Zobrazeno 1 - 10
of 32
pro vyhledávání: '"D. F. Hewett"'
Autor:
D. F. Hewett, Earl V. Shannon
Publikováno v:
American Journal of Science. :491-506
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::6fa1b144d767cb12d6bc5e792befc8a8
https://doi.org/10.2475/ajs.s5-1.6.491
https://doi.org/10.2475/ajs.s5-1.6.491
Autor:
Waldemar T. Schaller, D. F. Hewett
Publikováno v:
American Journal of Science. :29-38
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::1093c56ab3cad0598c935ba8adb059d2
https://doi.org/10.2475/ajs.s5-10.55.29
https://doi.org/10.2475/ajs.s5-10.55.29
Publikováno v:
Economic Geology. 62:186-206
During a study of hypogene manganese minerals, three silver-bearing manganese oxides were identified in "black calcite" associated with silver ores at the Aurora mine (Treasure Hill), Hamilton, Nevada. Specifically these are: (1) argentian chalcophan
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::20686f6312d54a577062b918f3fe14b7
https://doi.org/10.2113/gsecongeo.62.2.186
https://doi.org/10.2113/gsecongeo.62.2.186
Publikováno v:
Proceedings of the United States National Museum. 73:1-18
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::0752f4e16b37fa7b3691eaf37686dc4f
https://doi.org/10.5479/si.00963801.73-2737.1
https://doi.org/10.5479/si.00963801.73-2737.1
Autor:
A. S. Radtke, D. F. Hewett
Publikováno v:
Economic Geology. 62:1-21
The name black calcite has been applied from time to time to a dark gray to black variety of calcite or aragonite in metalliferous ore deposits in the Western States. Most of the material shows curved, roughly rhombic cleavage. The color is due to di
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::8f130448667ea38ee5181f35b07c7f14
https://doi.org/10.2113/gsecongeo.62.1.1
https://doi.org/10.2113/gsecongeo.62.1.1
Autor:
D. F. Hewett
Publikováno v:
The Journal of Geology. 28:536-557
The recognition in 1919 of blocks of Madison limestone (Mississippian) overlying beds of the Bridger epoch (middle Eocene) in the McCullock Peak region, 12 miles east of Cody, Wyoming, shows that the overthrust fault recognized by Dake (2) in 1916 is
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::b27f8e0b9c1f6a2000d8cd83ef83151d
https://doi.org/10.1086/622733
https://doi.org/10.1086/622733
Autor:
D. F. Hewett
Publikováno v:
Economic Geology. 61:431-461
Review of layered deposits of manganese oxides and carbonates throughout the world indicates that most of the large concentrations are in Precambrian or Tertiary rocks. Iron is generally 30 to 90 times as abundant as manganese in ordinary rocks, wher
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::3eac5317b3613f95b7f4425d947bc3c8
https://doi.org/10.2113/gsecongeo.61.3.431
https://doi.org/10.2113/gsecongeo.61.3.431
Autor:
D. F. Hewett
Publikováno v:
Economic Geology. 67:83-102
This paper is concerned with three of the fairly common, manganese oxide minerals, manganite, hausmannite, and braunite. The study includes the precise determination of the minerals: (1) by X-ray diffraction and (2) spectrographic analyses. Most of t
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::a38ccf5531cf168b096f04a9be2132bf
https://doi.org/10.2113/gsecongeo.67.1.83
https://doi.org/10.2113/gsecongeo.67.1.83
Autor:
D. F. Hewett
Publikováno v:
Economic Geology. 59:1429-1472
Characteristic minerals are psilomelane, hollandite, cryptomelane, and coronadite, more rarely ramsdellite and pyrolusite. Host rocks are Mn-deficient; 80 percent of examples are middle to late Tertiary layered volcanics. Though deposits are shallow,
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::f34618ded1c205aea753676f7c6087d7
https://doi.org/10.2113/gsecongeo.59.8.1429
https://doi.org/10.2113/gsecongeo.59.8.1429