Correspondence 0001062993-24-006204 from Enertopia Corp. (ENRT) (CIK 0001346022) (ENRT)
Enertopia Corp. (ENRT) (CIK 0001346022)
Date: March 12, 2024 · CIK: 0001346022 · Accession: 0001062993-24-006204
AI Filing Summary & Sentiment
File numbers found in text: 000-51866
Letter
March 12, 2024 VIA EDGAR Securities and Exchange Commission 100 F. Street, NE Washington, D.C. 20549-7410 Attention: John Coleman
Re: Enertopia Corp. ("we", "us", "our", the "Company") Form 10-K/A for the Fiscal Year Ended August 31, 2023 File No. 000-51866 Filed February 1, 2024
Dear Sirs:
We write in response to your letter of March 11, 2024 regarding the above referenced annual report. For your ease of reference, our responses to your comments are numbered in a corresponding manner:
1. We note your response to prior comment 3, acknowledging your responsibility to file a technical report summary to support your disclosures of mineral resources. Please submit the technical report summary for our review, along with your response. If the report is not yet available, advise us of the status of the work and the timeframe for completion.
Response: The Company includes herewith the requested technical report.
2. We note that you have proposed some revisions in response to prior comment 4, regarding assumptions underlying your estimates of resources. However, these continue to omit some of the required content. Please further modify your proposed disclosures to include (i) the point of reference in which the estimates of mineral resources were calculated, and(ii) the mineral price assumptions to comply with Item 1304(d)(1) of Regulation S-K.
Response: Please see attached amended disclosure that includes the above requested information.
Yours truly,
ENERTOPIA CORP.
Per: /s/ Robert McAllister
Robert McAllister
Chief Executive Officer
Item 2. Properties
Executive Offices
The address of our executive office is #18 1873 Spall Rd., Kelowna, British Columbia V1Y 4R2. Our main telephone number is (250) 870-2219. Our current location provides adequate office space for our purposes at this stage of our development.
West Tonopah Lithium Exploration Project
Property Introduction
The West Tonopah Lithium Project consists of 88 unpatented Lode Mining Claims that are 100% owned by Enertopia and encompass a contiguous land position of approximately 1,818 acers. The Property encompasses all of Sections 19 and 30 Township 42N and Range 4E, and parts of Section 20 Township 42N and Range 4E and Sections 24 and 25 Township 3N Range 41E (Fig. 1). The centroid of the Property in Lambert Conformal projection is at Latitude 38.092867028 and Longitude -117.305668157. The claims were acquired directly from the United States Department of the Interior, Bureau of Land Management. Estimated respective yearly holding fees to the BLM $14,520 and $1,068 to Esmeralda County NV. To date $10,500 has been capitalized to the project and $677,013 in exploration and property expenses have been recorded as mineral exploration expenses.
The lithium-claystone project occurs within the Big Smoky Valley basin of Esmeralda County, NV, approximately 4 miles (6.4 km) west of the Unincorporated Town of Tonopah. The Property can be accessed via the United States Highway Route 6, a well-maintained paved highway that divides the property into southern and northern portions. Additional road access within the property is via a paved two-lane road that extends north from US 6 and numerous trails located throughout the property. No written records have been located with respect to historic ownership or previous work on the project. However, several historic shallow pits believed to be from uranium exploration in the 1950's, 1960's exist on the project.
Enertopia has obtained surface authorization rights in the form of a Notice of Intent through the Bureau of Land Management Tonopah Field Office and a current NOI bond for $13,990 is held by the State of Nevada Minerals Division. There are no royalties applicable to the West Tonopah Lode Claims. If mineral extraction were to occur in the future on these claims, the State of Nevada would impose taxes.
Other State and Federal permits associated with an early exploration stage project include:
• In accordance with Nevada water law, the exploration company/individual must obtain a permit or waiver for the temporary use of water for mineral exploration prior to activities such as drilling. The acquisition of a water permit involves an application to the Nevada Division of Water Resources, which undergoes evaluation based on factors such as water availability, potential conflicts with existing rights, public interest, and impact on domestic wells (http://water.nv.gov).
• Plugging or exploration holes must usually begin within 30 days after data has been collected from the hole.
• Any mineral development or exploration activities conducted under the General Mining law of 1872 on National Forest System lands must be approved pursuant to the Surface management Regulations (36 CFR 228). An operator must provide information describing the proposed activity to the District Ranger (i.e., the approved Exploration Plan of Operations and bond).
