DESCRIPTIONS OF BIT CUTTINGS
FROM JPRCO TEST WELL #1 - LEONARD GEOPHYSICAL OBSERVATORY SITE
By W. R. Robinson, 1961.
Figures in km/sec are approximate P wave velocities calculated
from the sonic log.
Ft. Scott Limestone
80-90 FT Limestone, very clayey, micritic, fossil fragments, hard, medium
gray. 3.6-5.1 km/sec.
90-100 Ft Limestone as above, becoming shaly with some slightly calcareous
claystone. 2.5-4.2 km/sec
100-150 Ft Claystone, slightly calcareous, medium hard, medium dark gray
micaceous. 2.5-3.3 km/sec
150-190 Ft Claystone as above, more micaceous. 2.7-3.2 km/sec
190-200 Ft Clay shale, dark gray, medium hard micaceous. 2.8 km/sec
Verdigris Limestone
200-210 Ft Clay shale as above with moderately clayey and non-clayey micrite.
Fossiliferous medium gray limestone. 2.7-3.7 km/sec
210-220 Ft Sandstone, very fine-grained, very silty, quartzose, very light
gray, moderately siliceous, micaceous, poor porosity. 3.1 km/sec
220-225 Ft Sandstone as above, with carbonaceous plant fragments. 3.1 km/sec
225-240 Ft Siltstone, slightly-moderately clayey, medium gray, with carbon-
aceous plant fragments. 3.1 km/sec
240-250 Ft Clay shale, medium gray, medium hard. 2.6-3.1 km/sec
250-260 Ft Clay shale, very silty, medium gray, interbedded with very clayey
siltstone, micaceous with carbonaceous plant remains. 2.7-3.1 km/sec
260-265 Ft Clay shale, slightly silty, medium gray, micaceous. 2.7-3.8 km/sec
265-270 Ft Limestone, granular, fossiliferous, slightly sandy, buff, slightly
glauconitic. 3.6-4.2 km/sec
Skinner Sandstone
270-300 Ft Siltstone, moderately sandy, slightly calcareous with carbonaceous
plant fragments, micaceous. 3.1-3.5 km/sec
300-310 Ft Shale, very silty, medium gray, interbedded with very clayey silt-
stone, fairly soft, micaceous. 3.3 km/sec
310-320 Ft Shale, very silty, medium gray, medium hard. 3.3 km/sec
320-350 Ft Clay shale, medium gray, soft. 2.8-3.3 km/sec
350-360 Ft Shale, moderately silty, medium gray with white siltstone string- ers. 3.3 km/sec
360-370 Ft Shale, moderately silty, medium gray, medium hard, micaceous.
3.3 km/sec
370-390 Ft Sandstone, very fine-grained, very light gray, moderately silty,
slightly-moderately siliceous, quartzose, micaceous, much plant
remains, poor porosity. 3.2-3.3 km/sec
390-401 Ft Sandstone, very fine-grained to fine-grained, slightly siliceous,
very light gray-yellow-gray, micaceous, quartzose, carbonaceous
fragments and partings, good porosity. 3.2 km/sec
401-409 Ft Shale, moderately silty, medium dark gray. 3.1-3.3 km/sec
409-415 Ft Sandstone, medium-grained, spotty oil stain, slightly-moderately
siliceous, quartzose, good porosity. 3.1-3.2 km/sec
415-424 Ft Sandstone, fine-grained, very light gray, slightly siliceous,
quartzose, carbonaceous fragments, asphaltic residue, slightly
micaceous and glauconitic, good porosity. 2.7-3.1 km/sec
424-450 Ft Shale, moderately silty, medium gray, slightly micaceous with
2 ft bed of sandstone, fine-grained light gray, moderately siliceous,
slightly calcareous, quartzose, micaceous. 3.0-3.5 km/sec
450-470 Ft Sandstone, very fine-grained, slightly silty, very light gray,
slightly-moderately siliceous, micaceous, with carbonaceous partings, fair porosity. 3.2-3.5 km/sec
470-520 Ft Shale, slightly silty, medium dark gray, micaceous, with some
carbonaceous fragments. 3.2-3.5 km/sec
520-560 Ft Clay shale, medium dark gray, medium hard, micaceous. 3.0-3.5 km/sec
560-590 Ft Clay shale, dark gray, medium hard-soft. 2.7-3.0 km/sec
590-600 Ft Clay shale, dark gray, becoming harder and more blocky. 3.0-3.9
km/sec
600-610 Ft Siltstone, very light gray, medium hard, micaceous with interbed-
ded shale, very silty, medium light gray, few limestone fragments
(probably cavings). 3.4-3.7 km/sec
610-620 Ft Shale, moderately silty, medium dark gray, medium hard, micaceous.
