NCGS Core Repository

Coastal Plain Office and Core Repository (CPO)

The North Carolina Geological Survey’s Coastal Plain Office and Core Repository (CPO) archives: 1) the Legacy Core and Cuttings Collection (LCCC), 2) post-1988 Onshore Core Collections, 3) Offshore Core Collections, 4) Core Photographs, 5) Research Samples, 6) Hard Copy Metadata associated with coring projects (e.g. geophysical logs, core logs, seismic sections, analytical results, field books, etc.), 7) the Low-Level Radioactive Waste Site Characterization (LLRW) archives, and 8) Hard Rocks and Thin Sections.

The CPO is a small warehouse situated on a parcel with a gated area that includes 3 conexes for extra storage.  The CPO also functions as a field office for Coastal Plain and Piedmont mapping activities, and includes laboratories for stratigraphic, mineralogic and paleontologic studies.   Core samples range from soft-sediment, unconsolidated Coastal Plain and Continental Shelf deposits to completely consolidated, crystalline rock from mines in mountain belts. 

The ongoing inventory of the CPO’s holdings is partly funded by the U.S. Geological Survey’s (USGS) National Geologic and Geophysical Data Preservation Program (NGGDPP).  Support for geologic mapping is provided by the USGS administered National Cooperative Geologic Mapping Program (NCGMP), through STATEMAP and EARTH MRI Critical Minerals Mapping (Rare Earth Elements Mapping – REEMS) programs. 

Access to Collections

By legislative mandate, NCGS stores core and cuttings collections, seismic lines, maps, core photographs, and borehole data for the Coastal Plain, continental shelf, Triassic Basin, and Piedmont mining districts and makes these available to our stakeholders--federal, state, and other government agencies, university researchers, oil and gas and mineral exploration companies, teachers and students, and the public.  NCGS is currently inventorying the CPO’s contents and making these data available online; new data will be added as these are compiled.  If you or your organization needs access to specific data, especially cores and cuttings, please contact State Geologist, Dr. Kenneth B. Taylor (Kenneth.B.Taylor@ncdenr.gov), who will facilitate the viewing or subsampling of our collections, provided that NCGS guidelines are followed.

Holdings

The Legacy Core and Cuttings Collection (LCCC):  The LCCC is an ARCGIS geodatabase compilation of pre-1988 NCGS onshore holdings for 875 boreholes (Hoffman and Nickerson, 1988), referencing 11,000 ft of core, 365,000 ft of cuttings and 1250 geophysical logs. The 875 borehole records are categorized as: 1) WELLDATA, 2) OILTEST, 3) TRIASSIC, and HARDROCK.  WELLDATA includes borehole records for domestic, municipal, and industrial water wells, and mineral exploration core holes and stratigraphic tests. OILTEST includes records of oil and gas exploration wells.  TRIASSIC includes borehole records for the Triassic Basins.  HARDROCK includes borehole records for drilling in the Piedmont and mountain terranes, mostly related to mineral exploration.

A standardized naming schema was applied to all the boreholes, based on year drilled, county name, and order of acquisition.  Each borehole has a folder at the CPO, organized by county and the standardized name, that holds any hardcopy metadata related to the borehole (e.g. letters of transmittal, core logs, downhole logs).  Metadata schema for this collection include the Field Names: NCGS CODE, OTHER CODE, GW GRID, COUNTY, WELL NAME, OPERATOR, DEPTH, WELL DATUM, LATITUTE, LONGITUDE, DRILLED BY, DATE DRILLED, LOGGED BY, DATE LOGGED, LOGS, SAMPLES, SLIDES, LITH LOG, CTGS, CTGS INTERVAL(S), CORE, CORE INTERVAL(S), SWC AND SWC INTERVAL(S).

Borehole records in the WELLDATA and OILTEST categories include archived data that support the hydrostratigraphic framework of NC: 1) Brown, Miller and Swain, 1972; 2) Winner and Coble, 1996; 3) the NC Division of Water Resources on-line data pages (Fig. 3): https://deq.nc.gov/about/divisions/water-resources/water-resources-science-data; and 4) many other research reports and publications.  

