河北张家口以北的崇礼县至尚义县一带,分布着约1,700平方公里的中新世汉诺坝玄武岩,其岩性以碱性橄榄玄武岩、橄榄玄武岩和拉斑玄武岩为主,它们相间成层不整合覆于早期岩石之上,厚度一般东南厚西北薄,最大厚度可达400余米。其特殊之处在于碱性橄榄玄武岩中往往含有十分丰富的深源包体(或称岩球),包体形态各异,多呈浑圆状、椭球状,少数为扁平状。大 The Chongli County to Shangyi County, north of Zhangjiakou, Hebei Province, distribute about 1,700 square kilometers of the Miocene Hannover Basalt, which is dominated by alkaline olive basalt, olive basalt and tholeiite basalts, Layer unconformity over the early rock, the thickness of the general thickness of the northwestern northeast thin, the maximum thickness of up to 400 meters. The special feature is that basic olive basalts often contain very rich deep-sourced inclusions (or rock balls). The inclusions vary in morphology and are mostly rounded, ellipsoid and a few flattened. Big