3.4 km/sec
620-630 Ft Shale, slightly silty, medium dark gray, medium hard, pyritic,
micaceous. 3.3 km/sec
630-660 Ft Clay shale, medium dark gray, medium hard, micaceous. 2.9-3.2
km/sec
660-700 Ft Clay shale, dark gray, fairly soft. 2.7-3.1 km/sec
700-710 Ft Clay shale, medium dark gray, medium hard. 3.2-3.6 km/sec
Red Fork Sandstone
710-730 Ft Siltstone, medium gray, medium hard, sandstone, very fine-grained,
moderate oil show, slightly siliceous, quartzose. 3.0-3.5 km/sec
(e-log interval 694-714 Ft)
730-760 Ft Clay shale, medium dark gray, medium hard, waxy, much contamina
Tion. 2.9-3.5 km/sec
760-770 Ft Clay shale, dark gray, medium hard, micaceous. 3.0-3.4 km/sec
770-780 Ft Clay shale as above grading into light gray siltstone, medium
hard, micaceous. 3.1-3.6 km/sec
780-810 Ft Siltstone as above. 3.6 km/sec
810-830 Ft Siltstone, moderately clayey, medium dark gray, medium hard.
830-840 Ft Siltstone as above grading into shale, very silty, medium dark
gray, medium hard. 3.4-3.7 km/sec
840-870 Ft Clay shale, medium dark gray, medium hard. 3.0-3.5 km/sec
870-890 Ft Clay shale, dark gray, soft. 2.7-3.1 km/sec
890-900 Ft Clay shale, dark gray-grayish black, soft. 2.6-3.1 km/sec
Inola Limestone top at 908 Ft
900-910 Ft Shale as above with 1 ft bed of limestone, micritic, fossiliferous
(brachiopod) medium dark gray, hard. 2.7-3.5 km/sec
910-930 Ft Clay shale, medium gray, moderately-very calcareous, fossil casts,
medium hard. 2.8-3.7 km/sec
930-940 Ft Clay shale, medium dark gray, medium hard, micaceous with thin
interlaminations of sandstone, very fine-grained, very silty, very
light gray, slightly glauconitic. 3.3 km/sec
Bartlesville Sandstone, e-log top 943 Ft
940-952 Ft Clay shale as above with thicker laminations of sandstone, very
fine-grained, slightly silty, slightly siliceous, quartzose, very
light gray, slightly glauconitic. 3.4-3.9 km/sec
952-964 Ft Sandstone, very fine-grained to fine-grained, moderately calcareous
quartzose very light gray, medium hard, fair porosity. 3.5-3.9 km/sec
964-970 Ft Siltstone, slightly clayey, medium gray, medium hard, micaceous.
3.5-3.7 km/sec
970-980 Ft Siltstone as above
980-990 Ft Shale, medium dark gray, moderately silty, micaceous. 3.4 km/sec
990-1040 Ft Clay shale, dark gray, medium hard-soft, micaceous. 3.1-3.5 km/sec
1040-1050 Ft Clay shale, slightly sandy, medium gray, medium hard, waxy. 3.3-3.7
km/sec
1050-1070 Ft Shale, slightly silty, dark gray, medium hard, micaceous. 3.1-3.4
km/sec
1070-1080 Ft Clay shale, slightly-moderately calcareous, fossiliferous with
pyrite replacement, grayish black-black, medium hard, carbonaceous
fragments, some medium light gray clay shale. 2.9-3.2 km/sec
1080-1090 Ft Siltstone, very clayey, medium light gray, medium hard, pyritic.
2.7-5.0 km/sec
1090-1092 Ft Limestone, micritic, fossiliferous, pale yellow brown, hard, dense.