In 2012, Virginia Division of Geology and Mineral Resources staff scanned hard-copy (paper) metadata associated with the LCC collection and entered it into the National Geothermal Data System maintained by the Kentucky Geological Survey (http://kgs.uky.edu/kgsweb/geothermal/nc/).  This database includes state-wide well and borehole observation records for NC: ~4,800 scans from over 1,000 sites. Scanned records include geologist’s borehole lithology logs, geophysical logs, driller’s logs, cement bond logs, and formation test logs.

In the 1990s, part of the LCCC collection, mainly TRIASSIC and HARDROCK cores were moved to an off-site warehouse, called the Cary Annex; the relocated collections were not inventoried.  The roof of the Annex collapsed after a major hailstorm in 2017.  An FY17 NGGDPP grant provided funds for NCGS to salvage and to rescue the building’s contents.   The rescued contents included ~45 pallets of core (24,456 feet of core in 1,952 wet boxes) that remain stored and deteriorating in two, 40-ft conexes at the CPO.  An FY19 NGGDPP grant funded an inventory of ‘safe’ holdings stored in the CPO.  NCGS confirmed that 235 HARDROCK and TRIASSIC cores were not located inside the ‘safe’ CPO, and were part of collections moved to the Cary Annex.  These legacy cores are either lost, damaged, or remain at risk. 

Post-1988 Onshore Core Collections:  Since 1988, NCGS participated in a number of mapping and/or stratigraphic projects that included core collection, as either a collaborator with other state and federal agencies or universities, or as principal investigator (PI).  These cores are mainly unconsolidated, Coastal Plain cores, that are either boxed or in plastic or metal tubes, and drilled using a variety of methods.  Some of these collections include:  1) STATEMAP 2011-2019—Geoprobe Cores (Farrell); 2) STATEMAP—Raleigh 100K sheet – Split Spoon Cores (Nickerson and Gay); 3) Neuse River Basin Mapping Project–Wireline, Mud-Rotary, Split Spoon Cores, Vibracores (Farrell); 4) OBX-MLD Cores – ECU-USGS-NCGS collaboration, Rotosonic- Long Cores in Plastic Tubes (Farrell).

Offshore Core Collections:  Sets of cores associated with offshore sand resources, offshore heavy mineral deposits, and Miocene phosphates are archived at the CPO.  These are long, unconsolidated cores that are stored in plastic tubes that are split lengthwise.  Metadata for these core collections are not yet compiled in a modern spreadsheet format.  However, final and interim reports (paper copies and CD roms) that describe these data sets are located, as well as the original seismic lines (printouts)associated with the projects.  Inventorying these core collections, and compiling metadata electronically is a future inventory project.

Core Photographs: Core photographs exist for all the post-1988 Onshore Core Collections.  These occur as digital images, or slides that require scanning.  It is not known if the Offshore Core Collections were photographed. Cores associated with the LLRW Archives (Wake/Chatham and Richmond County sites) were also photographed; these photos occur as color prints that require scanning.

Research Samples: NCGS stores archives of retired university professors who conducted geologic research in North Carolina. 

Hard Copy Metadata associated with post-1988, onshore and offshore core collections (e.g. downhole geophysical logs, core logs, seismic sections, analytical results, field books, etc.) are for the most part unscanned and remain uninventoried.

LLRW Archives: The CPO stores two core collections associated with the Low-Level Radioactive Waste Project—The Wake/Chatham Site Core Collection, and the Richmond County Site Core Collection. Each corehole includes a hard-copy file folder with an engineering log and color photos of the core.  Also on-site, are ~200 boxes of paperwork associated with the abandoned project’s archives. For the FY19 inventory, staff located latitude and longitude data for the Wake/Chatham Core Collection.  Latitude and longitude data for the Richmond County Core Collection is not yet located and compiled into a spreadsheet. The sorting and organizing of this complete data set that includes cores, seismic lines, borehole records, photographs, geologic reports, fracture studies and so on, is a future inventory project for the NGGDPP.

