觀(guan)(guan)音山(Kuan-yin Mountain),舊稱新宜山,別(bie)名八里(li)坌山(淡水廳志載)。位于臺灣省新北(bei)市五股區(qu)、八里(li)區(qu)交界,海拔(ba)標高616米,由淡水河北(bei)岸(an)向南遙(yao)望,全區(qu)有十(shi)八連峰,區(qu)內有多(duo)座(zuo)古剎,更(geng)增添(tian)觀(guan)(guan)音山的靈性,其中有數間供奉觀(guan)(guan)世音菩薩的觀(guan)(guan)音寺。
觀(guan)音(yin)山(shan)(shan)(shan),亦有不少納骨塔及(ji)墓(mu)園錯(cuo)落其(qi)間,該山(shan)(shan)(shan)西臨(lin)臺灣海峽(xia),東北隔淡水河遠(yuan)望(wang)關渡,昔日的“坌嶺(ling)吐霧”為淡水八大景之一,山(shan)(shan)(shan)頂(ding)又稱“硬漢嶺(ling)”,全(quan)山(shan)(shan)(shan)屬北海岸及(ji)觀(guan)音(yin)山(shan)(shan)(shan)風景區。
觀音(yin)山(shan)(shan)自(zi)古便有(you)登山(shan)(shan)活動,目前八里(li)登觀音(yin)山(shan)(shan)的(de)路線(xian)共有(you)四(si)條主要(yao)路線(xian),其中(zhong)以(yi)乘車至觀音(yin)山(shan)(shan)風(feng)景區管理處,由凌(ling)云禪寺旁(pang)鐵漢(han)步道經硬漢(han)嶺(ling)(ling)拾階而上登頂為(wei)最(zui)熱門路線(xian)。硬漢(han)嶺(ling)(ling)為(wei)1961年憲兵(bing)學(xue)校300名學(xue)員開辟了(le)一條直達(da)山(shan)(shan)頂的(de)登山(shan)(shan)步道,為(wei)鼓勵學(xue)員學(xue)硬漢(han)而來作(zuo)硬漢(han)而去,而名硬漢(han)嶺(ling)(ling)。
硬漢嶺(ling)為火山碎屑巖(yan)與凝(ning)灰角礫巖(yan)所構成(cheng),1992,1993年(nian)來時有(you)豪(hao)雨山崩土石滑動,步道毀壞并危及凌云禪寺安全。寄望能有(you)效(xiao)妥當的維護整修以(yi)保持靈山古剎之原有(you)古樸(pu)韻(yun)味。
由于季風吹來臺灣海峽的水汽,遇到觀(guan)音山(shan)嶺(ling)的阻擋,便降下化為云霧,有如飄綿滾絮、變幻無常(chang),蔚為奇觀(guan).被文人(ren)雅(ya)士命名(ming)為“坌嶺(ling)吐霧”,名(ming)列清代(dai)淡(dan)北八景之一。同治年間(jian)大龍峒舉(ju)人(ren)陳維英曾(ceng)題(ti)詩贊(zan)曰:“坌嶺(ling)微茫八里間(jian),連朝吐霧罩鴉鬟,此中定有深藏貌,未許分明見(jian)一斑”。
觀音(yin)山(shan)(shan)在淡水河河口(kou)南(nan)畔,東與大屯山(shan)(shan)群峰隔河相峙,西南(nan)毗(pi)接林口(kou)臺(tai)地。形似仰(yang)臥之觀音(yin),山(shan)(shan)頂空(kong)曠怡人,立足其上可俯瞰河口(kou)及淡水鎮、臺(tai)北市郊(jiao)景色,為(wei)淡水八(ba)景之一(yi)。凌云(yun)古剎(cha)坐落(luo)山(shan)(shan)腰,后另(ling)建新(xin)廟于(yu)古剎(cha)后方約(yue)數百公(gong)尺處(chu)(即觀音(yin)山(shan)(shan)腹),名曰凌云(yun)禪寺,是游人休憩處(chu)。