• Road Use Permits and other Special Use Permits may be required for access and utilities.
If the West Tonopah Lithium Project ever advances to the production stage, an updated
Plan of Operations with all the construction and mining details needs to be submitted, and approved, by the BLM. A list of State and Federal permits and actions required during planning, development, construction, and before operation of Nevada mines and mills can take place has been summarized by the Nevada Bureau of Mines and Geology (2018).
Environmental Liabilities
With respect to environmental liabilities, the Company is subject to compliance with operating, reclamation, and monitoring measures outlined in the BLM's Notice NVN- 101244, and the general and specific performance standards outlined in 43 CFR subpart 3809.420.
Enertopia is exploring the Miocene-aged Siebert Formation sedimentary and volcaniclastic rocks in the Big Smoky Valley basin for their lithium-claystone potential. During 2021-2023, Enertopia conducted 1) 2021 prospecting and a winkie drill program, and 2) 2022 and 2023 sonic drill programs that collectively drilled 22 holes to a total depth of 4,913.0 feet (1,497.5 m). The Enertopia exploration program results demonstrate the Siebert Formation is enriched in lithium and that portions of the West Tonopah Lithium Project have a lithium inventory with reasonable prospects of eventual economic extraction. It is the Qualified Person's opinion that the exploration work conducted by Enertopia at the West Tonopah Lithium Project is reasonable and within the standard practices for the evaluation of lithium-claystone deposit type projects.
Property Location and Access Map Fig 1:
Claims Location Map Fig 2
Geological Setting
Tectonic extension, which began around 17 Ma, formed the Basin and Range Province physiography that is defined by alternating mountain ranges (horsts) and elongated valleys (grabens) attributed to crustal extension and faulting along the western margin of North America. Valleys and low-lying grabens in the Basin and Range Province are filled with sedimentary rocks eroded from nearby mountains, or accumulated evaporite deposits from playa lakes formed within the topographical lows. The Big Smoky Valley represents a drainage divide landform within the Tonopah Basin.
The Miocene Siebert Formation (17-13 Ma) was derived from volcaniclastic fluvial and lacustrine deposits that include mudstone, siltstone, sandstone, and conglomerate with intercalated pyroclastic flows and tuff. The mineralisation belongs to the lithium-claystone deposit type. The Siebert Formation, and particularly the mudstone dominant horizons, at the Western Tonopah Lithium Project are enriched in lithium. Of 754 sonic drill core samples logged and analyzed by Enertopia, the minimum and maximum lithium values range from below the minimum limit of detection (20 ppm Li) to 1,520 ppm Li with an average value of 583.1 ppm Li.
Mineral Resource Estimations
The mineral resource estimation work was conducted in accordance with the Canadian Institute of Mining, Metallurgy and Petroleum definition standards and best practice guidelines, National Instrument 43-101 Standards of Disclosure for Mineral Projects, and in accordance with the requirements of S-K 1300.
The lithium-claystone resources defined in the technical report are constrained 1) stratigraphically to the Siebert Formation sedimentary and pyroclastic rock strata, and 2) are spatially split into the west and east resource areas divided by a Qualified Person-interpreted north-south trending fault.
Critical steps in the determination of the lithium-claystone resource model and estimations included:
• Definition of the geology and geometry of the Siebert Formation sedimentary and pyroclastic rocks in the west and east resource areas utilizing a 10 m resolution Digital Elevation Model, and geological information from 5 winkie drillholes and 22 sonic drillholes.
• Lithium grade estimation of the Siebert Formation blocks utilizing 766 lithium assays including 12 and 754 assays from the winkie and Sonic drill programs, respectively. To ensure lithium metal grades were not overestimated, composites were capped to specified maximum values of 1,250 ppm and 670 ppm in the west and east resource areas.
• Based on the drillhole spacing and detail within the 3D geological model, a block model with a block size of 66 x 66 x 10 feet (or 20 m by 20 m in the horizontal directions and 3 m in the vertical direction was generated).
• The Ordinary Kriging (OK) technique was used to estimate the lithium at each parent block within the Siebert Formation wireframe. A two-pass method was employed that used two different search ellipses.
