PROPERTY, PLANT AND EQUIPMENT

12 Months Ended

Dec. 31, 2020

Property, Plant and Equipment [Abstract]

PROPERTY, PLANT AND EQUIPMENT

The following table indicates the carrying value of each of the major classes of our depreciable assets:

	(In Millions)
	December 31,
	2020		2019
Land, land improvements, and mineral rights	$	1,213	$	582
Buildings	703		158
Equipment	6,786		1,456
Other	151		101
Construction in progress	1,364		730
Total property, plant and equipment1	10,217		3,027
Allowance for depreciation and depletion	(1,474)		(1,098)
Property, plant, and equipment, net	$	8,743	$	1,929
1 Includes right-of-use assets related to finance leases of $361 million and $49 million as of December 31, 2020 and 2019, respectively.

We recorded depreciation expense of $298 million, $77 million and $66 million for the years ended December 31, 2020, 2019 and 2018, respectively.

We recorded capitalized interest into property, plant and equipment of $53 million, $25 million and $7 million during the years ended December 31, 2020, 2019 and 2018, respectively.

The net book value of the mineral and land rights are as follows:

	(In Millions)
	December 31,
	2020		2019
Mineral rights:
Cost	$	773	$	537
Depletion	(142)		(134)
Net mineral rights	$	631	$	403
Land rights	$	361	$	12

We recorded depletion expense of $8 million, $8 million and $7 million for the years ended December 31, 2020, 2019, and 2018, respectively.