觀音(yin)山(shan)為(wei)(wei)(wei)(wei)一(yi)錐(zhui)狀火山(shan),是大屯火山(shan)匯最西的一(yi)部分,其北(bei)側(ce)以火山(shan)熔(rong)巖(yan)(yan)(yan)為(wei)(wei)(wei)(wei)主,南側(ce)以火山(shan)碎(sui)屑流(liu)為(wei)(wei)(wei)(wei)主,火成(cheng)巖(yan)(yan)(yan)以安(an)山(shan)巖(yan)(yan)(yan)為(wei)(wei)(wei)(wei)主,另外含(han)有一(yi)些早期噴發的玄武(wu)巖(yan)(yan)(yan),越晚(wan)期的噴發則(ze)形成(cheng)含(han)角閃石的安(an)山(shan)巖(yan)(yan)(yan)。淡水(shui)河沿著(zhu)觀音(yin)山(shan)麓流(liu)入臺灣海峽,因兩側(ce)的火山(shan)熔(rong)巖(yan)(yan)(yan)與碎(sui)屑物漫(man)流(liu)入海,而形成(cheng)火山(shan)海岸。
山(shan)上(shang)坐落著不少(shao)名剎古寺(si),并可(ke)溯(su)溪觀瀑、觀鷹賞(shang)鳥、眺望半個臺北和壯麗(li)的(de)(de)大屯山(shan)列,是一處(chu)豐(feng)富的(de)(de)自(zi)然觀賞(shang)去處(chu)。觀音(yin)山(shan)上(shang)的(de)(de)山(shan)徑溪谷四通八達,登山(shan)路線(xian)林林總總、難易不同,登山(shan)客可(ke)以(yi)揀挑適(shi)合自(zi)己(ji)體力的(de)(de)山(shan)徑上(shang)山(shan)。其中最大眾化的(de)(de)路線(xian)是從(cong)五股的(de)(de)觀音(yin)山(shan)站牌(pai)出發,沿(yan)山(shan)階上(shang)登凌云禪寺(si),再由寺(si)后的(de)(de)牌(pai)樓(lou)往(wang)上(shang)走,約1小(xiao)時可(ke)抵(di)硬漢嶺。在(zai)此(ci)登高眺覽,視野(ye)遼闊,整個臺北市自(zi)新(xin)光(guang)大樓(lou)以(yi)北的(de)(de)市景都(dou)在(zai)眼下,而(er)對面的(de)(de)大屯山(shan)列及淡水河口(kou)山(shan)海(hai)相映的(de)(de)景象更是壯觀。
白天上觀音山,可隔(ge)著門墻老樹(shu)感受楞嚴閣(ge)、開山院的古(gu)樸莊(zhuang)嚴,遠眺(tiao)淡水八景之一(yi)的“坌領吐(tu)霧”;傍晚時(shi)分坐觀落日晚霞,淡水暮(mu)色最令人心動(dong);或于夜幕低垂時(shi)看淡水河畔夜景,萬家燈火(huo)閃(shan)爍明滅,另有一(yi)番擾攘人間之美。
在荷蘭人統治(zhi)時代,觀音(yin)山叫淡(dan)水山(出現在1654年荷蘭人‘淡(dan)水與其附近村社暨雞籠島略(lve)圖’中(zhong)編號37的(de)(de)Tamswijse berch),但漢人習稱八里分(坌)山,系(xi)因山邊的(de)(de)原住民部落八里坌社而得名。
康熙年(nian)(nian)間,乃延用八里(li)(li)坌(ben)山(shan)(shan)的(de)地(di)名(ming)(康熙二十四年(nian)(nian)蔣毓英“臺灣府志”)。清朝(chao)雍正(zheng)年(nian)(nian)間(西元1710年(nian)(nian)代)也曾改(gai)為“興直(zhi)山(shan)(shan)”,但在各地(di)方史籍中(zhong)仍以(yi)“八里(li)(li)坌(ben)山(shan)(shan)”稱之。后來改(gai)為觀(guan)音山(shan)(shan)的(de)說法有二:一說是(shi)乾(qian)隆17年(nian)(nian)(西元1752年(nian)(nian))客家(jia)籍貢生(sheng)胡焯(zhuo)猷(福建(jian)汀州永定人)在山(shan)(shan)路西云巖籌建(jian)大士(shi)觀(guan)(今五股(gu)區西云巖寺)而得名(ming),一說是(shi)由于山(shan)(shan)棱起伏變化(hua),從關渡一帶眺望時,山(shan)(shan)型起伏貌似(si)觀(guan)音菩(pu)薩(sa)的(de)面(mian)容(rong)仰天的(de)側面(mian)而得名(ming)。