• The West Tonopah Lithium Project is a project of merit in that there is a concentration or occurrence of lithium-claystone in such form, grade or quality and quantity that there are reasonable prospects for eventual economic extraction. A conceptual pit shell based on theoretical, but reasonable, parameters (such as a lithium recovery of 80%) demonstrated that blocks contained within the conceptual pit satisfy the test of reasonable prospects for eventual economic extraction.
• A nominal density of 1.70 g/cm3 was applied to convert the Siebert Formation block volumes to tonnage based on analogous Tonopah- and Siebert Formation-based mineral resource studies.
• In determining the lower cutoff value, the Qualified Person reviewed the Enertopia drill core assay database in conjunction with several lithium- claystone early-and advanced-stage projects in Nevada, including those in the Tonopah region (Fayram et al., 2020; Loveday and Turner, 2020; Cukor et al., 2022; Roth et al., 2022; RESPEC, 2023; Riordan et al., 2023). The QP considers a lower cutoff of 400 ppm Li is reasonable based on publicly available comparative information.
In consideration of Canadian Institute of Mining, Metallurgy, and Petroleum definition standards and S-K 1300, the west resource area is classified as indicated and inferred mineral resources and the east resource area is classified as an inferred mineral resource (Tables 1,2,3 below). Based on the total in-situ (global) on a cutoff of 400 ppm Li and on blocks contained within the conceptual pit shell, which utilizes a three year average lithium carbonate price of $26,500/tonne and a cutoff of 400 ppm li, the West Tonopah Lithium Project's mineral resource estimations are summarized as follows:
• The west resource area has an indicated lithium-claystone resource estimate of 44,000 short tons (40,000 metric tonnes) of elemental Li (Table 1). The global (total) lithium carbonate equivalent (LCE) for the west indicated resource area, which is calculated by multiplying elemental lithium by a factor of 5.323, is 233,000 short tons (212,000 metric tonnes) LCE.
• The west resource area has an inferred lithium-claystone resource estimate of 87,000 short tons (79,000 metric tonnes) of elemental Li (Table 2). This translates to 463,000 short tons (420,000 metric tonnes) LCE.
• The east resource area has a lithium-claystone inferred resource estimate of 5,000 short tons (5,000 metric tonnes) of elemental Li (Table 2). This translates to 27,000 short tons (25,000 metric tonnes) LCE.
Mineral resources are not mineral reserves and do not have demonstrated economic viability. There is no guarantee that all or any part of the mineral resource will be converted into a mineral reserve. The estimate of mineral resources may be materially affected by geology, environment, permitting, legal, title, taxation, socio-political, marketing, or other relevant issues. An inferred mineral resource has a lower level of confidence than that applying to an indicated mineral resource and must not be converted to a mineral reserve. It is reasonably expected that most inferred mineral resources could be upgraded to indicated mineral resources with continued exploration.
Table 1 West Tonopah Lithium Project west resource area indicated lithium-claystone resource estimate. The indicated mineral resource is reported for the Siebert Formation as a total (global) volume and tonnage using a lower cutoff of 400 ppm Li (bold font highlighted in grey)
West Resource Area Indicated Mineral Resource Estimate
Rock Mass
Contained Metal
Metric
Metric tonnes
Short tons
Li Cutoff tonnes Short tons (t)
(st) Average Li Grade
(ppm) (t) (st) Li LCE
Li LCE (ppm)
65,322,000 72,005,000 40,000 212,000
44,000 233,000
Rock Mass Contained Metal
Metric tonnes(t)
Short tons(st)
Li Cutoff (ppm) Metric tonnes (t) Short tons (st) Li LCE
Li LCE Average Li Grade (ppm)
80,428,000 88,657,000 45,000 240,000
50,000 265,000
65,322,000 72,005,000 40,000 212,000
44,000 233,000
46,476,000 51,231,000 31,000 166,000
34,000 184,000
30,221,000 33,313,000 22,000 119,000
25,000 131,000
7,646,000 8,428,000 7,000 35,000
7,000 39,000
264,000 291,000 - 1,000
- 2,000
Note 1: Mineral resources are not mineral reserves and do not have demonstrated economic viability.
Note 2: The weights are reported in United States short tons (2,000 lbs or 907.2 kg) and metric tonnes (1,000 kg or 2,204.6 lbs). The tonnage numbers are rounded to the nearest 1,000 unit, and therefore, may not add up.
Note 3: The density used to convert volume to tonnage is 1.70 g/cm3 for the Siebert Formation and the overburden/pediment.