3.4-4.0 km/sec
1092-1140 Ft Clay shale, dark gray, medium hard-soft, micaceous. 3.0-4.4 km/sec
1140-1150 Ft Clay shale, medium dark gray, slightly sandy, medium hard-soft,
waxy, micaceous. 3.1-3.6 km/sec
1150-1156 Ft Clay shale, dark gray, medium hard, micaceous. 3.1-3.3 km/sec
1156-1166 Ft Siltstone, slightly calcareous, light gray, medium hard, micaceous. 3.2-4.2 km/sec
1166-1190 Ft Clay shale, medium dark gray-dark gray, medium hard, micaceous.
3.1-4.3 km/sec
1190-1200 Ft Siltstone, slightly calcareous, light gray, medium hard, micaceous. 3.5-4.4 km/sec
1200-1210 Ft Clay shale, medium dark gray, medium hard, micaceous. 3.1-3.9 km/sec
1210-1220 Ft Siltstone, medium gray, medium hard. 3.3-3.9 km/sec
1220-1245 Ft Clay shale, dark gray, medium hard-soft, micaceous. 3.4-3.6 km/sec
1245-1260 Ft Shale, slightly silty, dark gray, grading into siltstone, slightly
clayey, medium dark gray, medium hard, micaceous. 3.2-4.2 km/sec
1260-1300 Ft Clay shale, dark gray-grayish black, medium hard-soft, slightly
micaceous becoming slightly-moderately silty near the base. 2.9-4.2
km/sec
1300-1320 Ft Clay shale as above. 3.1-4.2 km/sec
1320-1344 Ft Shale, slightly silty, medium gray-medium dark gray, medium hard,
micaceous. 3.2-3.9 km/sec
1344-1350 Ft Siltstone, buff yellow gray, medium hard, micaceous. 3.2-4.1 km/sec
1350-1360 Ft Shale, moderately silty, medium dark gray-grayish black, medium
hard, micaceous. 3.4 km/sec
Tanaha Sandstone
1360-1370 Ft Siltstone-very fine-grained sandstone, slightly-moderately
siliceous, quartzose, buff - very light gray, good. 2.9-4.0 km/sec
1370-1390 Ft Silstone, buff-very light gray, slightly harder than above,
micaceous. 3.2-4.0 km/sec
1390-1420 Ft Shale, moderately silty, medium dark gray-dark gray, medium
hard, micaceous. 3.11-3.6 km/sec
1420-1445 Ft Clay shale, slightly calcareous, dark gray, medium hard-soft,
micaceous. 2.9-4.6 km/sec
Dutcher "lime" top 1451 Ft
1445-1461 Ft Claystone - very fine siltstone slightly clacareous, medium
hard, glauconitic. 2.9-4.6 km/sec
1461-1470 Ft Limestone, micritic, moderately sandy, quartzose, hard,
glauconitic. 3..6-5.0 km/sec
1470-1476 Ft Siltstone, medium light gray, hard, some pyrite. 3.0-3.1 km/sec
1476-1486 Ft Shale, moderately silty, medium dark gray, medium hard, micaceous.
2.8-3.9 km/sec
1486-1501 Ft Siststone, slightly calcareous, very light gray, moderately
siliceous. 3.0-3.4 km/sec
Lower Dutcher Sandstone
1501-1523 Ft Sandstone, medium-grained, good oil show. Very slightly-moderately
siliceous, quartzose, sub-angular to sub-rounded, well developed
secondary crystal faces, very good porosity. 3.6-4.2 km/sec
1523-1525 Ft Silty shale as above. 3.6-4.0 km/sec
Pitkin Limestone
1525-1540 Ft Limestone, skeletal (brachiopods, bryozoa, crinoids), micritic,
buff, hard. 3.6-5.4 km/sec
1540-1542 Ft Shale, moderately calcareous, dark gray, medium hard-hard. km//sec
1542-1552 Ft Limestone, micritic-skeletal, slightly clayey, medium light gray-
medium dark gray, hard, dense. 5.9 km/sec
1552-1553 Ft Shale, dark gray-grayish black, elongate fragments. 4.6 km/sec
1553-1558 Ft Limestone as above. 5.3 km/sec
1558-1563 Ft Shale as above. 3.1 km/sec
1563-1576 Ft Limestone as above. 5.5 km/sec
1576-1580 Ft Shale as above. 3.7 km/sec
1580-1590 Ft Limestone as above, non-clayey, with siltstone, moderately sandy,
slightly calcareous, medium dark gray, medium hard, glauconitic,
and some shale as above. 4.2-5.2 km/sec
1590-1598 Ft Siltstone as above, with shale, slightly calcareous, dark gray.