據臺灣著名(ming)的(de)地(di)名(ming)學者-陳國(guo)章教授所著的(de)臺灣地(di)名(ming)詞典(dian),認為該地(di)的(de)地(di)名(ming)是因“形(xing)似觀(guan)音(yin)菩(pu)薩的(de)山”而得名(ming)。
1937年(nian)12月(yue)27日,日本殖民當局以臺灣寶島山(shan)水風光秀麗籌(chou)劃成(cheng)立(li)大(da)屯觀音山(shan)、次高山(shan)太魯(lu)閣和新(xin)高阿里山(shan)三(san)座(zuo)公(gong)園,并于1941年(nian)3月(yue)10日發行(xing)紀念郵(you)票、小全張(zhang)及(ji)臺灣公(gong)園寫真集(ji),可惜因戰爭而延宕(dang)。
二(er)次世(shi)界大(da)戰結(jie)束后,臺灣回歸(gui)中國,觀音山(shan)(shan)優良的屏障、視(shi)野的寬闊好(hao)山(shan)(shan)好(hao)水(shui),為(wei)國人(ren)所認為(wei)風水(shui)寶地,濫(lan)挖濫(lan)葬,一(yi)片零亂有(you)礙視(shi)野觀瞻(zhan)。相(xiang)較(jiao)之下,景觀資(zi)源大(da)不如往昔,已失去(qu)了(le)成為(wei)公園(yuan)之基(ji)本要件(jian),十(shi)分可惜。
觀音山(shan)(shan)是(shi)(shi)臺灣北部火(huo)(huo)成巖(yan)(yan)區中(zhong)(zhong)最西北側(ce)之(zhi)(zhi)(zhi)火(huo)(huo)山(shan)(shan)單元,以(yi)淡水河與(yu)大(da)屯火(huo)(huo)山(shan)(shan)群遙遙相望,基本上為單一中(zhong)(zhong)心噴(pen)發的火(huo)(huo)山(shan)(shan)碎(sui)屑、凝(ning)灰巖(yan)(yan)與(yu)熔巖(yan)(yan)交替(ti)組成之(zhi)(zhi)(zhi)復式火(huo)(huo)山(shan)(shan)。觀音山(shan)(shan)火(huo)(huo)山(shan)(shan)之(zhi)(zhi)(zhi)主體(ti)可能是(shi)(shi)一中(zhong)(zhong)央噴(pen)發之(zhi)(zhi)(zhi)錐狀火(huo)(huo)山(shan)(shan),錐體(ti)半徑約1~2公里(li),噴(pen)發中(zhong)(zhong)心在(zai)(zai)觀音山(shan)(shan)主峰之(zhi)(zhi)(zhi)東南方。在(zai)(zai)凌云山(shan)(shan)一帶之(zhi)(zhi)(zhi)半環形之(zhi)(zhi)(zhi)連(lian)峰可能是(shi)(shi)火(huo)(huo)山(shan)(shan)口壁之(zhi)(zhi)(zhi)西側(ce)。
在(zai)(zai)此以(yi)東(dong),于石壁坑(keng)附近之地(di)形,呈馬蹄(ti)狀(zhuang)(zhuang)之半圓形凹陷(xian)可(ke)能(neng)是火(huo)山(shan)口(kou)所(suo)在(zai)(zai),但(dan)火(huo)山(shan)口(kou)之東(dong)壁已經爆破或(huo)(huo)(huo)熔(rong)巖(yan)溢流巖(yan)漿(jiang)庫匱空(kong)塌(ta)陷(xian)而(er)崩塌(ta),其部分碎(sui)屑構成(cheng)分布于凌云山(shan)以(yi)東(dong)地(di)區之集(ji)塊巖(yan)或(huo)(huo)(huo)原先(xian)之火(huo)山(shan)碎(sui)屑流與火(huo)山(shan)礫巖(yan)。