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CORRESP
1
filename1.htm
Enertopia Corporation: CORRESP - Filed by newsfilecorp.com
March 12, 2024
VIA EDGAR
Securities and Exchange Commission
100 F. Street, NE
Washington, D.C. 20549-7410
Attention: John Coleman
Dear Sirs:
Re: Enertopia Corp. ("we", "us", "our", the "Company")
Form 10-K/A for the Fiscal Year Ended August 31, 2023
File No. 000-51866
Filed February 1, 2024
We write in response to your letter of March 11, 2024 regarding the above referenced annual report. For your ease of reference, our responses to your comments are numbered in a corresponding manner:
1. We note your response to prior comment 3, acknowledging your responsibility to file a technical report summary to support your disclosures of mineral resources. Please submit the technical report summary for our review, along with your response. If the report is not yet available, advise us of the status of the work and the timeframe for completion.
Response: The Company includes herewith the requested technical report.
2. We note that you have proposed some revisions in response to prior comment 4, regarding assumptions underlying your estimates of resources. However, these continue to omit some of the required content. Please further modify your proposed disclosures to include (i) the point of reference in which the estimates of mineral resources were calculated, and(ii) the mineral price assumptions to comply with Item 1304(d)(1) of Regulation S-K.
Response: Please see attached amended disclosure that includes the above requested information.
Yours truly,
ENERTOPIA CORP.
Per: /s/ Robert McAllister
Robert McAllister
Chief Executive Officer
Item 2. Properties
Executive Offices
The address of our executive office is #18 1873 Spall Rd., Kelowna, British Columbia V1Y 4R2. Our main telephone number is (250) 870-2219. Our current location provides adequate office space for our purposes at this stage of our development.
West Tonopah Lithium Exploration Project
Property Introduction
The West Tonopah Lithium Project consists of 88 unpatented Lode Mining Claims that are 100% owned by Enertopia and encompass a contiguous land position of approximately 1,818 acers. The Property encompasses all of Sections 19 and 30 Township 42N and Range 4E, and parts of Section 20 Township 42N and Range 4E and Sections 24 and 25 Township 3N Range 41E (Fig. 1). The centroid of the Property in Lambert Conformal projection is at Latitude 38.092867028 and Longitude -117.305668157. The claims were acquired directly from the United States Department of the Interior, Bureau of Land Management. Estimated respective yearly holding fees to the BLM $14,520 and $1,068 to Esmeralda County NV. To date $10,500 has been capitalized to the project and $677,013 in exploration and property expenses have been recorded as mineral exploration expenses.
The lithium-claystone project occurs within the Big Smoky Valley basin of Esmeralda County, NV, approximately 4 miles (6.4 km) west of the Unincorporated Town of Tonopah. The Property can be accessed via the United States Highway Route 6, a well-maintained paved highway that divides the property into southern and northern portions. Additional road access within the property is via a paved two-lane road that extends north from US 6 and numerous trails located throughout the property. No written records have been located with respect to historic ownership or previous work on the project. However, several historic shallow pits believed to be from uranium exploration in the 1950's, 1960's exist on the project.
Enertopia has obtained surface authorization rights in the form of a Notice of Intent through the Bureau of Land Management Tonopah Field Office and a current NOI bond for $13,990 is held by the State of Nevada Minerals Division. There are no royalties applicable to the West Tonopah Lode Claims. If mineral extraction were to occur in the future on these claims, the State of Nevada would impose taxes.
Other State and Federal permits associated with an early exploration stage project include:
• In accordance with Nevada water law, the exploration company/individual must obtain a permit or waiver for the temporary use of water for mineral exploration prior to activities such as drilling. The acquisition of a water permit involves an application to the Nevada Division of Water Resources, which undergoes evaluation based on factors such as water availability, potential conflicts with existing rights, public interest, and impact on domestic wells (http://water.nv.gov).
• Plugging or exploration holes must usually begin within 30 days after data has been collected from the hole.
• Any mineral development or exploration activities conducted under the General Mining law of 1872 on National Forest System lands must be approved pursuant to the Surface management Regulations (36 CFR 228). An operator must provide information describing the proposed activity to the District Ranger (i.e., the approved Exploration Plan of Operations and bond).
• Road Use Permits and other Special Use Permits may be required for access and utilities.