Hard Rocks and Thin Sections: Rock samples collected by Piedmont mappers for STATEMAP and other projects are stored in ~ 200 labelled buckets on shelves in the 20 ft conex. These are well-organized and labelled but are not inventoried electronically. Thin sections are not inventoried yet.

Results of FY19 Inventory of Core and Cuttings Collections:

The NGGDPP recently funded an inventory of the onshore, core and cuttings collections that are stored safely inside the CPO.  Eleven borehole collections (Table 1) were identified; these were described and uploaded into the National Digital Catalog.  A description of each collection is provided below.  Collections included 3,416 borehole records, that described 688,440 ft of borehole data.  The inventory included 8,027 core boxes, 2931 boxes of cuttings, 2118 Geoprobe tubes (4 ft length), and an unspecified number of vibracore tubes (1 m length).

Table 1.  Generated Products: List of collections that were inventoried, defined and uploaded into the NDC for the FY19 NGGDPP grant.

 

The Legacy Core and Cuttings Collection (LCCC): 

A historical account of the LCCC is described in the Holdings section overview. Table 1 summarizes the subcollections described during the FY19 inventory of safe holdings.

The ORIGINAL MASTER LCCC included 875 boreholes.  The inventory confirmed that: 1) cores and/cuttings for 640 borehole records were identified as safe; 2)   no cores or cuttings for 235 boreholes were located in the CPO; these holdings include 1622 boxes of core that were either lost in the Annex collapse or remain damaged on pallets; 3) another 330 boxes of core rescued from the Annex are not part of the LCCC; these remain undocumented; and 4). NCGS has not yet secured funding to complete the rescue of the 47 pallets of at-risk cores removed from the Annex.

LCCC is organized in the NCGS geodatabase as follows:  1) Legacy Core and Cuttings Collection – ORIGINAL MASTER; 2) Legacy Core and Cuttings Collection – CONFIRMED; 3) Legacy Core and Cuttings Collection – AT RISK OR LOST; 4) Legacy Core and Cuttings Collection – CUTTINGS ONLY; 5) Legacy Core and Cuttings Collection – DUPLICATE CUTTINGS; and 6) Legacy Core and Cuttings Collection—CORE ONLY. 

1) Legacy Core and Cuttings Collection (LCCC) – ORIGINAL MASTER

The ORIGINAL MASTER is the inventory of NCGS’s Legacy Core and Cuttings Collection, prior to any loss or damage of core and cuttings incurred as described below.

2) Legacy Core and Cuttings Collection (LCCC) – CONFIRMED

The CONFIRMED collection describes the subset of the Legacy Core and Cuttings Collection - ORIGINAL MASTER that remains safe and stored in the NCGS’s Coastal Plain Office and Core Repository, in Raleigh, NC. 

3) Legacy Core and Cuttings Collection (LCCC) – AT RISK OR LOST

The AT RISK OR LOST collection describes the subset of the Legacy Core and Cuttings Collection - ORIGINAL MASTER that remains LOST or AT RISK after the collapse of the roof of an off-site outbuilding, the Cary Annex.  ~45 pallets of rescued core remain stored in conexes or in aisles at the NCGS’s Coastal Plain Office and Core Repository, in Raleigh, NC. 

4) Legacy Core and Cuttings Collection (LCCC) – CUTTINGS ONLY

The CUTTINGS ONLY collection identifies boreholes in the CONFIRMED COLLECTION from which cuttings were collected, and remain stored in the NCGS’s Coastal Plain Office and Core Repository. These are confirmed ‘safe’.

5) Legacy Core and Cuttings Collection (LCCC) – DUPLICATE CUTTINGS

The DUPLICATE CUTTINGS collection identifies duplicate cuttings samples for a number of boreholes in the Legacy Core and Cuttings Collection.  These remain stored in the NCGS’s Coastal Plain Office and Core Repository, but are shelved separately from the ORIGINAL MASTER collection of cuttings.  These are confirmed ‘safe’.