觀(guan)音(yin)山(shan)火(huo)山(shan)活動時可(ke)能(neng)不(bu)猛烈,因而(er)出露之主(zhu)體并未(wei)含有(you)可(ke)觀(guan)的火(huo)山(shan)碎(sui)屑巖(yan),仍以(yi)厚(hou)層的巖(yan)流為主(zhu)。觀(guan)音(yin)山(shan)噴出熔(rong)巖(yan)流也和大屯火(huo)山(shan)群相(xiang)似,均以(yi)安山(shan)巖(yan)為主(zhu)。一般安山(shan)巖(yan)常(chang)呈灰或(huo)(huo)(huo)灰黑(hei)色(se),且(qie)多呈斑(ban)狀(zhuang)(zhuang)結構,由結晶較粗大之斑(ban)晶散布在(zai)(zai)石質細密之石基中(zhong)。斑(ban)晶礦物(wu)以(yi)鎂鐵(tie)礦物(wu)為多,包括橄欖石、輝石、紫(zi)蘇(su)輝石、角閃石、黑(hei)云母等礦物(wu),此外(wai)還有(you)灰白色(se)的斜(xie)(xie)長(chang)(chang)石。石基以(yi)斜(xie)(xie)長(chang)(chang)石和一些鎂鐵(tie)礦物(wu)的微晶(肉眼不(bu)能(neng)分辨(bian)的)和無(wu)結晶的火(huo)山(shan)玻璃(li)所(suo)組成(cheng)。
本區安山(shan)巖(yan)(yan)熔巖(yan)(yan)依噴發之先(xian)后,由下而上(shang)可分(fen)(fen)別(bie)為三層,各層巖(yan)(yan)石在組織上(shang)和成分(fen)(fen)上(shang)都有多少不同。
底(di)層(ceng)(ceng)(或第一層(ceng)(ceng))是粗粒(li)普通輝(hui)(hui)石(shi)(shi)(shi)(shi)(shi)玄(xuan)武巖(yan)或玄(xuan)武巖(yan)質安山(shan)(shan)巖(yan)熔巖(yan)。主要露出于火山(shan)(shan)錐體(ti)之(zhi)(zhi)中(zhong)(zhong)心地(di)帶(dai),包括石(shi)(shi)(shi)(shi)(shi)壁坑及其東側(ce)之(zhi)(zhi)米倉村、烏山(shan)(shan)頭,至(zhi)福隆山(shan)(shan)等地(di)。安山(shan)(shan)巖(yan)顏(yan)色深(shen)灰,呈斑(ban)狀結構有(you)許(xu)多(duo)黑綠(lv)色之(zhi)(zhi)普通輝(hui)(hui)石(shi)(shi)(shi)(shi)(shi)斑(ban)晶(jing)(jing),散布(bu)在(zai)灰色細晶(jing)(jing)之(zhi)(zhi)石(shi)(shi)(shi)(shi)(shi)基中(zhong)(zhong),斑(ban)晶(jing)(jing)大者可達5公里(li)左右。在(zai)顯微鏡(jing)下(xia)觀(guan)察巖(yan)石(shi)(shi)(shi)(shi)(shi)薄片,這些(xie)斑(ban)晶(jing)(jing)多(duo)成雙晶(jing)(jing)或叢晶(jing)(jing)(由(you)(you)數個晶(jing)(jing)體(ti)結集而成),輝(hui)(hui)石(shi)(shi)(shi)(shi)(shi)之(zhi)(zhi)外還有(you)多(duo)數斜長(chang)石(shi)(shi)(shi)(shi)(shi)和少(shao)數橄(gan)欖石(shi)(shi)(shi)(shi)(shi)。中(zhong)(zhong)層(ceng)(ceng)(或第二層(ceng)(ceng))的(de)熔巖(yan)是由(you)(you)兩輝(hui)(hui)安山(shan)(shan)巖(yan)構成。