# Relationship history for MSHA mine 4000840

Current hierarchy: **Cemex S A → CEMEX Construction Materials Atlantic, LLC → Knoxville Cement Plant**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Ideal Basic Industries-Cement Division → Knoxville Cement Plant; 1950-01-01 to 1983-12-11; source msha-controller-operator-history
- **controller_controls_mine:** Ideal Basic Industries Inc → Knoxville Cement Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ideal Basic Industries Inc → Ideal Basic Industries-Cement Division; 1950-01-01 to 1983-12-11; source msha-controller-operator-history
- **controller_controls_mine:** Southdown Inc → Knoxville Cement Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Dixie Cement Company Inc → Knoxville Cement Plant; 1983-12-12 to 1988-09-05; source msha-controller-operator-history
- **controller_controls_mine:** Moore Mc Cormack Resources Inc → Knoxville Cement Plant; 1983-12-12 to 1988-09-05; source msha-controller-operator-history
- **controller_controls_operator:** Moore Mc Cormack Resources Inc → Dixie Cement Company Inc; 1983-12-12 to 1988-09-05; source msha-controller-operator-history
- **operator_operates_mine:** Southdown Inc → Knoxville Cement Plant; 1988-09-06 to 2001-02-27; source msha-controller-operator-history
- **controller_controls_operator:** Southdown Inc → Southdown Inc; 1988-09-06 to 2001-02-27; source msha-controller-operator-history
- **controller_controls_mine:** Cemex S A → Knoxville Cement Plant; 1994-09-09 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Cemex Inc → Knoxville Cement Plant; 2001-02-28 to 2010-03-08; source msha-controller-operator-history
- **controller_controls_operator:** Cemex S A → Cemex Inc; 2001-02-28 to 2010-03-08; source msha-controller-operator-history
- **controller_controls_mine:** Cemex S A → Knoxville Cement Plant; 2008-08-20 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** CEMEX Construction Materials Atlantic, LLC → Knoxville Cement Plant; 2010-03-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cemex S A → CEMEX Construction Materials Atlantic, LLC; 2010-03-09 to current/open; source msha-controller-operator-history