Acute Subdural Hematoma

A 68-year-old man on warfarin for atrial fibrillation presents to the emergency department after a fall from standing height. CT head shows a crescentic hyperdense collection marked **A** in the diagram, with 8 mm midline shift and sulcal effacement. Which of the following best describes the pathophysiology of the structure marked **A**?

A 62-year-old woman on warfarin for atrial fibrillation is brought to the emergency department after a high-speed motor vehicle collision. She has a GCS of 9 with an anisocoric left pupil (5 mm, sluggishly reactive) and right-sided hemiparesis. On urgent non-contrast CT head, there is a hyperdense crescentic extra-axial collection along the left cerebral convexity measuring 14 mm at its thickest, extending from frontal to occipital regions, with 9 mm midline shift to the right and early uncal herniation. The structure marked **A** in the diagram represents this hyperdense crescentic collection. Which of the following is the PRIMARY mechanism of formation of this lesion?