294 



BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



Preliminary description of the limestone samples and list of species of Foraminifera from 



the Bermuda well. 



No. of specimen 



and depth 

 below surface. 



(0-6 feet) 



2 (61-110 feet) 



3 (110-216 feet) 



4 (216-241 feet) 



5 (241-286 feet) 



6 (286-331 feet) 



7 (331-341 feet) 



8 (341-383 feet) 



Description. 



Light cream-colored limestone; mixture of cal- 

 cite and aragonite; most of the constituent 

 particles angular; largely or mostly broken 

 remains of organisms; occasional small round 

 grains 0.10 mm. or less in diameter, may be 

 aggregates of chemically precipitated calcium 

 carbonate. Largely or mostly an organic 

 limestone. 



Light cream-colored limestone; mixture of cal- 

 cite and aragonite; constituent particles most- 

 ly angular, Foraminifera and broken tests of 

 other organisms present; a few rounded grains 

 0.04 mm. or less in diameter, may be aggre- 

 gates of chemically precipitated material. 

 Largely or mostly an organic limestone. 



Light cream-colored limestone; mixture of cal- 

 cite and aragonite, apparently but little ara- 

 gonite; largely a recrystallized limestone, 

 without conspicuous grains; some small pock- 

 ets contain pulverulent calcium carbonate; 

 some pieces granular. A few grains 0.05 to 

 0.8 mm. in diameter resemble small oolite 

 grains. The rock is mostly a foraminiferal 

 limestone, the Foraminifera embedded in a 

 cryptocrystalline matrix. 



Whitish limestone, very slight yellowish tinge, 

 some blackish particles; mixture of aragonite 

 and calcite ; specimen consists mostly of broken 

 rock fragments; an occasional small pebble, 

 one 2.5 mm. as maximum diameter; constit- 

 uent material largely organic, Foraminifera, 

 fragments of mollusks, shells, etc. Most small 

 particles angular; a few less than 0.12 

 mm. appear oolitic. One 0.09 by 0.17 mm. 

 in size had form of an oolitic ellipsoid. Mostly 

 an organic limestone. 



Whitish, faintly yellowish, pulverulent lime- 

 stone ; mixture of calcite and aragonite . Com- 

 paratively few tests of organisms, some Fora- 

 minifera, many small rounded grains and 

 cryptocrystalline material. Some of the round 

 grains appear oolitic; one of these is 0.11 by 

 0.15 mm. in size. It appears that a consider- 

 able proportion of this bed is a chemical pre- 

 cipitate. 



White, pulverulent limestone; mixture of cal- 

 cite and aragonite. No organic tests were ob- 

 served. Round grains up to 0.1 or 0.2 mm. 

 appear to be oolite; small round grains 0.04 

 mm. in diameter. Much cryptocrystalline 

 material. This bed appears to be largely a 

 chemical precipitate. 



White, friable limestone; mixture of calcite and 

 aragonite. Round grains which range in di- 

 ameter from 0.22 to 0.45 mm., may be oolitic. 

 Small grains, 0.09 mm. in diameter seem defi- 

 nitely oolitic. Besides the rounded, there are 

 broken angular grains and much cryptocrys- 

 talline material. Few or no organic tests. 

 This appears to be largely a chemical precip- 

 itate. 



Light-colored, earthy, yellowish-gray, impure 

 limestone; some iron pyrites; mostly calcite, 

 if aragonite is present the proportion is small. 

 Many Foraminifera, Nummulites, fragments of 

 coral, Bryozoa, etc.; many rounded grains 

 which may be detrital; no definitely oolitic 

 grains were observed. A thin section shows 

 many Foraminifera embedded in a cryptocr ys- 

 talline matrix. This bed is an impure, forami- 

 niferal, shoal water limestone. It may con- 

 tain some chemically precipitated material. 



Species of Foraminifera. 



Textularia agglutinans d'Orbigny. 

 Polystomella striata punctata Fichtel 



& Moll. 

 Polystomella species. 

 Amphistegina lessonii d'Orbigny. 

 Quinqueloculina reticulata d'Orbigny. 

 Q. oblonga Montagu. 

 Q. auberiana d'Orbigny. 

 Peneroplis pertusus Forskal. 

 Orbiculina adunca Fichtel & Moll. 



Textularia agglutinans d'Orbigny. 

 Polystomella striatopunctata Fichtel 



& Moll. 

 Polystomella species. 

 Amphistegina lessonii d'Orbigny. 

 Quinqueloculina reticulata d'Orbigny 

 Q. auberiana d'Orbigny. 

 Orbiculina adunca Fichtel & Moll. 



Clavulina angularis d'Orbigny. 

 Planorbulina larvata Parker & Jones. 

 Truncatulina species. 

 Polystomella striatopunctata Fichtel 



& Moll. 

 Amphistegina lessonii d'Orbigny. 

 Triloculina cf. T. circularis Borne- 



mann. 

 Orbiculina adunca Fichtel & Moll. 



Truncatulina species. 

 Pulvinulina canariensis d'Orbigny. 

 Polystomella striatopunctata Fichtel 



& Moll. 

 Polystomella species. 

 Amphistegina lessonii d'Orbigny. 

 Triloculina linneana d'Orbigny. 

 Orbiculina adunca Fichtel & Moll. 



Bolivina species. 



Truncatulina species. 



Discorbis vilardeboana d'Orbigny. 



Amphistegina species. 



Quinqueloculina reticulata d'Orbigny • 



Biloculina species. 



None reported. 



Amphistegina species. 



Nummulites species. 



