Characteristics of Organic Macerals and Their Influence on Hydrocarbon Generation and Storage: A Case Study of Continental Shale of the Yanchang Formation from the Ordos Basin, China

Table 1

Main identification features of organic macerals under FE-SEM for Chang 7 shale in the Ordos Basin.

Maceral	Submaceral	Characteristics under FE-SEM	EDS
Vitrinite	Provitrinite	Visible cell structure, distorted cell wall, cell cavity filled with inorganic minerals, undeveloped pore	C: 80%~90%; O: <10%
	Euvitrinite	Invisible cell structure, banded and cloddy, undeveloped pore
	Vitrodetrinite	Obvious protrusions, fragmentary with sharp edges, undeveloped pore
Inertinite	Semifusinite	Swelling cell wall, combined with the surrounding matrix tightly, cell cavity filled with minerals, ribbon-shaped, underdeveloped pore	C: 80%~90%; O: >10%
	Inertodetrinite	Invisible cell structure, fragmentary with angular, arc-shaped, or other morphologies, transverse microcracks developed
Exinite	Sporophyte	Ellipsoidal, worm-like, and irregular shapes, cluster distribution round-elliptical large pores developed	C: 60%~70%; O: >10%
	Resin	Elliptical or irregular without cell structure, flat surface, circular-elliptical large pores developed
Sapropelite	Algae	Various shapes, cluster distribution, uneven surface, jagged edges, honeycomb-shaped pores developed	C: 40%~60%; O: >10%
	Mineral asphalt matrix	No fixed shape, unclear outline, mixed with inorganic minerals, large honeycomb pores developed