巖(yan)石(shi)(shi)(shi)(shi)(shi)外觀(guan)灰色,普通輝(hui)(hui)石(shi)(shi)(shi)(shi)(shi)之(zhi)(zhi)斑(ban)晶(jing)(jing)雖粗大易見但(dan)甚稀少(shao),細長(chang)之(zhi)(zhi)紫蘇(su)輝(hui)(hui)石(shi)(shi)(shi)(shi)(shi)晶(jing)(jing)體(ti)頗多(duo)但(dan)均細小(xiao)。本(ben)(ben)巖(yan)石(shi)(shi)(shi)(shi)(shi)之(zhi)(zhi)石(shi)(shi)(shi)(shi)(shi)基占量較(jiao)多(duo),由(you)(you)斜長(chang)石(shi)(shi)(shi)(shi)(shi)和紫蘇(su)輝(hui)(hui)石(shi)(shi)(shi)(shi)(shi)細晶(jing)(jing)以及火山(shan)(shan)玻璃所組成。本(ben)(ben)層(ceng)(ceng)是觀(guan)音山(shan)(shan)中(zhong)(zhong)露出面積最廣的(de)熔巖(yan),主要分布(bu)于觀(guan)音山(shan)(shan)主峰北側(ce)之(zhi)(zhi)山(shan)(shan)坡(po)。
第二(er)層(ceng)斑(ban)晶(jing)稀疏之(zhi)(zhi)(zhi)兩(liang)(liang)輝(hui)安(an)(an)山(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(yan),常含(han)(han)(han)第一層(ceng)輝(hui)石(shi)(shi)斑(ban)晶(jing)多(duo)而聚集成叢(cong)的(de)(de)普(pu)(pu)通(tong)輝(hui)石(shi)(shi)安(an)(an)山(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(yan)之(zhi)(zhi)(zhi)捕獲巖(yan)(yan)(yan)(yan)(yan)(yan)塊(kuai),根(gen)據(ju)年代對比(bi)的(de)(de)包裹定律,即(ji)可(ke)知其(qi)(qi)發(fa)生之(zhi)(zhi)(zhi)先后順序,乃輝(hui)石(shi)(shi)安(an)(an)山(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(yan)(第一層(ceng))早(zao)于兩(liang)(liang)輝(hui)安(an)(an)山(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(yan)(第二(er)層(ceng))。頂層(ceng)(第三(san)層(ceng))紫(zi)(zi)蘇輝(hui)石(shi)(shi)安(an)(an)山(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(yan)與(yu)一部分角(jiao)(jiao)閃石(shi)(shi)紫(zi)(zi)蘇安(an)(an)山(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(yan)為(wei)(wei)其(qi)(qi)特征,顏色淡灰(hui)色或(huo)灰(hui)紫(zi)(zi),斑(ban)晶(jing)細小(xiao)(xiao)不顯著。有(you)時可(ke)見有(you)細長(chang)之(zhi)(zhi)(zhi)紫(zi)(zi)蘇輝(hui)石(shi)(shi)或(huo)角(jiao)(jiao)閃石(shi)(shi)之(zhi)(zhi)(zhi)小(xiao)(xiao)晶(jing),石(shi)(shi)基較多(duo)包含(han)(han)(han)微晶(jing)與(yu)玻璃質(zhi)(zhi)。本層(ceng)主要(yao)分布(bu)在(zai)火(huo)(huo)(huo)山(shan)(shan)(shan)(shan)中(zhong)央之(zhi)(zhi)(zhi)頂部,由觀音(yin)(yin)山(shan)(shan)(shan)(shan)主峰至(zhi)崩山(shan)(shan)(shan)(shan)一帶。