If the West Tonopah Lithium Project ever advances to the production stage, an updated
Plan of Operations with all the construction and mining details needs to be submitted, and approved, by the BLM. A list of State and Federal permits and actions required during planning, development, construction, and before operation of Nevada mines and mills can take place has been summarized by the Nevada Bureau of Mines and Geology (2018).
Environmental Liabilities
With respect to environmental liabilities, the Company is subject to compliance with operating, reclamation, and monitoring measures outlined in the BLM's Notice NVN- 101244, and the general and specific performance standards outlined in 43 CFR subpart 3809.420.
Enertopia is exploring the Miocene-aged Siebert Formation sedimentary and volcaniclastic rocks in the Big Smoky Valley basin for their lithium-claystone potential. During 2021-2023, Enertopia conducted 1) 2021 prospecting and a winkie drill program, and 2) 2022 and 2023 sonic drill programs that collectively drilled 22 holes to a total depth of 4,913.0 feet (1,497.5 m). The Enertopia exploration program results demonstrate the Siebert Formation is enriched in lithium and that portions of the West Tonopah Lithium Project have a lithium inventory with reasonable prospects of eventual economic extraction. It is the Qualified Person's opinion that the exploration work conducted by Enertopia at the West Tonopah Lithium Project is reasonable and within the standard practices for the evaluation of lithium-claystone deposit type projects.
Property Location and Access Map Fig 1:
Claims Location Map Fig 2
Geological Setting
Tectonic extension, which began around 17 Ma, formed the Basin and Range Province physiography that is defined by alternating mountain ranges (horsts) and elongated valleys (grabens) attributed to crustal extension and faulting along the western margin of North America. Valleys and low-lying grabens in the Basin and Range Province are filled with sedimentary rocks eroded from nearby mountains, or accumulated evaporite deposits from playa lakes formed within the topographical lows. The Big Smoky Valley represents a drainage divide landform within the Tonopah Basin.
The Miocene Siebert Formation (17-13 Ma) was derived from volcaniclastic fluvial and lacustrine deposits that include mudstone, siltstone, sandstone, and conglomerate with intercalated pyroclastic flows and tuff. The mineralisation belongs to the lithium-claystone deposit type. The Siebert Formation, and particularly the mudstone dominant horizons, at the Western Tonopah Lithium Project are enriched in lithium. Of 754 sonic drill core samples logged and analyzed by Enertopia, the minimum and maximum lithium values range from below the minimum limit of detection (20 ppm Li) to 1,520 ppm Li with an average value of 583.1 ppm Li.
Mineral Resource Estimations
The mineral resource estimation work was conducted in accordance with the Canadian Institute of Mining, Metallurgy and Petroleum definition standards and best practice guidelines, National Instrument 43-101 Standards of Disclosure for Mineral Projects, and in accordance with the requirements of S-K 1300.
The lithium-claystone resources defined in the technical report are constrained 1) stratigraphically to the Siebert Formation sedimentary and pyroclastic rock strata, and 2) are spatially split into the west and east resource areas divided by a Qualified Person-interpreted north-south trending fault.
Critical steps in the determination of the lithium-claystone resource model and estimations included:
•
Definition of the geology and geometry of the Siebert Formation sedimentary and pyroclastic rocks in the west and east resource areas utilizing a 10 m resolution Digital Elevation Model, and geological information from 5 winkie drillholes and 22 sonic drillholes.
•
Lithium grade estimation of the Siebert Formation blocks utilizing 766 lithium assays including 12 and 754 assays from the winkie and Sonic drill programs, respectively. To ensure lithium metal grades were not overestimated, composites were capped to specified maximum values of 1,250 ppm and 670 ppm in the west and east resource areas.
•
Based on the drillhole spacing and detail within the 3D geological model, a block model with a block size of 66 x 66 x 10 feet (or 20 m by 20 m in the horizontal directions and 3 m in the vertical direction was generated).
•
The Ordinary Kriging (OK) technique was used to estimate the lithium at each parent block within the Siebert Formation wireframe. A two-pass method was employed that used two different search ellipses.
•
The West Tonopah Lithium Project is a project of merit in that there is a concentration or occurrence of lithium-claystone in such form, grade or quality and quantity that there are reasonable prospects for eventual economic extraction. A conceptual pit shell based on theoretical, but reasonable, parameters (such as a lithium recovery of 80%) demonstrated that blocks contained within the conceptual pit satisfy the test of reasonable prospects for eventual economic extraction.
