Description of manganese nodules collected in a metamorphic limestone Cambrian formation near Philipsburg, Montana

In the Philipsburg district, in western Montana a low arch of a Paleozoic limestones has been cut and deformed on the east and a south sides by a small batholith of Tertiary granodiorite. The manganese deposits are confined to an area of about 2 square miles underlain by sedimentary rocks and adjacent to the granodiorite body. The ore, chiefly pyrolusite, was apparently derived from rhodochrosite that was abundant in the veins and had replaced the adjacent limestones. The oxide ore is found chiefly within 600 feet of the surface, though one small body was mined at a depth of 700 feet. Commonly these bodies are aggregates of nodules or spheroids that range in size from that of an egg to that of a coconut or larger. In some places they show an irregular texture somewhat like that of a sponge, and in others the material composing them is loose and friable and apparently structureless. Psilomelane is the principal constituent of many of the nodules, in which it forms layers that alternate with softer oxides.

Pseudo-organic structures from the Precambrian Bass limestone in Arizona / [by] Matthew H. Nitecki --

v.23:no.1(1971)

(Table T1) Strontium isotopic composition and ages of limestone samples from ODP Hole 180-1118A

Limestone from Unit VI (857.1-859.15 meters below seafloor) collected at Site 1118 contains a planktonic foraminiferal fauna indicating a latest Miocene to early Pliocene age. Globorotalia tumida is recorded in Sample 180-1118A-68R-4, 46-48 cm, indicating an early Pliocene (N18) age at this level (J. Resig, pers. comm., 2000). Based on their known range in the western Papuan Basin, the presence of (rare) Lepidocyclina and common Amphistegina in some samples suggests that abundant shallow-water bioclastic debris present in these limestones may be reworked from older, possibly middle or early late Miocene sediments. Four samples were selected for whole-rock strontium isotopic analysis to further investigate this possibility. A petrographic examination of samples analyzed was also conducted.

Streamflow recharge to the Madison Limestone and the Casper Formation in the Glenrock area, east-central Wyoming /

Mode of access: Internet.

Ueber fossile Hydrocorallinen (Stromatorpora und ihre Verwandten) überhaupt mit besonderer Berückscihtigung der in den Unter-Permschichten (Middle Productus-Limestone) der Salt-Range auftretenden Formen. Nebst einem Anhange.

Inaug. Dissert. mat. u. naturw. Kaiser Wil.-Univ.

High-calcium limestone near Morris, Illinois

At head of title: State of Illinois. Department of registration and education. Division of the State geological survey.

Tests of low-density marine limestone for use in breakwaters /

"May 1976."

Preliminary report on relation of structure to uranium mineralization in the Todilto limestone, Grants District, New Mexico /

"September 10, 1952."

Oil production from the Ste. Genevieve limestone in the Exchange area, Marion County, Illinois /

Bound with no. 430-no. 437 subsequent to publication.