在(zai)本地(di)(di)區(qu)內除(chu)上(shang)(shang)述之(zhi)(zhi)(zhi)三(san)層(ceng)熔(rong)巖(yan)(yan)(yan)(yan)(yan)(yan)流之(zhi)(zhi)(zhi)外,還有(you)兩(liang)(liang)處獨立之(zhi)(zhi)(zhi)小(xiao)(xiao)規模火(huo)(huo)(huo)山(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(yan)體(ti)(ti),一是(shi)(shi)(shi)在(zai)觀音(yin)(yin)山(shan)(shan)(shan)(shan)站北側(ce)公(gong)路(lu)旁出(chu)露之(zhi)(zhi)(zhi)黑云母角(jiao)(jiao)閃安(an)(an)山(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(yan)脈(mo)(mo),為(wei)(wei)一厚(hou)約20~40公(gong)尺(chi)之(zhi)(zhi)(zhi)脈(mo)(mo)狀小(xiao)(xiao)侵入體(ti)(ti)(或(huo)稱觀音(yin)(yin)坑巖(yan)(yan)(yan)(yan)(yan)(yan)脈(mo)(mo)),穿入觀音(yin)(yin)山(shan)(shan)(shan)(shan)層(ceng)之(zhi)(zhi)(zhi)粉砂巖(yan)(yan)(yan)(yan)(yan)(yan)之(zhi)(zhi)(zhi)中(zhong)。另一處是(shi)(shi)(shi)突出(chu)于成子寮附近(jin)低地(di)(di)上(shang)(shang)之(zhi)(zhi)(zhi)萬年塔小(xiao)(xiao)山(shan)(shan)(shan)(shan),巖(yan)(yan)(yan)(yan)(yan)(yan)石(shi)(shi)是(shi)(shi)(shi)橄(gan)欖石(shi)(shi)玄(xuan)武(wu)巖(yan)(yan)(yan)(yan)(yan)(yan),可(ke)能是(shi)(shi)(shi)一火(huo)(huo)(huo)山(shan)(shan)(shan)(shan)側(ce)噴發(fa)之(zhi)(zhi)(zhi)巖(yan)(yan)(yan)(yan)(yan)(yan)體(ti)(ti)。萬年塔所產出(chu)者,其(qi)(qi)橄(gan)欖石(shi)(shi)含(han)(han)(han)量較普(pu)(pu)通(tong)輝(hui)石(shi)(shi)為(wei)(wei)多(duo),與(yu)福(fu)隆山(shan)(shan)(shan)(shan)玄(xuan)武(wu)巖(yan)(yan)(yan)(yan)(yan)(yan)略有(you)不同。根(gen)據(ju)結晶(jing)分化(hua)的(de)(de)效應,玄(xuan)武(wu)質(zhi)(zhi)巖(yan)(yan)(yan)(yan)(yan)(yan)漿(jiang)經(jing)由橄(gan)欖石(shi)(shi)、輝(hui)石(shi)(shi)與(yu)斜長(chang)石(shi)(shi)的(de)(de)結晶(jing)分化(hua)可(ke)以產生安(an)(an)山(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(yan)。