3.2-4.4 km/sec
1598-1610 Ft Limestone, micritic, very finely crystalline, slightly fossilif-
erous, medium dark gray, some sparry calcite with shale, slightly
calcareous, dark gray, medium hard. 2.9-4.6 km/sec
1610-1622 Ft Limestone as above. 3.2-7.4 km/sec
1622-1632 Ft Shale as above. 2.8-4.2 km/sec
1632-1637 Ft Limestone as above. 3.0 km/sec
Fayetteville Shale
1637-1660 Ft Shale as above. 2.5-3.9 km/sec
1660-1690 Ft Shale, slightly calcareous, dark gray-grayish black. 2.5-3.1 km/sec
1690-1700 Ft Shale as above with scattered pyrite, thin limestone break.
2.6-3.1 km/sec
1700-1725 Ft Shale, moderately calcareoous dark gray-grayish black, medium hard. 2.6-3.0 km/sec
1725-1730 Ft Limestone, micritic-skeletal slightly clayey, medium gray-medium
dark gray, very hard.. 5.9 km/sec
1730-1735 Ft Limestone as above, medium gray, non clayey. 4.4-5.5 km/sec
1735-1770 Ft Siltstone, light oil stain, slightly calcareous, medium gray-
medium dark gray, medium hard, micaceous. 3.6-4.5 km/sec
1770-1780 Ft Siltstone as above, very calcareous. 3.9-4.9 km/sec
1780-1782 Ft Shale, dark gray, splintery, medium-hard. 4.9 km/sec
1782-1792 Ft Limestone, micritic, very finely crystalline, fossiliferous,
moderately sandy, medium gray, hard. 4.4-5.6 km/sec
1792-1800 Ft Siltstone as above, oil stained. 4..2-5.5 km/sec
1800-1803 Ft Shale, slightly calcareous, dark gray, splintery. 4.0 km/sec
1803-1828 Ft Limestone, micritic, very-finely crystalline, slightly
fossiliferous (brachiopods), very silty sands, medium gray, hard.
4.2-5.8 km/sec
1828-1840 Ft Siltstone, coarse, light oil stain, very calcareous, medium gray,
hard. 4.2-5.1 km/sec
1840-1870 Ft Siltstone to very fine-grained sandstone, very light oil stain,
very calcareous, medium gray, medium hard. 4.2-5.3 km/sec
1870-1884 Ft Siltstone, calcareous as above. 4.6-5.5 km/sec
1884-1900 Ft Limestone, micritic, finely crystalline, very light oil stain,
hard. 4.2-5.5 km/sec
1900-1920 Ft Limestone as above, slightly-moderately silty. 4.4-5.4 km/sec
Woodford Formation
1920-1930 Ft Limestone as above with 2' shale break, slightly silty, slightly calcareous, dark gray, micaceous. 4.0-5.5 km/sec
1930-1940 Ft Siltstone, moderately siliceous, buff-yellow gray, medium hard,
micaceous. 3.7-5.2 km/sec
1940-1950 Ft Siltstone as above with interbedded clay shale, medium dark gray,
flaky. 3.7-4.0 km/sec
1950-1972 Ft Siltstone as above slightly-moderately calcareous, medium hard.
3.6-4.0 km/sec
1972-1978 Ft Clay shale, slightly calcareous, dark gray, hackly, flaky. 3.7 km/sec
1978-2010 Ft Shale, grayish black-black, soft, flaky, pyritic, micaceous, very
organic. 3.1-3.6 km/sec
Wilcox Sandstone
2010-2032 Ft Sandstone, very fine-grained to fine=grained, buff, slightly-
moderately siliceous, quartzose with thin interbedded shale stringers, grayish black, splintery, micaceous. 3.4-5.2 km/sec
2032-2044 Ft Shale, green-gray, slightly silty-snady, medium hard, interbedded
with medium light gray and dark gray shale, hard. 3.5-5.0 km/sec
2044-2050 Ft Sandstone, very fine-grained to medium=grained, green-white,
poorly sortedd, moderately siliceous. 3.7-4.8 km/sec
2050-2060 Ft Siltstone, moderately siliceous, greenish gray, hard, micaceous.
