Joshua |last2=Marzoli |first2=Andrea |last3=Bertrand |first3=Hervé |last4=Youbi |first4=Nasrrddine |last5=Schaltegger |first5=Urs |title=Exploring the pre-eruptive history of the Central Atlantic Magmatic Province (CAMP) and the link with the end Triassic extinction using high precision U-Pb zircon and baddeleyite geochronology |url=https://ui.adsabs.harvard.edu/abs/2015EGUGA..17.9479D/abstract |website=EGU General Assembly Conference Abstracts |publisher=EGU General Assembly |access-date=30 December 2025 |pages=9479 |language=en |date=April 2015}}</ref>
==Geological history== {{see also|Pangea}} thumb|Location of the Culpeper Basin
The Central Atlantic Magmatic Province was the initial pulse of magmatism associated with the rifting a break up of Pangea. Pangea formed ~330 Ma with the closing of the Rheic Ocean <ref>{{cite journal |last1=Nance |first1=R. Damian |last2=Gutiérrez-Alonso |first2=Gabriel |last3=Keppie |first3=J. Duncan |last4=Linnemann |first4=Ulf |last5=Murphy |first5=J. Brendan |last6=Quesada |first6=Cecilio |last7=Strachan |first7=Rob A. |last8=Woodcock |first8=Nigel H. |title=A brief history of the Rheic Ocean |journal=Geoscience Frontiers |date=March 2012 |volume=3 |issue=2 |pages=125–135 |doi=10.1016/j.gsf.2011.11.008 |url=https://www.sciencedirect.com/science/article/pii/S1674987111001113?via%3Dihub |access-date=30 December 2025 |language=en|doi-access=free }}</ref><ref>{{cite journal |last1=Nance |first1=R. Damian |last2=Gutiérrez-Alonso |first2=Gabriel |last3=Keppie |first3=J. Duncan |last4=Linnemann |first4=Ulf |last5=Murphy |first5=J. Brendan |last6=Quesada |first6=Cecilio |last7=Strachan |first7=Rob A. |last8=Woodcock |first8=Nigel H. |title=Evolution of the Rheic Ocean |journal=Gondwana Research |date=March 2010 |volume=17 |issue=2-3 |pages=194–222 |doi=10.1016/j.gr.2009.08.001 |url=https://www.sciencedirect.com/science/article/pii/S1674987111001113 |access-date=30 December 2025 |language=en|url-access=subscription }}</ref> During Pangea's formation, many different island arc (exotic terranes) collided with Laurentia and subsequently formed the Appalachian Mountains. The three mountain-building events that raised the Appalachians were the Taconic, Acadian, and Alleghanian oroganies.<ref>{{cite journal |last1=Marzen |first1=Rachel E. |last2=Shillington |first2=Donna J. |last3=Lizarralde |first3=Daniel |last4=Harder |first4=Steven H. |title=Constraints on Appalachian Orogenesis and Continental Rifting in the Southeastern United States From Wide‐Angle Seismic Data |journal=Journal of Geophysical Research: Solid Earth |date=July 2019 |volume=124 |issue=7 |pages=6625–6652 |doi=10.1029/2019JB017611 |access-date=30 December 2025}}</ref>
These mountain building events not only raised the Appalachian Mountains to possibly as high as the present day Himalayan Mountains, but the continued accreation of island arc terranes created zones of weakness in the crust.<ref>{{cite journal |last1=Hillenbrand |first1=Ian W. |last2=Williams |first2=Michael L. |title=Paleozoic evolution of crustal thickness and elevation in the northern Appalachian orogen, USA |journal=Geology |date=1 August 2021 |volume=49 |issue=8 |pages=946–951 |doi=10.1130/G48705.1 |url=https://www.researchgate.net/publication/353402317_Paleozoic_evolution_of_crustal_thickness_and_elevation_in_the_northern_Appalachian_orogen_USA |access-date=30 December 2025 |language=en}}</ref> These would be used by magma during the CAMP eruptions as an easy pathway for magma to reach the surface.<ref>{{cite journal |last1=Whalen |first1=Lisa |last2=Gazel |first2=Esteban |last3=Vidito |first3=Christopher |last4=Puffer |first4=John |last5=Bizimis |first5=Michael |last6=Henika |first6=William |last7=Caddick |first7=Mark J. |title=Supercontinental inheritance and its influence on supercontinental breakup: The C entral A tlantic M agmatic P rovince and the breakup of P angea |journal=Geochemistry, Geophysics, Geosystems |date=October 2015 |volume=16 |issue=10 |pages=3532–3554 |doi=10.1002/2015GC005885 |url=https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2015GC005885|access-date=30 December 2025 |language=en}}</ref>{{AI-retrieved source|date=February 2026}}
==Sander Basalt== {{see also|Culpeper Basin}} thumb|Sander Basalt was not a single volcanic vent. Instead it was an extremely long fissure eruption that was possibly hundreds of miles long. The Bárðarbunga Volcano pictured is the type of eruption Sander basalt would have been, but on a much larger scale The Sander Basalt was the third eruptive event in the Culpeper Basin (with the Mount Zion Church Basalt and Hickory Grove Basalt preceding it.) The eruption was not one continuous eruption for its duration. There is evidence for at least nine different flows; by far the most of the three eruptive pulses (both the Mount Zion Church Basalt and the Hickory Grove Basalt had two flows each).<ref>{{cite web |last1=Tollo |first1=Richard |last2=Gottfrled |first2=David |last3=Froellch |first3=Albert |title=Field Guide to the Igneous Rocks of the Southern Culpeper Basin, Virginia |url=https://pubs.usgs.gov/of/1987/0251/report.pdf |website=Pubs USGS |publisher=United States Geological Survey |access-date=31 December 2025 |language=en |date=14 May 1987}}</ref> Each individual lava flow is separated by a thin layer of sedimentary layer of sandstone and siltstone.
Sanders Basalt is slightly different than the other two Culpeper Basin basalt flows. It has a distinctive curved columnar joints. It is also has a slightly different chemistory than the other two basalt flows. It is high-titanium, high-iron, quartz-normative Tholeiitic basalts.<ref>{{cite web |last1=Weems |first1=Robert |last2=Olsen |first2=Paul |title=Synthesis and revision of groups within the Newark Supergroup, eastern North America |url=https://www.ldeo.columbia.edu/~polsen/nbcp/weems.olsen.97.pdf |publisher=United States Geological Survey |access-date=30 December 2025 |language=en |date=February 1997}}</ref>
==References== {{Reflist}}
Category:Lava fields Category:Geology of Virginia Category:Flood basalts Category:Large igneous provinces Category:Triassic geology of Virginia