同樣的(de)(de)由混(hun)染(ran)作用,也就是(shi)(shi)(shi)由基性的(de)(de)巖(yan)(yan)(yan)(yan)(yan)(yan)漿(jiang)與(yu)酸性的(de)(de)巖(yan)(yan)(yan)(yan)(yan)(yan)漿(jiang)混(hun)合,或(huo)是(shi)(shi)(shi)由玄(xuan)武(wu)質(zhi)(zhi)巖(yan)(yan)(yan)(yan)(yan)(yan)漿(jiang),混(hun)雜了沈積物或(huo)地(di)(di)殼物質(zhi)(zhi)都可(ke)能衍(yan)生成安(an)(an)山(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(yan)。在(zai)觀音(yin)(yin)山(shan)(shan)(shan)(shan)地(di)(di)區(qu)安(an)(an)山(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(yan)或(huo)玄(xuan)武(wu)巖(yan)(yan)(yan)(yan)(yan)(yan)中(zhong),常含(han)(han)(han)有(you)火(huo)(huo)(huo)山(shan)(shan)(shan)(shan)體(ti)(ti)基底的(de)(de)砂巖(yan)(yan)(yan)(yan)(yan)(yan)或(huo)硅質(zhi)(zhi)片巖(yan)(yan)(yan)(yan)(yan)(yan),顯示地(di)(di)殼物質(zhi)(zhi)的(de)(de)混(hun)染(ran)作用具有(you)舉足輕(qing)重的(de)(de)角(jiao)(jiao)色。
觀(guan)音(yin)山(shan)(shan)各(ge)火(huo)山(shan)(shan)體的噴(pen)發(fa)時代,根據鉀-氬法定年(nian)的結果來(lai)看,觀(guan)音(yin)山(shan)(shan)火(huo)山(shan)(shan)之(zhi)活(huo)動(dong)盛行(xing)于第四紀。由六十余(yu)萬(wan)(wan)年(nian)前開始;接(jie)著是(shi)(shi)五十余(yu)萬(wan)(wan)年(nian)前底層(ceng)輝(hui)石玄武巖(yan)或(huo)玄武巖(yan)質熔巖(yan)之(zhi)噴(pen)發(fa);其(qi)次則(ze)為四十余(yu)萬(wan)(wan)年(nian)前,第二層(ceng)兩(liang)輝(hui)安山(shan)(shan)巖(yan);再依次為三(san)十余(yu)萬(wan)(wan)年(nian)前第三(san)層(ceng)紫(zi)蘇(su)(su)輝(hui)石與(yu)紫(zi)蘇(su)(su)輝(hui)石角閃(shan)安山(shan)(shan)巖(yan)之(zhi)噴(pen)發(fa);最(zui)后以二十余(yu)萬(wan)(wan)年(nian)前橄欖玄武巖(yan)落幕。由火(huo)山(shan)(shan)噴(pen)發(fa)年(nian)代與(yu)塌陷破(po)火(huo)山(shan)(shan)口地貌看來(lai),觀(guan)音(yin)山(shan)(shan)非(fei)為活(huo)火(huo)山(shan)(shan),有可能是(shi)(shi)座休眠火(huo)山(shan)(shan)或(huo)死火(huo)山(shan)(shan)。
1937年(nian)12月(yue)27日(ri)成(cheng)(cheng)立大屯公園(yuan),觀音(yin)山(shan)(shan)亦在其中。但戰(zhan)后(hou)成(cheng)(cheng)立的(de)陽明山(shan)(shan)公園(yuan)剔除觀音(yin)山(shan)(shan)(2002年(nian)方另成(cheng)(cheng)立北(bei)海岸及觀音(yin)山(shan)(shan)風景區管理),以及民間認為(wei)此(ci)山(shan)(shan)為(wei)風水(shui)寶地,埋下日(ri)后(hou)濫墾(ken)濫葬及水(shui)土(tu)保持(chi)的(de)問題。據估(gu)計目前(qian)山(shan)(shan)上非法(fa)墓計4萬處(chu),成(cheng)(cheng)為(wei)發(fa)展(zhan)阻礙。