•
A nominal density of 1.70 g/cm3 was applied to convert the Siebert Formation block volumes to tonnage based on analogous Tonopah- and Siebert Formation-based mineral resource studies.
• In determining the lower cutoff value, the Qualified Person reviewed the Enertopia drill core assay database in conjunction with several lithium- claystone early-and advanced-stage projects in Nevada, including those in the Tonopah region (Fayram et al., 2020; Loveday and Turner, 2020; Cukor et al., 2022; Roth et al., 2022; RESPEC, 2023; Riordan et al., 2023). The QP considers a lower cutoff of 400 ppm Li is reasonable based on publicly available comparative information.
In consideration of Canadian Institute of Mining, Metallurgy, and Petroleum definition standards and S-K 1300, the west resource area is classified as indicated and inferred mineral resources and the east resource area is classified as an inferred mineral resource (Tables 1,2,3 below). Based on the total in-situ (global) on a cutoff of 400 ppm Li and on blocks contained within the conceptual pit shell, which utilizes a three year average lithium carbonate price of $26,500/tonne and a cutoff of 400 ppm li, the West Tonopah Lithium Project's mineral resource estimations are summarized as follows:
•
The west resource area has an indicated lithium-claystone resource estimate of 44,000 short tons (40,000 metric tonnes) of elemental Li (Table 1). The global (total) lithium carbonate equivalent (LCE) for the west indicated resource area, which is calculated by multiplying elemental lithium by a factor of 5.323, is 233,000 short tons (212,000 metric tonnes) LCE.
•
The west resource area has an inferred lithium-claystone resource estimate of 87,000 short tons (79,000 metric tonnes) of elemental Li (Table 2).
This translates to 463,000 short tons (420,000 metric tonnes) LCE.
•
The east resource area has a lithium-claystone inferred resource estimate of 5,000 short tons (5,000 metric tonnes) of elemental Li (Table 2). This translates to 27,000 short tons (25,000 metric tonnes) LCE.
Mineral resources are not mineral reserves and do not have demonstrated economic viability. There is no guarantee that all or any part of the mineral resource will be converted into a mineral reserve. The estimate of mineral resources may be materially affected by geology, environment, permitting, legal, title, taxation, socio-political, marketing, or other relevant issues. An inferred mineral resource has a lower level of confidence than that applying to an indicated mineral resource and must not be converted to a mineral reserve. It is reasonably expected that most inferred mineral resources could be upgraded to indicated mineral resources with continued exploration.
Table 1 West Tonopah Lithium Project west resource area indicated lithium-claystone resource estimate. The indicated mineral resource is reported for the Siebert Formation as a total (global) volume and tonnage using a lower cutoff of 400 ppm Li (bold font highlighted in grey)
West Resource Area Indicated Mineral Resource Estimate
Rock Mass
Contained Metal
Metric
Metric tonnes
Short tons
Li Cutoff
tonnes
Short tons
(t)
(st)
Average Li Grade
(ppm)
(t)
(st)
Li
LCE
Li
LCE
(ppm)
400
65,322,000
72,005,000
40,000
212,000
44,000
233,000
609
Rock Mass
Contained Metal
Metric tonnes(t)
Short tons(st)
Li Cutoff (ppm)
Metric tonnes (t)
Short tons (st)
Li
LCE
Li
LCE
Average Li Grade (ppm)
300
80,428,000
88,657,000
45,000
240,000
50,000
265,000
561
400
65,322,000
72,005,000
40,000
212,000
44,000
233,000
609
500
46,476,000
51,231,000
31,000
166,000
34,000
184,000
673
600
30,221,000
33,313,000
22,000
119,000
25,000
131,000
739
800
7,646,000
8,428,000
7,000
35,000
7,000
39,000
859
1000
264,000
291,000
-
1,000
-
2,000
1061
Note 1: Mineral resources are not mineral reserves and do not have demonstrated economic viability.
Note 2: The weights are reported in United States short tons (2,000 lbs or 907.2 kg) and metric tonnes (1,000 kg or 2,204.6 lbs). The tonnage numbers are rounded to the nearest 1,000 unit, and therefore, may not add up.
Note 3: The density used to convert volume to tonnage is 1.70 g/cm3 for the Siebert Formation and the overburden/pediment.