Southeastern Section - 64th Annual Meeting (19–20 March 2015)

Paper No. 32
Presentation Time: 8:00 AM-12:00 PM


STURGES, Rachel N., Geography and Geology, University of North Carolina Wilmington, 601 South College Rd., Wilmington, NC 28403 and SMITH, Michael S., Department of Geography and Geology, University of North Carolina Wilmington, 601 South College Road, Wilmington, NC 28403,

St. Georges is located along the northwestern edge of the full graben that bisects the central portion of the island of St. Croix, USVI. The soils are the Hogensborg Clay Loam (contain early to middle Miocene carbonate materials) and the Glynn gravelly loams. The drainages eroding into the graben are dissecting the upper Cretaceous (Judith Fancy Fm.) northwestern horst. These sediments contain volcaniclastic intermediate material rich in quartz, feldspar (plagioclase and k-feldspar), white mica, amphibole, biotite, epidote and opaque minerals (hematite and magnetite).

Ceramic sherd samples from the Anderson Collection, provided by the USVI National Park, were defined as Cedrosan Saladoid (500 BCE – 400 CE) by type and form. Petrographic investigation of 9 sherds found their aplastic composition was dominated by very coarse to medium mineral fragments (quartz, feldspar and amphibole), volcaniclastic and carbonate rock fragments and some contained fossil and shell fragments. In comparison, the soil sample from the region contained very coarse to medium carbonate (fossiliferous to micritic) and volcaniclastic material. Both the soil and sherd samples contained similar mineral fragments, volcaniclastic and crystalline carbonate rock fragments, as well as micritic mud. The micritic mud in the soil sample contained some mineral grains (hornblende and feldspar). The soil sample also contained white mica and volcaniclastic rock fragments (feldspar + biotite) while the sherd samples do not. The fossil fragments in the sherd and soil samples are elongate shell fragments and gastropods. The soil sample contained a coral fragment and lath-like opaque material (organic debris).

Based upon the petrography of the St. Georges sherds, their materials could have been derived from either the graben sediments or the eroded materials from the northwestern horst. 3 of the 9 sherds contain only volcaniclastic rock and mineral fragments that could be evidence for manufacture in another area and relocation to St. Georges. The remaining sherds all have crystalline and micritic mud carbonate rock fragments. These could have been formed due to erosion of the volcanic material into the graben and incorporation into the clay loams. Study of additional sherds from this region could help define the provenance question more precisely.