Patent US4581531A successfully refreshed from Google Patents.
US4581531A
Expired / Lapsed
US
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Method for identifying hydrothermal alteration areas of the earth
Assignee: Mobil Oil AS
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Filing: 1983-11-16
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Granted: 1986-04-08
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Expires: 2003-11-16
Abstract
Abstract An aerial natural gamma radiation survey is conducted over an exploration region. A change in the measured T1-208/K-40 ratio in the exploration region in contrast to a region known not to be hydrothermally altered identifies the exploration region as a hydrothermal alteration. A surface natural gamma radiation survey is conducted over the hydrothermally altered exploration region. A change in the T1-208/K-40 ratio at specific sites within the exploration region indicates the location of alteration products.
Inventors
- 👤 Eric P. Dion
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:35
CPC Classifications
G; G01; G01V; G01V5/00; G01V5/02
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
284 words
A method for identifying hydrothermal alteration areas of the earth comprising the steps of: (a) conducting a first aerial natural gamma radiation survey over a known non-hydrothermal alteration area, (b) identifying a first T1-208/K-40 ratio of said known non-hydrothermal alteration area from the measured natural gamma radiation of said first aerial survey, (c) conducting a second aerial natural gamma radiation survey over an exploration area, (d) identifying a second T1-208/K-40 ratio over said exploration area from the measured natural gamma radiation of said second aerial survey, (e) comparing said second T1-208/K-40 ratio from the second survey over said exploration area with said first T1-208/K-40 ratio from the first survey over said known non-hydrothermal alteration area, (f) identifying said exploration area as a hydrothermal alteration region wherever said second T1-208/K-40 ratio for said exploration area is changed from said first T1-208/K-40 ratio for said known non-hydrothermal alteration area, (g) conducting a third surface natural gamma radiation survey over said exploration area, (h) identifying a third T1208/K-40 ratio over said exploration area from the measured natural gamma radiation of said third surface survey, (i) comparing said third T1-208/K-40 ratio from the third surface survey over said exploration area with said second T1-208/K-40 ratio from the second survey over said exploration area, (j) identifying an ore deposition site within said exploration area wherever said third T1-208/K-40 ratio for said site is changed in a first direction from said second T1-208/K-40 ratio from the second survey for said exploration area, and (k) identifying an ore leaching site within said exploration area whenever said third T1208/K-40 ratio for said site is changed in a second direction from said second T1-208/K-40 ratio from the second survey for said exploration area.
Claim 2
Independent Claim
284 words
A method for identifying hydrothermal alteration areas of the earth comprising the steps of: (a) conducting a first aerial natural gamma radiation survey over a known non-hydrothermal alteration area, (b) identifying a first T1-208/K-40 ratio of said known non-hydrothermal alteration area from the measured natural gamma radiation of said first aerial survey, (c) conducting a second aerial natural gamma radiation survey over an exploration area, (d) identifying a second T1-208/K-40 ratio over said exploration area from the measured natural gamma radiation of said second aerial survey, (e) comparing said second T1-208/K-40 ratio from the second survey over said exploration area with said first T1-208/K-40 ratio from the first survey over said known non-hydrothermal alteration area, (f) identifying said exploration area as a hydrothermal alteration region wherever said second T1-208/K-40 ratio for said exploration area is changed from said first T1-208/K-40 ratio for said known non-hydrothermal alteration area, (g) conducting a third surface natural gamma radiation survey over said exploration area, (h) identifying a third T1208/K-40 ratio over said exploration area from the measured natural gamma radiation of said third surface survey, (i) comparing said third T1-208/K-40 ratio from the third surface survey over said exploration area with said second T1-208/K-40 ratio from the second survey over said exploration area, (j) identifying an ore deposition site within said exploration area wherever said third T1-208/K-40 ratio for said site is changed in a first direction from said second T1-208/K-40 ratio from the second survey for said exploration area, and (k) identifying an ore leaching site within said exploration area whenever said third T1208/K-40 ratio for said site is changed in a second direction from said second T1-208/K-40 ratio from the second survey for said exploration area.
Claim 3
Dependent Claim
59 words
The method of claim 1 wherein said alteration product site is identified as a site of ore deposition wherever the T1208/K-40 ratio for said site is higher than that of said hydrothermal alteration region and is identified as a site of ore leaching whenever the T1208/K-40 ratio for said site is lower than that of said hydrothermal alteration region.
References Cited (Backward Citations)
US3919547A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-04-07 | 1989-10-07 | 1990-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-07 | 1993-10-07 | 1994-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-07 | 1997-10-07 | 1998-04-08 | $7700.00 | Window Closed / Lapsed |