6) Legacy Core and Cuttings Collection (LCCC) – CORES ONLY

The CORES ONLY collection identifies boreholes in the CONFIRMED COLLECTION from which cores were collected, and remain stored in the NCGS’s Coastal Plain Office and Core Repository. These are confirmed ‘safe’.

STATEMAP Raleigh 100K - Coastal Plain Borehole Collection:

From 1991 to 1997, NCGS staff Geologists John G. Nickerson and Norman K. Gay (mapped the Coastal Plain portion of the Raleigh 100K sheet. For the subsurface analysis associated with this mapping, 392 boreholes were drilled in an area that included the following quadrangles:  Angier, Bailey, Clayton, Edmondson, Flowers, Fuquay Varina, Garner, Knightdale, Kenly East, Kenly West, Lucama, Lake Wheeler, Middlesex, Powhatan, Stancils Chapel, Selma, Spring Hope, and Zebulon.  Many of the boreholes were drilled by Patterson Exploration Services, Inc., of Sanford, NC.  Total footage drilled was 10,089 ft using a variety of drilling methods (e.g. split-spoon sampling, machine and hand augering); maximum penetration depth was 90 ft.   Continuous core (6895.3 ft) was collected from 219 boreholes; discontinuous, disturbed samples were collected from 173 boreholes as cutting samples removed from augers, for example.  Unconsolidated Pleistocene and Pliocene deposits were targeted, with refusal mostly in unconsolidated Cretaceous or younger units, or in crystalline basement rocks (or saprolite).

EPA 319H - Coastal Plain - Shallow Aquifers and Confining Units – Borehole Collection:

From 1999 to 2006, Senior Geologist Kathleen M. Farrell worked closely with Dr. Harold E. (Ted) Mew, III, Senior Hydrogeologist of the North Carolina Division of Water Quality (DWQ, now part of the Division of Water Resources) to characterize shallow aquifers and confining units on the Coastal Plain of eastern North Carolina.   The projects were funded by the Environmental Protection Agency’s 319H Non-Point Source Grant Program, administered through the NC DWQ’s Non-Point Source Program. 

The funding to NCGS was divided into three parts:  1) 1999-2001 – $25,000 for NCGS to geologically characterize the Lizzie Research Station for the purpose of developing a 3D ground water flow model; 2) FY2001 Grant $96,000 to NCGS to upscale the geologic characterization and modelling to the scale of the Little Contentnea Creek Watershed, and 3) and a three-year FY2003 Grant--$150,000 to upscale the geologic characterization and modelling to the subbasin scale.  Cores collected for each of these base grants are respectively referred to as: 1) the Lizzie Cores, 2) the Little Contentnea Creek (LCC) Cores, and 3) the Croatan Cores.  The Lizzie and LCC cores are located in Pitt, Greene, Wilson and Edgecombe Counties.   The Croatan cores are located in Craven, Jones, Pamlico, and Pitt counties.

Coreholes (total = 172) were drilled using a variety of methods (split-spoon, wireline coring, mud-rotary, and vibracore) to collect more than 9,358 ft of mostly unconsolidated core; gamma logs (natural gamma) were acquired in all boreholes except for the 12 vibracore holes.  Maximum penetration depth was 205 ft.  At the Lizzie Site, surficial units consist of Early Pleistocene deposits on interfluve areas, with younger terrace deposits inset in the drainages. The entire Quaternary section was cored.  At the Lizzie Research Station, the target depth for local basement consisted of a confining unit in the Cretaceous (black clay with glauconite).  In the Croatan area, cores bottomed out in Oligocene or Eocene limestones or siliciclastic Cretaceous units. The DWQ’s drilling program collected many of the cores.  Other cores were collected by Patterson Exploration Services, Inc., or its subcontractors.  NCGS staff collected the vibracores.  Unfortunately, Ted Mew passed away on February 16th, 2005 and the integration between the geology and the modelling remains incomplete. 