4.1-4.6 km/sec
2060-2085 Ft Siltstone as above with interbedded shale, slightly silty, hard.
3.6-4.4 km/sec
2085-2090 Ft Limestone, very sandy, slightly chalky, very light gray. 4..4-5.8 km/sec
2090-2110 Ft Shale, dark gray, flaky, medium hard, miicaceoous. 3.7-4.7 km/sec
2110-2148 Ft Shale, slightly sandy, medium light gray, medium hard.
3.7-5.1 km/sec
2148-2153 Ft Limestone as above. 4.8 km/sec
2153-2168 Ft Shale as above, slightly glauconitic, 3.9-4.6 km/sec
Burgen Sandstone
2168-2188 Ft Sandstone, very fine-graained to fine-grained with some medium-
grained, white-light gray slightly-moderately siliceous, slightly
calcareous, quartzose, poor poorosity. 4.2-5.5 km/sec
2188-2192 Ft Shale, dark graay, medium hard, splintery. 3.5 km/sec
2192-2208 Ft Sandstone, very fine-grained to fine-grained, white, moderately,
3.6-5.0 km/sec
2208-2220 Ft Siltstone, slightly calcareous, slightly sandy, very light gray, medium hard-hard. 3.7-5.9 km/sec
2220-2223 Ft Shale, grayish red and greenish gray, interbedded, medium hard.
4.6 km/sec
2223-2228 Ft Siltstone as above. 4.8 km/sec
2228-2234 Ft Sandstone as above, fair porosity. 5.0-5.5 km/sec
2234-2240 Ft Siltstone as above. 5.3 km/sec
2240-2278 Ft Dolomite, micritic, very finely crystalline, slightly sandy, buff-
pale yellow brown, vuggy porosity. 5.2-6.1 km/sec
Arbuckle Dolomite
2278-2312 Ft Dolomite, micritic, very finely crystalline, pale yellow brown- buff, slightly cherty, hard, vuggy porosity with occasional shaly
streak. 5.3-6.2 km/sec
2312-2314 Ft Shale, dark gray, splintery, medium hard. 5.3 km/sec
2314-2350 Ft Dolomite as above and occasional shale break as above. 5.0-6.0 km/ sec
2350-2360 Ft Dolomite as above, slightly calcareous. 5.4-6.0 km/sec
2360-2370 Ft Dolomite, micritic, very finely crystalline, pale yellow brown-
pale brown. 5.4-6.2 km/sec
2370-2380 Ft Dolomite, calcareous as above. 6.2-6.7 km/sec
2380-2390 Ft Dolomite, finely crystalline (rhombic crystals) buff, cherty.
6.2-6.7 km/sec
2390-2410 Ft Dolomite as above with vugular porosity. 6.0-6.7 km/sec
2410-2450 Ft Dolomite, micritic, very finely crystalline, buff-pale yellow
brown, very cherty, dense. 5.4-6.5 km/sec
2450 TD.
Cutting log by W. R. Robinson
In 1995 the uncased 2450 Ft bore (100 m W of this bore) was reamed and
washed out. The bore was then drilled to 2777 Ft. Total Depth. The cuttings
from 2450 to 2777 ft appeared the same gray color, and they fizzed with
dilute hydrochloric acid. It was presumed that this indicated a continuation
of the Arbuckle Dolomite from 2450 Ft. to 2777 Ft. The entire 2777 Ft. bore,
named the Crosstimbers Borehole, was cased with 5.5 inch pipe and cemented.
The reworking of the Crosstimbers bore was done with DEPSCoR/ARPA funding.
The same contract provides for placement of a Guralp three component
broadband seismometer at the bottom of the bore. The Guralp CMG-1 will
have 24 bit digitizers and optical digital data transmitters in the
seismometer case.
A well drilled in 1923 in Leonard village found the top of the Spavinaw
Granite at elevation -2754 Ft. IF the Spavinaw Granite is level between
the 1923 well (Thomas Hulputta No. 1) and the Oklahoma Geological Survey
Observatory, The Spavinaw Granite would be about 3600 Ft below the surface
at the Observatory.