STATEMAP FY10-19 - Coastal Plain Quaternary Geoprobe Core Collection:

The North Carolina Geological Survey (NCGS) was awarded a succession of STATEMAP Grants to map Coastal Plain deposits in the vicinity of the Surry Paleoshoreline complex.  This area includes Fountain, Falkland, Farmville and Walstonburg quadrangles, and portions of Pitt, Greene, Wilson and Edgecombe counties.  The Surry paleoshoreline is along-strike from Trail Ridge.  NCGS maps from the known to the unknown; hence the area for detailed mapping was chosen because a significant amount of high-quality subsurface data already existed in the same area because of the EPA 319h Grants awarded to NCGS.  NCGS has a small drill rig called a Geoprobe, that it uses to collect continuous core samples through Pliocene and Pleistocene deposits using the discrete sampling method.  Thus far, NCGS has drilled 213 coreholes with the Geoprobe, and collected 8,181 ft of unconsolidated core.  Maximum penetration depth is 72 ft.

Cherry Point Marine Corp Air Station (MCAS) – Coastal Plain Borehole Collection:

For a hydrogeologic site characterization project at the Cherry Point Marine Corp Air Station (MCAS) nine coreholes were drilled by the USGS (Raleigh Water Resources Division in Raleigh) over the period 1994-2005. Five of these continuous cores were donated to the NCGS for permanent storage in its Coastal Plain Office and Core Repository (CPO).  The collection currently includes 1244 ft of core, from five boreholes.  The location of the other four cores is unknown.  Maximum penetration depth was 305 ft.  Eocene through Quaternary deposits were intercepted.  A report on the cores by Beth M. Wrege and Philip S. Jen, Data from Stratigraphic Test Holes Drilled at the U.S. Marine Corps Air Station, Cherry Point, North Carolina, 1994-2001, and Periodic Water Levels, 2000-2003, USGS Open-File Report 2004–1434, is located at: https://pubs.usgs.gov/of/2004/1434/report.html

LLRW Wake/Chatham Potentially Suitable Site - Triassic Core Collection

The CPO permanently archives geologic and geophysical data from the NC Low-Level Radioactive Waste Project.  Currently, the collection for the potentially suitable Wake/Chatham site includes 18,184.6 ft of core collected from 160 boreholes with a maximum penetration depth of 560 ft.  Borehole records for these drill sites exist as paper data in flat files at the CPO.  Photographs of the core are available as color prints.  Additional information on the geology or geophysics of the site remain unsorted and stored in ~200 boxes.

References:

Winner, M.D., Jr., and Coble, R.W., 1989, Hydrogeologic framework of the North Carolina Coastal Plain aquifer system: U.S. Geological Survey Open-File Report 87-690, 155 p.

Brown, P.M., Miller, J.A., and Swain, F.M., 1972. Structural and stratigraphic framework and spatial distribution of the permeability of the Atlantic Coastal Plain, North Carolina to New York: U.S. Geological Survey Professional Paper 796, 79 p.

Hoffman, C.W. and Nickerson, J.G., 1988, North Carolina Geological Survey Repository of Core, Cuttings and Well Logs, NCGS OFR 88-1, 5 p.

 

The North Carolina Geological Survey’s Coastal Plain Office and Core Repository

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 1.  A. The North Carolina Geological Survey’s Coastal Plain Office and Core Repository (CPO) is a small warehouse that is shared with the Wildlife Commission.  A gated area includes space for three conexes.  Two forty ft conexes hold pallets of at-risk cores rescued from the Cary Annex, which had a roof collapse. A 20-ft conex now stores shelved, buckets of rock that support the Piedmont mapping program.  B.  Front view of the CPO. C.  Photo of shelving inside CPO that shows parts of the Legacy Core and Cuttings Collection; boxes holding cuttings samples are on the upper shelves; wooden boxes containing core are on the lowest shelf shown.  D.  Closeup of cardboard core boxes that store core for the 319H Neuse River Basin Mapping program.  E.  View of aisle with 319H cores on left, and geoprobe cores on right: shelving to store 4 ft long plastic tubes full of unconsolidated core was constructed as insets in bottom three shelfs.  F.  Example of cores stored in tubes stored at the CPO; these are vibrasonic cores collected in 3.5 inch diameter plastic tubes.

 
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